Re-afforestation and water
conservation in drylands
Guideline for Students and Researchers

March 2014

Preface
Tree planting in the drylands posses a big challenge to farmers in arid and semi-arid areas.
There is therefore need for better technical information to promote tree planting in water
deficient soils. This guideline was compiled based on the results of research activities jointly
conducted by Japan International Forestry Promotion and Cooperation Center (JIFPRO) andKenya Forestry Research Institute (KEFRI). The series of research activities, including
literature review as well as field studies, were conducted from the year 2009 to 2014 with thesupport from the Forestry Agency of Japan.
This guideline demonstrates a better way of re-afforestation in arid and semi-arid areas
and the following sections items have been described in a comprehensive manner.
1) The relationship between water and forest (trees)2) New method for the selection of potential distribution range of trees were introduced,
and a result of the trial were described3) Typical technologies necessary for re-afforestation in arid and semiarid-area
4) Characteristics of 15 drought-tolerant tree species
This publication has been prepared as guideline for students and researchers.
We hope and trust that the guideline will be useful for students and researchers who are
involved in research activities on re-afforestation in arid and semi-arid lands.
Dr. Yoshikawa Ken
Professor
Okayama University
Okayama, 2014

Dr. Ben N. Chikamai
CEO, KEFRI
Nairobi, 2014i

Acknowledgements
The policy, component and methodology for the research activities were examined anddecided by an advisory committee that was organized specifically for this project. I would liketo offer a special word of thanks to all of the members of the committee.
Especially, Dr. Yoshikawa, Dr. Tsuboyama and Dr. Oyabu actually conducted field survey
and have provided valuable information to this guideline.
This research activity could not have favorable outcome without the cooperation of KEFRIs’
scientists. The Director, Dr. Ben N. Chikamai and The Deputy Director, Dr. Bernard Kigomo,
for giving us valuable advice. Mr. Albert Luvanda, Mr. Samuel Auka, Pauline Bala and Mr.
Michael Okeyo provided valuable support during the project implementation period. The
KEFRI editorial team of Dorothy Ochieng, Bernard Kamondo, Josphine Wanjiku provided
valuable comments to the guideline. I would like to thank to them from the bottom of myheart.
Additionally, we couldn’t show the new method for the selection of potential distribution
range of trees without technical assistance of Mr. Masahiro Horikawa’s (Toyota Motor
Corporation) enthusiastic cooperation. He analyzed the data by ROC analysis and prepared
the potential distribution map. I appreciate his cooperation.
Moreover, we would like to express our appreciation to all of the officers of International
Forestry Cooperation Office, Forestry Agency of Japan, who led us as a supervisor andcounselor.
Dr. Sasaki Satohiko
President, JIFPROTokyo 2014ii

Members of the Advisory Committee and the Contributors, Implementers
Member of the advisory committee- Dr. Yoshikawa Ken, Graduate School of Environmental Science, Okayama University- Dr. Fujieda Motohisa, former Associate Research Coordinator, FFPRI*- Mr. Mishima Seiichi, Japan Overseas Forestry Consultants Association- Dr. Ohte Nobuhito, Graduate school of Agriculture and Life Science, The University of Tokyo- Mr. Onishi Mistunobu, Asia Air Survey Co., Ltd.
- Dr. Oyabu Takashi, Graduate School of Landscape Design and Management, University of Hyogo- Dr. Tsuboyama Yoshio, Department of soil and water conservation, FFPRI*FFPRI: Forestry and Forest Research Institute

KEFRI contributers and implementers- Dr. Gabriel M. Muturi, Dryland Forestry Research Programme- Dr. James K. Ndufa, Dryland Eco-Region Research Programme- Mrs. Josephine Musyoki, Research Officer- Mr. David K. Muchiri, Research Officer- Mr. Bernard K. Kigwa, Research Officer- Mr. Damaris Munyao, Dissemination Officeriii

Table of Contents

Chapter 1.

Introduction ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 1

Chapter 2.

Re-afforestation and Water Environment in Arid and Semi-Arid Area ・・・・・ 2

Section 1.

Strategies for Water Sharing ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 2

1) Drought tolerance ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 2
2) Using unique Water Source

・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 23) Utilizing water leftovers by other plants ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 3
Section 2.

Strategies to Use Various Water Sources ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 3

1) Rain Water ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 3
2) River Water ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 53) Ground Water ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 6
4) Fog and Dew ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 8
Section 3.

Water-Use Efficiency ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 10

Chapter 3.

Afforestation Technologies for Tropical Semi-Arid Areas ・・・・・・・・・・・・・・・・・ 11

Section 1.

Selection of appropriate tree species ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 11

Section 2.

Fifteen highly drought-tolerant tree species ・・・・・・・・・・・・・・・・・・・・・・・・・・・ 12

Section 3.

Selection of site for re-afforestation

・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 12

1) Suitable planting areas from a Macro Perspective ・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 122) Suitable planting area from a Micro Perspective ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 15
Section 4.

Comparison of Properties between Acacia senegal and Melia volkensii

・・ 161) Comparison of drought tolerance through plant physiological studies ・・・・・・・・・・・ 16
2) Effect of differences of density on growth ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 16
Section 5.

Water Management in the Re-afforestation Site ・・・・・・・・・・・・・・・・・・・・・・・・ 18

1) Soil moisture environment in the re-afforestation site ・・・・・・・・・・・・・・・・・・・・・・・・・ 18
2) Water catchment and water saving methods in the re-afforestation site ・・・・・・・・・ 20(1) Water-harvesting technologies(2) Water-saving technologies(3) Watering and irrigation
3) Re-afforestation and forest management techniques suitable for drylands ・・・・・・・・・・・・・ 28(1) Raising high quality seedlingsv

(2) Planting methods(3) Management and maintenance of planted trees(4) Felling cycle and timing
Section 6.

Tree Planting by Agroforestry Approach ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 31

1) Agroforestry and water management ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 31
2) Agroforestry niches ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 32
3) Tree planting in agricultural lands ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 32
4) Competition over water between crops and trees ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 34
5) Tree species suitable for agroforestry ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 36
6) Planting in other areas than agricultural lands ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 38

Chapter 4.

For Re-afforestation in Concerning of Local Water Balance ・・・・・・・・・・・・・・ 40

1.

Capacity building on accurate information ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 40

2.

Re-afforestation decreases the amount of available water

3.

Water resource conservation ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 40

4.

Proper forest structure for wood production ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 41

5.

Techniques appropriate to maintain stand density in low level ・・・・・・・・・・・・・・・・・ 41

6.

Consideration for micro-scale differences in site condition ・・・・・・・・・・・・・・・・・・・・・ 41

7.

The right tree in the right place ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 42

8.

Monotonous and large scale plantation is impractical ・・・・・・・・・・・・・・・・・・・・・・・・・ 42

9.

Robustness under harsh and dry environment ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 42

・・・・・・・・・・・・・・・・・・・・・ 40

10. Difference between agroforestry and re-afforestation ・・・・・・・・・・・・・・・・・・・・・・・・・・ 43
11. Issues in agroforestry ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 43
12. Conclusions ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 44

References: ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 45

Annex:
Determination of potential planting area by “ROC analysis” and “Classification tree models” ・ 47
Tree species that has high drought-tolerance
1) 15 highly drought-tolerant tree species and its properties ・・・・・・・・・・・・・・・・・・・ 57
2) List of highly drought-tolerant tree species distribute in Kenya ・・・・・・・・・・・・・・ 72
Agro-climatic zone of Kenya ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 79viChapter 1.

Introduction

In arid and semi-arid area, vegetation is prone to deterioration due to human activities
which lead to deforestation, land degradation and desertification that directly and indirectly
affects water resources Reforestation and afforestation in such regions will not only
contribute to natural environment conservation, but also to improvement of rural community
livelihood by production of building materials and fuel wood. Further, in the long term,
restoration of forest vegetation can improve soil properties contributing to the local waterbalance by flood control in rainy season and mitigation of drought in dry season. Thus
re-afforestation is a very important and effective environmental measure.
However, at the same time, re-afforestation causes an increase of water consumption due toevapotranspiration from newly established forests. Therefore increase in re-afforestation
decreases the water resource in arid and semi-arid area further, resulting in shortage ofwater for daily life and agricultural production. In addition, the decrease of river flow may
affect the ecosystem of river basin, which is likely to damage their biodiversity and adversely
affect community livelihoods.
Therefore, there is a great demand to improve re-afforestation technologies that canpromote restoration and management of forests and increase the available amount of water
while preserving the water environment. However, a high amount of water consumption byafforestation using species such as Eucalyptus introduced to increase the local timber
production has led to a serious concern that the groundwater level is decreasing. Mesquite
species introduced to restore degraded lands has grown in to thick forests and spread even to
agricultural lands and water paths other than the target areas due to its strong
environmental tolerance and high productivity and this impedes agricultural production insome cases. Thus, planting methods are not the only challenge in the arid and semi arid areas
but also forest management after planting. Destruction and degradation of forests, have led
to increase in desertification and water shortage, are caused by excessive man-made stresses
from longstanding deforestation and land development in huge forest area.

Capacitybuilding and cooperation with local communities are essential for restoration andconservation of forests. For this purpose, it is necessary to propose re-afforestation andmanagement methods that benefit the lives of the local residents, to change in attitude of thelocal residents and to enhance their capabilities.
An experimental field study was conducted on re-afforestation and its management in arid
and semi-arid area in Kenya where desertification and water shortage have become
increasingly serious, with the collaboration of local community members. The aim was todevelop appropriate re-afforestation and management practices taking into accountshort-term negative effects of forest tree planting on the local water balance.
Based on the keywords "Water Consumption by Trees", this guideline provides overview ofissues in re-afforestation in arid and semi-arid areas, outcomes of previous studies on
re-afforestation, and it describes re-afforestation and management techniques aiming at
sustainable use of water resources.

－1－

Chapter 2.

Re-afforestation and Water Environment in Arid and Semi-Arid area

Section 1. Strategies for Water Sharing
In dry land ecosystem, many plant species can coexist by using the wisdom of sharing
water resources under severe water stress in harsh environment. In arid areas , intra- andinter-specific competition for water is acute and intense due to the lack of water. Although thewisdom of sharing water resources for coexistence under water stress must come into play insuch environment, the competitive exclusion principle means that two species using the same
niche cannot coexist. This is a fundamental principle in ecology (Gause, 1932). Therefore,
plants that seem to be able to share water basically use different water resources. There arevarious types of water resources and a specific strategy is necessary to use each water
resource type; it is not possible to use many types of water resources with only one strategy.
At the same time, the water environment in arid areas does not allow one species to evolvewith many strategies. In scientific terms, wisdom in ecology is a life history strategy. Each
plant species can employ species specific strategy to secure a water source but it can use only
a part of water resource and, as a result, they can coexist as a member of the arid land
ecosystem in a volume appropriate for the amount of available water.
There are three possible strategies for plants to survive water shortage: drought tolerance;
use of unique water source; and utilizing water leftover by other plants.
1) Drought tolerance
In cases of water shortage, morphological modification of above ground plant parts andfunctional adaptation are the most effective way of drought tolerance. The most typicalmorphological measure to tolerate desiccation is the thick and small leaves with thick cuticle
layer to inhibit the transpiration loss. To improve the water-use efficiency, plants adopt
control of stomata opening and enhancement of photosynthetic rate as functional adaptation.
Decreasing water potential of leaves to absorb limited amount of water faster than otherplants do is likely to cause cavitation in xylem (air bubbles formed in vessel become a cavity
inhibiting the hydraulic function). Adjustment of the vessel diameter, which affects the waterflow efficiency, is one of the effective countermeasures against cavitation in xylem (Tateno,
2003). Further, storage of a good amount of water in plant tissues is an effective measure tocope with the drought stress.
2) Using unique Water Source
The key to secure a unique water resource that is not used by other plants is the capacity ofmorphological and functional adaptation of root system. Osmoregulation to increase thewater absorbing power by decreasing the osmotic potential of epidermal cells of root is
employed in almost all plants as an effective way to respond to acute water stress. In
addition, plants with both lateral and tap roots can transport soil water via roots across soilsof different water contents, which is referred to as “Hydraulic Redistribution” (HR). HR
makes possible exclusive use of underground water and/or surface water. Lateral roots in the－2－ground surface may exploit dew condensation water, and some plants are capable of pooling
an amount of water larger than the maximum water amount that can be retained insurrounding soils by forming an intense root system like a mat near the ground surface(Mooney et al., 1980). Trapping fog by using aboveground part is also an effective strategy tosecure a unique water source.
3) Utilizing water leftover by other plants
There are a limited number of environmental conditions under which plants can sharewater with other plants or be parasitic on other plants. When deep groundwater istransported to the surface layer, other plants may exploit such hydraulically lifted water
faster. When fog is trapped by branches of a tree and then dropped to the ground, other plantson the ground surface may exploit the water first. Although most of these cases of water
sharing are limited, utilizing water leftover seem to be fairly common.

Section 2. Strategies to Use Various Water Sources
The origin of water used by plants is rain water. In the process in which rain water flows
down the slope, rain water become to various water sources such as river water andunderground water. All plants struggle for their water sources by their properties and havestrategies as countermeasures.
1) Rain water
The mean annual precipitation over the ground surface of the world is 880mm. This isenough for grassland to grow at above 5°C of the annual mean temperature and conifer forest
can be established below 5°C. However, spatial distribution of rainfall is not homogeneous;
the world's highest record is over 10000mm/year while some regions have experienced no
rainfall for years (Fig. 1) (UNEP, 1997).
In a rich environment with sufficient water and temperature, forest with high biodiversity
can be formed. However, when water supply becomes short, competition becomes severe andforest structure starts to deteriorate. Canopy can be closed only when the rainfall over thecrown projection area is higher than the evapotranspiration from the crown. The larger therainfall amount is than the necessary amount, the more vertically complex the canopy
becomes. The optimum state of such condition is the tropical rainforest where the tree heightexceeds 50 meter and multilayer canopy is formed. In contrast, when the rainfall over theland covered by crowns becomes less than the evapotranspiration, plants have to absorb
water from an area broader than the area covered with their own crowns and competition
over water among neighbors is started. As a result, crowns grow apart from each other andthe forest becomes an open forest (Photo 1) where sunlight can reach the ground surface
through the spaces within the canopy. This promotes evaporation further and water shortageis accelerated and the air and soil become dry. Most forests in arid and semi-arid area areunder such conditions.

－3－

When rain water wets leaves only, plants cannot use it to grow. For water to be used forplant bioactivities, it must infiltrate downward into the soil and then be absorbed by the rootsystem. Only a part of rain water that reaches the ground surface infiltrate into the soil whilemost of it flows down over the ground surface (surface runoff). The more effectively the forest
floor can infiltrate this runoff, the more efficiently the rain water is used. Generally, forests
can improve the infiltration capacity of soil by litter fall (organic matters). However, suchcapacity of soil formation is weak in open forests and therefore the proportion of runoff waterout of the rainfall is high, resulting in dry soil. Most plants that grow in arid areas havecapacity to extend their roots deep in order to use stable water sources in deeper soil layer(Wei et al., 2011). However, tree planting and forest management must not be designed basedon the amount of water in deep soil layer where soil water cannot be recharged by rain but
based on the amount of available rain water by using measures to promote infiltration of
runoff into the ground, e.g. micro-catchments (De Pauw, 2008).

Fig. 1: Mean annual precipitation (UNEP, 1997)

Photo 1: Open forest of Elm trees
Hunshandake Desert (China)

Rainfall is temporally distributed heterogeneously hence it is not the same in every year. In
humid areas, vegetation is never damaged severely even if there is less rainfall, so thefluctuation of rainfall is not a serious problem. However, arid area is the marginal area forvegetation, because of high frequency of severe drought that may destroy the vegetation
completely (Fig. 2). Annual plants can survive even such severe drought and establish almost
the same level of vegetation after drought, because they can start from seeds in every springand grow according to the rainfall of the year. Central Asia and Sahel Strip suffer from severe
drought every few years and harsh environments for perennial arbors and therefore grass
plants can dominate. In other words, grassland ecosystem is caused by temporal
heterogeneity of rainfall (Fig. 3). However, if perennial arbors are killed by drought, a large
amount of plant biomass accumulated for years is lost and the ecosystem is forced to change
substantially.
Even in such an environment, perennial trees can survive through drought on sand dune
where only sparse vegetation can be supported normally but sufficient amount of water isretained (Photo 2). The level of variation of soil water content during drought determines thevegetation structure. Stabilization of soil water content or prevention of soil from becoming－4－drier than the threshold for tree growth must be taken into account for maintenance offorests in arid and semi-arid areas.
1200

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0

Fig. 2: Annual variability of the precipitation (Saint-Louis, Senegal)

Fig. 3: Distribution of grassland in the world

Photo 2: Shrub forest existing on the top of dune
Hustai National Park (Mongolia)

2) River Water
When rain water flows over the ground surface, it becomes a river that can reach to distantplaces quickly. With such river water, vegetation can be established even in a desert with norain. In Central Asia, there are many rivers derived not only from rain water but also fromglacier-fed water and their amount of flow has increased due to global warming. Accessible
river water is a valuable source in arid areas. One of the big forests in arid area is theriparian forest of Populus euphratica (Euphrates Poplar) along Tarim River that crosses the
Taklamakan Desert. Along the Hoarusib River in Namib Desert with annual rainfall of 50mm, acacia forests are established and many kinds of wildlife such as elephants, lions andgiraffes inhabit this forest. Although river water is a relatively stable water source, not many
plants can effectively exploit this water resource. Therefore, most of P. euphratica forests are
pure forests.
Amount of river flow also varies from year to year and season to season; the Tiva Riverflowing beside the Tiva Pilot Forest in Kenya has a large amount of flow in the rainy season
but almost dries up during the dry season (Photo 3). Although even a riparian forest
undergoes a strong water stress, most of them can survive and maintain their forest－5－

structure for long time. Generally, plants composing a forest in arid area are hard to die. P.

euphratica is also a diehard plant (Yoshikawa et al., 2007). During drought, leaves at the tipof tree crowns die (dieback) to reduce the total amount of leaves to the level that can be
maintained by the available water (Photo 4). When drought ceases, the trees extend theirbranches again with more leaves but it can only restore to the original size. So tree height isalways within a certain range of height. On the other hand, the stem diameter continues togrow steadily and these trees finally become stocky shape. For example, average height andDBH of P. euphratica in Ejina Oasis are 9 m and 40 cm, respectively (Monda et al., 2008). For
plantation in arid and semi-arid area, tree species that can steadily survive by flexibility ofleaf size (eg. leaf volume) such as P. euphratica and Juniperus spp. (Juniper) are appropriate
rather than species that are good loser to water stress such as Cryptomeria japonica(Japanese Cedar) and Chamaecyparis obtusa (Japanese Cypress).

Photo 3: State of the Tiva river during the rainy season and the dry season(Tiva, Kitui Country. Eastern Province, Kenya)

Photo 4: Die-backed Populus euphratica （Euphrates Poplar） by drought condition

3) Ground Water
The origin of ground water is rain that has infiltrated and stored in to the soil, or isadvecting slowly in the water saturated soil layer (where soil pore spaces are fully filled up
with water from the upper reaches). Being free from evaporation, the amount of ground water
is considerably stable. However, the longer the time that water remains under the ground,－6－the higher the salinity hence lowering the water quality.
Plants that depend on the ground water are called“Phreatophyte” (Goudie & Wilkinson, 1987). The well-known
tree is date palm (Phoenix dactylifera) (Photo 5). It maintains
large crown on a sterile dry land and stands gallantly, giving
an impression that the tree successfully survives the harshenvironment of desert. Mesquite (Prosopis spp.) planted on alarge scale for combating desertification is also a typicalphreatophyte. A record of the deepest root of phreatophyte is
68 m below the ground surface, which was confirmed during
well digging in Kalahari Desert (Canadell et al., 1996). In
order for roots to extend deep into dry soil to where rain watercannot reach, a special strategy (hydraulic redistribution) as
mentioned later is necessary. Particularly, how fast a small

Phto 5: Date palm is one of thephreatophyte

seedling can access the ground water after germination is adeterminant factor for survival of a phreatophyte. In other words, the key issue inestablishment of a tree seedlings is whether roots can extend to the ground water quickly
before the rain water that enabled germination dries up.
By the analysis of stable isotope ratio of soil water, ground water and water in bundles of

Sabina vulgaris (Savina Juniper, an evergreen conifer), Artemisia ordosica (Ordos
Wormwood, deciduous shrub), and Salix matsudana (Chinese willow, deciduous arbor)
inhabiting in the Mu Su Desert in the north-central China, remarkable difference in source ofwater was confirmed among these sympatric trees that inhabit in the same area. S. vulgaris
absorb both soil water and ground water from all soil layers, and is therefore able tosecurewater in all seasons. A. ordosica can use only soil water within 0 to 50 cm below the ground,because it can wait for rain during a short rainy season. S. matsudana (Chinese willow,
deciduous arbor) does not use shallow soil water to 1.5 m depth, but can use soil water andground water in deeper layers.
Hydraulic redistribution (HR) which is the soil water transportation via roots has beenrecognized (Richards and Caldwell, 1987) for various kinds of taxonomic groups and life
forms under many kinds of environment (Leffler et al., 2995). After cessation of transpiration,soil water passively moves via roots between soil layers along the gradient of soil water
potential. For example, when the surface soil becomes wet after little rain and the deep soil
remains dry, plants having both lateral and tap roots absorbs rainwater from the surface soil
by lateral root and transports it via tap root and releases it into deep dry soil during
nighttime (Fig. 4). Although plants cannot extend their roots to the ground water level dozens
of meters below the ground surface after one rainfall occasion, they may transport a small
amount of rainwater from the surface to the deeper soil layer by HR and exclusively use thewater to extend their tap roots up to the ground water. Then phreatophyte cannot exist
without HR (Burgess et al., 1998). In addition, transportation of rainwater on the groundsurface into deep layers by HR reduces the amount of water loss due to evaporation indaytime and this increases the rainwater use efficiency (Caldwell et al., 1998; Oliveira et al.,－7－

2005).
(1) DAY(2) NIGHT

DRY

DRY

DRY

WET

DRY

WET

(3) DOWNWARD(4) LATERAL

WET

WET

WET

DRY

DRY

Fig. 4: Water transfer by three types of HR(1) Water transfer in the daytime, (2) HL in the nighttime, (3) transfer to downward – HD, (4) Horizontal transfer - HR

However, HR is not always effective for all plants having HR capacity. When the surface
soil layer becomes dry due to lack of rainfall, phreatophyte lifts up soil water by tap root andextracts water from lateral roots into dry surface soil layer during nighttime. If shallowrooted plants are absent in the vicinity, such hydraulically lifted up water can be used fortranspiration in daytime by HR plants, but shallow-rooted herbaceous plants in the vicinity
can also get leftovers of the soil water (Ludwug et al., 2003).
Although HR capacity is an important factor for selection of plants suitable foragroforestry, quantitative assessment of HR capacity is not enough (Meinzer et al., 2004) andtherefore development of silviculture methods taking advantages of HR capacity has not yet
been started. More so, the effects of tree planting on crop growth must be revealed further interms of soil moisture transportation.
4) Fog and Dew
As most fog generation is determined by hydrological conditions and geography, fog occurs
frequently only in limited locations. However, the frequency of fog is more stable than that ofrain. Fog-dependent forests have been established in coastal desert such as Namib Desert,
Baja California Peninsula where climate is dry but fog occurs frequently (Kimura, 2005). On
the Red Sea side of the Arabian Peninsula, dense forests of Juniperus procera are maintainedat mountaintop above 2000 m by frequent and dense fog from the Red Sea (Photo 6). In somecases, lichen (Usneaceae) is formed on dead branches to trap fog (Photo 7). Water trapped on
the tree leaf surface is directly absorbed through the cuticle layer. After water falls down to
the ground as water drops, both trees and grasses growing on forest floor uses trapped fog
moisture with severe competition.
Dew condensation water is also a stable and effective source of water. Dew on leaves islargely taken into the plant directly (Photo 8) but it may fall down to the ground as water－8－

drops or be formed directly on the ground surface. Such water is lost quickly due toevaporation after sunrise, but is also a valid water source if absorbed before dawn. If water
saturation deficit (shortage of water) within a plant caused by transpiration in the previous
day is not recovered by the next morning, dew condensation water on the ground can beabsorbed by lateral roots before the first sunlight of the dawn. Most of plants growing on sanddune therefore, have long lateral roots spreading on the ground surface (Photo 9).
As it is not easy to quantify amount of water supplied from fog and dew, importance of
these water sources has not yet been fully evaluated. In the future, development of
re-afforestation methods that can promote usage of fog and dew as one of the important water
sources in arid area is desired.

Photo 6: Fog generated in the Juniper (Juniperus spp.) forest

Photo 7: Beard Lichen epiphyte on a Juniper branch(Saudi Arabia)

Photo 8: Water that had condensed on leaves
Savin Juniper (Inner Mongolia, China)

Photo 9: Roots extending crawling on ground (Inner Mongolia, China)－9－Section 3. Water-Use Efficiency
One of the key indicators of water use by plants is WUE (water-use efficiency). WUE refers
to the primary production per unit water consumption. The higher the WUE of the plant is,
the more efficiently the plant can perform photosynthesis with less water. The natural
selection generally influences plants of higher WUE in arid environment (Fischer and Turner,
1978). Therefore the higher WUE of S. vulgaris than those of A. ordosica and S. matsudana in
the Mu Su Desert (O’Leary, 1978) indicates the high adaptability of S. vulgaris to arid areas.
In areas where a certain amount of rainfall is expected like in the Mu Su Desert, deciduous
shrub trees like A. ordosica place priority on accelerating photosynthesis rather thanincreasing WUE in order to concentrate the production of photosynthesis on a short term byusing the rain water. Once the rainy season ends, A. ordosica sheds its leaves quickly in orderto reduce the loss of water. S. matsudana has also a distinct property; it does not supress
water consumption, but its leaf growth period is longer than for A. ordosica. Water resources
necessary for this type of growth largely depend on expanded root system, which can absorb
water from a wide range. The capacity of root growth which elongates much deeper into thesoil than the height growth of above ground part can guarantee adaptation to unreliable
environment in arid areas.

－ 10 －

Chapter 3.

Afforestation Technologies for Tropical Semi-Arid Areas

Section 1. Selection of appropriate tree species
Selection of appropriate tree species suitable for a given natural environment is imperativein order to make forest establishment successful. The key to success of afforestation intropical semi-arid areas is selection of highly drought-tolerance tree species. Selection ofindigenous tree species should be prioritized for sustainable forest management to ensure
effective use and conservation of water resources. In case of introduction of useful exotic tree
species, trees must be managed based on water-use properties of each species.
Except in cases where special budget as part of a governmental policy or external support
is provided, individual farmers take the primary responsibility for re-afforestation. Therefore
species selection should also be based on the farmers’ needs. Often, "multi-purpose trees" arepreferred for re-afforestation as they meet multiple needs of the farmers. As trees are often
planted as part of agroforestry, it is necessary to understand properties of respective trees
and consider planting and management methods to reduce crop-tree competition over water.
In tree selection, it is important to focus on tree species that are on the verge of depletionby exploitation as fuel wood and also tree species retained intentionally by farmers for
traditional use. Therefore, table that describes properties and use of trees that have highly
drought-tolerant among them is provided at the end of this guideline.

Photo 10: Tree species that have been planted willingly in semi-arid areas of Kenya
Left: Eucalyptus sp., Center: Grevillea robusta, Right: Melia volkensii

Photo 11: Charcoal burning for sale and fuel wood for domestic use
Fuel wood is an important energy source in the area where supply of alternative sources of energy is underdeveloped－ 11 －

Section 2. Fifteen highly drought-tolerant tree species
This guideline provides descriptions of properties and management methods for 15 species
that have adapted well in arid and semi-arid areas.
The descriptions of each species are summarized in the table and listed at the end of thisguideline.

Section 3. Selection of site for re-afforestation
1) Suitable planting areas from a Macro Perspective
a. Introduction
Determination of suitable planting sites for selected tree species has been largely
depending on accumulated experiences of farmers and knowledge of scientists. However, inorder to promote re-afforestation activities strategically and effectively in wide areas,development of tools to identify and present “Potential habitat” is required. An analysis was
conducted in order to identify the “Potential habitat” based on existing weather factor
information and actual distribution data recorded for each tree species. The “Potential
habitat” in Kenya for 19 species were identified on a trial basis and the results are presented
in this guideline.
b. Analyzed tree species
A total of eighteen tree species that have been planted preferentially in arid and semi-arid
areas and for which past research papers are available were targeted for this “Potential
Habitat” analysis. The species include both indigenous and exotic tree species namely: Acaciasenegal, Acacia tortilis, Acacia xanthophroea, Azadirachta indica, Balanites aegyptiaca,
Combretum acleatum, Combretum collinum, Combretum molle, Combretum shumannii,
Eucalyptus camaldulensis, Eucalyptus globulus, Eucalyptus saligna, Faidherbia albida,
Melia volkensii, Senna siamea, Senna singuneana, Senna spectabilis and Tamarindus indica.
c. Method for the analysis
The distribution map for each tree species provided in the “Useful Trees and Shrubs for
Kenya” published by “World Agroforestry Centre” and WORLDCLIM’s “BIOCLIM weather
factor data” were used for this analysis. The correlation among them was analyzed by using“Classification Tree Model” to identify the “Potential habitat” (Fig. A-1-1). The prediction
accuracy of the model was determined based on ROC (Receiver Operating Characteristic)
analysis (Fig. A-1-2).
d. Procedure of the Analysis
The land of Kenya was divided into 20 sq km grids at first and 1,440 meshes were acquired.
Then data on the presence of respective tree species extracted from the “Useful Trees andShrubs for Kenya” were mapped on each mesh and shown as “Presence Maps” (Fig. A-1-4 (Left－ 12 －

side)). Nineteen weather factors of BIOCLIM (Fig. A-1-3, Table A-1-1) distributed into meshesof the same scale, then compared with the “Presence Maps” and analyzed by “S-Plus”. Thenthe correlation value was calculated and the “Classification Tree Model” was indicated.
In the next stage, "Suitable habitat" and "Marginal habitat" were determined and mappedby ROC analysis using the cut-off point as a reference point to determine presence or absenceof distribution (Fig. A-1-4 (Right side)). The meshes with distribution probability of lower than
0.01 were categorized as "Potential non-habitat" as it was determined that distribution ishardly from the view point of statistics.
e. Interpretation of the maps
"Suitable habitat" and "Marginal habitat" were regarded as the "Potential habitat" forforest establishment of respective tree species.
Among them, the "Suitable habitat" are regarded as environments with high distribution
probability and suitable for survival of respective tree species. General planting method isdeemed possible except in case where there are special limitations such as soil conditions that
may compromise the survival. The "Marginal habitat" are regarded as areas with low
distribution probability where additional requirement(s) must be met to ensure survival. In
these areas it is deemed necessary to include management measures for planted trees e.g.
introduction of micro-catchments to improve soil moisture condition, while taking account theexistence of other limitations such as soil properties.
f. Factors to consider in Potential Habitat Analysis
To understand the correlation between tree species distribution and weather factors inmore details and improve the accuracy of the "Potential habitat" determination, it isimportant to use more existing distribution data and finer meshes.
For the present study, 20 sq km meshes were used because the plots in the base data wereconsistent with the size. However, if more data are available and a more detailed analysis isrequired, 1 sq km meshes should be used.
Ideally, there should be more observation points for species presence/absence in each grid,but sufficient study data does not exist for commercially minor or exotic tree species.
For these reasons, this analysis should be perceived as exploratory.
g. Results of the analysis
Interpretation of the data was tried on the assumption that under the above-mentioned
limitations. The results of the interpretation of factors are described below. Generally, details
are analyzed by extracting items of higher distribution probability indicated by the“Classification Tree Models”, and identifying weather factors influencing the figures andtheir values. But, in this analysis data were interpreted by comparing the map showing“Potential habitat” with the map of BIOCLIM weather factors with high degree of theDeviance Weighted Score (DWS) (Table A-1-2).
- The limiting factor of 3 Eucalyptus species was interpreted as the amount of annual
rainfall. Eucalyptus saligna is the most resistant species to drought and the areas with－ 13 －

annual rainfall of ≥401 mm are "Potential habitat", and the areas with ≥801 mm rainfall
are "Suitable habitat". The second most resistant species among them is E.

camaldulensis, and the areas with annual rainfall ≥801 mm are "Suitable habitat" forthis species, whereas areas with >1,000 mm rainfall are “Suitable habitat” for E. globules(Fig. A-1-4 (10)-(12), Fig. A-1-3 (BI 12)).
-For Acacia senegal, “Potential habitat” include areas with annual rainfall ≥401 mm andmean temperature of <27.5

oC

in the wettest quarter. Areas with the averagetemperature of between 17.6 oC to 27.5 oC are designated as "Suitable habitat" (Fig. A-1-4(01), Fig. A-1-3 (BI 01, 08, 12)).

-For Melia volkensii, the conditions with mean temperature of between 17.6 oC to 22.5 oC
in coldest quarter were identified as "Potential habitat" with the temperatures for“Suitable habitat” ranging between 20.1 oC to 22.5 oC (Fig. A-1-4 (14), Fig. A-1-3 (BI 11)).

-For Acacia tortilis and Balanites aegyptiaca, the temperature is regarded as theprimary limiting factor. For A. tortilis, the conditions with mean temperature of ≤25.0 oC
in warmest quarter are required for "Potential habitat" and it must be <20.0 oC for"Suitable habitat" (Fig. A-1-4 (02), Fig. A-1-3 (BI 10)). For B. aegyptiaca, the conditions withminimum temperature of ≤15.0 oC in coldest month is regarded as "Suitable habitat" inaddition to the conditions with annual mean temperature ≤22.5 oC (Fig. A-1-4 (05), Fig.
A-1-3 (BI 01, 06)).

-

For Acacia xanthophloea, the maximum temperature of warmest month must be <35.0
oC for “Suitable habitat”. Also, the conditions with mean temperature of driest quarter as≤20.0 oC and annual rainfall of ≥801 mm constitutes “Suitable habitat” (Fig. A-1-4 (03), Fig.
A-1-3 (BI 05, 09, 12)) .

-For Combretum schumannii, the conditions with annual mean temperature of between
22.5 oC to 30.0 oC, and rainfall as ≥301 mm in wettest month are designated as "Potential
habitat" (Fig. A-1-4 (09), Fig. A-1-3 (BI 01, 13)).

h. Challenges
The analysis was conducted by using rough meshes and under the limited number ofexisting presence/absence data. Therefore, some areas were categorized as the “Potential
habitat" and not in the "Suitable habitat", according to the analysis results despite being
plotted in the “Presence Maps”. In addition, we must note that the result of this trial does notmean that the area determined as the “Suitable Habitat” are only the area each species can
grow. This analysis is based on the current presence data from existing literature. Probabilityof the existence of the area where there is no experience of planting despite that each species
can grow cannot be denied. There is also a probability of the existence of the area where eachspecies was lost due to some reason despite being once well distributed in the area. Therefore,
the result of this trial does not deny the possibility of growth of each species in the area where
it was determined as the "Potential non-habitat", especially in the area surrounding theareas where distribution is actually confirmed.
In the future, it is expected that more accurate prediction will be possible by planting
respective tree species in the areas surrounding the areas regarded as the “Potential habitat”－ 14 －

and accumulating the data. In addition, for detailed identification of the "Marginal habitat",
it is also important to accumulate information about site factors that are conducive for
growth of each tree species.
2) Suitable planting areas from a Micro Perspective
a. Natural environmental factors
Even within a limited range, water retention capacity of soil varies depending on microtopography, soils types and vegetation. Generally, lands suitable for growth of trees are also
suitable for growth of crops and in such lands agricultural production activities are generally
prioritized. If extra lands under weather and soil conditions similar to productive crop lands
are available, they can be used as optimal planting sites. In addition, it is expected that lands
that are not suitable for agriculture due to other conditions such as land slope angle despite
the same weather and soil conditions with crop lands are proactively utilized for forest
establishment.
For the lands with low agricultural productivity due to water shortage, tree planting can bepracticed using measures such as micro- catchments. It is also important to consider whether
soil with poor water retention capacity can be improved by mixing it with organic matters.
There is need to consider whether profits gained are proportional to the investment costs.
Although fruit trees can be grown in arid and semi-arid areas, it is advantageous to growthem in lands where there are water sources such as small rivers, considering annual
fluctuation of rainfall amount and the need for stabilization of yields.
For some tree species, it is imperative to select areas with less risk to termites’ damages
which are more prevalent in the drier environment.
b. Social factors
Accessible areas where it is easy to plant and maintain the trees planted with less effort
are desired as a location for tree planting by farmers. A low risk of illegal cutting is also an
important requirement. If watering is necessary for plant growth, it is indispensable toacquire water use rights through obtaining a thorough understanding of the local community.
Tree planting to demarcate boundaries of own land, and also to prevent livestock browsing
can also be strong incentives for local residents to plant trees.
Local community members can also be important actors in promoting re-afforestation
activities. Tree planting on the mountain ridge to prevent soil erosion in agricultural land,
protection of river bank, and also to generate fund for management and maintenance of
public facilities and schools is an important activity in which community could participate. In
such cases, it is required that if the land is communal, common perceptions are shared among
the community members. There is need to establish systems for provision of labor and fair
distribution of profits in promoting tree planting by local communities.

－ 15 －

Section 4. Comparison of Properties between Acacia senegal and Melia volkensii
In the Tiva Pilot Forest of KEFRI-Kitui Regional Research Centre, various types ofexperimental stands have been established with the support of JICA. Among theseexperiments are, plant physiological studies and studies on forest stand density effects for

Acacia senegal and Melia volkensii.
1) Comparison of drought tolerance through plant physiological studies(1) Acacia senegal’'s maximum daytime transpiration rate that indicates the degree of water
loss from stomata is less than half of M. volkensii. Thus, drought tolerance of A. senegal
is stronger than that of M. volkensii, which is said to have strong competitiveness overwater than other plants (Mulatya et al., 2002).
(2) Although no significant difference was observed in power of water absorption of leaves, it
is determined that A. senegal may photosynthesize with less moisture (Mizobuchi, 2013).
(3) In dry season when water resources becomescarce, both Acacia and Melia defoliate toprevent loss of water from their leaves (Broadhead, 2000).
(4) How deep plants can absorb water from the soil layer is an important factor to determine
their drought tolerance. According to a study on water depth for absorption by 11-years A.

senegal and for 15-years by M. volkensii using stable isotope, it was estimated that water
is absorbed from much deep soil layers, at least deeper than 1 m. It was therefore impliedthat both species have a root system that can obtain necessary water from the soil indeep layer for long period without rain in the dry season.
2) Effect of differences of density on growtha. Melia volkensii
Effect of tree density on survival, height and diameter growth of M. volkensii were
evaluated in four spacing (2.5 x 2.5 m, 3.0 x 3.0 m, 3.5 x 3.5 m, and 4.0 x 4.0 m) experimental
stands that were established in November 2002. Melia trees turned 11-years old in November
2012. The change of survival rate is shown in Fig. 5. Although survival rate decreased in all
the density plots from 2007 through 2010, no change has been observed since 2010. As at
2012, although the tree height was approximately 8 m in any density plots, the Diameter at
Breast Height (DBH) showed a large value in order; 11.0 cm, 12.4 cm, 12.8 cm and 13.6 cm inaccordance with increase in spacing (Fig. 7, 8, Table 1). Both tree height and DBH increased
most rapidly during the first 3 to 4 years after planting, and then the growth increment
sharply decreased.

－ 16 －

100

100

95

95
90

85

2.5

80

3.0

75

3.5

70

4.0

Survival rate(%)

Survival rate(%)

90

65

85
1.0

80

3.5

75

4.0

70

60

5.0

65

55

60

50

1996 1998 2000 2002 2004 2006 2008 2010 2012 2014

2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

Physical time(yr)Physical time(Yｒ）Fig. 5: Trends in survival rate of M. volkensii

Fig. 6: Trends in survival rate of A. senegal

10

18

9

16

8

14

2.5

6

Mean DBH(cm)Mean Height(m)

7

3.0

5

3.5

4

4.0

12

4.0

10

3.5

8

3.0

6

2.5

3
4

2

2

1
0
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 201302003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

Physical time(yr)physical time(yr)Fig. 7: Trends in growth of tree height of M. volkensii

Fig. 8: Trends in growth of DBH of M. volkensii

Table 1: Survival ratio, height and diameter growth of M. volkensii in each spacing standMeasurement
Year,month
2004,Jun

2005,Nov

2007,Jul

2010,Jun

2011,May

2012, Oct

Spacing
(m)

Plot
size

Number ofplantedNumberof trees

Number of
trees

2.5
3.0
3.5
4.0
2.5
3.0
3.5
4.0
2.5
3.0
3.5
4.0
2.5
3.0
3.5
4.0
2.5
3.0
3.5
4.0
2.5
3.0
3.5
4.0

23x20
19x17
22x22
21x18
23x20
19x17
22x22
21x18
23x20
19x17
22x22
21x18
23x20
19x17
22x22
21x18
23x20
19x17
22x22
21x18
23x20
19x17
22x22
21x18

1636
1120
784
667
1636
1120
784
667
1636
1120
784
667
1636
1120
784
667
1636
1120
784
667
1636
1120
784
667

45
29
30
20
43
29
30
18
43
29
29
18
39
23
24
17
39
23
24
17
39
23
24
17

978
898
620
529
935
898
620
476
935
898
599
476
848
712
496
450
848
712
496
450
848
712
496
450

Height(m)mean±S.Dmaxmin
1.9 ± 0.7 a
3.2
0.2
2.2 ± 0.8 a
3.5
0.2
2.8 ± 0.7 b
3.8
0.9
1.8 ± 0.6 a
3.1
0.7
4.3 ± 1.3 a
6.5
0.3
4.7 ± 1.3 ab
6.2
1.2
5.4 ± 0.8 b
6.8
3.0
5.3 ± 0.9 b
6.3
3.0
5.9 ± 1.5 a
8.7
1.6
6.3 ± 1.7 a
7.9
1.4
6.7 ± 0.9 a
8.1
4.0
6.8 ± 0.8 a
8.2
5.1
7.4 ± 1.5 a
10.0
2.4
8.1 ± 0.8 a
9.2
5.9
7.4 ± 1.2 a
9.2
4.2
7.5 ± 1.3 a
9.2
3.1
8.0 ± 1.6 a
10.7
3.1
8.4 ± 0.8 a
9.4
6.3
7.9 ± 1.2 a
9.6
4.6
7.8 ± 1.4 a
9.4
3.3
8.2 ± 1.5 a
10.7 3.4
8.6 ± 0.8 a
9.8
6.4
7.9 ± 1.0 a
9.2
5.8
8.0 ± 1.3 a
9.8
4DBH(cm)mean±S.DMax
2.4 ± 0.8 a
3.9
2.5 ± 0.9 a
4.1
3.4 ± 1.0 b
5.1
1.9 ± 0.8 a
3.4
6.1 ± 1.9 a
9.4
7.0 ± 1.8 ab
9.5
8.0 ± 1.6 c
9.8
8.4 ± 2.4 bc 11.5
8.1 ± 2.8 a
12.4
9.1 ± 3.2 ab 12.8
10.4 ± 1.9 b
13.1
10.9 ± 2.6 b
14.3
10.4 ± 2.5 a
14.6
11.6 ± 2.2 ab 15.2
12.2 ± 2.7 b
15.5
12.9 ± 3.3 b
17.6
10.8 ± 2.6 a
15.1
12.0 ± 2.2 ab 15.6
12.5 ± 2.8 b
16.3
13.3 ± 3.4 b
18.0
11.0 ± 2.8 a 15.6
12.4 ± 2.3 ab 16.1
12.8 ± 2.9 b 17.0
13.6 ± 3.5 b 18.6

min
0.9
1.0
1.2
1.0
1.6
1.9
2.6
2.9
0.4
0.6
3.8
4.4
3.5
6.1
3.8
5.1
3.6
6.8
3.8
5.2
3.6
7.2
3.8
5.2

Basal
area
0.4
0.4
0.6
0.1
2.9
3.4
3.2
2.9
5.4
6.6
5.3
4.7
7.6
8.2
6.0
6.2
8.2
8.7
6.3
6.6
8.6
9.2
6.7
6.9

b. Acacia senegal
Effect of tree density on survival, height and diameter growth of A. senegal were evaluatedin four spacing (1.0 x 1.0 m, 3.5 x 3.5 m, 4.0 x 4.0 m and 5.0 x 5.0 m) experimental stands thatwere established in November 1998. Acacia trees turned 15-years old in November 2012. Thechange of survival rate is shown in Fig. 6. In 1.0 m plot it decreased to 84% in 2010 and further－ 17 －

decreased to 72% and 68% in 2011 and 2012 respectively, while in other density plots
decreased to around 90% and then became stable. As at 2012, the tree height wasapproximately 6 m in all density plots. Although the observed annual average growthincrement was 30 to 40 cm, some trees decreased in height hence it can be concluded thatgrowth in height almost stopped (Fig. 9). With increase in spacing, the DBH showed large
values of 4.2 cm, 9.1 cm, 9.3 cm and 10.9 cm. In 3.5 m and 4.0 m square espacements, nosignificant difference was observed in the survival rate, tree height and DBH, but in 5.0 m x
5.0 m plot, the DBH was larger than in other plots and the stem diameters increased
vigorously (Table 2).
9

160

8

140
120

6

1.0

5

3.5

4

4.0

3

5.0

2
1
1998

2000

2002

2004

2006

2008

2010

2012

4.0

80

3.5
60

1.0

40
20
0
1996 1998 2000 2002 2004 2006 2008 2010 2012 2014

0
1996

5.0

100

Mean Basal area (cm 2 )Mean Height(m)

7

2014

Physical time(yr)physical time(yr)Fig. 9: Trends in tree height of A. senegal

Fig. 10: Trends in growth of mean basal area of A. senegal

Table 2: Survival ratio, height and diameter growth of A. senegal in each spacing standMeasurement
Year,month

1998,Jul

2010,Jun

2011,May

2012.Nov

Spacing
(m)

Plot
size
(m)

Number ofplantedtrees(N/ha)

Numberof trees(N)

Number oftrees(N/ha)

1.0
3.5
4.0
5.0
1.0
3.5
4.0
5.0
1.0
3.5
4.0
5.0
1.0
3.5
4.0
5.0

5x5
11x8
9x10
11x11
5x5
11x8
9x10
11x11
5x5
11x8
9x10
11x11
5x5
11x8
9x10
11x11

10000
1364
1000
744
10000
1364
1000
744
10000
1364
1000
744
10000
1364
1000
744

25
12
9
9
21(0)
11(2)
8(1)
8(2)
18(0)
11(2)
8(1)
8(2)
17(0)
11(2)
8(1)
8(2)

10000
1364
1000
744
8400
1250
889
661
7200
1250
889
661
6800
1250
889
661

Height(m)mean ± S.D
0.9 ± 0.3
1.1 ± 0.3
1.0 ± 0.3
1.0 ± 0.2
6.1 ± 1.5
6.5 ± 0.7
6.4 ± 1.1
5.5 ± 0.5
6.7 ± 1.2
6.7 ± 0.7
6.7 ± 1.1
5.7 ± 0.6
7.0 ± 1.2
6.3 ± 0.7
6.5 ± 1.0
5.5 ± 0.6

a
a
a
a
ab
a
ab
b
a
a
a
a
a
ab
ab
b

max
1.7
1.6
1.6
1.3
7.8
7.6
7.7
6.3
8.1
7.8
8.1
6.5
8.5
7.2
7.8
6.5

DBH(cm)Basal area(cm2)
min
0.5
0.6
0.5
0.7
2.5
5.1
4.8
4.7
3.9
5.3
5.4
4.8
4.0
5.1
5.2
4.9

mean
1.5
2.0
1.7
2.0
15.8
72.4
67.1
95.3
14.9
76.1
70.6
100.0
15.9
77.2
74.9
102.8

±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±
±

S.D
0.6 a
0.6 a
0.7 a
0.8 a
14.5 a30.7 b38.9 b31.7 b
13.5 a32.6 b40.0 b
32.6 b
14.1 a32.7 b
42.1 b33.3 b

Max
3.1
3.1
3.1
3.1
51.7
127.0
133.1
133.8
52.8
133.2
138.9
147.4
54.1
134.7
149.6
153.9

min
0.4
0.8
0.8
0.8
2.5
19.1
21.2
40.1
2.0
18.9
22.4
51.5
1.8
19.6
27.2
56.9

mean±S.D
1.4 ± 0.3
1.6 ± 0.2
1.4 ± 0.3
1.6 ± 0.3
4.1 ± 1.8
8.8 ± 1.8
8.7 ± 3.0
10.5 ± 2.4
4.1 ± 1.6
9.0 ± 1.9
9.0 ± 3.0
10.8 ± 2.3
4.2 ± 1.7
9.1 ± 1.99.3 ± 3.0
10.9 ± 2.3

a
a
a
a
a
b
b
b
a
b
b
b
a
b
b
b

Max
2.0
2.0
2.0
2.0
8.1
11.0
13.0
13.1
8.2
11.5
13.3
13.7
8.3
11.5
13.8
14.0

min
0.7
1.0
1.0
1.0
1.8
4.9
4.0
6.4
1.6
4.9
4.2
7.1
1.5
5.0
4.5
7.4

Basal
area
(m2/ha)
1.5
0.3
0.2
0.1
13.3
9.1
6.0
6.3
10.7
9.5
6.3
6.6
10.8
9.6
6.7
6.8

Section 5. Water Management in the Re-afforestation Site
1) Soil moisture environment in the re-afforestation site
The value obtained by subtracting the evapotranspiration amount from rainfall amount iscalled “Available Renewable Freshwater Resources” and is regarded as the theoretical upper
limit of available water resources. However, soil moisture is more important in terms of water
environment in re-afforestation site. Available soil water varies with rainfall andevapotranspiration, and has significant influence on plant growth. It is known that the
proportion of evapotranspiration in rainfall amount is relatively high in forest than barelands and grass lands, and the depth of water to be absorbed by the root system varies with－ 18 －

tree species, the vegetation conditions also affect the soil moisture.
In terms of water management in semi-arid lands re-afforestation, the goal is to use thelimited amount of rain water efficiently for tree growth. Although it is not easy to achieve thisgoal, the relationship between forests and soil water in Kenya’s semi-arid areas is introducedin this section to illustrate how trees and soil water correlate.
In this study, soil moisture was measured using the device called “profile probe” (Delta-T
Devices Ltd. Type PR6) in each study plot set in the natural stand and spacing trials of Melia

volkensii and Acacia senegal and bare lands (grass lands) within nursery of KEFRI-Kitui
Regional Research Centre’s Tiva Pilot Forest. The study was started in June 2010 andadditional measurements taken from November 2011. Besides measurements at Tiva, soil
moisture assessment using the same method started for 3 tree species (Melia volkensii,

Eucalyptus camaldulensis and Gmelina arborea) in the Matinyani experimental station
under KEFRI Kitui Center where WUE, growth and survival of these tree species are being
evaluated.
Measurement of vertical profile of soil moisture was basically conducted at the interval of
one month. Changes in water content in spacing trials of Acacia and Melia at depth of 10, 20,
30, 40, 60, and 100 cm are indicated in Fig. 11 and Fig. 12. The relation between planting
density and average water content is not so simple, but the average water content of the plots
with the shortest planting interval (1 m x 1 m for Acacia and 2.5 m x 2.5 m for Melia) is thelowest.
Figure 13 shows the measurement results (average water content) for 3 tree species at theMatinyani experimental station. Although the three species were planted in the same density(4 m x 4 m) at the same time (December 2007), soil in Eucalyptus stand was consistently
drier than soil in Melia stand throughout the study period. The tree height difference
between Eucalyptus and Melia was already remarkable (Photo 12) though only 5 years after
planting in December 2007, and such difference in growth rate was thought to be influencing
the soil moisture.
Acacia plots
2x2

3.5x3.5

Melia plots
4x4

5x5

2.5x2.5

30

30

25

25

20

20

Soil moisture (%)

Soil moisture (%)

1x1

15
10
5
0
2010/1/1

3x3

3.5x3.5

4x4

15
10
5

2011/1/1

2012/1/1

2012/12/31

0
2010/1/1

2011/1/1

2012/1/1

2012/12/31

Fig. 11, 12: Seasonal change of the average water content (Soil depth between 10-100cm)(Spacing trials of Acacia, from July 2010 to July 2012)(Spacing trials of Melia, from July 2010 to July 2012)－ 19 －

Matinyani
Eucalyptus A

Eucalyptus B

Gmelina A

Gmelina B

Melia A

Melia B

45
40

Soil moisture (%)

35
30
25
20
15
10
5
0
2011/11/1

2011/12/31

2012/2/29

2012/4/29

2012/6/28

2012/8/27

Fig. 13: Seasonal change of the average water content(Matinyani experimental site, from Nov. 2011 to Aug. 2012)

Photo 12: Eucalyptus and Melia stand in Matinyani
Eucalyptus (left), Melia (right) (Feb. 2013)

As soil moisture also varies depending on micro-topography and soil properties, the above
results cannot be applied broadly without discretion. However, these data imply that soil
moisture may vary depending on tree species planted at the same density. Results have also
revealed that species like Melia which hardly dries the soil relative to Eucalyptus may dry
the soil if plantedat close spacing.
2) Water catchment and water saving methods in the re-afforestation site
Water conservation is important especially in arid and semi-arid areas where not only
plant growth but also human lives are affected by water shortage. Re-afforestation activity inarid areas must therefore be carried out carefully. Basically, plantation size and the numberof trees should be determined on the basis of water consumption of the forest at the time offorest maturity. Effective use of rain water is also an important measure to increase biomassat the time the forest has matured. To ensure high survival rate of the planted trees, it isimportant to keep the soil moisture condition appropriate for plant growth during the period
in which root system is not well developed.
For this purpose, there are 2 possible measures in particular, “Water-harvesting” and“Water-saving”.
(1) Water-harvesting technologies
Water-harvesting technologies are used to collect surface water and overflow water, and let
it infiltrate into the soil and increase the water amount available to plants. Besides
harvesting water, micro-catchments also prevent soil erosion.
Table 3 describes features of various water-harvesting technologies and their areas ofapplication. Contour ridge, bench terrace and fanya juu are applied to large areas including
agriculture production, while the others are basically applied to individually planted trees.
Selection and application of water-harvesting technologies should be determined by the;geography, precipitation, soil properties, plantation size, available labor force, andavailability of materials, among other factors.

－ 20 －

Table 3: Characteristics and applicable area of each water-harvesting technology
Types ofwater catchment
1.
2.

Negarim

b)
c)

5.
6.
7.
8.

flat - gentle

Annualrainfall
Feasible even
150mm below

Agro-forestry

Labor
requirement

Remarks

difficultslightly large

have high adaptability to severearid condition

Half-moon MC

a)

4.

Slope

most adaptable to arid condition
among 3 types
correct run-off water on one
point
improve soil moisture in wide range(comparison with other 2)

W-shape MC

gentle200-750mm

possibleslightly large

V-shape MC

gentle200-750mm

possiblesmall

U-shape MC

gentle200-750mm

possiblesmall

gentle(200)
350-700mm

optimum

largemainly use to agro-forestry

optimumvery large

mainly use to agro-forestry
adaptable to steep terrain

optimumlarge

Contour ridge
Bench terrace
Fanya-juu

gentle – steep(20-50%)gentle(5-20%)

Circular MC

basically flat

Big hole

flat - gentle

100-600mm
700mm
or morebasically
watering
500-600mm(in Myanmar)

possiblesmall

possibleslightly large

mainly use to agro-forestry
periodically watering is basic
requirement
effective in root development
as well as soil moisture retention

a. Half-moon micro-catchment
A micro-catchment is constructed by preparing a semi-circle shaped mound to collectsurface runoff water into it. The open part of the half-moon should face the top of the slope.
Soil inside the mound is scooped out and heaped up on the mound part. Size and design of themound is determined by the slope, precipitation and target plants, but, in general a 3- m
diameter mound is used for tree planting. The typical height of the mound is 15 - 20 cm, but
this should also be adjusted according to the slope of the land (Fig. 14).
This technology can be applied in areas with rainfall of 200 to 750 mm. Although ideal
slope of ≤2% for optimal water harvesting efficiency, it is also possible to apply in areas witha slope of ≥5% by increasing the height of the mound. This technology can be applicable withrelatively less labor.
Despite that it is categorized as "Half-moon", various shapes including U-shape, V-shape
and W-shape are used depending on rainfall amount and slope condition. Since U-shapepromotes water infiltration into a wide area of land, it is expected to benefit plants other thanthe planted trees (Fig. 16). V-shape is effective in concentrating water on one point, and it issuitable for tree planting in areas with severe dry conditions. W-shape consists of connected
V-shape mounds in a row along the contour line to harvest all surface runoff and is used in
extremely dry areas (Fig. 17). Since surface runoff is collected from wider area than othertypes do, the mound of this type becomes weak structurally. Use of other types isrecommended in the area where rainfall per incident is a lot.
Regular maintenance and repair of the mounds is necessary after rainy season. The
mounds can be made more stable by using materials like pebbles. The structure must be
maintained for at least 2 or 3 years until planted trees can use water at the groundwaterlevel.
The position for planting trees should be determined according to characteristics of the tree
species to be planted and soil properties (Fig. 15). In general, trees are planted inside themound where water is concentrated. However, tree species such as Melia volkensii that areprone to root rot should be planted outside of the mound.

－ 21 －

Fig. 14: Proceeding & concept of MC

Fig. 15: Planting point

Fig. 16: An arrangement of U-shape MC

Fig. 17: An arrangement of W-shape MC

b. Negarim system
For this technology, square or rhombic compartments separated by mounds are established(Photo 13). A hole is dug at the lowest part of each compartment to store the water. The size ofeach compartment is determined by the number of trees to be grown per unit area and as
influenced by the rainfall amount. Typical size of each compartment is 10 to 100 m2, with size
increasing with rainfall decrease. For the water storage section, the area of 1 m2 is dug down
to a depth of 40 cm and the removed soil is used for constructing the mound (Photo 14, Fig. 18).
The one side of the water storage section has ramped part where trees are planted. This
technology is applicable in the areas with annual rainfall amount ≤150 mm, and can beapplied on land of slope up to 5%. However, because the runoff water in each compartment isconcentrated on one point, this system is not suitable for agriculture use.

Bund

Water Water

25cm

75cm
40cm Depth

Waterlogging
Seedling planting spot

－ 22 －Negarim water catchment
Photo 13: An arrangement of Negarim MC (Previous pager left)
Photo 14: Concept of Negarim MC (Left)
Fig. 18: Structure of Negarim MC (Previous pager right)

c. Contour ridge system
For this technology, ditches are excavated along the contour line of the slope in order tostore water (Photo 15). The removed soils are heaped on the lower part of the slope below theditches where trees can be planted. Typical depth of the ditch is 30 to 45 cm, and interval
between ditches is 10 to 15 m. This is primarily used for tree plantation within agriculturallands for the purpose of ensuring water supply to crops (Fig. 19).
This technology is effective for areas with annual rainfall of 350 to 700 mm and may be
applied in regions with annual rainfall of about 200 mm if tree planting is the primary
purpose. The interval between ditches is determined by slope and rainfall amount. If therainfall of the area is extremely low and the primary purpose is tree planting, the trees
should be planted on the upper side of the ditches. If the water flows in a lateral direction, theditch will be divided into several sections by embankments.

Fig. 19: Concept of contour ridge

Photo 15: An example of contour ridged. Bench terracing
This technology is used to promote infiltration of surface runoff by reshaping the land into
terraces in steep terrains. It is used in areas with annual rainfall of 100 to 600 mm, andslopes of between 20% to 50%. The primary objective for applying this technology is for
agriculture and trees are planted to protect the terrace edge (Fig. 20, Photo 16). Although theearthwork volume is large and a lot of labor and funds are required, the terrace is established
as a permanent structure. This technology therefore should be introduced if appropriate
benefits can be realized over a long time.

－ 23 －

Fig. 20: Concept of bench terrace

Photo 16: An example of bench terrace

e. Fanya-juu terracing
Fanya-juu is a Swahili term means “throwing the soil on the upper side”. This is an
improved version of “Bench terracing”. Ditches are excavated along the contour line, andremoved soils are heaped up on the upper side of the slope. Ditches are 50 to 60 cm in width,
60 to 100 cm in depth on the upper side of the slope, and 50 to 60 cm in depth on the lower
side (Photo 17, 18). Mound should be built to the size of 1 m in width and about 50 cm in height.
Ridges are established along the contour line of the terrace section in order to promote runoff
infiltration and to store water in the ditch so as to maintain soil moisture for long term use.
This technology can be used in areas where annual rainfall is 700 mm or higher, and theslope is 5% to 20%.

Photo 17: An example of Fanya-juu terracing

Photo 18: A variation of Fanya-juu terracing

f. Circular micro-catchment
With this technology, planted trees are encircled by a circular mound and water is pooled
inside the mound (Photo 23). This technology is primarily applied for fruits production withinflat land where watering is possible. Diameter of the circle is generally determined by the
spread of tree canopy. Combining this micro-catchment with mulching can improve water
retention.
g. Large-scale planting pit
By making planting pit larger, the amount of water maintained in soil can be increased. In－ 24 －

the case of semi-arid area in Myanmar, the planting pits were made by digging 2 m x 50 cm toa depth of 50 cm, and then digging down 30 x 30 cm at the center to an additional depth of 80
cm. This is effective not only for long-term maintenance of soil water obtained during rainyseasons, but also for promotion of early development of the root system to the groundwaterlevel (Fig. 21). Large size seedling of about 1 m in height will be planted in each pit.

Fig. 21: Large-scale planting pit
Upper left: Installation of large-scale planting pit
Upper right: A proceeding to backfill
Left: Water harvesting and infiltration(2) Water-saving technologies
a. Tillage (Soil plowing)
Traditionally, tillage is practiced in various regions for improvement of soil physicalproperties, suppression of weeds, and preventing capillary water loss. Since it promotes
runoff infiltration, tillage is also regarded as one of the water harvesting technology. However,tillage has risks of reducing soil organic matter and increasing soil erosion which can be
mitigated by addition of organic matter and considering it applicability depending on slope.
For trees, soil under the range of canopies should be plowed up to 30 cm in depth (Photo 19,
20).

b. Mulching
Mulching is a technique for controlling evaporation of soil moisture from soil surface bycovering soil surface with either tree branches, grasses, stones or pebbles (Photo 21). Mulchingalso helps to adjust the temperature variation within soil and provides an environment
suitable for plant growth. Where organic materials are used, mulching also adds organic
nutrients.
Mulching is generally an effective technique during stages where development of tree
canopies is still in progress. However, there is a risk of plant mulches sheltering termites.
Hence, of this technique should preferably be avoided for tree species vulnerable to termites－ 25 －

and in areas where termites’ damages frequently occur.
c. Cover plants
Plants covering the soil surface are expected to reduce evaporation from the soil surface.
However, this also poses a risk of causing water competition among trees. Therefore, theplants that spread wide leaves horizontally across the soil surface like “creeping beans” issuitable to use (Photo 22).

Photo 19: An example of Tillage (for fruit trees)

Photo 20: An example of Tillage (for agro-forestry)

Photo 21: Example of mulching (Left: sawdust, Right: twigs)

Photo 22: Green gram(a form suitable as a cover plants)

d. Complete weeding
This is a technique that was developed during Social Forestry Training Project and verified
during the Social Forestry Extension Model Development project, technical cooperation
projects implemented by JICA and KEFRI in Kenya. Weeds are uprooted to reduce theircompetition for water with trees and also to reduce capillary water loss from the soil.

Azadirachta indica first year growth is reportedly 4 times higher in complete weeded plots
than in slash weeded plots. Growth difference was continuously maintained in some test
plots. Floor plants provide the covering effect on the soil surface, whereas complete weeding
poses a risk of soil erosion and loss of nutrients as with tillage (soil plowing). Complete
weeding should not be applied in sloping lands. Spot weeding should be done around the trees
in such site.

－ 26 －

e. Direct sowing and direct use of cuttings
Tree nurseries consume a large amount of water especially during dry seasons. Therefore,
it is important to consider direct seed sowing and use of cuttings for direct planting for tree
species that are adaptable to these techniques. This is effective for saving on labor andseedling production costs (soil, plastic pot, etc.).
Direct sowing has been reported to be applicable for species such as A. nilotica, A. senegal,

S. siamea, A. indica, Balanites aegyptiaca, Moringa oreifera and Ziziphus mauritaniana.
Pre-treatment to promote germination is required for some of the species, and sowing must
be done at the appropriate season. Countermeasures must be taken against water and lightcompetition with weeds and damages by livestock browsing.
Direct planting of cuttings is a technology that has already been adopted for hedges of

Euphorbia tirucalli, Gliricidia sepium and Commiphora species such as Commiphoraafricana. There are many cases where thick and long branches are used to allow the trees toserve as hedges in early stages. However, trees that are propagated by use of stem cuttingscannot develop taproot but develop shallow lateral roots instead. In order to avoid watercompetition with crops, the use of root cuttingsis preferred to general method such as potted
seedling.
(3) Watering and irrigationa. Watering
In

some

cases,

circularmicro-

catchments are installed for watering offruits trees (Photo 23). This is applicableto the trees that can generate highprofits in short time considering theinitial investment and running costs. Asa certain amount of water is consumed
by watering, consensus building amongcommunity members is required before
the application of this method.

Photo 23: Circular micro-catchment

Photo 24: Watering by PVC tube

PVC tubes and plastic bottles are usedas small-scale facilities for watering (Photo 24). These can be applicable only to easily
accessible areas because regular management is required.
b. Irrigation
Local consensus building among community members living in the downstream areas isessential depending on their land use systems. This is not a practical technique except in thecase where it is to be implemented by government department/ ministry. In the long term,
where water is limited, there is a risk of soil salinity.

－ 27 －

3) Re-afforestation and forest management techniques suitable for drylands
This section describes re-afforestation and management techniques in tropical arid andsemi-arid areas.
(1) Raising high quality seedlings
In semi-arid areas, seedlings are often grown as potted seedlings under favorable
conditions such as sufficient watering and shading in the nursery. Acclimatization of theseedlings to strong light and drought are required before planting, to make them droughttolerant.
To improve their drought tolerance, hardening off the seedlings is done at least 2 weeks
before planting through water rationing (to 1/2 to 1/3 of the normal amount) and increasing
the solar radiation (if seedlings are covered). Through these processes, root systemdevelopment within the pots is promoted and the balance between aboveground parts andunderground parts (T-R ratio) will be improved to ideal ratio. Strengthening of stem andleaves, and development of cuticle layer are promoted and this makes the seedlings moredrought tolerant and highly resistant to pests and diseases (Fig. 22).
Although sunken beds are often used in arid and semi-arid areas to maintain soil moisturein pots (Photo 25), thickened taproots sometimes will develop into the soil. A situation thatmakes it necessary to cut thick roots must be avoided as much as possible to ensure highsurvival rate. The positions of the pots should be changed on a periodical basis and root
pruning should be done by cutting roots extending outside of the pots before they grow thick.

Photo 25: A typical seedbed in arid area

Fig. 22: Benefit from hardening treatment(2) Planting methods
a. Planting density
Planted trees compete with other plants such as weeds for water, but also start competingwith each other several years after planting. In arid and semi-arid areas, it is difficult to haveclosed canopy forests, and therefore re-afforestation plan should be designed with wider
spacing from the early stage.
There are differences in water consumption by tree species, annual precipitation in theplanting site, and water retention capacity of soil. It is therefore practically difficult to－ 28 －

determine planting intervals without good understanding of these factors. KEFRI reported
that 5 m x 5 m planting interval is adequate for Melia volkensii (KEFRI, 2010) and thisspacing which gives 400 trees per hectare showed the most prominent diameter growthamong the spacing trials in Tiva Pilot Forest. For Grevillea robusta and Senna siamea thatare recognized as low drought tolerance tree species, approximately same or smaller numberof trees should be planted in comparison with Melia. Acacia species with high droughttolerance can survive under a relatively higher density. Acacia trees with planting density of1 x 1 m in Tiva endured the severe drought in 1992.
In testing growth of Prosopis species in agroforestry system in India, it was reported that it
is optimal to control the stand density to 833 trees ha-1 for 2 to 3- year old stand and to 208
trees ha-1 for 12- year old stand, without significant decrease in crop yields.
b. Planting hole
Typical size of a planting hole is from 30 cm diameter x 30 cm depth to 45 cm x 45 cm, andholes within this size range are generally used in drylands region of Kenya. According to thesurvey result among farmers with experiences in planting, the size of planting hole was notconsidered as a decisive factor affecting the survival rate.
In a case study in central arid zone in Myanmar (annual rainfall amount: 800 mm, dryseason: 7 months), large planting holes were reported to improve survival rate to nearly 100%.
If soil in the planting site is heavy clay and tends to be solidified in dry seasons and theplanting hole is small, plant’s root system cannot extend to surrounding soil and sufficient
growth cannot be expected. In such cases, the planting hole must be larger.
Planting holes should be dug before the end of the dry season. This is to ensure sufficientwater infiltration to the bottom of planting holes at the start of the rainy season. Anotherreason is that there is a concern that hole digging may take a long time if the number of trees
to be planted is large.
c. Planting
Tree planting should generally be carried out as soon as possible when adequate moisture
has accumulated in the soil to ensure long growth period for planted seedlings and to promote
sufficient root development and attain high survival rate. Normally, adequate moisture isthought to be achieved after a cumulative rainfall of 100 mm. However, long duration
between rainfall events in arid and semi-arid areas complicates the decision as to whenadequate moisture is achieved. Soils in arid and semi-arid areas are generally fine and poor
in water retention hence organic matters should be put at the bottom of planting holes toimprove its water retention capacity.
Planting work should be carried out carefully. Fine roots suffer damage when planting andthis will be a significant factor that decreases the survival rate in arid areas. To improve thesurvival rate, cut off branches leaving the

top 2 or 3 branches to ensure good balance

between evapotranspiration and water absorption in broad-leaved trees.

－ 29 －

d. Watering planted trees
Arid and semi-arid areas have limited water resources so securing water for domestic andagricultural use is a priority. It is therefore difficult to secure extra water for planted trees
especially in the dry season. Re-afforestation sites are generally located away from water
sources and it is practically difficult to develop irrigation system or carry water to each site.
Re-afforestation success will therefore depends on selections of drought tolerant tree species,
growing healthy seedlings, planting the seedlings at the beginning of the rainy season, andsecuring a sufficient growth period during the rainy season.
Watering is done when sufficient growth period has not been secured due to delay in out
planting and when the rains are too low to attain the standard accumulative amount of
100mm. For trees planted around human dwellings domestic waste water can be used forwatering them. In such cases, watering at the regular intervals is more preferable forpromoting root development rather than watering every day with small amounts of water.
(3) Management and maintenance of planted trees
Re-afforestation programmes in arid and semi-arid areas are always faced with the risk offorest fires and damages due to livestock browsing.
Main causes of forest fire are: fires used for clearing land for agriculture and grazing; fires
used for hunting; and other accidental fires. Fires can easily spread to dried grasses andbranches of shrubs in the dry season. Effective countermeasures against forest fires include:
removal of combustible material such as dried undergrowth, and installation of firebreak(streaky weeding or streaky planting of trees hard to burn) along the ridge line for fire
prevention. Since most causes of forest fire are man-made, it is important to createawareness of local residents and obtain cooperation of local communities regarding forest fire
prevention. It is also important to establish systems for monitoring and firefighting.
Grazing of cows and goats has been a traditional practice by the local community, hence itis difficult to prohibit by law. Browsing is a serious problem affecting management andmaintenance of planted sites. The most reliable measure is to enclose each planting site byfence but this cost is high and is not practical. As with forest fire, it is necessary to obtainunderstanding and cooperation among local residents and make rules of grazing taking
measures to secure livestock feedstuff such as by planting of fodder trees. It is important to
set rules among local residents through discussion in order to enhance management andmaintenance of planting sites. Tree planting in arid and semi-arid area should be carried out
by local farmers as intended by Kenya government policies, and immediate countermeasures
are promotion of tree planting using agroforestry systems in agricultural lands and on landboundaries where management and maintenance are relatively easy.
(4) Felling cycle and timing
a. Felling cycle
In order to get the benefit efficiently, it is important to make a good management plan
based on proper knowledge of demands and commodity standards in each region. In the casestudy in Kitui, Kenya, the market value of coppiced Eucalyptus is generated when the sprout－ 30 －

attains 8cm diameter, and the sprout can be felled in 3-year cycle.
b. Felling time
Although the market value, time and fluctuation of demand are significant factors todetermine felling time, it is recommended to focus attention on water competition with crops
if trees are planted within agricultural lands. It is known that pollarding and pruning reduce
the total root volume and also limit its stretching range. Pruning before starting of the dry
season is expected to mitigate the water competition with crops in the dry season.
Thinning is generally applied to increase biomass but in the case of drylands agroforestry
thinning can be regarded as a technology to mitigate the water competition with crops.
Felling of trees before the start of the dry season can also be regarded as an effective
technique to reduce water competition with crop in the dry season. Especially for theplantation of semi-deciduous trees and evergreen trees, this application can be presumed as
effective. When applying this technology, it is important to determine the number of trees tobe felled considering the negative effect of increased evaporation of soil moisture caused bydirect rays of the sunlight.

Section 6. Tree Planting by Agroforestry Approach1) Agroforestry and water management
Securing good site for planting trees is a significant challenge to farmers not only in arid
and semi-arid areas but also other areas because preferable natural conditions are generally
allocated to agriculture by priority. In the areas where there is high risk of trees getting
damaged due to livestock browsing and illegal cutting among other deforestation activities,
farmers want to grow and manage trees in the site within their eyeshot. As a result,agricultural lands and its surroundings are often selected as tree planting sites. Technologies
that optimize tree-crop production are required and such technologies are commonly referred
to as agroforestry.
a. Features of agroforestry
Agroforestry is not a mere combination of different production activities, but what is to be
adopted in order to comprehensively generate some kind of benefits not achieved by any
mono-culture system. There is no fixed format of agroforestry and various forms are adopted
according to purposes, natural, social and economic conditions.
b. Positive and negative effects of tree planting in agricultural lands
Although agroforestry is adopted to generate some kind of benefits, combinations of
production activities for different objectives have risks of negative effects in some cases.
Expected positive effects of agroforestry include: provision of shades; efficient use of light;
improvement of micro-meteorology/micro-climate; prevention of soil erosion;

improvementof soil; increase of biomass per unit area; effective use of space; inhibition of overgrowth of－ 31 －

weeds; provision of shades by trees; and provision of manure from livestock dung.
Negative effects of agroforestry include: competition for water, light and nutrients; risk ofallelopathy; containment of plant toxins; browsing and trampling by livestock; and risk ofbeing a host of disease and pest.
Competition over water between trees and crops is a significant issue for agroforestry
especially in arid and semi-arid areas and measures to avoid or mitigate it are needed.
2) Agroforestry niches
According to a questionnaire survey conducted in Kenya, there are not many sites
dedicated to tree planting except wood lots, farm forests or private plantations. Since most
farmers own limited land, trees are planted within the homesteads or compound, in crop
lands and grazing land as hedges and land boundaries.
3) Tree planting in agricultural lands
Tree planting in agricultural lands is adopted to generate profits as much as possible inlimited land areas, and this is regarded as a typical style of agroforestry.
In positioning of trees and crops, there are various forms. However, planting patterns canbe categorized into four: planting along the contour line for prevention of soil erosion;planting at certain intervals for improvement of microenvironment by leafy shades; plantingof trees and crops in rows as alley cropping; andplanting of trees concentrated on fixed

sections (Photo 26-30). The biggest problem in tree planting in agricultural lands is decreased
yields of crops due to water shortage caused by competition between trees and crops. However,there are also positive effects on crop growth such as prevention of soil erosion, improvementof runoff water filtration in to the soil, and improvement of microenvironment by leafy shade.
Management techniques are necessary for success in any form of agroforestry system.
Agroforestry system should be designed considering items such as: appropriate planting
layout of trees to fully achieve the intended effects (prevention of soil erosion, etc.); planting
intervals; tree species selection; effective use of space and soil moisture by means of mixed
planting; density control (tree thinning, etc.), branch pruning, and root pruning.

Photo 26: A typical agro-forestry style(Gentle slope; native trees + hedges + crop)

Photo 27: Tree planting by setting a compartment(Eucalyptus + maize + other crops)－ 32 －

Photo 28: A typical agro-forestry(Flat terrain; trees + green gram)

Photo 29: Hedge planting of

Photo 30: Intercropping underGrevillea robusta

Eucalyptus

Important properties required for trees to grow well under agroforestry system areabsorption of water primarily from soil depth different from that of crops; expected soil
improvement effects by coexistence with nitrogen fixing bacteria; and a high capacity tosupply organic nutrients. For plants used as hedge-row important factors for species selection
include: promotion of surface runoff infiltration in to the soil and prevention of soil erosion;ease of planting and management; fast growth and benefits as fodder trees.
Tree spacing and the number of trees that can be planted are limited by the rainfall
amount. In case of Melia volkensii planting in Kenya, 5 m interval is observed in Mbitini area,
Kitui Country with annual rainfall below 900 mm (agro-climatic zone*1) V-2; mean annual
temperature: 21 to 23°C) while 15 to 20 m interval is observed in Mutomo area, Kitui Country
with annual rainfall of about 450 mm (agro- climatic zone V-1; 23 to 29°C) (Photo 31, 32). For
the former case, the land owner explained that the original interval was 3 m but it waschanged later to secure crop yields. The number of trees that can be grown on a given landsize varies depending on differences in geography, weather, soil conditions and accumulated
experiences of farmers.

Photo 31: An example of spacing for Melia volkensii (1)Spacing: 5x5m

Photo 32: An example of spacing for Melia volkensii (2)Spacing: 15-20 x 15-20m(Annual rainfall: 900mm below, mean a. temp.: 21-23 oC)(Annual rainfall: around 450mm, mean a. temp.: 23-29 oC)

Introduction of water harvesting techniques such as micro-catchments to promote water
harvesting and infiltration of surface runoff water in to the soil, and planting of trees with－ 33 －

root system in different development depths (water-use depth) are also important factors for
effective use of soil moisture. Installation of micro-catchments is also effective for preventionof surface soil loss.
*) Concept and map of the Agro-climatic zone in Kenya is indicated at the end of this guideline.

4) Competition over water between crops and trees
a. Reality of competition
According to result of research, the effects of water competition on crop yields are muchgreater than those of shading in arid and semi-arid areas. Through the observation of crop
yield when crop were intercropped with Grevillea robusta in Kenya, there were no effects ofplanted trees on crop yields for the first 2 years, but afterwards significant reduction of crop
yields was observed. Maize yield was only a halved even in years of unusually high rainfall. A
similar study with Melia volkensii revealed a yield decline of more than 50%, and negative
effects on yields was confirmed in the range within 13 m from M. volkensii trunk.
In JICA’s technical cooperation project in Kenya, maize and beans were intercropped withthe width of 1 m (vegetation covering ratio by crops: 25%), 2 m (50%) and 3 m (75%) among S.

siamea trees was planted at the intervals of 4 m (maize were planted in a reticular pattern at
the intervals of 33 cm, and beans were sowed at the intervals of 16 cm between them). As aresult, despite the crop yields in 50% crop acreage doubled compared to 25%, yields in 75%
crop acreage presented no significant difference from 50% and negative effects on the growthin height of Senna siamea were observed. In this case, it was estimated that possibility ofintercropping with the planting intervals of trees of 4 m is limited within 2 years.
b. Techniques to mitigate water competition
i. Thinning, Coppicing, Pruning and Pollarding
Competition for water by plants can be controlled by reducing plant biomass. Water
consumption by planted trees can be regulated by reducing transpiration from leaves andlimiting the range within which the root system is extending. Techniques to reducetranspiration include Thinning, Coppicing, Pruning and Pollarding. These techniques arecommonly carried out to produce fuel wood, poles and fodder. These operations should beundertaken before the onset of the dry season to reduce water competition with crops during
dry season. These management practices are applicable to evergreen and semi-deciduous tree
species.
In Coppicing, sprouting capacity significantly varies with tree species. Although Acacia
species are generally said to be poor in coppicing, some reports argue it is possible in someAcacia species. Since many of Acacia are important for fuel wood, it is important to researchon conditions that may promote their coppicing. Even species for which coppicing is possible,
sprouting capacity might decrease in the thickened portion. Generally, the portion of ≤10 cm
in diameter maintains high sprouting ability. In the first felling, stem will be cut at 20 to 30
cm above ground height (Fig. 23). In the case of Eucalyptus camaldulensis coppicing in asemi-arid area in Kenya, sprouts grown to ≥8 cm in diameter were picked at 3-year cycle forpole production.

－ 34 －

“Pruning” is applied in order to increase the value of wood in general. If high value-added
timber production is the main purpose, branches should be pruned while they are still thin
(Fig. 25). Generally, it is recommended to cut off branches up to two third of the tree height.
For “Pollarding”, the trunk will be used as timber in the future, so the top branches are cutat the height of 1.5 to 2 m avoiding livestock browsing damages on sprout (Fig. 24). Grown
sprouts are used as poles and fuel wood. Young sprouts and leaves may be used as livestock
feedstuff depending on tree species.
ii. Root pruning
Root pruning mitigates water competition with crops. Roots are mostly pruned at 30 to 50
cm away from the trunk and at depths of 30 to 50 cm (Fig. 26). Roots are pruned by excavating
trench which can be back-filled or be used as a water storage pit.
Root pruning inhibits the growth of planted trees therefore, this technique should beundertaken in consideration of economic impact caused by tree growth reduction. However, insome cases trees whose roots are pruned have revealed better growth rate than unpruned
trees. This is likely to be as a result of rejuvenation of more efficient roots immediately after
the pruning.

Fig. 23: Procedure for coppicing

Fig. 24: Procedure for pollarding

Fig. 25: Procedure for pruning

Fig. 26: Procedure for root pruning－ 35 －

Photo 33: Pollarding of Lannea sp.

Photo 34: Coppicing of E. camaldulensis

Photo 35: Pollarding of Mango treesiii. Cultural control techniques to avoid water competition
Designing of spatial layout of plants (underground part)As mentioned in an earlier part of this guideline, plants are segmented by using water at
different depths under natural circumstances. By grasping the properties of root distributionof target plants and positioning them suitably, it may be possible to ensure effective use of thelimited soil moisture and thereby increase the profit per unit area.
Crops such as pigeon pea, sorghum and pearl millet extend their roots vigorously at thedepth of 2 m, 90 cm and near the ground surface, respectively. Maize develops its roots down
to the depth of 75 cm from the ground surface while green gram and cowpea develop theirroots deep and wide. Trees such as A. nilotica are deep-rooted and Eucalyptus species are
generally known for development of the root system in horizontal directions along with its
taproot. Tree species that can survive in arid areas are deep-rooted; however, there have been
no in-depth study on these species except for a few species. Regarding water competition withcrops, tree species that extend their roots horizontally in a vigorous way like Eucalyptus,
must be avoided or given special management attention.
Designing distribution of growth period
Required growth period varies depending on crops; green gram can mature in 3 months,
whereas pigeon pea matures in about 10 months. Effective use of soil moisture according toseasonal changes is possible by determining the crops that require a long growth period
assuming a standard water shortage condition in the dry season, and planting earlymaturing crops in the rainy season.
5) Tree species suitable for agroforestry
Agroforestry is often expected to provide various forestry products for basic needs of local
residents in the limited land area hence “Multipurpose trees” are positively selected. Suchtrees are sources of not only timber but also fuel wood, food, medicine, fodder, bee forages aswell as functions of improving the environment (leafy shade and soil preservation) which aremuch prized. Planting many tree species rather than a single species is preferred to reduce
the risks associated with mono culture.

－ 36 －

During land preparation, indigenous tree species are often retained and there is no doubtthat such species are already adaptable to the local environment. The choice of which species
to spare should also be guided by tree utilization by local communities. This fact indicatesthat those trees are worth to be left without cutting despite the negative effect on watercompetition with crops.
Farmers who mainly plant Melia volkensii (for timber production) in semi-arid areas in
Kenya (annual rainfall: about 450 mm, mean annual temperature: 23 to 29°C) have deviced a
way of increasing diversity by planting other species such as; Azadirachta indica (timber andmedicine), Tamarindus indica (timber and fruit), Mangifera indica (fruit) and Annona

senegalensis (fruit tree). Also, they retaining useful indigenous trees species such as; Acacia
tortilis (feedstuff and bee forage, etc.), Sterculia spp. (timber and fiber), Adansonia digitata(fruit and fiber), Comiphora spp. (timber), Berchemia discolor (fruit) and this shows theirusefulness to the farmers.

Photo 36: Acacia tortilis

Photo 38: Combretum sp.

Photo 37: Berchemia discolor

Photo 39: Adansonia digitata

Photo 41: Tamarindus indica (planted)

Photo 40: Sterculia africana

Photo 42: Senna siamea (planted)－ 37 －

6) Planting in other areas than agricultural lands
a. Hedge planting
Thorn plants and toxic trees can be planted densely as hedges enclosing agricultural lands
for prevention of livestock and human intrusion. Due to ease in establishment, Euphorbia

tirucalli was planted for this purpose in Africa in the past. However, due to the risk ofaccidental ingestion of toxic sap by children and limited usage, the use of the species has
declined. Thorn plants popularly used in Africa are Dovyalis caffra and Acacia species.
Characteristics required basically for such trees to be planted are: possibility of
propagation by cuttings; tolerance to pruning; high adaptability to dense planting and ease inmanagement. Preferential selection of tree species that can be used for other purposes suchas for fuel wood and fodder is necessary for livelihood improvement.
Live fence species are densely planted, hence they have a negative effect on soil water.
However, the number of trees to be planted may be reduced by using tree species whosebranches can be raddled with those of neighboring trees. Tree species for which pruning andpollarding are possible should be selected. If the inside of the hedges is an agricultural land,
additional management such as root pruning is required to prevent reduction of crop yields.

Photo 43: Hedge planting(Euphorbia tirucalli )Photo 44: Direct planting of cuttings(Euphorbia tirucalli )Photo 45: Fence of deadwoodb. Tree planting on Land Boundaries
In areas where land registration and administration system is incomplete, clarification ofboundaries to third parties is the most important concern for land owners. Since trees are
long-lived, they can be planted for boundary demarcation. In such cases, dense planting suchas hedge line is not required. Therefore, planting intervals can be adjusted according torainfall amount and financial status. Existing useful trees may also be used for this purpose.
For new planting, tree species are selected in consideration of the possibility to use themfor timber and fuel wood. As with hedges’ case, if the inside area is an agricultural land, tomitigate the water competition with crops, root pruning and branch pruning is required.
c. Tree planting within the compound (homestead)Routine management of trees in the homestead is easy, therefore tree species whose value－ 38 －

is commensurate with inputs used are often selected for this site. Improvement of living
environment (leafy shade) and contribution to landscaping are also the selection criteria.
Trees of high value such as timber trees, fruit trees and ornamental trees are preferentiallyplanted within the compound/homestead. Water harvesting by micro-catchments andwatering with a PVC tube should be applied depending on rainfall amount.

Photo 46: Boundary planting (Grevillea robusta )Photo 47: Boundary planting (Comiphora sp.)

d. Tree planting in Grazing Land
For tree planting in grazing land, special care about watercompetition with other plants is not an important factor.
Instead, consideration should be given to whether the area has
sufficient rainfall amount for sound growth of planted trees.
Micro-catchments structures cannot be maintained over a long
period because they are frequently trampled by livestock. Since
the grazing land is located away from residential areas, tree
species that can endure extensive management must be
selected.
Planting of trees useful as source of fodder is required andcriteria for selection include: high nutrition value; livestock’s
preference; absence of toxin and high coppicing ability.

Photo 48: Enclosure for grazing
prevention

Protection by fences is necessary after planting until trees develop firm roots and growenough as fodder trees for livestock (Photo 48).

－ 39 －

Chapter 4. For Re-afforestation in Concerning of Local Water Balance
1. Capacity building on accurate information
From household interviews done in 2010 among 90 farmers (in Eastern Province，Kitui
Country in Kenya) on farmers’ perception about forests and water relationship, the majorityof the residents noticed the positive effects of tree plantation on the water catchment.
However most of them believed some false information such as re-afforestation can increase
rainfall and raise the ground water level. Native species including Acacia spp., Lannea spp.
and Ficus spp. and other species like Grevillea robusta, Jacaranda mimosifolia andTamarindus indica were believed to have such positive effects, while only Eucalyptus spp.
was thought to have adverse effects on water catchment (Josephine Musyoki, Pauline Bala,
2011, unpublished work). From the results of previous studies, about 70% of the farmers
considered that Melia volkensii planted for agroforestry in their croplands can grow withoutcompetition or eliminate competition with crop if pruning is performed appropriately.
It was noted that there is lack of precise knowledge on the relation between water and trees(except Eucalyptus) hence dissemination of accurate information and knowledge is necessary.
However, quality of guidance provided by forestry extension specialists is still notenough. Capacity building of residents is necessary for giving precise information about thefunction of re-afforestation on the local water resource, such as increase of water infiltration
rate of forest soil, repression of evapotranspiration from forest floor and better rainwater use
efficiency relative to bare lands. The lack of information poses challenges in designingappropriate agroforestry systems. It is important to establish a system (networks or
platform) where those who are actually involved in on-site tree planting activities collectand accumulate hands-on information and share such information with local
communities. Public research institutes should package their research findings on tree
planting and management such that they are accessible to the local community
members as much as possible.
2. Re-afforestation decreases the amount of available water
A forest can conserve water as a green dam, which can be effective for water storage, butcannot increase the rainfall (Hino, 2005). Besides, the water available to the downstream
must be decreased by re-afforestation in upper reach because of a large amount of water
consumption for evapotranspiration. When re-afforestation is done in bare land of Loess
Plateau and evapotranspiration increases by 10 %, the amount of river flow is expected todecrease by 9 % (Zhang et al., 2008). It is necessary to make it clearly known among the local
community members concerned with re-afforestation in arid and semi-arid areas to restore
vegetation has to exploit a large amount of water to maintain forest for long time. It could
therefore decrease available water for other uses.
3. Water resource conservation
As water is used for various purposes and is essential for human life, re-afforestation
techniques that can conserve water resources and minimize water loss from plantation areas－ 40 －

should be developed.
Planted seedlings use only a small amount of water, but the water consumption increases
continuously as trees grow big. As trees grow over many years, without any control of tree
growth or leaf biomass, the water that flows out from the forest will continuously decrease forlong period and a large amount of water is necessary for their transpiration until harvest.
Therefore, re-afforestation should be designed in accordance with available water andmanagement should be aimed at controlling water consumption for a long period so that the
local water balance can be maintained.
4. Proper forest structure for wood production
From the mountain areas of Kenya, farmers were forced to move to arid low lands due tothe increase in population and the immigrants planted trees around their settlement as they
have done in their original area. These trees consumed a large amount of water which
increased the pressure on the water resource and failed to harvest their agricultural
production (Rumley et al., 2006).
Re-afforestation should be conducted after clarifying the aim of forest production such as
suitable size and form of timber and quantity of woody products. In other words, the desirable
forest structure and its re-afforestation management methods must be proposedcomprehensively taking into account of demands of residents, amount of local water resource,
and physiological and ecological properties of planted trees.
5. Techniques appropriate to maintain stand density in low level
As forests in arid and semi-arid area play important roles in enhancing community
livelihoods by supplying fuel wood and timber and contributing to environmental
conservation e.g. soil protection, appropriate density control being most suitable for the aimof forest production is necessary. Sometimes it is also important to suppress timber
production by well-timed control of tree density, because low stand density is not always
preferable for the conservation of forest environment. In low-density stands, evaporationfrom the forest floor is promoted by strong solar radiation. Shrub forest can conserve soil
condition by dense vegetation and produce fire wood. On the other hand, open forest can
produce high quality wood material. Development of techniques appropriate to control standdensity at low level in arid and semiarid area are necessary for the water resource
conservation through a variety of researches. However, there have been no general researchoutcomes on low density control that are broadly applicable to different tree species.
6. Consideration for micro-scale differences in site condition
Even in wet area such as Japan with enough rainfall for tree growth, site conditions for
re-afforestation largely vary with locations (upper or lower part of the slope and sides of the
Sea of Japan or Pacific Ocean) and, as a result, tree species for plantation and their
management methods also widely vary. Similarly, as conditions in arid and semi-arid area
also largely vary with small differences in undulation and slope direction, tree species andmanagement must be adopted in consideration of the difference in micro site conditions.

－ 41 －

Annual rainfall in arid and semi-arid area largely varies from 10 mm to 800 mm(Yoshikawa et al., 2004). Variation of rainfall significantly influences the changes in soil
moisture content after plantation establishment. For example, if Robinia pseudoacacia (black
locust) is planted in lands with sufficient amount of rainfall over 600 mm in annual average,
the water retention capacity of soil is improved as the planted trees grow. On the other hand,planting of this tree species in arid area where drought occurs frequently will cause soil
aridification (Jin et al., 2011).
7. The right tree in the right place
Although the total amount of water is not sufficient in arid and semi-arid area, there arevarious forms of available water sources and many kinds of plants can inhabit with various
life history strategies to enable them to use different water sources.
To secure a wide range of alternative selection of tree species appropriate for planting
under different site conditions, growth characteristics of as many plant species as possible
should be revealed. Very long period of management is necessary to achieve planting
objectives because of slow rate of tree growth. Furthermore various types of tree form andforest structure are established depending on different procedures during long management
period. Therefore long-term prospect is necessary for the selection of planting tree species.
8. Monotonous and large scale plantation is impracticalIn order to mitigate the human pressure on remaining natural forests, tree plantation
should be proactively promoted.However large-scale and monotonous plantations in arid andsemi-arid areas should be avoided to conserve water resources, because of the difficulty tomake consideration for the micro difference of site conditions.
However, large-scale plantations in arid and semi-arid areas should be done with a lot of
precaution considering conservation of water resources. Most of the monotonous andlarge-scale re-afforestation in the northern China caused a drying up of the Yellow River due
to the lack of consideration of local water balance. Moreover, most of them were conducted indegraded

crop

lands

and

mountainousbarren

land

which

were

unsuitableforre-afforestation. Therefore any attempt of large-scale re-afforestation simply aiming toincrease a forest biomass for carbon fixation poses a great risk of water source depletion andis not appropriate in arid area (Cao et al., 2010).
To make matters worse, some big re-afforestation projects have succeeded to establish
beautiful but tentative and small forest vegetation, which gives an impression that
re-afforestation is possible even in a degraded barren land if a proper management isperformed. However these short-term and small-scall outcomes should not support
large-scale and long-term re-afforestation policies in arid and semi-arid area (Cao et al.,2010) without a lot of precaution.
9. Robustness under harsh and dry environment
As the rainfall largely varies across years in arid and semi-arid area, forest structure andtree properties must have some drought tolerance for their sustainability.

－ 42 －

Therefore re-afforestation techniques must focus on the securement of robustness of forest
vegetation under harsh environment by the coordination of forest water consumption withthe control of leaf biomass (=water loss from forest) based on the selection of tree species that
can adjust its leaf biomass by itself (dieback) when there is low rainfall or during drought.
10. Difference between agroforestry and re-afforestation
Tree plantation should be started in consideration of the relation between forest andhuman life. Therefore, a completely different point of view of forest management is required
between agroforestry tree planting within the compound and tree plantation established in
the rural farms away from the settlement area.
Trees planted within the compound can be protected from illegal harvesting andlivestock browsing hence maintaining a stable forest environment for tree growth. On
the other hand, for re-afforestation in rural farms away from homestead has
prerequisites such as low risk of illegal cutting. There are also other essential
requirements such as selection of tree species suitable for extensive management andconsideration of countermeasures such as fences to prevent livestock grazing. The mostimportant concern for re-afforestation in such sites is the profits of grown trees andtimbers. On the other hand, trees for agroforestry need to have positive effects on crops
and to conserve and improve agricultural land conditions. There are clear differences
between agroforestry in cropland and re-afforestation as concerns the management
methods including tree species, planting density and management practices such as
pruning. Re-afforestation in rural area requires consideration on water environment inscale of plantation area to eliminate adverse effects of tree growth on local waterbalance. On the other hand, trees for agroforestry are required to have positive effects on
crops to conserve and improve conditions of farmland. Because agroforestry requiresconsideration on crop production to minimize adverse effects on yields of crops grownunder planted trees.
11. Issues in agroforestry
Agroforestry is a result of compromise between forestry and crop production by segregationand competition over water. Apart from timber production, tree species used for daily life
are often planted. Management techniques appropriate for tree species which areimportant for livelihood of residents but minor in commercial sense are less developed.
For example, ecological and physiological properties of minor tree species are also lessunderstood; distribution and capacity of water absorption of the root system thatsignificantly affect interspecific competition for water with crops have not yet been
revealed. However, a bottleneck of dry land agroforestry is the lack of crucial
information about growth properties of respective tree species and management
techniques appropriate for tree production that ensures effective use of space and water
resources. It is necessary for the management of agroforestry to have consideration of theeffect of tree growth on soil water in re-afforestation area which must be depressed as trees
grow big.

－ 43 －

12. Conclusions
New method of forest management which aims to conserve local environment and todevelop human life is necessary to base on the precise information such as re-afforestation
should depress the amount of available water both in the lower reaches and the concerned
forest.
The selection of tree species and the execution of forest management are completely
different between agroforestry and re-afforestation which support crop production and water
resource cultivation, respectively.
As it is easy to consider unfamiliar environment to be a simple and monotonous condition,
the necessity to select the right tree in the right place is hard to accept for re-afforestation in
unfamiliar arid and semi-arid area. Even for the local residents who do not have any
information about such delicate selection of tree species for re-afforestation around theirresidence shows a tendency to make simple and monotonous forest.
To secure a wide range of alternative selection of tree species being appropriate forre-afforestation objectives under different site condition, growth properties and way ofnursing and cultivation of as many tree species as possible should be revealed.
Water in dry lands is an indispensable currency which can preside over all lives including
human society.
Forest management based on the maintenance of local water balance is the fundamental
issue for appropriate wood production corresponding to the initial objectives of sustainable
development of forestry under persistent water consumption.

New systematized techniques

for re-afforestation in dry lands are desired to establish and to maintain the open forest withadequate tree density control. Especially to clarify the effects of tree density on the forest
development, many kinds of forests which have precise past management history arenecessary to compare growth properties under many kinds of site conditions. Then it is theissue of dry land forestry which should be started immediately, because a long time isnecessary to establish suitable experimental forests.

－ 44 －

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patterns of uptake and hydraulic redistribution of soil water in contrasting woody vegetation types.. Treephysiology, 24, : 919-928.
Monda, Y., Miki, N. & Yoshikawa, K. : Stand structure and regeneration of Populus euphratica forest in
the lower reaches of the Heihe River, NW China. Landscape Ecol Eng 4, 115-124, 2008
Oliveira, R.S., Dawson, T.E.. and Burgess, S.S.O.(2005)Evidence for direct water absorption by theshoot of the desiccation-tolerant plant Vellozia flavicans in the savannas of central Brazil.. Journal of
Tropical Ecology, 21, : 585-588.
Richards, J. H. and Caldwell, M. M.(1987)Hydraulic lift : Substantral nocturnal water transport－ 45 －

between soil layers by Artemisia tridentata roots. Oecologia, 73, 0: 486-489.
UNEP(1997)Atlas of Desertification (2nd ed.). Arnold, , : pp.182.
Wei, J., Liu, G., Shan, L., Zhang, X. and Li, S.(2011)Response of root distribution of Haloxylon
ammodendron seedlings to different irrigation amount in the hinterland of Taklimakan desert. Advancesin Biomedical Engineering, 1, : 49-55.
Yoshikawa, K., Abbasi, T., Saito, M., Abdulrahman, R., Al Harbi, R. & Yamamoto, F. : Ecology of thejuniper woodlands of the Asir Mountains The joint study project on the conservation of juniper
woodlands in the Kingdom of Saudi Arabia final report , 69-113, 2007
Cao, S., Tian, T., Chen, L., Dong, X., Yu, X. and Wang, G.(2010)Damage caused to the environment byreforestation policies in arid and semi-arid areas of China. AMBIO, 39, : 279–283.
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Rumley, R, Muthuri, C. and Ong, C.(2006)More trees with less water. World Agroforestry Centre
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Hydrological Processes, 22, : 1996–2004.

－ 46 －

Annex 1

Determination of potential planting area
by
“ROC analysis” and “Classification tree models”－ 47 －Distribution of trees (response variable)

Classification tree model

M. volkensii

A. senegal

A. senegal

M. volkensii

Latest climatic data (1960-90)
19 factor of BIOCLIM (explained variable)
Bio01

Bio02

Bio03

Bio04

Bio05

Bio06

Bio07

Bio08

Bio09

Bio10

Bio11

Bio12

Bio13

Bio14

Bio15

ROC Analysis
Stochasticity threshold todetermine the potential area

Bio16

Bio17

Bio18

Bio19

Prediction of the potential area
Suitable habitat・Marginal habitat

Fig. A-1-1: Flowchart for analysis

ROC Analysis of A. senegal

ROC Analysis of M. volkensii

Sensitivity

Sensitivity＊Cut-off point＊Cut-off point

AUC=0.86

AUC=0.99

1-Specificity

1-Specificity

Accuracy of the model： “very good”(Swets 1988)

Accuracy of the model: “Excellent”(Swets 1988)

Suitable Habitat: The area where has much feasibility more than the cut-off point
Marginal Habitat： The area where has feasibility between 0.01 and cut-off point
Fig. A-1-2: Verification of the accuracy of the classification tree model and its feasibility threshold value－ 49 －

Fig. A-1-3: Map of 19 climatic factors by BIOCLIM and map of topography (altitude)

<12.5
15.0
17.5
20.0
22.5
25.0
27.5
30.0<

BI 01

5.0 - 7.5
7.6 - 10.0
10.1 - 12.5
12.6 - 15.0
15.1 - 17.5
17.6 - 20.0

BI 02

543 - 750
751 - 1000
1001 - 1250
1251 - 1500
1501 - 1644

BI 04

3.7 – 5.0
5.1 – 7.5
7.6 – 10.0
10.1 – 12.5
12.6 – 15.0
15.1 – 17.5
17.6 – 20.0
20.1 – 22.8

19.4 - 20.0
20.1 – 25.0
25.1 – 30.0
30.1 – 35.0
35.1 – 39.8

BI 06

11.5 – 12.5
12.6 – 15.0
15.1 – 17.5
17.6 – 20.0
20.1 – 22.5
22.6 – 25.0
25.1 – 27.5
27.6 – 29.8

9.9 – 12.0
12.1 – 14.0
14.1 – 16.0
16.1 – 18.0
18.1 – 20.0
20.1 – 21.5

BI 08

11.8 – 12.5
12.6 – 15.0
15.1 – 17.5
17.6 – 20.0
20.1 – 22.5
22.6 – 25.0
25.1 – 27.5
27.6 – 30.3

BI 10

BI 03

BI 05

BI 07

64 – 65
66 – 70
71 – 75
76 – 80
81 – 85
86 - 9010.0 – 12.5
12.6 – 15.0
15.1 – 17.5
17.6 – 20.0
20.1 – 22.5
22.6 – 25.0
25.1 – 27.5
27.6 – 29.2

BI 09

9.8 – 12.0
12.1 – 15.0
15.1 – 17.5
17.6 – 20.0
20.1 – 22.5
22.6 – 25.0
25.1 – 27.5
27.6 – 28.6

BI 11

－ 50 －

177 – 200
201 – 400
401 – 600
601 – 800
801 – 1000
1001 – 1200
1201 – 1400
1401 – 1600
1601 – 1837

BI 12

31 – 40
41 – 50
51 – 60
61 – 70
71 – 80
81 – 90
91 – 100
101 – 110
111 – 120
121 – 133

0 – 10
11 – 20
21 – 30
31 – 40
41 – 50
51 – 60
61 – 70
71 – 79

47 – 100
101 – 150
151 – 200
201 – 250
251 – 300
301 – 350
351 – 384

BI 13

BI 14

BI 15

90 – 100
101 – 200
201 – 300
301 – 400
401 – 500
501 – 600
601 – 700
701 – 818

29 – 50
51 – 100
101 – 150
151 – 200
201 – 250
251 – 300
301 – 350
351 – 400
401 – 450
451 – 579

0 – 5051 – 100
101 – 150
151 – 200
201 – 250
251 – 308

BI 16

BI 17

BI 18

0 – 5051 – 100
101 – 150
151 – 200
201 – 250
251 – 300
301 – 350
351 – 400
401 – 450
451 – 551

8 –

200

201 –

400

401 –

600

601 –

800

801 – 1000
1001 – 1200
1201 – 1400
1401 – 1600
1601 – 1800
1801 – 2000
2001 – 2200
2201 – 2400
2401 – 2600
2601 – 2800
2801 – 2977

BI 19

Altitude

Table A-1-2: Nineteen climatic factors of BIOCLIM

BI01
BI02
BI03
BI04
BI05
BI06
BI07
BI08
BI09
BI10

Climatic Factor
Annual Mean Temperature
Mean Diurnal Range (Mean of monthly (max. temp. – min. temp.))
Isothermality (BI02 / BI07) (* 100)
Temperature Seasonality (standard deviation * 100)
Max. Temperature of Warmest Month
Min. Temperature of Coldest Month
Temperature Annual Range (BI05 – BI06)
Mean Temperature of Wettest Quarter
Mean Temperature of Driest Quarter
Mean Temperature of Warmest Quarter－ 51 －

BI11
BI12
BI13
BI14
BI15
BI16
BI17
BI18
BI19

Climatic Factor
Mean Temperature of Coldest Quarter
Annual Precipitation
Precipitation of Wettest Month
Precipitation of Driest Month
Precipitation Seasonality (Coefficient of Variation)
Precipitation of Wettest Quarter
Precipitation of Driest Quarter
Precipitation of Warmest Quarter
Precipitation of Coldest Quarter

Fig. A-1-4: Present distribution and Suitable/Marginal habitat of each tree species
01. Acacia senegal

Presence distribution

02. Acacia tortilis

Suitable/Marginal habitat

Presence distribution

03. Acacia xanthophloea

Presence distribution

04. Azadirachta indica

Suitable/Marginal habitat

Presence distribution

05. Balanites aegyptiaca

Presence distribution

Suitable/Marginal habitat

06. Combretum aculeatum

Suitable/Marginal habitat

Presence distribution

07. Combretum collinum

Presence distribution

Suitable/Marginal habitat

Suitable/Marginal habitat

08. Combretum molle

Suitable/Marginal habitat

Presence distribution

Legends:－ 52 －

Presence

Suitable/Marginal habitat

Suitable habitat

Marginal habitat

09. Combretum shumannii

Presence distribution

10. Eucalyptus camaldulensis

Suitable/Marginal habitat

Presence distribution

11. Eucalyptus globulus

Presence distribution

12. Eucalyptus saligna

Suitable/Marginal habitat

Presence distribution

13. Faidherbia albida

Presence distribution

Suitable/Marginal habitat

14. Melia volkensii

Suitable/Marginal habitat

Presence distribution

15. Senna siamea

Presence distribution

Suitable/Marginal habitat

Suitable/Marginal habitat

16. Senna singuneana

Suitable/Marginal habitat

Presence distribution

Legends:－ 53 －

Presence

Suitable/Marginal habitat

Suitable habitat

Marginal habitat

17. Senna spectabilis

Presence distribution

18. Tamarindus indica

Suitable/Marginal habitat

Presence distribution

Legends:

Suitable/Marginal habitat

Marginal habitat

Suitable habitat

Presence

Table A-1-2: Deviance Weighted Score (DWS）
Bioclim parameters
BI 01

BI 02

BI 03

BI 04

BI 05

BI 06

BI 07

BI 08

BI 09

BI 10

BI 11

BI 12

BI 13

BI 14

BI 15

BI 16

BI 17

BI 18

BI 19

Acacia senegal
Melia volkensii
Acacia nilotica
Acacia tortilis
Acacia xanthophloea
Azadirachta indica
Balanites aegyptiaca
Combretum aculeatum
Combretum collinum
Combretum molle
Combretum schumannii
Eucalyptus camaldulensis
Eucalyptus globulus
Eucalyptus saligna
Faidherbia albida
Prosopis chilensis
Senna siamea
Senna singuneana
Senna spectabilis
Tamarindus indica

2.7
0.0
2.0
0.0
0.0
1.9
6.1
7.6
0.0
12.1
33.4
4.1
0.0
0.0
0.0
5.2
3.4
10.6
6.1
7.4

2.8
0.0
0.0
3.3
0.0
36.1
10.1
3.7
4.7
4.3
8.7
3.0
3.0
0.0
0.0
13.7
0.0
3.9
0.0
3.4

4.2
0.0
0.0
0.0
0.0
3.9
0.0
4.2
0.0
8.1
0.0
0.0
4.3
3.2
0.0
0.0
0.0
0.0
0.0
0.0

14.5
4.7
9.2
15.9
3.0
14.1
7.6
9.1
9.4
15.9
0.0
10.1
4.2
0.0
28.2
20.3
13.1
12.1
7.6
6.8

3.2
16.5
29.4
0.0
12.5
5.8
8.5
0.0
3.7
0.0
7.3
3.3
0.0
0.0
0.0
3.8
33.7
0.0
0.0
27.6

0.0
6.2
0.0
7.7
2.6
3.3
38.9
4.1
2.7
28.8
0.0
0.0
0.0
0.0
0.0
6.4
2.3
6.5
0.0
2.5

3.6
7.4
4.0
10.1
3.1
6.2
3.1
9.4
0.0
3.0
0.0
2.6
7.3
6.8
15.5
14.7
0.0
0.0
0.0
4.9

20.2
0.0
0.0
0.0
0.0
4.0
0.0
4.0
3.3
0.0
2.4
0.0
0.0
0.0
0.0
0.0
5.9
0.0
0.0
0.0

10.9
7.1
2.7
3.5
31.0
0.0
0.0
3.6
5.3
2.2
0.0
3.5
4.5
0.0
0.0
17.4
0.0
0.0
0.0
0.0

0.0
7.0
7.3
19.7
0.0
1.1
7.5
0.0
3.4
0.0
2.3
10.1
0.0
4.9
0.0
0.0
0.0
0.0
0.0
0.0

0.0
20.0
0.0
0.0
0.0
0.0
0.0
3.5
0.0
0.0
0.0
3.4
0.0
7.3
0.0
0.0
0.0
7.9
0.0
7.8

14.2
0.0
20.5
0.0
27.1
5.4
3.4
8.2
3.6
11.2
4.8
49.7
48.9
45.8
15.0
0.0
3.0
18.1
26.6
4.6

3.0
12.2
2.4
5.8
0.0
0.0
0.0
0.0
9.0
14.3
9.4
6.3
0.0
4.8
9.2
0.0
7.0
27.8
13.9
3.9

3.3
2.0
0.0
14.6
2.3
3.6
2.9
13.8
0.0
0.0
0.0
0.0
0.0
2.0
0.0
0.0
0.0
0.0
8.8
0.0

0.0
0.0
13.1
6.0
0.0
9.8
0.0
3.7
0.0
0.0
5.5
0.0
0.0
0.0
0.0
11.5
5.6
0.0
0.0
9.2

9.0
6.0
3.0
2.7
3.7
0.0
5.4
4.5
3.3
0.0
23.2
0.0
17.3
8.5
0.0
4.1
8.4
9.5
14.0
11.1

3.7
3.4
3.1
5.5
5.5
5.0
2.8
0.0
0.0
0.0
3.1
0.0
7.7
0.0
8.8
0.0
3.6
0.0
0.0
4.7

0.0
2.7
0.0
5.2
9.3
0.0
3.9
16.0
40.5
0.0
0.0
0.0
2.8
13.9
8.6
3.0
3.7
3.8
12.5
0.0

4.9
4.8
3.3
0.0
0.0
0.0
0.0
4.5
11.1
0.0
0.0
4.0
0.0
2.8
14.9
0.0
10.4
0.0
10.5
6.2

BI 11
BI 12
BI 13
BI 14
BI 15
BI 16
BI 17
BI 18
BI 19

Mean Temperature of Coldest Quarter
Annual Precipitation
Precipitation of Wettest Month
Precipitation of Driest Month
Precipitation Seasonality (Coefficient of Variation)
Precipitation of Wettest Quarter
Precipitation of Driest Quarter
Precipitation of Warmest Quarter
Precipitation of Coldest Quarter

DWS (%)

DWS (%)

BI 01
BI 02
BI 03
BI 04
BI 05
BI 06
BI 07
BI 08
BI 09
BI 10

Annual Mean Temperature
Mean Diurnal Range (Mean of monthly (max temp - min temp))
Isothermality (BIO2/BIO7) (* 100)
Temperature Seasonality (standard deviation *100)
Max Temperature of Warmest Month
Min Temperature of Coldest Month
Temperature Annual Range (BIO5-BIO6)
Mean Temperature of Wettest Quarter
Mean Temperature of Driest Quarter
Mean Temperature of Warmest Quarter－ 54 －

Annex 2

Tree species that has high drought-tolerance

1) 15 highly drought-tolerant tree species and its characteristics- Acacia nilotica (L.) Del. (subsp. Nilotica)- Acacia senegal (L.) Willd.
- Acacia tortilis (Forssk.) Hayne- Acacia xanthophloea Benth.
- Azadirachta indica A. Juss.
- Balanites aegyptiaca (L.) Del.
- Combretum spp. (C. aculeatum, C. collinum, C. molle, C. shumannii)- Eucalyptus camaldulensis Dehnh- Eucalyptus saligna Smith- Faidherbia albida (Del.) A. Chev.
- Gliricidia sepium (Jacq.) Walp.
- Grevillea robusta A. Cunn. ex R. Br.
- Melia volkensii Guerke- Senna siamea (Lam.) Irwin et Barneby- Tamarindus indica L.

2) List of highly drought-tolerant tree species distribute in Kenya－ 55 －

－ 57 －Drought resistant and occurs in plain, flator gently undulating ground and ravines(1). The subspecies nilotica is adapted toperiodic flooding followed by extended
droughts (2).

Strong light requirement. Grows best on
alluvial soils in ravine areas subject toperiodic inundation (1) but also grow well on
heavy, clay soil with a pH range of 5 to 9 (2).

Soil water
regimes

Suitable site forplanting-1-1-1
L , 0.16 g L and 0.77 g L for Acacia, Albizzia, Azadirachta
and Eucalyptus respectively (6). A. noltica, also other two
native species, showed traits of low water comsumption andsmall biomass production in comparison with E. camludulensis .

http://www.kew.org/plants-fungi/Acacia-nilotica.htm

Since the time of the Pharoahs, large timber trees have been exploited from the riverine forests of the Nile.
Sapwood is yellowish-white and heartwood reddish-brown, hard, heavy, durable, difficult to work, although it
takes a high polish. Because of its resins, it resists insects and water, and it is harvested for boat making,posts, buildings, water pipes, well planking, ploughs, cabinet work, wheels, tool handles, carts, mallets andother implements. It is an attractive wood, good for carving and turnery. Sudan forests have been managed
on a 20-30 year rotation producing termite resistant timber especially suitable for railway sleepers(1).
In irrigated plantations in the Sind and Punjab, 10-15 seeds are spot sown at 2 x 3 m spacing on the topsof trenches. They are thinned to three to four seedlings after three to four months. Further thinning occurs atfive year intervals. Rotations are 20-25 years. In the Thal desert, Pakistan (where there is 250 mm annual
rainfall), promising growth resulted from irrigation at ten day intervals. Growth rates varied considerably
depending on the sites, with maximum mean annual increment of 13 m3 /ha at 20 years old and 10.5 m3 /ha
at 30 years recorded (2).

Plantations for timber production

In the Central plain of Indian subcontinent A.nilotica grow naturally in the agricultural fields and forms animportant agroforestry system. It was reported that A. nilotica generally reduced crop yield under its canopy
and this reduction varies with distance from the tree trunk. Crop production depend upon distance from tree
trunk and tree canopy size. Reduction in grain yield was maximum (30%) under the large tree canopy andlowest (12%) under the small tree canopy due to decreased availability of light by 44 to 62% under the
canopy that resulted in slow photosynthetic rates and growth(4). However, when the tree is felled after thecompletion of rotation cycle (>12 years) grain yield increased 126% for the first cropping season and 30 % for
the fifth cropping season at 1 m distance from the tree stump and declined with distance (5). These results
suggest that the crop may exploit the greater amount of nutrients to increase productivity, if the tree canopy is
open to facilitate greater light availability.
When intercropped with A. nilotica ssp. nilotica in semi-arid Nigeria, sorghum showed heavily depressed
yields (1).

Agroforestry(6) Zaid, D.M., F-UR-R. Shah and A. Majeed (2010) Planting Eucalyptus camaldulensis in Arid Environment - Is It Useful Species under Water Deficit System? Pak. J. Bot., 42(3): 1733-1744(4) Pandey, C.B., Singh, A.D. and Sharma, D.K. (2000) Soil properties under Acacia nilotica trees in a traditional agroforestry system in central India. Agroforestry Systems 49: 53-61(5) Pandey C.B. and D.K. Sharma, D.K. (2005) Ecology of Acacia nilotica based traditional agroforestry system in Central India. Bull. NIE, 15: 109-116.

(3)Invasive Species Compendium (Copyright © 2013 CABI.)
http://www.cabi.org/isc/?compid=5&dsid=2342&loadmodule=datasheet&page=481&site=144(2) Royal Botanic Gardens, Kew. Acacia nilotica (acacia)(1) Tree Functional and Ecological Database: Tree species (by Harja, D., Rahayu, Karlan, S.N.) , World Agroforestry Centre
http://worldagroforestrycentre.org/regions/southeast_asia/resources/db/AFTdatabase

Reclamation: In India, this species is used on degraded saline and alkaline soils.
Medicine: It is used for stomach upset and pain, the bark is chewed to protect against scurvy, an infusion is taken for
dysentery and diarrhoea.
Poison: The aqueous extract of the fruit, rich in tannin (18-23%), has shown algicidal activity againstChroccoccus,
Closteruim, Coelastrum, Cosmarium, Cyclotella, Euglena, Microcystis, Oscillatoria, Pediastrum, Rivularia, and etc.
Food: Tender pods and shoots are used as a vegetable, and roasted seed kernels are sometimes used in Sudan for foodflavouring. Air-dried seeds contain crude protein and are eaten raw or roasted in India in time of acute food scarcity.
Fodder: The crude protein content of the leaves is 14-20%, and 11-16 % for the highly palatable pods. Pods and shoots areused as forage for camels, sheep and goats, especially in Sudan, where it is said to improve milk from these animals.
Apiculture: The fragrant flowers are popular bee forage.
Fuel: The calorific value of the sapwood is 4500 kcal/kg, while that of the heartwood is 4950 kcal/kg. This valuable sourceof firewood and charcoal has been used in locomotives, river steamers and small industries. In India and Pakistan riverine
plantations are managed on a 15-20 year rotation for fuel wood and timber.
Tannin or dyestuff: The pods have been used for tanning in Egypt for over 6 000 years. The inner bark contains 18-23%
tannin, which is used for tanning and dyeing leather black.

Benefit and Products (1, 2)

Forms a deep and extensive root systemon dry sites, the tap root developing first
and then the laterals, which becomecompact and massive, but on flooded
sites the root system is largely lateral (3).

Grows on a wide variety of soils, thriving on
alluvial soils, black cotton soils, heavy clay
soils, and can tolerate poorer soils. (1)Soils innatural range

Root system

According to the experiment comparing water use of four
species ( Acacia nilotica, Albizia procera, Azadirachta indica
and Eucalyptus camaldulensis ) grown in pots in a green
house, water consumption by one year old Eucalyptus wasmore than three times that of by Acacia and Azadirachta .

200-1270 mm (1)Mean annual rainfall

However, water use efficiency was found as 0.32 g L -1, 0.48 g

Ecophysiology of water use

0-1340 m a.s.l. (1)The species will tolerate only light frost, but is extremely resistant to drought and heat. It is also tolerant ofsaline soil. Young trees coppice well, and the species can be propagated from truncheons, root suckers andcuttings.But the subspecies nilotica coppices very weakly (1). Some subspecies can be invasive (and can be
extremely invasive in exotic habitats). The species can be direct seeded or established by seedlings. In thenursery long poly-tubes (20 x 7 cm) should be used so as not to restrict rapid tap root growth. Frequent root
pruning is advised. Nursery grown seedlings are usually planted out after six months, but in some cases stayin the nursery for up to a year. Establishment varies depending on the site. Seedlings are shade intolerant(2).
Young seedlings are said to require full sun and frequent weeding (1).

The trees generally lose their leaves during the dry season,
though riverine subspecies can be almost evergreen.The
flowers are bright yellow and borne on globe-shaped flower
heads. The flowers are sweetly scented and appear near the
beginning of the rainy season. Flowering is prolific, and canoccur a number of times in a season. Often only about 0.1% offlowers set pods. The nutritious pods retain their seeds atmaturity and are dispersed by animals (2).

Tree Management
Planting and weeding

Phenology and Ecophysiology
Phenology

Altitude

Environmental reqirements

Moderate-sezed evergreen tree, with a short , thick andcylindrical trunk, growing to a height of 25 m. It has
considerable variation with nine subspecies presently
recognized, three occurring in the Indian subcontinent and six
throughout Africa. (1).

General description

Acacia nilotica (L.) Del. (subsp. nilotica ) (Fabaceae)

－ 58 －

Soils innatural range

For firewood production, trees can be cut on a rotation of 20 years using coppice with standards, lopping
up to 50% of the lower crown in rainy season. Seedlings are rather slow growing with initial annual
increments of 30-40 cm. For firewood production, trees can be cut on a rotation of 20 years using coppicewith standards, lopping up to 50% of the lower crown in rainy season. Wood yields of 120-190 cubic metres
per hectare, with annual increments of 0.5-1.0 cubic metres per hectare have been recorded(1).
Plant spacing experiment in Tiva Experimental Forest (Kitui, Kenya) showed that height growth of trees
were not differed among the spacings until 14 years of age when it seems to reach its peak. At 15 yeas old,the mean tree height in 5 m x 5 m spacing (height 5.5 m tall) was significantly lower than that in 1 m x 1m
spacing (height 7 m tall). and reached almost its peak (ca. 12 m) at 10 years old. Total stand volumes were
not diffrent among the spcings. On the contrary, stand basal area and mean stem volume were significantly
small in 1 m x 1 m spacing than other spaccings. From the view point of timber production at 15 years ofage, the spacing 5 m x 5 m seems to be best with most stems >= 11 cm in dbh.

Plantations for timber production

Today, A. senegal is grown primarily for gum, but plays a secondary role in agricultural systems, restoringsoil fertility and providing fuel and fodder. It is a highly suitable tree for agroforestry systems, widely grown in
combination with watermelon, millets and forage grasses (1). The study on nitrogen fixation of three varietiesof A. senegal revealed their ablity to fix nitrogen from the air in their natural ecosystems.The species, hence,
can be utilized as plantations in agriculture and land rehabilitation programs (5, 7). In Sudan, it is grown in'gum gardens' for gum as well as to restore soil fertility. A traditional bush-fallow system is followed with a 20year rotation during which time it is grown for 15 years. Agricultural crops are grown for five years (millet,
sesame, sorghum, groundnuts), followed by five years with young, unproductiveA. senegal trees, which later
produce gum during the last 10 years of the rotation. Corresponding to this rotation, 1/4 of the land is kept inagricultural crops, 1/4 in young unproductive trees and 1/2 in productive trees(1).

(4) M. Malagnoux, E.H. Sène and N. Atzmon 2007 Forests, trees and water in arid lands: a delicate balance. Unasylva 229 (Vol. 58)(5) Githaea, E. W., Gacheneb, C. K. K., Njokab, J. T. and Omondic S. F. (2013) Nitrogen Fixation by Natural Populations of Acacia senegal in the Drylands of Kenya Using 15N Natural Abundance. Arid Land Research and Management Volume 27: 327-336(6) Royal Botanic Gardens, Kew. Acacia senegal (gum arabic)
http://www.kew.org/plants-fungi/Acacia-senegal.htm(7) Eunice W. Githae, Charles K. K. Gachene and Jesse T. Njoka (2011) Soil physicochemical properties under Acacia senegal varieties in the dryland areas of Kenya. African Journal of Plant Science Vol. 5: 475-482(8) Yawata, H. (2001） A short-term expert report (on-farm reforestation) for the Social Forestry Extension Model Development (SOFEM) Project, pp41, JICA (in Japanese)(9) Okamoto, K. (2002） A long-term expert report (on-farm reforestation) for the Social Forestry Extension Model Development (SOFEM) Project, pp41, JICA (in Japanese)(3) Milimo, P. B.; Dick, J. McP.; Munro, R. C. (1994) Domestication of trees in semi-arid East Africa: the current situation.
In: Leakey, R. R. B.; Newton, A. C., (eds.) Tropical trees: the potential for domestication and the rebuilding of forest resources. London, HMSO, p.210-219. (ITE Symposium, 29)(2) Beentje, H. J. (1994) Kenya Trees, Shrubs and Lianas. National Museums of Kenya, Nairobi, Kenya, 722pp.

(1) Orwa, C., Mutua, A., Kindt, R., Jamnadass, R. and Simons, A. (2009) Agroforestry Database 4.0, World Agroforestry Centre
http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=108
http://www.worldagroforestry.org/treedb/AFTPDFS/Acacia_senegal.pdf* The Social Forestry Extension Model Development Project (SOFEM: 1997-2002) by Japan International Cooporation Agency (JICA)

Gum or resin: Gum arabic exudes from the duct of the inner bark; it is tapped in the hot season (May-June) when the trees
are stressed. Tapping commences after leaf fall and ceases during the colder months of the dry season. Gum nodules formin 3-8 weeks, exuding from the former broken abscission scars. Annual yields stand at 188-2856 g for young trees and 3796754 g for older trees (7-15 years). Gum production is excellent on poor soils and higher in stressed trees(4).
Food: The seeds are dried and preserved for human consumption as a vegetable (1).
Fodder: Leaves and pods are browsed by sheep, goats and camels. Crude protein values are 20% for leaves, 22% forgreen pods, and 20% for dry pods (expressed as a percentage of dry matter)(1).
Apiculture: Bees seek the nectar from the flowers. Honey amber in colour, with a mild aroma and granulates rapidly(1).
Fuel: An excellent fuelwood, the calorific value is estimated at 3000 kcal/kg. The dense wood also yields charcoal(1).
Fibre: The long, flexible surface roots yield a strong fibre used for cordage, ropes and fishing nets(1).
Timber: The heartwood is almost black and takes polish well. It is used for making carts and Persian wheels, sugar cane
crushers, agricultural implements, horse girths and tool handles. Essential oil: Seeds contain fat (khakhan), which is usedboth for medicine and for soap making. Medicine: Roots are used to treat dysentery, gonorrhea and nodular leprosy(1).

Root system

Suitable site forplanting

Occasional favourable rainy seasons trigger explosive
natural regeneration. This explains the occurrence of large
even-aged stands on sandy soils with no apparent capacity toretain water. The species also grows in thick stands on alluvial
soils in depressions that have collected fine alluvial material(4).

Ecophysiology of water use

Weeding should be immediate in the season following planting and for the following 2 growing seasons.
Seedlings are rather slow growing with initial annual increments of 30-40 cm. Protection of young trees fromlivestock browsing is essential (1).
Microcatchment water harvesting was introduced by the SOFEM Project* and v-shaped cactchments are
more registant to erosion than w-shaped ones (9). Soil moisture contents increase in the themicrocatchments preventing surface runoff of rainwater (8).

Agroforestry

Planting and weeding

The tree usually flowers during the rainy season and loses
its leaves during the dry season (1, 6).
In Tiva Experimental Forest (Kitui, Kenya), it flowring peak is
in February-March and July-August in the end of dry season.
Most fruits ripen in July-August. Leaves flush mostly in therainy seasons (December-January and March-April), and turn
red from December reaching its peak in January to February.
Canopy coverage reaches 60 - 80％ in December and MarchApril and decreases to 40 - 55 % in Junaury-February and
May-November. Radial growth occurs twice a year in Octoberearly December and late December-mid January.

Tree Management

Phenology

Phenology and Ecophysiology

Benefit and Products

300-450 mm (1)coarse-textured, deep sandy soils to dry,rocky soils, slightly acidic to moderately
alkaline (1)Drought and heat resistant (6), tolerates
seasonal inundation (4),intolerant to to water-logging (1)Mainly sandy soils with pH 5-8, but also
grows well in cotton soil , requiring strong
light (1, 6). Gum production is better onpoor soils and higher in stressed trees(1).
Deep rooted, when water is only
available at great depth, deeply
penetrating tap roots can develop up to
30 m in depth (6).

Mean annual rainfall

Soil water
regimes100-1,700 m a.s.l. (1)Altitude

Environmental reqirements

Small deciduous tree, usually branched from the ground,growing to a height of 5-12m with a trunk up to 30 cm indiameter. Native to semi-desert regions of Sub-Saharan Africa,
as well as Oman, Pakistan, and northwestern India (1).

General description

Acacia senegal (L.) Willd. (=Senegalia senegal Britton) (Fabaceae)

－ 59 －

Benefit and Products (1, 4)

compared to A. tortilis trees of comparable sizes (20 kg d -1)
during favorable conditions of soil water availability (SWC).
Decline in SWC reduced water use and the onset and rate of
decline in sap flux was determined by the rooting depth (2).

A. xanthophloea showed greater (40 kg d -1) water use

Ecophysiology of water use

http://www.hort.purdue.edu/newcrop/duke_energy/Acacia_tortilis.html

http://www.fao.org/ag/agp/AGPC/doc/gbase/DATA/pf000139.htm(7) James A. Duke. 1983. Handbook of Energy Crops (Acacia tortilis (Forsk.) Hayne)(6) CIAT/FAO, Grassland species profiles ( Acacia tortilis (Forssk.) Hayne)(3) A.K. Mishra, H.S. Tiwari and R.K. Bhatt (2010) Growth, biomass production and photosynthesis of Cenchrus ciliaris L. under Acacia tortilis (Forssk.) Hayne based silvopastoral systems in semi arid tropics, Journal of Environmental Biology, 31(6) 987-993(4) Danida Forest Seed Centre (2000) Seed Leaflet No. 19 ( Acacia tortilis )(5) D. A. Hines and K. Eckman (1993) Indigenous multipurpose trees of Tanzania : Uses and economic benefits for people
http://www.fao.org/docrep/x5327e/x5327e0f.htm#acacia tortilis*(2) D.O. Otieno, M.W.T. Schmidt, J.I. Kinyamario and J. Tenhunena (2005) Responses of Acacia tortilis and Acacia xanthophloea to seasonal changes in soil water availability in the savanna region of Kenya, Journal of Arid Environments 62, 377–400, ELSEVIER(1) Orwa et al. (2009) Agroforestry Database 4.0, World Agroforestry Centre
http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=118 http://www.worldagroforestry.org/treedb/AFTPDFS/Acacia_tortilis.pdf

The timber is used for planking, boxes, poles, moisture-proof plywood, gun and rifle parts, furniture, house
construction and farm implements. The wood is moderately soft, not very strong, and is readily attacked bydecay-causing fungi and insects. It should be promptly converted after felling and subjected to rapid drying
conditions (1).
Eleven-year old trees in deep sandy soils at Jodhpur averaged 6.4 m tall and 14 cm DBH. In shallow sandy
loams over hardpan at Pali, India, 7-year old trees (98% survival) averaged 4.8 m tall, and 10 cm DBH. In
sanddunes at Barmer, India, 5-year old trees averaged 3 m tall, 7 cm DBH. An average tree yields 6 kg podsof which 2.6 kg is clean seed. One tree is said to yield 14–18 kg pods and leaves per year in India (Muthanaand Arora, 1980). Acacia tortilis has been reported to yield giraffe forage at 5 MT/ha/yr(7).
Firewood harvested as needed, but 10-year rotations are suggested. A 12-year-old plantation in India
yielded 54 MT/ha fuel, suggest, annual returns of 4.5 MT/ha, not a bad return for the desert(7).

Plantations for timber production

Studies conducted on its nitrogen-fixing ability, photosynthetic efficiency, seedling morphology and drought
resistance have shown that it is relatively a better species than Prosopsis juliflora (1).
Poor herbaceous growth under A. tortilis has been reported. In India clusterbean, cowpea and mothbean
are said to have failed when planted in association with A. tortilis . However, yields of mungbean, andsorghum have been shown to increase when lateral roots of A. tortilis are trenched (1). Probably throughhydraulic lift by A. tortilis , which improves the water status of the upper soil layers and allowing water accessby shallow rooted plants (3). On an average the full grown canopy of A. tortilis at the spacing of 4x4 m
allowed 55% of total Photosynthetically Active Radiation which in turn increased Relative Humidity andreduced under canopy temperature to -1.75oC over the open air temperature. Cenchrus ciliaris (buffelgrassor African foxtail grass) attained higher height under the shade of A. tortilis (3). A. tortilis is a good shade tree
for people and for silvipastoral agroforestry uses in arid areas. It is not good for intercropping or near
farmland due to wide, shallow roots. Useful for sand dune stabilization, shelterbelts along canals and roads,
and in sandy arid areas. It is recommended for semiarid areas on sandy soils with low rainfall, for fuelwood
production. Plantations have been established in India (5).

Agroforestry

Plantation by direct seeding of treated seeds should always be preferred in order to avoid the trauma oftransplanting and disturbing the tap-root that grows about ten times faster than the stem(6).
The plant assumes shrubby growth and must be widely spaced for the lateral root growth. Planting is done
in pits 60 cm deep dug at a spacing of 5 x 5 m and filled with weathered soil. If raised as a windbreak, 3 rows
are planted spaced at 9 x 10 m, and 50 gm/plant of ammonium sulphate is applied at watering time. Plants
grow to about 1.5 m in 2 years, should be protected from grazing and mulching should be practised. 2
weedings in the 1st year and 1 in the 2nd year are considered sufficient(1).
Containerized seedlings may be planted at about 10 months when 0.5 m to 1 m tall, in pits 60 cm3.
Recommended spacing is 3×3 m to 5×5 m, on sites with deep, sandy soil. Young plants in plantations as wellas natural regeneration require protection from browsing for 3 to 5 years. Mature plants tolerate heavybrowsing. Suppression of weed competition is essential initially (5).

A. tortilis is an evergreen tree and a hermaphrodite. In India,
trees flower between May and June and fruit by mid July, andin Nigeria flowers appear in May-June and fruits in July (1).

Tree Management
Planting and weeding

Phenology and Ecophysiology
Phenology

Fodder: It is an important source of fodder for cattle in India, West Africa, Somalia and Ethiopia. Foliage and fruits form
important browse. A 10-year-old A. tortilis yields about 4-6 kg dry leaf and 10-12 kg pods per year(1). Pods and leaves havea good level of digestible protein (mean = 12%) and energy 6.1 MJ/kg dry matter, as well as being rich in minerals. Seeds
are high in crude protein (38%) and phosphorus, an element usually scarce in grasslands(4).
Fuel: Fuel: A. tortilis starts producing fuelwood at the age of 8-18 years, at the rate of 50 kg/tree. Its fast growth and goodcoppicing behaviour, coupled with the high calorific value for its wood (4400 kcal/kg), make it suitable for firewood andcharcoal.
Poison: A. tortilis is a powerful molluscicide and algicide. The fruits are placed in fish ponds to kill the snail species thatcarry schistosomiasis, without affecting the fish.
Medicine: The dried, powdered bark is used as a disinfectant in healing wounds; in Senegal it serves as an anthelmintic. In
Somalia the stem is used to treat asthma. Seeds are taken to treat diarrhoea.
Tannin or dyestuff: The bark is reported to be a rich source of tannin.
Boundary, barrier or support: The thorny branches are suitable material for erecting barriers.

Root system

Suitable site forplanting

Soil water
regimes

Soils innatural range

100-1000 mm (1)Mean annual rainfall

The tree favors alkaline soils and grows
in sand dunes, sandy loam, rocky soils
and other soils that drain well. It also
does well on light brown, sandy soil withlittle or no calcium carbonate, and pH
ranges of between 7.95-8.30 (1).
A. tortilis is drought resistant, cantolerate strong salinity and seasonal
waterlogging (1).
A. tortilis generally forms open, dry
forests in pure stands or mixed with otherspecies. It grows fairly well even on
shallow soils less than 25 cm deep (1).
The long taproot and numerous lateralroots enable it to utilize the limited soil
moisture available in the arid areas (1).
A. tortilis behaves as a phreatophyte,with aquifers as deep as 40 -50 m or
more (6).

0-1000 m (1)Altitude

Environmental reqirements

Small to medium-sized evergreen tree or shrub that grows up to
21 m tall; well-developed multiple boles support a flat-topped orrounded, spreading crown (1).

General description

Acacia tortilis (Forssk.) Hayne (Fabaceae - Mimsoideae)－ 60 －

A. xanthophroea wood has density of the wood: 0.532 g/cm3, calorific value of wood 4.4 kj/g and calorificvalue of charcoal 7.9 kj/g, and it showed relatively high value compared with other Acacias and otherfuelwood tree species (4).
A. xanthophloea is one of the fastest-growing thorn-tree species in southern Africa, with a growth rate of 11.5 m/year. It can withstand lopping (5).

Plantations for timber production

Birds often build their nests on the A. xanthophloea branches, promoting the biodiversity of the site. The
tree is recognized as a stabilizer of swamplands, riverbanks and dams (6).
Trees are planted as live fences (5).

Agroforestry

A. xanthophloea is easily grown from seed (5).
Planting out should be done carefully so that the long taproot is not damaged (5).

Planting and weeding

Tree Management(6) GCW (2001) Acacia xanthophloea Benth. – The global compendium of weeds(3) D.O. Otieno, M.W.T. Schmidt, J.I. Kinyamario and J. Tenhunena (2005) Responses of Acacia tortilis and Acacia xanthophloea to seasonal changes in soil water availability in the savanna region of Kenya, Journal of Arid Environments 62, 377–400, ELSEVIER(4) N. M. Oduor, W. Ngugi and T. Gathui (2012) Sustainable Tree Management for Charcoal Production - Acacia Species in Kenya(5) World Agroforestry Centre (2014) Agroforestree Database
http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=125(1) Forest & Landscape, University of Copenhagen (2010) Seed Leaflet No. 151 ( Acacia xanthophloea )(2) Kenya Forestry Research Institute, Tree Seed Information Leaflets, Leaflet No. 1 ( Acacia xanthophloea )Wood: The wood is hard, heavy and is valuable as timber but should be seasoned before use, as it is liable to crack. It isalso used for poles and posts.
Fodder: Foliage and pods provide food for livestock.
Fuel: The species is used as fuelwood although it produces a gum that leaves a thick, black, tarlike deposit when burnt.
Medicine: The roots and powdered bark of the stem are used as an emetic and as a prophylactic against malaria.
Agroforestry: It is a nitrogen fixing species that can be used as shade intercropping tree in agroforestry systems, where thethorny habit is also utilized as live fences.
Apiculture: Trees produce good bee forage (5).

Root system-1compared to A. tortilis trees of comparable sizes (20 kg d )during favorable conditions of soil water availability (SWC).
Decline in SWC reduced water use and the onset and rate of
decline in sap flux was determined by the rooting depth (3).

A. xanthophloea showed greater (40 kg d -1) water use

Ecophysiology of water use

Flowers are hermaphroditic. Development from flower to fruit
takes 4-6 months. In southern Africa, flowering occurs from
September to November while fruiting is from January to April.
Despite the production of a large number of flowers, there isoften poor fruit development (1).

Phenology

Phenology and Ecophysiology

Benefit and Products (1, 5)

A. xanthophloea grows in semievergreen bushland and woodland inareas with a high groundwater table andoften forms dense stands in seasonally
flooded areas (5).
A. xanthophloea grows near swamps,
riverine forests or at lakesides and isable to tolerate several degrees of frost(5).
A. xanthophloea probably has most of
their roots located within the upper soil
layers, which dried out quickly soon after
the rains (3). This species does not havean aggressive taproot, but because of its
large size it should not be planted close
to buildings (5).

Soil water
regimes

Suitable site forplanting

A. xanthophloea is mostly found on
sandy soil.

600-1200 m (2)Soils innatural range

Mean annual rainfall

Altitude

Environmental reqirements

Large tree, 15-25 m tall, with a crown that is somewhat
spreading, branching fairly up the trunk (5). Large tree with a flatcrown and light foliage (2).

General description

Acacia xanthophloea Benth. (Fabaceae - Mimsoideae)

－ 61 －

Benefit and Products (1)L-1, 0.16 g L-1 and 0.77 g L -1 for Acacia, Albizzia, Azadirachta
and Eucalyptus respectively (6). A. indica, also other two
native species, showed traits of low water comsumption andsmall biomass production in comparison with E. camludulensis .
Neem appears to be a highly mycorrhizal-dependent
species. The intensity of infection varies with availability ofwater. The deep‐rooted growth habit along with vesiculararbuscular mycorrhizal (VAM) infections of desert vegetation
may be a survival mechanism in competition for water andnutrients with shallow‐rooted and fast‐growing plant species(3).

However, water use efficiency was found as 0.32 g L , 0.48 g-1

According to the experiment comparing water use of four
species ( Acacia nilotica, Albizia procera, Azadirachta indica
and Eucalyptus camaldulensis ) grown in pots in a green
house, water consumption by one year old Eucalyptus wasmore than three times that of by Acacia and Azadirachta .

Ecophysiology of water use(3) K. Bala, A.V. Rao & J.C. Tarafdar (1989) Occurrence of VAM associations in different plant species of the Indian desert, Arid Soil Research and Rehabilitation, vol. 3: 391-396(2) CIAT/FAO, Grassland species profiles ( Azadirachta indica Juss.)
http://www.fao.org/ag/agp/AGPC/doc/gbase/new_grasses/azaind.htm(1) Orwa et al. (2009) Agroforestry Database 4.0, World Agroforestry Centre
http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=271 http://www.worldagroforestry.org/treedb/AFTPDFS/Azadirachta_indica.pdf

A. indica is a species of the mahogany family, and although it has some of the characteristics of acabinetry wood, its grain is rough and does not polish well. The wood is, nevertheless, used to makewardrobes, bookcases and closets, as well as packing cases because its insect repellent quality helps toprotect the contents from insect damage. The main stem of the tree is also widely used to make posts forconstruction or fencing because the wood is termite resistant. The density of the wood is 720-930 kg/cubic m
at 12% mc (1).
Plantation in 8 x 8 m pits is recommended. Usually deep parallel furrows 8 m apart are used (2).

Plantations for timber production

Intercropping A. indica with pearl millet, Pennisetum glaucum, has given good results in India (1).
A traditional agricultural practice involves the production of ‘neem tea’. The seeds are dried, crushed andsoaked in water overnight to produce a liquid pesticide that can be applied directly to crops. Crushed seedkernels are also used as a dry pesticide application, especially to control stem borers on young plants(1).
Because of its low branching, it is a valuable asset for use as a windbreak (1).

Agroforestry

Broadcast seeding on ploughed land does not yield good results. The seed would readily germinate on topof the soil, but should be slightly buried to reduce damage from insects and rodents. Thinning is carried out
later, in order to leave one seedling every 8 m (2).
Weeding of A. indica plantations in dry areas is essential, as the tree cannot withstand competition,
especially from grasses. It responds well to chemical and organic fertilizers. Trees coppice freely, and early
growth from coppice is faster than growth from seedlings. A. indica withstands pollarding well, but seedproduction is adversely affected when trees are lopped for fodder (1).

A. indica is a usually evergreen tree. The flowers bisexual or
male on same tree, white or pale yellow, slightly sweet
scented. A. indica trees may start flowering and fruiting at theage of 4-5 years, but economic quantities of seed are produced
only after 10-12 years. Certain isolated trees do not set fruit,suggesting the occurrence of self-incompatibility. The floweringand fruiting seasons largely depend on location and habitat. In
Thailand for instance, the flowers and fruits throughout theyear whereas in East Africa (with pronounced dry and wet
season) flowering and fruiting are restricted to distinct periods.
Fruits ripen in about 12 weeks from anthesis and are eaten bybats and birds, which distribute the seed. They can live for over
200 years (1).

Tree Management
Planting and weeding

Phenology and Ecophysiology
Phenology

Food: Fruits are eaten fresh or cooked, or prepared as a dessert or lemonade-type drink. The young twigs and flowers areoccasionally consumed as vegetables.
Fuel: Charcoal made from A. indica wood is of excellent quality and the wood has long been used as firewood. Its oil isburned in lamps throughout India.
Tannin or dyestuff: Tree bark contains 12-14% tannins. This compares favourably with conventional tannin chemicals.
Lipids: A. indica oil has long been produced in Asia on an industrial scale for soaps, cosmetics, pharmaceuticals and othernon-edible products. The seed oil yield is sometimes as high as 50% of the weight of the kernel.
Poison: Extracts from leaves and other tissues acts as an insect repellant, inhibiting feeding, and disrupting insect growth,
metamorphosis and reproduction. Formulations based on A. indica do not usually kill insects directly but alter their
behaviour in significant ways to reduce pest damage to crops, and reduce their reproductive potential. Azadirachtin affects
insect physiology by mimicking a natural hormone. It has been shown to affect egg production and hatching rates.
Medicine: Neem has proved effective against certain fungi that infect humans. Various parts of A. indica have anthelmintic,
antiperiodic, antiseptic, diuretic and purgative actions, and are also used to treat boils, pimples, eye diseases, hepatitis,
leprosy, rheumatism, scrofula, ringworm and ulcers. Leaf teas are used to treat malaria.

Root system

A. indica is said to grow ‘almost
anywhere’ in the lowland tropics. A.
indica requires large amounts of light, but
it tolerates fairly heavy shade during the
1st few years (1).
Being drought resistant with a welldeveloped root system capable ofextracting nutrient from the lower soil
levels, it is a suitable tree for dunefixation (1).

Soils innatural range

Suitable site forplanting

It grows on a wide variety of neutral toalkaline soils but performs better than most
species on shallow, stony, sandy soils, or inplaces where there is a hard calcareous orclay pan not far below the surface. It grows
best on soils with a pH of 6.2-7 (1).

It quickly dies in waterlogged soils (1).

400-1200 mm (1)Mean annual rainfall

Soil water
regimes0-1500 m (1)Altitude

Environmental reqirements

Small to medium-sized tree, usually evergreen, up to 15 (30max.) m tall, with a round, large crown up to 10 (20 max.) m indiameter; branches spreading; bole branchless for up to 7.5 m,
up to 90 cm in diameter (1).

General description

Azadirachta indica A. Juss. (Meliaceae)

－ 62 －

(3) Von-Maydell H-J. (1984) Arbres et arbustes du Sahel: leurs caractéristiques et leurs utilisations. Eschborn: GTZ, p. 531(4) Danida Forest Seed Centre (2000) Seed Leaflet No. 21 (Balanites aegyptiaca (L.) Del.), DANIDA(5) D. A. Hines and K. Eckman (1993) Indigenous multipurpose trees of Tanzania : Uses and economic benefits for people
http://www.fao.org/docrep/x5327e/x5327e0m.htm#balanites aegyptiaca(2) International board for plant genetic resources/Royal Botanic Gardens Rome (IPGRI) (1984) Forage and browse plants for arid and semi-arid Africa, 101-102.

(1) Orwa et al. (2009) Agroforestry Database 4.0, World Agroforestry Centre
http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=279 http://www.worldagroforestry.org/treedb/AFTPDFS/Balanites_aegyptiaca.pdf

The wood is hard, durable, worked easily and made into yokes, wooden spoons, pestles, mortars, handles,
stools and combs. The wood saws cleanly and easily, planes without difficulty to a smooth finish and is easy
to chisel. The timber has traditionally been a minor product. The usually small log size and the prevalence ofstem fluting makes sawmill processing difficult (1).

Plantations for timber production

As a thorny tree, this tree is useful for fencing to demarcate the land. Cut branches are used to makelivestock enclosures (1).
Traditionally it has been, and still is, actively managed. It is planted in agroforestry along the banks ofirrigation canals and as a boundary marker. The tree attracts numerous insect species and could be used inagroforestry as a trap tree. B. aegyptiaca is worth considering for difficult sites, where water is the main
limiting factor (5).
The usually evergreen behaviour potentially makes B. aegyptiaca an attractive element to introduce into
shelterbelts, although because of its slow growth, it is not suitable as a principal species (1).

Agroforestry

Requires weeding and protection from browsing up to the initial fruiting period (at least 3 years). Weeding
is important due to slow growth, as high grass can compete for light. Weeds can also impede regenerationand grass fires can destroy young plants. It coppices vigorously. Roots spread far, and throw up suckers at aconsiderable distance from the trunk (5).
Coppices and pollards well and can regenerate after lopping and heavy browsing. Where fruit is theprincipal interest, pollarding and coppicing for obtaining fodder are seldom employed (1).
This tree suffers from repeated locust and beetle attack and a high degree of parasitic infestation (1).

Benefit and Products (1)The soils in its range tend to be deep
sands, sandy clay loams, sandy loams or
clays (1).
The tree is drought and fire resistant, andwithstands up to 2 months flooding inareas near a river but it cannot tolerate
prolonged water logging (2).
It has wide ecological distribution;
however, it reaches its maximum
development as an individual tree on lowlying level alluvial sites with deep sandy
loam and uninterrupted access to water(1).

0-2000 m (1),up to 1000 m (4)250-1200 mm (1),
250-400 mm (4)Planting and weeding

Balanites aegyptiaca is an evergreen tree (3). Flowering
behaviour varies. There is no definite time for flowering in the
Sahel, although flowering most likely takes place in the dry
season. The 1st fruiting is at 5-8 years, yields increasing until
25 years of age for the tree. The fruit apparently takes at least
1 year to mature and ripen. Birds and mammals eat the fleshy
and edible fruit, discarding, regurgitating or evacuating thestone (1).

Tree Management

Phenology

Phenology and Ecophysiology

Food: The fleshy pulp of fruit is edible. The fruit is processed into a drink and sweetmeats in Ghana, an alcoholic liquor in
Nigeria, a soup ingredient in Sudan. Young leaves and tender shoots are used as a vegetable. The flowers are a
supplementary food in West Africa. Flowers are sucked to obtain nectar.
Medicine: Roots is used to treat malaria, against oedema and stomach pains, and as an emetic. Bark infusion is used totreat heartburn. Wood gum is used to treat chest pains. The bark is used to deworm cattle in Rajasthan.
Fodder: The fresh and dried leaves, fruit and sprouts are all eaten by livestock. Kernel meal, the residue remaining after oil
extraction, is widely used in Senegal, Sudan and Uganda as a stock feed. The tree is lopped for fodder in India.
Fuel: The wood produces considerable heat and very little smoke, making it particularly suitable for indoor use. It produces
high-quality charcoal and the nutshell is suitable for industrial activated charcoal. The calorific value is estimated at 4600
kcal/kg.
Fiber: A strong fiber is obtained from the bark.
Lipids: The kernels produce edible oil used for cooking. Its free fatty acid content is low.

Root system

Suitable site forplanting

Soil water
regimes

Soils innatural range

Mean annual rainfall

Altitude

Environmental reqirements

Multibranched, spiny shrub or tree up to l0 m high. Crown
rounded, dense with long stout branchlets (1).

General description

Balanites aegyptiaca (L.) Del. (Balanitaceae)

－ 63 －

Soils innatural range

Benefit and Products (1)(3) P. Maundu and B. Tengnäs (2005) Useful Trees and Shrubs for Kenya, Technical Handbook No.35, p. 159 ( C. aculeatum ), p. 160 (C. collinum ), p. 161 (C. molle ), p. 162 (C. shumannii ), World Agroforestry Centre(4) D. A. Hines and K. Eckman (1993) Indigenous multipurpose trees of Tanzania : Uses and economic benefits for people, Cultural Survival Canada and Development Services,
http://www.fao.org/docrep/x5327e/x5327e0r.htm#combretum molle*(1) Orwa et. Al. (2009) Agroforestry Database 4.0, World Agroforestry Centre
http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=556 http://www.worldagroforestry.org/treedb/AFTPDFS/Combretum_aculeatum.pdf ( C. aculeatum )http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=558 http://www.worldagroforestry.org/treedb/AFTPDFS/Combretum_collinum.pdf ( C. collinum )http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=566 http://www.worldagroforestry.org/treedb/AFTPDFS/Combretum_molle.pdf ( C. molle )(2) Millennium Seed Bank Project (2007) Seed Leaflet No. 127 ( Combretum aculeatum Vent.), DANIDA

The timber of C. collinum is fairly hard, not very durable, has an interlocked grain and a course texture. It is
used for wagon building, canoes and tool handles (1).
C. molle wood is hard, coarse, brittle when dry and rots easily. It is said to be reasonably termite resistantand is suitable for implement handles, poles, stools, construction and fence posts (1).
The very durable heartwood is termite resistant and used a great deal at the coast for carving (C.
shumannii ) (3).

Plantations for timber production

C. aculeatum is a tree to respond to coppicing (3).
C. collinum is a slow-growing tree to respond well to coppicing, lopping and pollarding (1).
C. molle produces root suckers (3). C. molle is a slow-growing tree to tolerates to lopping and coppicing(4).
C. shumannii is a slow-growing tree to respond to lopping, coppicing (3).

The yellowish-white fragrant flowers are bisexual, withgreenish to dark red sepals. Flowering occurs at the end of thedry season and during the rainy season. A tree can bear
flowers and ripe fruit simultaneously (2). In Sudan flowering
occurs from March to June and fruits from July to October (1)(C. aculeatum ).
C. collinum is a semi-deciduous tree. In southern Africa,
flowers are often produced with the previous season’s leaves
in August to October, and fruiting occurs from January toAugust (1).
C. molle is a deciduous tree. Flowers appear before theleaves and are attractive to insects, which probably pollinate
them. Flowering in southern Africa occurs from September toNovember; in Zambia, between July and October; fruit ripens
between June and September (1).

Tree Management
Planting and weeding

Phenology and Ecophysiology
Phenology

Fodder: The plants provides browse for livestock in Senegal, Sudan and northern Kenya (C. aculeatum ).
Fiber: The lianous branches are supple and are used in Kenya to make donkey panniers and wicker baskets for holding
milk vessels (C. aculeatum ).
Medicine: The plants is used as diuretic and purgative. It is also used in Burkina Faso and Senegal for leprosy. The boiled
roots are taken in Kenya for stomach upsets (C. aculeatum ). Roots are boiled and the decoction drunk warm as treatment fordysentery and snakebite (C. collinum ). Boiled root decoction is used to induce abortion and treat constipation, leprosy,headaches, stomach pains, fever, dysentery, general pains, swellings and as an anthelmintic for hookworm. The bark
exudes a gum that can be used to treat wounds, or crushed dried or fresh leaves can be used for the same purpose.(C.
molle ).
Apiculture: Flowers produce good nectar for honey (C. collinum ). Flowers attract bees and make good forage for honeyproduction (C. molle ).
Fuel: The wood is a source of firewood and makes very good charcoal (C. collinum ). The wood burns slowly, giving intense
heat, and is suitable for firewood and production of high quality charcoal (C. molle ).
Tannin or dyestuff: A red dye can be obtained from the leaves and yellow dye from the roots(C. molle ).

Root system

Suitable site forplanting

C. aculeatum is found in dry savannah,
thickets on dry soils and is sometimes
riverine (1). C. collinum occurs at medium to
low altitudes in open woodlands (1).

900-1200 mm (C. molle ) (1)Sandy or loamy soils (C. aculeatum ) (1).
It has a wide edaphic adaptation growing
on alluvial soils and sandy, stony or clay
soils (C. aculeatum ) (2).

Mean annual rainfall

Soil water
regimes0-2300 m (C. molle ) (1)Altitude

Environmental reqirements

A scrambling shrub up to 0.5-4 m in height with virgate
branches, or scandent to 8 m (C. aculeatum ) (1). A small to
medium-sized, semi-deciduous tree 4-18 m in height, with arounded or flat, heavy crown (C. collinum ) (1). A shrub or small,graceful, deciduous tree 3-13 m high. Branching heavy anddrooping, giving a rounded or flat-rounded, sometimes oval,crown (C. molle ) (1). A tall tree, to 20m, leaves dense, drooping,crown narrow (C. shumannii ) (3).

General description- C. aculeatum Vent., C. collinum Fresen, C. molle R.Br. ex G.Don, C. shumannii Engl.

Combretum spp. (Combretaceae)

－ 64 －

Benefit and Products (1)Under natural conditions, E.
camaldulensis occurs typically alongwatercourses and on floodplains. It grows
under a wide range of climatic conditions,from temperate to hot and from humid toarid zones. The length of the dry season
may vary from 0 to 8 months (1).

Because of its great strength and good durability, the wood is suitable for many structural applications, forexample, railway sleepers, poles, posts, floorings, wharves, ship building and heavy construction(1).
Seedling growth may exceed 3 m per year for well-adapted provenances on favourable sites(1).
Some provenances coppice well for six or more rotations, on good sites, plantations are managed on
coppice rotations of 7–10 years (2).
According to NAS (1980a), annual wood yields or 20–25 m3/ha in Argentina, 30 m3 from Israel, 17–20
from Turkey in the first rotation, and 25–30 in subsequent coppice rotations. On poor arid sites, yields are
only 2–11 m3 (ca 1–5 cords) on 14 or 15 year rotations. Litterfall ran about 3.6–5.8 MT/ha/yr in an Australian
redgum swamp (Briggs and Maher, 1983) (2).
According to the phytomass files (Duke, 1981b), standing biomass in an Israeli plantation is ca 110 MT/ha.
At Calistoga, California, this was calculated to yield 4.3 m3/ha/yr or 2 cords and total energy yields of
15,000,000 kcal/ha/yr (Standiford and Donaldson, 1982) (2).
Termites and aphids and rodents may be troublesome to the tree, and both physical and chemicalmeasures are used to control them (1).

(2) James A. Duke. 1983. Handbook of Energy Crops (Eucalyptus camaldulensis Schlecht.)
http://www.hort.purdue.edu/newcrop/duke_energy/Eucalyptus_camaldulensis.html(1) Orwa et al. (2009) Agroforestry Database 4.0, World Agroforestry Centre
http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=760 http://www.worldagroforestry.org/treedb/AFTPDFS/Eucalyptus_camaldulensis.pdf

Apiculture: E. camaldulensis is a major source of honey, producing heavy yields of nectar in good seasons. The honey islight gold and of reasonable density with a distinctive flavour.
Fuel: The firewood is suitable for industrial use in brick kilns but is not preferred for domestic use because it is too smoky
and burns too fast. However, it makes good-quality charcoal.
Fiber: E. camaldulensis is used for pulp and paper production. It is also planted for hardboard, fiberboard and particleboard.
Medicine: The oils are used as an inhalant with steam and other preparations for relief of colds and influenza symptoms.
Because of its refreshing odour and its efficiency in killing bacteria, the oil is also used as an antiseptic.
Essential oil: Some tropical provenances of E. camaldulensis are rich in 1,8-cineole leaf oil and are potential commercial
sources of medicinal-grade eucalyptus oil.

Root system

Suitable site forplanting

Soil water
regimes

Plantations for timber production

With its light crown, E. camaldulensis is well suited for growing in arable fields. Intercropping maize withtrees planted at 5 x 5 m gives satisfactory yields (1).

Soils innatural range

Agroforestry

250-2500 mm (1)Grows best on deep, silty or loamy soils
with a clay base and accessible watertable. It is one of the species found to be
most tolerant to acid soils (1).
Tolerates waterlogging and periodic
flooding (1).

Mean annual rainfall

Seeds, long lived when sealed in dry cold storage, are usually started in nursery containers, thentransplanted to the field (as close as 2 x 2 m for firewood). Extensive weeding may be mandatory(2).
Poor competition ability with weeds and the development of an open crown necessitate frequent weeding,up to 3 times a year, until the canopy closes 3-5 years after planting. A thinning of less than 700 stems/ha at
5 years provides posts, poles, fuelwood and pulpwood, leaving the better trees for the production of otherproducts, such as sawn timber after 10 years. Coppices readily. Application of 100 g of NP or NPK (3:2:1)
fertilizer to each tree at planting to assist establishment and early growth is common (1).

0-1500 m (1)Planting and weeding

Time of flowering in natural stands depends on thegeography of a given location. Seeds ripen about 6 months
later. E. camaldulensis does not develop resting buds andgrows whenever conditions are favorable (1).

Tree Management

Phenology

Phenology and Ecophysiology

Altitude

Environmental reqirements

Commonly grows to 20 m tall, occasionally reaching 50 m, witha trunk diameter of 1 (max. 2) m. In open formations has ashort, thick bole and a large, spreading crown. In plantations hasa clear bole of 20 m with an erect (1).

General description

Eucalyptus camaldulensis Dehnh (Myrtaceae)

－ 65 －

Benefit and Products (1)(3) James A. Duke. 1983. Handbook of Energy Crops (Eucalyptus saligna Sm.)
http://www.hort.purdue.edu/newcrop/duke_energy/Eucalyptus_saligna.html(2) Kenya Forest Research Institute, Tree Seed Information Leaflet, Leaflet No. 10 ( Eucalyptus saligna )(1) Orwa et al. (2009) Agroforestry Database 4.0, World Agroforestry Centre
http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=812 http://www.worldagroforestry.org/treedb/AFTPDFS/Eucalyptus_saligna.pdf

E. saligna has proved to be highly suited for short-rotation plantations in tropical montane regions(1).
The heartwood has a density of about 900 kg/cubic m, is easy to work and polishes. It is an important
general-purpose hardwood in Australia, and is favoured for construction, flooring, cladding and paneling(1).
Stands grown for timber are thinned to about 50% of the original stem density when trees are 5-8 years
old. Additional thinning is carried out every 8-10 years thereafter. At a rotation of about 35 years, the final
thinning, which should be done when the trees reach marketable age, should leave approximately 70-120
stems/ha. Rotations of 6-10 years are used for producing fuelwood and pulpwood(1).
A 4-year old stand in Brazil had standing biomass of 56 MT/ha (38 aboveground, 8 litter, and 10
belowground). But annual biomass productivity was estimated at 15–17 MT/ha. Fenton et al. (1977) reportwood yields of 19 m3/ha/yr (3).

Plantations for timber production

This fast-growing, light-demanding tree is highly sensitive to competition from weeds during the 1st 2
years, and therefore measures to control emerging weed growth must be carried out several times. The rapid
early growth allows E. saligna to dominate competing vegetation (1).

E. saligna is a heterophyllous and it has juvenile and adultphases. Seed production commences when the tree is about 78 years old (1). Flowering and fruiting occur throughout theyear (2).

Tree Management
Planting and weeding

Phenology and Ecophysiology
Phenology

Essential oil: The essential oil yield is 0.3-0.5%.
Apiculture: E. saligna is not reliable as a honey producer. It is however useful in stimulating colonies and may be
helpful in queen-rearing and re-stocking programs. The honey is strongly flavoured, rather dark and frequently lacks
density. It does not store well.

Root system

Suitable site forplanting

Soil water
regimes

Soils innatural range

800-1800 mm (1)Mean annual rainfall

Best development occurs on goodquality, alluvial sandy loams. Other soils
include Podsols and volcanic loams.
Soils it prefers are generally moist but
well drained (1).
Although it can tolerate short dry periods,
best growth is achieved on sites with ahigh rainfall well distributed throughout
the year (1).
The preferred climate is warm temperate
to subtropical with a mild dry season of
not more than 4 months. E. saligna is alight-demanding tree (1).

0-1100 m (1)Altitude

Environmental reqirements

Tall tree, 30-50 m in height, with a diameter at breast height ofup to 2 m. Exceptional specimens grow 65 m tall and attain adiameter of 2.5 m. The trunk is generally of excellent form,
straight and clear of branches for 1/2 to 2/3 of the total treeheight (1).

General description

Eucalyptus saligna Smith (Myrtaceae)

－ 66 －

Benefit and Products (1)The tree does not conserve moisture but is effective inobtaining water for transpiration, as amply demonstrated by its
vegetative vigor in the dry season, in the total absence of rain,when temperatures are high, humidity is low, andevapotranspiration is at a maximum. To achieve this, its rootsystem has a taproot that grows very rapidly and will reach thewater table if it is within range; depths of about 40 m have beenrecorded (Lemaftre 1954). When on its preferred sites, notably
in association with water, the species prefers deep sandy soils
easily exploited by its root system (11).

http://www.hort.purdue.edu/newcrop/duke_energy/Acacia_albida.html(11) P.J.Wood (1992) The Botany and Distribution of Faidherbia albida , Faidherbia albida in the West African Semi -Arid Tropics, 9-17, ICRAF(10) James A. Duke. 1983. Handbook of Energy Crops (Acacia albida Del.)(9) V. Shitumbanuma (2012) Analyses of Crop Trials under Faidherbia albida –Results of Crop Yields for the 2010/2011 Agricultural Season and Overall Summary of Yields and Yield Trends from 2008 to 2011-, University of Zambia(8) D. Louppe and N'Klo Ouattara (1992) Growth of Faidherbia albida in Nurseries: Standard Production Techniques or Air Pruning?, Faidherbia albida in the West African Semi -Arid Tropics, 141-143, ICRAF(7) M.I Cisse and A.R. Kone (1992) The Fodder Role of Acacia albida Del: Extent of Knowledge and Prospects for Future Research, Faidherbia albida in the West African Semi -Arid Tropics, 29-37, ICRAF(6) S.A.N. Samba (1992) Regeneration of Acacia albida with Direct Seeding, Faidherbia albida in the West African Semi -Arid Tropics, 139-140, ICRAF(3) P. Maundu and B. Tengnäs (2005) Useful Trees and Shrubs for Kenya, Technical Handbook No.35, p. 234, World Agroforestry Centre(4) O. Roupsard, A. Ferhi, A. Granier, F. Pallo, D. Depommier, B. Mallet, H. I. Joly and E. Dreyer (1999) Reverse phenology and dry-season water uptake by Faidherbia albida (Del.) A. Chev. in an agroforestry parkland of Sudanese west Africa, Functional Ecology 13, 460(5) P. Beckman (1992) Direct Seeding Experiments with Faidherbia albida in an Arid Environment, Faidherbia albida in the West African Semi -Arid Tropics, 137-138, ICRAF(2) Danida Forest Seed Centre (2000) Seed Leaflet No. 28 ( Faidherbia albida (Del.) A. Chev.), DANIDA(1) Orwa et al. (2009) Agroforestry Database 4.0, World Agroforestry Centre
http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=1 http://www.worldagroforestry.org/treedb/AFTPDFS/Faidherbia_albida.pdf

Trees have reached 2 to 4 m after only 3 or 4 years growth (10).

Plantations for timber production

Feed-value analyses have revealed that pods and leaves are rich in parietal content. Leaves, pods, andseeds contain respectively 200, 150, and 260 g TP kg-1 of dry matter (8). According to FAO (1980) a fullgrown tree can produce more than 100 kg pod/yr. Felker (1978) notes that pod yields range from 6–135
kg/tree (10).
Results of the crop trials conducted by the CFU to demonstrate the yield benefits of growing crops undercanopies of mature F. albida trees have shown that yields of maize grown under canopies of F. albida weresignificantly higher than those of maize grown outside canopies in all the four regions of Zambia where thetrials were conducted and in the four agricultural seasons during which the trials were conducted. The
average yield of maize under the canopies of F. albida was about 5.0 metric tonnes per hectare compared toan average of about 2.0 metric per hectare for maize grown outside canopies of F. albida . No statisticallysignificant differences were observed between yields of cotton, soya bean and groundnuts grown under andoutside canopies of F. albida (9). Yield increases under Acacia albida (F. albida ) correlate with a several foldincrease in soil N and organic matter, coupled with improved soil water-holding capacity (10). In mesic
Sahelian regions (400–600 mm/yr), yields of millet, peanuts, and sorghum are increased from ca 500 to ca
900 kg/ha/yr by growing under the canopy of Acacia albida (Felker, 1978) (10).
Branches lopped for fencing compounds and livestock enclosures (1).

Agroforestry

F. albida can be propagated by direct sawing (3). Generally, the physical scarification techniques gave
better results than the control and the hot water treatment. The 15-mm sowing depth gave significantly better
results than the 10-mm treatment, due partially to less predation by mice and ants (5). Direct seeding can berecommended provided that seeding is done when the soil is moist to a depth of over 50 cm. Weeds must be
suppressed and the site must be adequately reparated to encourage rapid taproot development(6). Air
pruning of F. albida seedlings, induced by desiccation of root meristems emerging at the base of containers,
was successfully achieved in the nursery. This is better than standard nursery techniques(7).
Pruning in the 2nd year to about half the tree height may be needed to control low branching. Repeatedpruning during periods of average biomass production stimulates leaf production. It can be pruned twice ayear. Resulting regrowth is especially vigorous in the 1st year but decreases as exploitation continues; trees
show stress at the end of the 6th year. Regular lopping (once every 3-4 years) removing 0.4-0.5m³ of foliage(or 35% of the total volume) at the start of the growing season is recommended. The tree responds well tocoppicing (1).

Ecophysiology of water use

Planting and weeding

The plant has an ‘inverted phenology’. Deciduous in the wet
season and foliated in the dry season. The flowering ofindividual trees is often not uniform. First flowering occurs inthe seventh year and subsequent flowerings occur 1-2 months
after the start of the dry season for up to 5 months. Ripe fruit
falls towards the end of the dry season. The seeds are
dispersed by animals, which eat the pods (1). In some areas
flowering may occur twice in a year. Not all trees flower every
year. In East Africa seeds mature in July-October (2).

Tree Management

Phenology

Phenology and Ecophysiology

Fodder: The leaves and pods are palatable to domestic animals and an important source of protein for livestock in the dry
season.
Apiculture: For bee-keepers, it has the advantage of producing flowers at the end of the rains while most of the sahelian
species flower just before or during the rains. It therefore becomes the main source of pollen and nectar at this time.
Fuel: The plant stems are used as fuelwood. The calorific value is estimated at 19.741 kJ/kg of dry wood. Charcoal yields
are as low as 17%.
Medicine: The bark and roots are widely used for either externally or internally against respiratory infections, digestive
disorders, malaria and other fevers. The bark is used to clean teeth and an extract is used for toothache in humans and eye
infections in livestock.
Shade or shelter: F. albida is maintained and protected on farms to shade coffee and to provide shade for livestock in thedry season.
Reclamation: The plant's spreading root system offers excellent protection to the banks of watercourses.

Root system

Suitable site forplanting

Soil water
regimes

Soils innatural range

250-1200 mm (1)Mean annual rainfall

Coarse-textured well-drained alluvial
soils (1). F. albida is successful in sandy
alluvium and sandy clay in the West
African Sahel and on alluvial soil in
Eastern and Southern Africa (9).
It tolerates seasonal water-logging andsalinity but cannot withstand heavy
clayey soils (1). Though faring best on
sandy soils, it will tolerate heavier soils
with some waterlogging (10).
F. albida grows on the banks of seasonal
and perennial rivers and streams on
sandy alluvial soils or on flat land where
Vertisols predominate. It thrives inclimates characterized by long summers,
or a dry season with long days (1).
Roots of F. albida were distributed
through the weathered rock, down to adepth of
7 m, and vanished in the vicinity of apermanent water-table (4).

270-2700 m (1)Altitude

Environmental reqirements

One of the largest thorn trees reaching 30 m in height, withspreading branches and a rounded crown (1). Large tree to 30 m
in height, 1m in diameter; normally only one stem (2).

General description

Faidherbia albida (Del.) A. Chev. (Fabaceae - Mimsoideae)

－ 67 －

According to an examination of soil water, crop yield and fineroots of 3 – 4 year-old Grevillea robusta and Gliricidia sepium
growing in association with maize in semiarid Kenya during thelong rains of 1996 -1997, plots containing G. sepium trees
always contained more tree roots than plots containing G.
robusta trees and Gliricidia was more competitive with maizethan Grevillea. Overall, Gliricidia reduced crop yield by about
50% and Grevillea by about 40%. There was less soil moisturein plots containing trees than in control plots. Plots containing
Gliricidia trees contained less soil water than plots containing
Grevillea trees (4).

Ecophysiology of water use

Benefit and Products (1, 2)

Pure sand to deep alluvial lake-bed
deposits. Soils are acidic (pH 4.5-6.2);
however, where parent material islimestone, the soils are slightly alkaline(1).
Prefers freely draining soils and tolerates
seasonally impeded drainage. It tolerates
brief flooding, but areas prone towaterlogging should be avoided (2).
Best in deep, medium-textured, welldrained, fertile soils, with near neutral
acidity. It tolerates rocky (shallow orskeletal) soils that are high in available
calcium, and soils with textures fromsands to clays (2).
Roots propagated from cuttings areshallow and laterally extensive.
Seedilings develop taproots but it isunclear if the taproots endure throughout
the life of plant. (3).

600-3500 mm (1)
900-1500 mm (2)0-1200 m a.s.l. (2)(3) Elevitch, C.R., Francis, J.K. 2006. Species Profiles for Pacific Island Agroforestry. Permanent Agriculture Resources (PAR), USA, 18pp
(4) Odhiambo, H.O., C.K. Ong, J.D. Deans, J. Wilson, A.A.H. Khan1 & J.I. Sprent . 2001. Roots, soil water and crop yield: tree crop interactions in a semi-arid agroforestry system in Kenya. Plant and Soil 235: 221–233, 2001
(5) Broadhead, J.S., C.K. Ong, C.R. Black. 2003. Tree phenology and water availability in semi-arid agroforestry systems. Forest Ecology and Management 180: 61–73(6) Oluwafemi, O.A. and Adegbenga, S. O. 2007. Preliminary Report on Utilization Potential of Gliricidia sepium (Jacq.) Steud for Timber. Research Journal of Forestry, 1: 80-85.

(1) Orwa C, A Mutua, Kindt R , Jamnadass R, S Anthony. 2009 Agroforestree Database:a tree reference and selection guide version 4.0 (http://www.worldagroforestry.org/sites/treedbs/treedatabases.asp)(2) Cook, B.G., Pengelly, B.C., Brown, S.D., Donnelly, J.L., Eagles, D.A., Franco, M.A., Hanson, J., Mullen, B.F., Partridge, I.J., Peters, M. and Schultze-Kraft, R. 2005. Tropical Forages: an interactive selection tool., CSIRO, DPI&F(Qld), CIAT and ILRI, Brisbane, Australia.
(Gliricidia sepium http://www.tropicalforages.info/key/Forages/Media/Html/Gliricidia_sepium.htm)

Fuelwood plantations in Central America are typically established with Iooo-5000 trees/ha for rotations of
5y ears. In Asia, fuelwood plantations are set out at 1 x 1 m to 2.5 x 2.5 m spacings for pruning at 1-or 2-year
intervals. Fuelwood yields from stands harvested every 2-3 years are I0-20 mJ/ha. Wood production from aliving fence has been reported at 9 mJ /km. On intermediate quality sites in Guatemala，Honduras，El
Salvador，Nicaragua，Costa Rica，and Panama，annual fuel wood increment reached a peak of 4.5 kg/tree
at 2 years of age，although cutting usually takes place on rotations of 5-8 years.
The wood is light to dark olive-brown, very hard and heavy, strong, coarse-textured, with an irregular grain.
It seasons well and takes ah igh polish. It is highly durable, and valued for house construction and corner
fence posts. Declining availability of the prime economic species in timber market has led to the introductionof Lesser-Used-Species (LUS). G. sepium has potential to be a major LUS timber and could substitute some
economic species in timber market od developping countries (6).

Wood production

Gliricidia is a popular shade or nurse tree for crops including coffee, tea, cacao, pepper, passion fruit, andvanilla, in many varied spatial arrangements. Spacing of about 10 x 10 m interspersed with crops such as
coffee and cacao is common. The shade trees are pruned seasonally to maximize benefit to the understory
crop, and to minimize competition for water and nutrients. It has been intercropped in alley cropping systems
with maize, cassava, taro, cucurbits, and other food crops. In such systems, pruningGliricidia back regularly
provides mulch for the crops and controls competition by the Gliricidia for light, water and nurients (3).
Pruning and pollarding are the main management activities. Pruning at 0.3-1.5 m will stimulate leaf
production. Pollarding at 2 m or above is recommended for optimal wood biomass production. Coppicing isused where the primary objective is fuelwood production. Gliricidia has been shown to tolerate lopping andbrowsing (1).
According to an examination of phenological patterns in relation to climatic conditions in the bimodal
rainfall regions of Kenya to identify factors which dictate the intensity of competition between trees and crop,
G. sepium exhibited a period of low leaf cover during the long dry season and did not regain full leaf coveruntil mid-way through the short rains. G. sepium during the short rains would decrease competition for waterwith adjacent crops, but is also likely to decrease tree growth (5).

Agroforestry

The tree tolerates only light shade.Seedlings that are planted in heavy shade can survive but will not grow.
Seedlings that have been suppressed by shade for even 3-4 years will recover and grow rapidly if the
sheltering overstory is removed (2).

Flowering and fruiting may begin as early as the end of thefirst growing season and almost always begins by the fifth
growing season. Flowering occurs during the dry season,
depending on the local climate. If rainfall is evenly distributed
throughout the year, flowering may occur at any time,irregullarly throughout the year, but in lower quantities
compared with seasonal climates (3).
Gliricidia is largely deciduous in the dry season. To prevent
leaf loss at this time, cut at the end of the rains and again at 8
weeks into the dry season. A final cut at 16 weeks into the dry
season may be possible (2).

Tree Management
Planting and weeding

Phenology and Ecophysiology
Phenology

Fodder: Leaves are rich in protein and highly digestible, and low in fibre and tannin, which improve animal production (bothmilk and meat) when G. sepium is used as a supplement.
Apiculture: The flowers attract honeybees (Apis spp.).
Fuel: Often used for firewood and charcoal production. The calorific value of a 5-year-old tree is 4550 kcal/kg.
Medicine: Crude extracts have been shown to have antifungal activity. Reported to be expectorant, sedative andsuppurative. Madre de cacao is a folk remedy for alopecia, boils, bruises, burns, colds, cough, debility, eruptions, erysipelas,fever, fractures, gangrene, headache, itch, prickly heat, rheumatism, skin tumours, ulcers, urticaria and wounds.
Erosion control: Hedgerows in alley cropping serve to suppress weed growth and control erosion.
Nitrogen fixing: The tree is capable of fixing atmospheric nitrogen. As a green manure, G. sepium increases soil organic
matter; it aids in recycling of soil nutrients as it produces much litter.

Root system

Suitable site forplanting

Soil water
regimes

Soils innatural range

Mean annual rainfall

Altitude

Environmental reqirements

Small to medium-sized thornless tree up to 10-12 (15) m
high.Branching frequently from the base． Bark is smooth,varying in colour from whitish grey to deep red-brown. Trees
display spreading crowns． Native to seasonal dry forest ofCentral America (2).

General description

Gliricidia sepium (Jacq.) Walp. (Fabaceae)

－ 68 －

Benefit and Products (1)Rainfall distribution has a summer
maximum in the natural range, but G
robusta also grows well in climates witha winter maximum or a bimodal rainfall
regime (1). Prefers light, well-drainedsoils, mildly acid to neutral. Light
demanding (7).
A deep rooting system causes little
interference with shallow-rooted crops,
and it can be successfully intercropped
with banana, tomato and otheragricultural crops (1).

Seedlings are planted out when they are 30cm tall (4-6months) (8). Outplanting is done 6-8 months aftersowing when plants are 20-30 cm. Weeding is necessary for the first 1-2 years after planting(9).

(3) D.M. Smith, N.A. Jackson, J.M. Roberts1 and C.K. Ong (1999) Root distributions in a Grevillea robusta -maize agroforestry system in semi-arid Kenya, Plant and Soil 211: 191–205(4) J.E. Lotta, S.B. Howarda, C.K. Ong, C.R. Blacka (2000) Long-term productivity of a Grevillea robusta -based overstorey agroforestry system in semi-arid Kenya: I. Tree growth, Forest Ecology and Management 139: 175-186(5) J.E. Lott, S.B. Howard, C.K. Ong, C.R. Black (2000) Long-term productivity of a Grevillea robusta -based overstorey agroforestry system in semi-arid Kenya: II. Crop growth and system performance, Forest Ecology and Management 139: 187-201(6) C.W. Muthuri, C.K. Ong, C.R. Black, V.W. Ngumi, B.M. Mati (2005) Tree and crop productivity in Grevillea , Alnus and Paulownia -based agroforestry systems in semi-arid Kenya, Forest Ecology and Management 212: 23–39(7) Anna Büchi (2007) Water competition in an agroforestry system of Grevillea robusta / live fences and maize in the semi-arid to semi-humid highlands of Mount Kenya, Thesis, Bern University(8) Kenya Forestry Research Institute, Tree Seed Information Leaflet, Leaflet No. 11 ( Grevillea robusta )(9) Danida Forest Seed Centre (2000) Seed Leaflet No. 15. ( Grevillea robusta Cunn. ex R. Br.)

(2) J.E. Lott, A.A.H. Khan, C.R. Black, C.K. Ong (2003) Water use in a Grevillea robusta –maize overstorey agroforestry system in semi-arid Kenya, Forest Ecology and Management 180 (2003) 45–59(1) Orwa et al. (2009) Agroforestry Database 4.0, World Agroforestry Centre
http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=921 http://www.worldagroforestry.org/treedb/AFTPDFS/Grevillea_robusta.pdf

In Kenya, the trees have been pruned and pollarded repeatedly to produce firewood and poles,and will
eventually be harvested as saw logs (1).
Grevillea yields a medium-weight hardwood with a density of 540-720 kg/cubic m at 15% moisture content.
The timber has economic potential. It is easy to work with hand and machine tools. The wood is used in
making railroad ties, plywood, panelling, air-freight cases and furniture, parquetry, turnery, boat building,interior trim, cabinet work, parquet flooring, boxes, toys and novelties (1).
Moderate to fast growing. When climate and soil are suitable and weed competition is not severe, annual
height and diameter increments of at least 2 m and 2 cm, respectively, are usually achieved for the 1st few
years in row planting on farms (1).
A plant density of 800-1200 trees/ha is recommended for plantations. Seedlings are normally planted at a
spacing of 2.5-3 x 3-4 m (1).
For firewood production, rotations of 10-20 years are applied and annual volume increments of 5-15 cubicm/ha may be expected. A growth reduction after 20 years is reported(1).

Plantations for timber production

G. robusta regrows well after complete defoliation following pruning and pollarding, which can be carriedout repeatedly to yield wood and to regulate shading and competition with adjacent crops(1).
The above-ground biomass and grain yield of understorey crops were not significantly affected by thepresence of Grevillea during the first two years, but were greatly reduced in subsequent years and the yieldof maize was decreased to less than 50% of the sole crop values (5). G. robusta reduced maize yield by 36%
close to the tree rows at Thika, Kenya, whereas yield reductions were negligible adjacent toPaulownia
fortunei (6). However, in a case study in Kenya indicating that agroforestry treatments ofG. robusta wereable to utilize off-season rainfall, comprising 16% of the total annual rainfall, and residual water remaining inthe soil profile after the cropping period (2). In case study in Kenya, the farmers using root pruning wereconvinced from the positive effect on the water competition. But, most of the farmers questioned and did notprune the roots because they feared the effects on the tree growth(7). Competition between G. robusta andmaize for soil water stored near the surface was unavoidable, although pruning reduced its impact;
complementary use of water by the trees and crop would only have been possible if alternative sources ofwater were available (3). Careful consideration of the tradeoffs between the loss of crop production and the
additional value provided by tree products is essential (2).

Agroforestry

Planting and weeding

In its natural range, the species is semi-deciduous, shedding
most of its leaves in the dry season. The tree first flowers whenabout 6 years old. In its natural range, flowering occurs over a
few weeks in October-November, but when planted inequatorial latitudes, flowering is sporadic throughout the year
or absent. The flowers are bisexual, and pollen is shed before
the stigma becomes receptive. The period from fertilization to
fruit maturity is about 2 months (1).

Tree Management

Phenology

Phenology and Ecophysiology

Apiculture: The golden flowers are attractive to bees, making it an important honey plant. G. robusta honey is dark amber,of high density with a pronounced flavour.
Fuel: G. robusta is popular for firewood and charcoal. It is also used to fuel locomotives and river steamers, power boilers
and small industries. The calorific value of sapwood is about 4800 kcal/kg, while that of heartwood is 4950 kcal/kg.
Fiber: Mean fiber length is about 1.5 mm and width about 26 μm; the wood is suitable for pulping.
Gum or resin: By virtue of their solubility, viscosity and relatively high resistance to hydrolysis,G. robusta gums may havesome industrial applications.
Shade or shelter: This is a well known shade tree in coffee and tea plantations. Its spreading branching system makes it
ideal for windbreaks or shelterbelts against wind-induced mechanical damage, high rates of transpiration and surface
evaporation.

Root system

Suitable site forplanting

Soil water
regimes

Soils innatural range

600-1700 mm (1)Mean annual rainfall

Establishes well in riverine habitats, on
alluvial soils that are free of waterlogging
and mildly acid to neutral. Loam soil ispreferred. It also occurs on clay loam andsand (1).
The species can stand up to 6 months ofdrought (1).

0-2300 m (1)Altitude

Environmental reqirements

Medium-sized to large tree 12-25 (max. 40) m tall; crownconical, dense, with branches projecting upwards. Bole straight,
branchless for up to 15 m, up to 80 (max. 120) cm in diameter,
usually without buttresses (1).

General description

Grevillea robusta A. Cunn. Ex R. Br. (Proteaceae)

－ 69 －

Deep rooted, cuttings are more
shallowly rooting than seedlings,
and have higher competitivity (7)Root system

M. volkensii showed high specific hydraulic conductivity andgrowth, with no symptoms of die-back, implying that amechanism associated with the deciduous habit results indrought avoidance by reducing the re-quirement for water
during the dry season (6).

Ecophysiology of water use

The recommended spacing is 5 m by 5 m. Melia, in its initial stages, does not compete with agricultural
crops as it has a light crown and intercropping is possible for 3-4 years. However, under plantation, only shortcrops such as beans are suitable to plant in the first year since taller crops such as maize shade the tree(2).Melia produces timber in shorter rotations than any other timber species in the drylands of Kenya and thetree can be harvested for timber in 12-15 years (2). It coppices well and is fast growing with a rotation of 1015 years.In some districts in Kenya, however, Melia was found to produce poles in less than 3 years andtimber in less than 5 years from coppiced stems (5). SOFEM recommends pruning from the 1st year onwards
to maintain a clean straight bole (9).
Plant spacing experiment in Tiva Experimental Forest (Kitui, Kenya) showed that height growth of trees
were not differed among the spacings and reached almost its peak (ca. 12 m) at 10 years old. The best
timber production at 10 years of age was obtained from 4 m x 4 m spacing with 80 % of trees >= 7 cm in dbh.

(8) Yawata, H. (2001） A short-term expert report (on-farm reforestation) for the Social Forestry Extension Model Development (SOFEM) Project, JICA, 41pp (in Japanese).
(9) Okamoto, K. (2002） A long-term expert report (on-farm reforestation) for the Social Forestry Extension Model Development (SOFEM) Project, JICA, 122pp (in Japanese).
(10) Melia Volkensii : Adapting Climate Change. Creating Wealth. Transforming Landscapes http://meliaproject.org/ (Copyright 2013: Creating Wealth for smallholder farmers in arid and semi areas of Kenya: The Case of Mukau ( Melia Volkensii ))(7) Mulatya, J.M.; Wilson, J.; Ong, C.K.; Deans, J.D.; Sprent, J. I. (2002) Root architecture of provenances, seedlings and cuttings of Melia volkensii : implications for crop yield in dryland agroforestry. Agroforestry Systems 56: 65-72(6) Kondoh, S., Yahata, H., Nakashizuka,T. and Kondoh, M. （2006）Interspecific variation in vessel size, growth and drought tolerance of broad-leaved trees in semi-arid regions of Kenya. Tree physiology 26: 899-904(4) Stewart, M., Blomley, T. (1994) Use of Melia volkensii in a semi-arid agroforestry system in Kenya. Commonwealth Forestry Review Volume 73, Issue 2, p.128-131(5) Rumley, R., Muthuri, C. and Ong, C. (2011) More trees with less water. World Agroforestry Center http://www.worldagroforestry.org/water/downloads/Synthesis%20Publications/decidious%20tree%20leaflet%20compressed.pd(3) Milimo, P. B.; Dick, J. McP.; Munro, R. C. (1994) Domestication of trees in semi-arid East Africa: the current situation.
In: Leakey, R. R. B.; Newton, A. C., (eds.) Tropical trees: the potential for domestication and the rebuilding of forest resources. London, HMSO, p.210-219. (ITE Symposium, 29).

(2) Bernard Muok, Akula Mwamburi, Ezekiel Kyalo and Samuel Auka (2010) Growing Melia volkensii. A guide for the farmers and tree growers in the dry lands. KEFRI Information Bulletin No.3, 11pp.

(1) Orwa, C., Mutua, A., Kindt, R., Jamnadass, R. and Simons, A. (2009) Melia volkensii . In "Agroforestry Database: a tree reference and selection guide", World Agroforestry Centre
http://www.worldagroforestry.org/sea/products/afdbases/af/asp/SpeciesInfo.asp?SpID=1142* The Social Forestry Extension Model Development Project (SOFEM: 1997-2002) by Japan International Cooporation Agency (JICA)

Environmental conservation: One of the most important potential uses of M. volkensii is greening the environment
through land reclamation, environmental conservation in arid and semi-arid areas (10).
Fodder: The tree comes into leaf and is pruned for fodder towards the end of the dry season, a time when fodder isextremely scarce. The fruit pulp is reported to contain almost 10% crude fat and over 12% crude protein; the mature leaves
are reported to contain over 5% crude fat and 21% crude protein (1).
Apiculture: The flowers are said to provide excellent bee forage (1)Timber: The wood is easily worked and shaped, making it suitable for making acoustic drums, containers and mortars. The
coarse-textured heartwood with a density of around 0.62 works easily, planes well, is durable and extremely termite anddecay resistant comparing favourably with Ocotea usambarensis, Vitex keniensis and Khaya species. The timber is valued
locally for door and window frames, doors shutters, rafters, poles and furniture (1).
Medicine: The bark of the Melia volkensii is used as source of medicine. This tree is used by the Taita community to curepains and aches in the body. The bark is boiled and a very small amount is taken while the root bark extract is used as ananti-cancer due to production of limonoids (10).
Fuel: The firewood produces an unpleasant smoke, and the tree is said to produce poor quality charcoal (1).

Plantations for timber production

To reduce tree-crop competition, the use of seedlings rather than cuttings is recommended. If cuttings areused, alternative methods such as root pruning need to be considered (7). Propagation method ofM.
volkensii from seed has been developped and described by KEFRI (2, 10). The tree tends to develop heavy
lateral branching, trees are grown well dispersed in cropland at a spacing exceeding 10-15m. Its effect on
adjacent crops is minimized by regular crown pruning and a wide range of crops can be grown right up to thestem (4).
When the crown is fully developed, it is thinned heavily each year to reduce shading on underplanted crops
like sorghum and millet. This operation is carried out in the dry season to provide clear conditions at planting
time. Pruning with the flush of new leaves and fruits coincides with the time when fodder is scarce. Some
farmers pollard their trees, however,many farmers believe that pollarding induces rot and is counterproductive (1).

Agroforestry

Planting holes are at least 45 cm square and 45 cm deep (2, 9). The ideal planting season in the eastern
drylands of Kenya is during October - December rains (2). Microcatchment water harvesting was introducedby the SOFEM Project* and v-shaped cactchments are more registant to erosion than w-shaped ones (9).
Soil moisture contents increase in the the microcatchments preventing surface runoff of rainwater (8).
SOFEM Project also intoroduced complete weed control (with 2-3 weedings per season within the first
three years) which is essential to promote survival and growth of young Melia (2, 9).

It remains green most of the year except for short spells
when it sheds its leaves twice a year just before flowering(1,10) .
In Tiva Experimental Forest (Kitui, Kenya), it flushes newleaves at the start of rainy season (March-May, OctovberDecember) and canopy coverage reaches 60 - 80 ％. Thencoverage decreases to 40 - 55% during dry season (JanuayFebruary, June-October). Leaf mass depends on a
precipitation. Stem growth increases after leaves unfolded in
March and October. Seeds form and remain on the tree
between March and August in Kibwezi, Tsavo and Kitui (10).

Tree Management
Planting and weeding

Phenology and Ecophysiology
Phenology

Benefit and Products

sandy/loamy soils with gooddrainage (2)Suitable site forplanting

sandy, clay, shallow stony (1)Soils innatural range

Requires moist, welldrained soils (3)Intolerant to black cotton soils or
areas prone to water-logging (2)300-800 mm (1)Mean annual rainfall

Soil water
regimes

350-1,700 m a.s.l. (2)Altitude

Environmental reqirements

Open crowned deciduous tree, hight 6-25 m tall and dbh 25 cm
in common at mature stage, distributes naturally in semi-aridzone of Ethiopia, Somalia, Kenya and Tanzania (1, 10) .

General description

Melia volkensii Guerke (Meliaceae)

－ 70 －

S. Siamea performs best on deep welldrained fertile soils with pH 5.5-7.5, but willgrow on degraded lateritic soils provided
drainage is not impeded. The species is
intolerant of saline soils (1).

Soils innatural range

Benefit and Products (1)Moisture conservation measures (trenching,microcatchments) help establishment and growth for S. siamea
planted in semi-arid areas (1).

Ecophysiology of water use

S. siamea is an evergreen tree. The flower clusters are
upright at ends of twigs with many bright yellow flowers. S.
siamea starts flowering and fruiting at the age of 2-3 years.
Once established, it flowers precociously and abundantly
throughout the year (1).

Phenology

Phenology and Ecophysiology(2) CIAT/FAO, Grassland species profiles ( Cassia siamea Lam.)
http://www.fao.org/ag/agp/AGPC/doc/gbase/data/pf000378.htm

Tree Management

S. siamea yields a medium-weight to heavy hardwood with a density of 600-1010 kg/m³ at 15% mc. The
wood is hard to very hard, resistant to termites, strong, durable. The dark heartwood of S. siamea, which isoften nicely figured, is used for joinery, cabinet making, inlaying, handles, sticks and other decorative uses.
The wood has also been used for poles, posts, bridges, mine poles and beams (1).
Planting density for S. siamea varies according to use. In fuelwood plantations, spacing ranges from 1 x 1
m to 1x 3 m. In hedges used for alley cropping or as a shelterbelt, spacing between plants in the row shouldbe 25-50 cm. A clear bole volume of 77 m/m³ after 15.5 years and a mean annual increment of wood of 20-35
m/ha are observed in a 10-year-old plantation. For the production of fuelwood and charcoal, plantations are
generally pollarded or regenerated by coppice leaving 2-3 shoots/stump after 1 year(1).
S. siamea is hardly used in afforestation in the Sahel, but in the Sudanian ecozone it is a rather fast
growing species for the production of pole timber and fuelwood, regenerates vigorously by coppicing, rotationof 4-7 years for pole production. When in appropriate size suitable for furniture, turnery and cabinet work ;poles and posts are widely used (2).

Plantations for timber production

Although not a nitrogen-fixing tree, S. siamea has been increasingly used in alley cropping systems, largely
because of its coppicing ability and high biomass production (1).
S. siamea is grown as a shade tree along roads and in cocoa, coffee and tea plantations. It is also planted
as a dense windbreak and shelterbelt (1). It is pruned into hedgerows and used as a live fence around foodcrops (1). Although not a nitrogen-fixing tree, S. siamea has been increasingly used in alley cropping systems,
largely because of its coppicing ability and high biomass production (1).
S. siamea issuitable for shelterbelt plantations, but not as shade tree in agroforestry because of root
competition (2).

Agroforestry

S. siamea can be propagated by seeds, stumps and nursery-grown seedlings(2).
Weeding is necessary in the 1st 1 or 2 years of growth.

Planting and weeding(1) Orwa et al. (2009) Agroforestry Database 4.0, World Agroforestry Centre
http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=461 http://www.worldagroforestry.org/treedb/AFTPDFS/Senna_siamea.pdf ( S. siamea )Fuel: The dense, dark-coloured wood of S. siamea makes good fuel, although it produces some smoke when burning. Theenergy value of the wood is 22 400 kJ/kg, and the density is 600-800 kg/m³. The wood was formerly preferred for locomotiveengines. Its charcoal is also of excellent quality.
Fodder: S. siamea is widely grown for fodder. The alkaloids and other secondary plant compounds in the leaves, flowers
and pods are highly toxic to non-ruminants, such as pigs and poultry, and these animals should be kept away fromS.
siamea plantations.
Tannin or dyestuff: All parts of S. siamea can be used for tanning. The concentrations of tannin vary slightly from 17% in
the leaves to 9% in the bark and 7% in the fruits.
Erosion control: When S. siamea is used as a hedgerow, it effectively increases topsoil infiltration, reducing runoff andcombating soil erosion.
Soil improver: Leaves of S. siamea are used as green manure, and a well-grown tree can yield 500 kg/year of fresh
leaves. It forms ecto-mycorrhizae and provides very useful mulch, especially in alley-cropping systems.

Root system

Suitable site forplanting

S. siamea will grow only when its roots
have access to groundwater, and the
maximum length of the dry period should
not exceed 4-8 months. (1).
S. siamea will grow in wide range ofclimatic conditions but is particularly
suited to lowland tropics with a monsoon
climate. Its light requirements are high(1).
The root system consists of a few thickroots, growing to considerable depth, anda dense mat of rootlets in the top 10-20
cm of soil, which may reach a distance of
7 m from the stem in 1 year andeventually a distance up to 15 m. (1).

400-2800 mm (S. siamea ) (1)Mean annual rainfall

Soil water
regimes0-1200 m (S. siamea ) (1)Altitude

Environmental reqirements

Medium-size tree growing up to 18 m tall, with a straight trunkof up to 30 cm in diameter. The bole is short. The crown isusually dense and rounded at first. Later it becoming irregularand spreading with drooping branches (S. siamea ) (1).

General description

Senna siamea (Lam.) Irwin et Barneby (Fabaceae - Caesalpinioideae)

－ 71 －

It grows in most soils but prefers welldrained deep alluvial soil (1).

Water logging conditions, swamps andoften flooded areas should be avoided(5). It should not be planted in low areas
where the roots may become
waterlogged (4).
It grows well over a wide range of soil
and climatic conditions, occurring in lowaltitude woodland, savannah and bush,
often associated with termite mounds. It
prefers semi-arid areas and wooded
grassland, and can also be foundgrowing along stream and riverbanks (1).
Being a deep rooted phreatophyte in thesemi-arid bioclimates it is very resistant
to storms, to fogs and to slight saline
spray in coastal districts (5). Its extensive
root system contributes to its resistanceto drought and wind (1).

Soils innatural range

Soil water
regimes

The wood is hard and very heavy with purple-brown heartwood that is used for furniture(2). Growth isgenerally slow and seedling height increasing by about 60 cm annually. The juvenile phase lasts up to 4-5
years, or longer. Young trees are pruned to allow 3-5 well-spaced branches to develop into the main scaffold
structure of the tree. After this, only maintenance pruning is required to remove dead or damaged wood(1).
The tree is long lived, over 200 years in some cases. The suggested rotation for timber is 50 to 60 years(4). In some countries it is planted at a spacing of 5×5 m, which may be thinned to 10×10 m as the trees
mature; linear spacing is 10 to 15 m (4).

Plantations for timber production

http://www.fao.org/ag/agp/AGPC/doc/gbase/data/pf000172.htm

http://www.hort.purdue.edu/newcrop/morton/tamarind.html(5) CIAT/FAO, Grassland species profiles ( Tamarindus indica L.)(6) J. Morton (1987) Fruits of warm climates, p. 115-121 (Tamarind)(3) Royal Botanic Gardens, Kew. Tamarindus indica http://www.kew.org/plants-fungi/Tamarindus-indica.htm(4) D. A. Hines and K. Eckman (1993) Indigenous multipurpose trees of Tanzania : Uses and economic benefits for people
http://www.fao.org/docrep/x5327e/x5327e1m.htm#tamarindus indica*(2) Danida Forest Seed Centre (2000) Seed leaflet No. 45 ( Tamarindus indica L.)(1) Orwa et al. (2009) Agroforestry Database 4.0, World Agroforestry Centre
http://www.worldagroforestry.org/treedb2/speciesprofile.php?Spid=1589 http://www.worldagroforestry.org/treedb/AFTPDFS/Tamarindus_indica.pdf

Food: The ripe fruit of the sweet type is usually eaten fresh, whereas the fruits of sour types are made into juice, jam, syrup
and candy. Fruit is marketed worldwide in sauces, syrups and processed foods. The juice is an ingredient of Worcestershire
Sauce and has a high content of vitamin B. The flowers, leaves and seeds can be eaten and are prepared in a variety ofdishes. Flour from the seed may be made into cake and bread (1). The brown, short-haired, sausage-like fruits contain anacidic pulp which is a much-prized ingredient of confectioneries, curries and pickles (3).
Fodder: The foliage has a high forage value, though rarely lopped for this purpose because it affects fruit yields.
Apiculture: Flowers are reportedly a good source for honey production.
Fuel: Provides good firewood with calorific value of 4 850 kcal/kg, it also produces an excellent charcoal.
Tannin or dyestuff: Both leaves and bark are rich in tannin. The bark tannins can be used in ink or for fixing dyes.
Medicine: The bark has astringent effect. The bark and young leaves may also be used to relives sores, ulcers, boils andrashes by incorporating into lotions or poultices. Leaf extracts are a common ingredient in cardiac and blood sugar reducing
medicines. A sweetened decoction of the leaves is good against throat infection, cough, fever, and even intestinal worms.

Root system

The tree may remain productive of fruits until it reaches old age, yielding up to 150 kg/tree or over 2 t/ha ayear (1). A mature tree may annually produce 330 to 500 lbs (150-225 kg) of fruits (6).
T. indica is not very compatible with other plants because of its dense shade, broad spreading crown andallelopathic effects (1). T. indica has been tested as an agroforestry species in India but although the
reduction in crop yield is less that e.g. with teak, the spreading crown makes it little compatible with otherspecies. The dense shade makes it more suitable for firebreaks as no grass will grow under the trees (2). T.
indica is not recommended as a shade tree due to allelopathic effects on understorey plants. It is used alongroads and for boundary plantings (4).
It is used also as a firebreak and planted at spacings of 2.5×2.5 m or 3×3 m for firewood plantations(4).

Agroforestry

Plantations may be established by direct sowing along cleared lines. It coppices well(4). The tree can also
be grown easily from cuttings, or by shield-budding, side-veneer grafting, or air-layering(6).
Spacing may be 33 to 65 ft (10-20 m) between trees each way, depending on the fertility of the soil. Withsufficient water and regular weeding, the seedlings will reach 2 ft (60 cm) the first year and 4 ft (120 cm) by
the second year (6).
Weeding is required during the first year, with hoeing around the trees until they are well-established(4).
Size control measures include close spacing (about 500 trees/ha) and pruning to rejuvenate the fruitingwood. The trees also respond to coppicing and pollarding. When establishing a pure plantation, spacing
should be at least 13 x 13 m (1).
The most serious pests of the tamarind are scale insects, mealy-bugs, and a borer (1).

T. indica is an evergreen tree. Flowering generally occurs insynchrony with new leaf growth, which in most areas is during
spring and summer. The flowers are hermaphroditic bisexual.
T. indica usually starts bearing fruit at 7-10 years of age, withpod yields stabilizing at approximately 15 years. Fruit areleathery, nutritive pods that do not dehisce until they havefallen from the tree, while the seeds are hard and smooth andtherefore hard to chew (1).

Tree Management
Planting and weeding

Phenology and Ecophysiology
Phenology

Benefit and Products (1, 3)

350-2700 mm (1)Mean annual rainfall

Suitable site forplanting

0-1500 m (1)Altitude

Environmental reqirements

Large evergreen tree up to 30 m tall, bole usually 1-2 m, up to 2
m diameter. The crown dense, widely spreading, rounded (1).
Tamarindus is a monospecific genus (1).

General description

Tamarindus indica L. (Fabaceae - Caesalpinioideae)

－ 72 －

Fabaceae (M)9 Acacia senegal

Bombacaceae

Apocynaceae

Fabaceae (M)Fabaceae (M)Fabaceae (M)Fabaceae (M)Sapindaceae

Anacardiaceae

Annonaceae

Euphorbiaceae

Arecaceae

Meliaceae

Balanitaceae

Balanitaceae

Balanitaceae

Balanitaceae

Fabaceae (C)Rhamnaceae

Bombacaceae

Arecaceae

Capparidaceae

Capparidaceae

14 Adansonia digitata

15 Adenium obesum

16 Albizia amara

17 Albizia anthelmintica

18 Albizia glaberrima

19 Albizia gummifera

20 Allophylus africanus

21 Anacardium occidentale

22 Annona senegalensis

23 Antidesma venosum

24 Areca catechu

25 Azadirachta indica

26 Balanites aegyptiaca

27 Balanites glabra

28 Balanites rotundifolia

29 Balanites wilsoniana

30 Bauhinia variegata

31 Berchemia discolor

32 Bombax rhodognaphalon

33 Borassus aethiopum

34 Boscia angustifolia

35 Boscia coriacea

Fabaceae (C) *11)

Fabaceae (M)

8 Acacia polyacantha

13 Acrocarpus fraxinifolius

Fabaceae (M)7 Acacia paolii

Fabaceae (M)Fabaceae (M)

6 Acacia nilotica

12 Acacia xanthophloea

Fabaceae (M)5 Acacia mellifera

Fabaceae (M)Fabaceae (M)

4 Acacia gerrardii

Fabaceae (M)Fabaceae (M)3 Acacia elatior

11 Acacia tortilis

Fabaceae (M)10 Acacia seyal

Fabaceae (M) *12)

Family2 Acacia drepanolobium

Scientific Name

1 Acacia brevispica

No.

Agro-climatic Zone
VI

III - IV

II - IVV - VII

II - IV

II - IV

VI - VII

IV - VI

IV - VIII - VI

III - VIII - IV

I - IIII - IVIII - IV

II - IV

III - IV

III - VI

IV - VII

III - VI

II - VI

II - VIII - VIV - VII

III - VIII - VII

III - IV

VI - VII

III - VI

I - VI

III - VIV - VII

II - VII - VI

Annual temp.
14-30

20-30

> 40

17-30

> 40

10-47

23.4-31.3

18-28

-4-48

4-47

Ecology

Annual rainfall
300-500

200-800

250-1,200

150-400

200-800

400-1,200

850-1,000

700-2,500－

400-1,000

400-1,000

300-900－

100-1,000

150-900

300-450200-800

500-1,000

400-900

500-1,300

0-2,100

Altitude100-1,500

up to 2,100

0-1,400

0-350

0-1,600-2,2000-1,200

50-1,350

1,400-1,800

250-2,000

0-1,500

1,500-5,000

0-1,900

0-2,400

0-2,400

0-900

0-1,350

500-2,000

0-1,500

0-1,300

1,900

600-2,100

600-2,300

0-1,650200-2,200

0-1,900

100-1,250

0-2,500

0-1,800

1,300-2,200

0-1,750

1,300-2,400

Description *1)
E

SD

SD

E

E

E

E

D

E

D

D

D

D

D - SD

D

Description *2)
Sh - St

Palm

Tt

Sh - Tt

St

St

Sh - St

Sh - St

Mt

Mt

Palm

Sh - St

Sh - StMt

Sh - StTt

Mt - Tt

Sh - St

Mt

Sh

Tt

Sh - St

Tt

St

Mt

Sh - StMt

Sh - St

St

Sh - St

Mt

Tt

Sh - St

Sh - St

Tree height
2-6m

25m

36m

18m

6m

6-12m

2-5m

2-4m

10m

20m

30m

6m

6m

15m

6m

20m

15-30m

4m

15m

2m

20m

10m

25m

5-8m

10m

9m

18m

4.5m

6m

9m

15m

25m

6m

5m

F

Firewood, Charcoal *3)
F

B

F

B

B

B

B

F

B

F

B

F

B

B

B

B

B

F

B

B

B

B

B
x

Timber, Furniture, Construction

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Poles
x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *4)
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Edible Fruit, Nut, Seed
x

x

x

x

x

x

x

x

x

x

x

Vegetable, Edible leaves/roots

x

x

x

x

x

x

Medicine
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *5)
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Fodder
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Bee forage
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Shade

Fodder Environmental factor

x

x

x

x

x

x

x

x

x

x

x

Soil conservation

Food

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *6)

Wood
Ornamental, Roadside tree

Descriptionx

Others *7)
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Live fence, Dead fence
x

x

x

x

x

x

x

x

x

x

x

x

x

Potencial of seed supply *8)
△

○

○

△

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

DANIDA

Information on seed
and seedlings *9)
○

○

○

○

○

○

KEFRI

2) Highly drought-tolerant tree species distribute in Kenya

Tiva natural stand *10)
○

○

○

○

I

OriginVII (riverine)

I

I

I

I

CoastalCoastal

E India, Tropical Asia, China

I

I

I

I

E India

E South East Asia

II

E Coastal area; Brazil, Callibean

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

Remarks

－ 73 －IV - VII
II - IV
VI - VII

Asteraceae

Longaniaceae

Capparidaceae

Fabaceae (P) *13)

Fabaceae (M)Mytraceae

Capparidaceae

Apocynaceae

Rutaceae

Fabaceae (C)Casuarinaceae

Casuarinaceae

Ulmaceae

Arecaceae

Combretaceae

Combretaceae

Combretaceae

Combretaceae

Burseraceae

Burseraceae

Combretaceae

Fabaceae (C)Boraginaceae

Boraginaceae

Fabaceae (P)Capparidaceae

Euphorbiaceae

Cupessaceae

Araliaceae

Fabaceae (P)Fabaceae (C)39 Buddleja polystachya

40 Cadaba farinosa

41 Cajanus cajan

42 Calliandra calothyrsus

43 Callistemon citrinus

44 Capparis tomentosa

45 Carissa edulis (C. spinarum)

46 Casimiroa edulis

47 Cassia abbreviata

48 Casuarina cunninghamiana

49 Casuarina equisetifolia

50 Celtis africana

51 Cocos nucifera

52 Combretum aculeatum

53 Combretum collinum

54 Combretum molle

55 Combretum schumannii

56 Commiphora africana

57 Commiphora eminii subsp. zimmermannii Burseraceae

Burseraceae

38 Brachystegia spiciformis

58 Commiphora myrrha (C. coriacea)

59 Commiphora rostrata

60 Conocarpus lancifolius

61 Cordeauxia edlis

62 Cordia monoica (C. ovalis)

63 Cordia sinensis (C. gharaf, C. rothii)

64 Cordyla africana

65 Crateva adansonii

66 Croton megalocarpus

67 Cupressus lusitanica

68 Cussonia holstii

69 Dalbergia melanoxylon

70 Delonix elata
V - VII

II - VI

III - IV

II - IIIIII - IV

III - VIII - IV

III - VII

II - IVV - VIIV - VIV - VII

III - VII - VII - VV - VII - IVI - VII - IVI - IVV - VII

II - IV

II - VIII - VII - IVIV - VI

III - VIV - VI

II - IV

III - IV

VI - VII

Burseraceae

VI - VII

Burseraceae

Family37 Boswella neglecta (B. hildebrandtii)

Scientific Name

Agro-climatic Zone

36 Boswellia microphylla

No.
Annual temp.
27

18-35

12-30

11-26

10-35

13-29

27

18

18-38

29

Annual rainfall
580

700-1,200

800-1,500

800-1,900-400

200-400

230-400

600-1,000

400-1,000－－－

200-3,500

500-1,500

1,400

－

500-1,800－

600-1,000

200-500

250-600

250-400

Altitude100-1,200

0-1,350

1,500-2,500

1,000-4,000

1,200-2,450

550-1,500

0-1,400

300-1,000

80-1,050

220-800

0-1,750

300-800

0-1,200

150-2,300

0-1,350

1,150-2,400

0-1,400

0-2,200

0-100

1,200-2,400

0-2,500

0-2,100

0-1,900

0-1,800

0-1,900

1,000-3,000

0-350

200-1,350

Description *1)
D

E

D

D

D

D

E

D

D

D

D

D

E

E

D

E

E

E

E

D

D

Description *2)
Sh - Mt

Sh - St

Mt

Tt

Tt

St

Tt

Sh - St

Sh - St

Sh

Tt

Sh - St

Sh - StMt

Sh - St

Tt

St

Sh - Mt

Sh

Palm

Mt

Tt

Tt

Sh - St

Mt

Sh

Sh

St

Sh

Sh

Sh - St

Sh - StMt - Tt

Sh - St

Sh - St

5m

Tree height
15m

7m

15m

35m

35m

3-10m

9-25m

3-12m

6m

3-4m

20m

4m

5m

5-18m

10m

20m

5-7m

10m

4m

20m

12m

20m

30m

10m

12m

5m

3m

6m

4-6m

2-3m

5m

4-5m

8-25m

5m

Firewood, Charcoal *3)
B

F

B

B

F

B

F

B

F

F

F

B

B

B

F

B

B

B

B

F

F

F

B

F

F

F

B

B

F

F

Timber, Furniture, Construction

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Poles
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *4)
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Edible Fruit, Nut, Seed
x

x

x

x

x

x

x

x

x

x

x

x

x

Vegetable, Edible leaves/roots

x

x

x

x

Medicine
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *5)
x

x

x

x

x

x

x

x

x

Fodder
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Bee forage
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Shade

Fodder Environmental factor

x

x

x

x

x

x

x

x

x

Soil conservation

Food

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *6)

Wood
Ornamental, Roadside tree

Description

Others *7)
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Live fence, Dead fence
x

x

x

x

x

x

x

x

x

x

x

x

x

Potencial of seed supply *8)
○

○

○

○

○

○

○

○

○

DANIDA

Information on seed
and seedlings *9)
○

○

○

KEFRI

Ecology

Tiva natural stand *10)○

OriginC. zimmermannii

Coastal area

I

I

I

E Mexico, Guatemara

I

I

I

I

I

E Coastal area ; Ethiopia, Somalia

E Coastal area; Somalia

I

I

I

I

I

I

I

I

E natulalizedI

E South East Asia, Australia

E Australia

I

E Central America

I

I

E Australia, New Zealand

E Central America

E South East Asia

I

I

I

I

I

Remarks

－ 74 －

Proteaceae

Moraceae

Moraceae

Moraceae

Moraceae

Flacourtiaceae

Euphorbiaceae

Guttiferae

Guttiferae

Fabaceae (P)Proteaceae

Tiliaceae

Tiliaceae

Tiliaceae

Tiliaceae

Tiliaceae

90 Faurea saligna

91 Ficus benjamina

92 Ficus sur (F. capensis)

93 Ficus sycomorus

94 Ficus thonningii (F. dekdekana)95 Flacourtia indica

96 Flueggea virosa (Securinega vilosa)

97 Garcinia livingstonei

98 Garcinia volkensii

99 Gliricidia sepium

100 Grevillea robusta

101 Grewia bicolor

102 Grewia plagiophylla

103 Grewia tembensis

104 Grewia tenax

105 Grewia villosa

Mytraceae

83 Eucalyptus camaldulensis

Fabaceae (M)Fabaceae (P)82 Erythrina melanacantha

89 Faidherbia albida

Fabaceae (P)81 Erythrina burtii

Euphorbiaceae

Fabaceae (P)80 Erythrina abyssinica

88 Euphorbia tirucalli

Celastraceae

79 Elaeodendron buchananii

Euphorbiaceae

Flacourtiaceae

78 Dovyalis caffra

Ebenaceae

Sterculiaceae

77 Dombeya rotundifolia

87 Euphorbia candelabrum

Sapindaceae

76 Dodonaea angustifolia

86 Euclea divinorum

Salvadoraceae

75 Dobera glabra

Mytraceae

Ebenaceae

74 Diospyros scabra

Mytraceae

Ebenaceae

73 Diospyros mespiliformis

85 Eucalyptus grandis

Fabaceae (M)84 Eucalyptus globulus ssp. globulus

Fabaceae (C)Family72 Dicrostachys cinerea

Scientific Name

71 Delonix regia

No.

Agro-climatic Zone
IV - VIIV - VII

III - VIII - VIII - VI

II - VIII - VI

III - IV

II - VII - VIII - VII - VII - VII

II - IV

II - IV

III - IV

IV - VII

II - VI

IV - VII - VI

II - VI - IVII - IVV - VI

IV - VII - VIII - IV

II - IV

II - IV

II - IV

IV - VIIV - VI

IV - VI

II - VI

II - IV

Annual temp.
14-31

4-48

0-40

18-30

17

-1-40

12-18

3-40

14-26

Annual rainfall
200-800

200-1,000

500-800

400-900

600-1,700－

500-2,000

250-1,200500

200-900－

700

100-1,800

500-1,500

250-2,500－

450

100-600> 700

Altitude0-1,500

0-1,250250-2,200

0-1,800

0-3,000

0-1,600

0-1,900

120-2,000

0-2,400

0-2,100

0-2,000

2,200-3,100

500-2,000

up to2,000

1,100-2,200

0-2,500

0-2,700

0-3,100

0-1,600

300-1,300

950-1,750

900-2,250

1,200-2,000

900-2,200

0-2,800

0-1,500900

20-1,100

0-1,600

Description *1)
D

D

SD

E

D

D

E

SD

D

E

D

D

E

D

D

D

E

D

E

D - SD

Mt

Description *2)
Sh

Sh

Sh

Sh - St

Sh - St

Tt

St

St

Sh - St

Sh

Sh - St

Tt

Tt

Tt

Mt

Sh - Tt

Tt

Sh - StMt

Sh- St

Tt

Tt

Tt

Mt

St - Mt

Tt

Sh

Sh - St

Sh - St

St

Sh - StMt - Tt

Sh - St

Tree height
3m

4m

4m

7m

2-10m

20m

8m

8m

2-10m

1-3m

3-5m

20m

25m

20m

10-20m

20m

30m

8m

15m

3-5m

55m

30m

12m

5-15m

6-12m

20m

3-5m

8m

2-8m

4-7m

7m

25m

8m

15m

Firewood, Charcoal *3)
F

F

F

F

B

B

F

B

B

F

F

F

F

B

B

F

F

F

B

B

F

B

F

F

F

F

B

F

F

Timber, Furniture, Construction

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Poles
x

x

x

x

x

x

x

x

x

x

x

x

Others *4)
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Edible Fruit, Nut, Seed
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Medicine
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *5)
x

x

x

x

x

x

Fodder
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Bee forage
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Shade

Vegetable, Edible leaves/roots

Fodder Environmental factor

x

x

x

x

x

x

x

x

x

Soil conservation

Food

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *6)

Wood
Ornamental, Roadside tree

Description

Others *7)
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Live fence, Dead fence
x

x

x

x

x

x

x

Potencial of seed supply *8)
○

○

○

△

○

○

○

○

○

○

○

○

○

○

○

○

DANIDA

Information on seed
and seedlings *9)
○

○

○

○

○

○

KEFRI

Ecology

Tiva natural stand *10)○○

Originreverse phenology

riverine in dry area

I

I

I

I

I

VII (riverine)

E Australia

E Central America, Mexico

I

I

I

I

I

I

I

E India, Malaysia, Indonesia

I

I

I

I

I

E Australia

E Australia

E Australia

I

I

I

I

E Southern Africa

I

I

I

I

I

I

E Madagascar

Remarks

－ 75 －

Rutaceae

Arecaceae

Bignoniaceae

Bignoniaceae

Anacardiaceae

Anacardiaceae

Anacardiaceae

Anacardiaceae

Anacardiaceae

Lythraceae

Sapindaceae

Sapindaceae

Fabaceae (M)Verbenaceae

Capparidaceae

Anacardiaceae

Euphorbiaceae

Sapotaceae

Sapotaceae

Sapotaceae

Euphorbiaceae

Meliaceae

Meliaceae

Rubiaceae

Sapotaceae

Sapotaceae

Annonaceae

Annonaceae

Asclepiadaceae

Asclepiadaceae

Moraceae

Fabaceae (M)Fabaceae (M)Fabaceae (P)Santalaceae

108 Jacaranda mimosifolia

109 Kigelia pinnata

110 Lannea alata

111 Lannea rivae (L. floccosa )112 Lannea schimperi

113 Lannea schweinfurthii

114 Lannea triphylla

115 Lawsonia inermis

116 Lecaniodiscus fraxinifolius

117 Lepisanthes senegalensis

118 Leucaena leucocephala

119 Lippia kituiensis (L. ukambensis)

120 Maerua decumbens

121 Mangifera indica

122 Manihot glaziovii

123 Manilkara mochisia

124 Manilkara sansibarensis

125 Manilkara sulcata

126 Margaritaria discoidea

127 Melia azedarach

128 Melia volkensii

129 Meyna tetraphylla

130 Mimusops kummel

131 Mimusops obtusifolia (M. fruticosa)

132 Mkilua fragrans

133 Monodora grandidieri

134 Moringa oleifera

135 Moringa stenopetala

136 Morus alba

137 Newtonia buchananii

138 Newtonia hildebrandtii

139 Ormocarpum kirkii

140 Osyris lanceolata

Family107 Hyphaene compressa

Scientific Name

106 Harrisonia abyssinicaNo.

II - V

Agro-climatic Zone
II - IV

IV - VI

IV - VI

II - VI

II - VV - VII

III - VI

II - IV

II - IV

IV - VII

III - IV

III - VIIV - VIII - VII - IV

II - IV

II - IVV - VIII-V

II - VIV - VI

III - VII - VII - VIIV - VIIIV - VI

III - VII - IV

IV - VV - VIII - VII - VII - VII

Annual temp.
24-30

12.6-40

23-27

19-35

19-27

20

Annual rainfall－

500-1,400< 350

300-800

350-2,000

600-700

500-2,500

200-4,200

400-600

500-1,500

900-1,300

Altitude900-2,550

100-1,000

600-2,200

up to 2,000

450-1,200

0-1,450

0-400

0-450

0-400

500-2,250

350-1,680

0-1,800

0-2,000

0-1,000

0-300

0-1,200

600-700

0-1,200

400-2,600

0-1,900

340-1,400

0-1,800

300-2,000

below 1,500

0-2,200

up to 2,200

0-1,000

Description *1)
E

D

D

E

E

D

D

D

E

E

D

E

E

E

D

D

D

D

SD

D

Tt

Description *2)
Sh - St

Sh - St

Tt

Tt

St

St

Sh - St

Sh - St

Mt

Tt

Sh

Mt

St

Tt

Sh - StMt

Sh - Mt

St

Mt

Sh

Sh

Sh - Mt

St - Tt

St - Mt

Sh - St

Sh - St

Sh - Mt

St

Sh - St

Sh

St

Tt

Palm

Tree height
1-6m

2-9m

25m

40m

9m

10m

6m

8m

15m

35m

2-4m

15m

5-6m

25m

3-6m

25m

3-20m

8m

10-15m

1-3m

3.5m

5-20m

6-21m

5-18m

4m

5m

20m

7m

1.5-6m

1.5-4m

9m

20m

25m

25m

Firewood, Charcoal *3)
F

F

B

F

F

F

F

B

B

F

B

F

F

B

F

F

B

B

F

B

B

F

B

F

F

B

Timber, Furniture, Construction

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Poles
x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *4)
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Edible Fruit, Nut, Seed
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Vegetable, Edible leaves/roots

x

x

x

Medicine
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *5)
x

x

x

x

x

x

x

x

x

x

x

x

Fodder
x

x

x

x

x

x

x

x

x

x

x

x

x

Bee forage
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Shade

Fodder Environmental factor

x

x

x

x

x

x

x

Soil conservation

Food

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *6)

Wood
Ornamental, Roadside tree

Descriptionx

Others *7)
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Live fence, Dead fence
x

x

x

x

x

x

x

x

Potencial of seed supply *8)
○

○

○

○

○

○

○

○

○

DANIDA

Information on seed
and seedlings *9)
○

○

○

KEFRI

EcologyOriginVII (rivirine)

K. africana, K. aethiopum

M. subcordata, M. edulis

Phyllanthus discoideus

VII (rivirine)

VII (rivirine)

VII (riverine)

I

I

I

I

E ChinaI

E India

I

I

I

I

I

I

E Asia, Australia

I

I

I

I

E Brazil

E VI, VII (riverine); India, BurmaI

I

E L. glauca, latisiliqua ; C. America

I

I

I

I

I

I

I

I

I

E Brazil

I

I

Remarks

Tiva natural stand *10)

－ 76 －

Anacardiaceae

Anacardiaceae

Salvadoraceae

Euphorbiaceae

Anacardiaceae

Anacardiaceae

Rhamnaceae

Fabaceae (C)Fabaceae (C)Fabaceae (C)Fabaceae (P)Sapotaceae

Asteraceae

Euphorbiaceae

Apiaceae

Sterculiaceae

160 Rhus natalensis

161 Rhus tenuinervis

162 Salvadora persica

163 Sapium ellipticum

164 Schinus molle

165 Sclerocarya birrea ssp. caffra

166 Scutia myrtina

167 Senna siamea (Cassia siamea)

168 Senna singueana (Cassia singueana)

169 Senna spectabilis (Cassia spectabilis)

170 Sesbania sesban

171 Sideroxylon inerme (S. diospyroides)

172 Solanesio mannii

173 Spirostachys venenifera

174 Steganotaenia araliacea

175 Sterculia africana

Labiatae

153 Plectranthus barbatus

Rhamnaceae

Fabaceae (M)152 Pithecellobium dulce

Arecaceae

Anacardiaceae

151 Pistacia aethiopica

159 Rhamnus staddo

Fabaceae (C)150 Piliostigma thonningii

158 Raphia farinifera

Arecaceae

149 Phoenix reclinata

Mytraceae

Arecaceae

148 Phoenix dactylifera

Fabaceae (M)Lauraceae

147 Persea americana

157 Psidium guajava

Rubiaceae

146 Pavetta crassipes

156 Prosopis juliflora

Chrysobalanaceae

145 Parinari curatellifolia

Fabaceae (M)Fabaceae (C)144 Parkinsonia aculeata

155 Prosopis chilensis

Sapindaceae

143 Pappea capensis

Salicaceae

Pandanaceae

154 Populus ilicifolia

Anacardiaceae

Family142 Pandanus kirkii

Scientific Name

141 Ozoroa insignis subsp. reticulata

No.

Agro-climatic Zone
V - VI

III - VI

III - IV

III - IV

I - IVII - IV

IV - VIII - IV

II - IV

III - VIII - VII - IVV - VI

IV - VI-V

II - IV

II - IVI-V

II - VII

IV - VII

III - VIII - IVIII - VI

III - IV

I - IVII - VIIVII

II - VII - VIII - IV

III - VII - VI-V

II - IV

Annual temp.
10-45

15-25

25-30

20-31

15-45

14-34

20

-15-50

-4-40

to 36

200-1,000

Annual rainfall－

500-2,000

800-1,000

500-1,000

400-2,800

200-1,370－

500-800－

1,000-2,000

50-1,200

700-1,400

100-300

300-2,500

700-1,500

Altitude
below 600

up to 2,000

0-1,450

0-2,600

350-1,900

up to 2,000

0-2,400

0-1,800

0-2,700

500-1,600

0-2,400

0-1,500

900-1,850

0-3,000

1,400-2,900

up to 1,400

0-2,000

0-1,500

0-1,500

800-2,400

0-1,850

0-2,600

up to 1,500

up to 2,200

0-2,100

0-1,300

1,050-2,400

0-2,200

Description *1)
D

D

D

E

D

E

E

SD

E

D

E

D

SD

SD

Description *2)
St

St

Sh - St

Sh - St

St

St - Mt

St

Mt

Sh

St - Mt

Mt

St - Mt

Sh - St

Sh - St

Sh - St

Sh - St

Palm

St

Sh - St

Sh - St

Tt

Sh

Sh - St

Sh - St

St

Palm

Palm

St

Sh - St

Sh - St

Sh - St

St

St

Sh - St

14m

Tree height
5-12m

5-7m

10m

12m

8m

10-20m

4-5m

20m

6m

10-18m

15m

20m

3-7m

6m

8m

5m

25m

8m

6m

8-15m

30m

1-4m

4-15m

3-15m

3-5m

15m

20-30m

10m

7m

15m

5-8m

6m

4-8m

Firewood, Charcoal *3)
F

F

B

B

B

B

B

B

B

F

F

B

B

F

F

F

B

F

B

B

B

B

Timber, Furniture, Construction

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Poles
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *4)
x

x

x

x

x

x

x

x

x

x

x

x

Edible Fruit, Nut, Seed
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Vegetable, Edible leaves/roots

x

x

x

x

Medicine
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *5)
x

x

x

x

x

x

x

x

x

x

x

Fodder
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Bee forage
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Shade

Fodder Environmental factor

x

x

x

x

x

x

x

x

x

x

Soil conservation

Food

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *6)

Wood
Ornamental, Roadside tree

Descriptionx

Others *7)
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Live fence, Dead fence
x

x

x

x

x

x

x

x

x

Potencial of seed supply *8)
○

○

○

△

○

○

○

○

○

DANIDA

Information on seed
and seedlings *9)
○

KEFRI

Ecology

Tiva natural stand *10)○I

OriginCoastal area

Heeria reticulata

Bauhinia thonningii

Riverine all area

I

I

I

I

I

Crassocephalum mannii

E Tropical America

I

E South East Asia

I

I

E Peru, Andes

I

I

I

I

I

I

E South and Central America

E Central America, Mexico

E Chile, Argentina

I

I

E Latin America

I

I

I

E riverine; Middle East etc.

E Central America

I

I

E Tropical America

I

I

Remarks

－ 77 －

Sterculiaceae

Sterculiaceae

Olacaceae

Longaniaceae

Longaniaceae

Mytraceae

Mytraceae

Fabaceae (C)Tamaricaceae

Combretaceae

Combretaceae

Combretaceae

Combretaceae

Combretaceae

Malvaceae

Malvaceae

Apocynaceae

Capparidaceae

Fabaceae (P)Asteraceae

Meliaceae

Ulmaceae

Meliaceae

Rubiaceae

Rubiaceae

Rubiaceae

Verbenaceae

Verbenaceae

Olacaceae

Annonaceae

Rutaceae

Rutaceae

Rhamnaceae

Rhamnaceae

Rhamnaceae

178 Strombosia scheffleri

179 Strychnos henningsii

180 Strychnos spinosa

181 Syzygium cordatum

182 Syzygium cumini

183 Tamarindus indica

184 Tamarix nilotica

185 Terminalia brownii

186 Terminalia mantaly

187 Terminalia orbicularis

188 Terminalia prunioides

189 Terminalia spinosa

190 Thespesia danis

191 Thespesia garckeana

192 Thevetia peruviana

193 Thylachium thomasii

194 Tipuana tipu

195 Tithonia diversifolia

196 Toona ciliata

197 Trema orientalis (T. guineensis)

198 Trichilia emetica

199 Vangueria apiculata

200 Vangueria infausta

201 Vangueria madagascariensis

202 Vitex mombassae

203 Vitex payos

204 Ximenia americana

205 Xylopia parviflora

206 Zanthoxylum chalybeum

207 Zanthoxylum usambarense

208 Ziziphus abyssinica

209 Ziziphus mouritaniana

210 Ziziphus mucronata

Family177 Sterculia foetida

Scientific Name

176 Sterculia appendiculata

No.

Agro-climatic Zone
IV - VI

III - VII

III - IV

III - IVV

III - IV

IV - VIII - IV

II - IV

II - VIII - IV

II - VII - IV

III - IV

II - IV

III - IV

III - IV

III - VIII - VIII - VII

IV - VV - VIV - VI

III - VIV - VV - VI

III - VII - IV

II - IV

III - IV

III - VIII - IVV - VIIV - VII

Annual temp.
> 47

Annual rainfall
650-850

600-800

450-900－

500-1,300

350-1,500> 1,000－

Altitude0-1,950

0-1,800

400-2,000

1,400-2,500

0-1,500

0-250

0-2,000

0-1,600

0-450

0-2,400

0-2,450

900-2,500

0-1,450

up to 2,200

0-1,800

550-1,950

1,200-2,200

0-1,300

500-1,500

0-1,200

100-1,500

0-2,000

700-2,000

0-1,050

0-1,500

0-1,800

0-2,500

0-1,800

0-2,300

1,200-2,300

Description *1)
SE

D

D

D

D

D

D

E

SE

SD

E

SD

D

SD

E

E

SD

E

D

Description *2)
Sh - St

Sh - St

Sh - St

Sh - St

Sh - StMt

Sh - St

St

Sh - St

Sh

Sh - St

Sh - StMt - Tt

Sh - St

St

Sh

Sh - Mt

Sh - St

Sh - St

Sh - St

Sh - St

St

Sh - St

Sh - St

St

St

Sh - St

Tt

Mt

Mt

Sh - St

Sh - St

Tt

St

Tree height
8m

10m

3-6m

5-8m

8m

24m

4m

8m

3-6m

4-6m

8m

6m

15-30m

12m

10m

1-3m

20m

5m

4m

3-10m

1-6m

15m

3-10m

6m

10m

7-13m

6m

30m

15-18m

8-15m

2-5m

6m

30m

40m

Firewood, Charcoal *3)
B

B

B

B

F

F

F

F

F

F

F

F

B

B

B

F

F

B

B

F

B

F

B

B

B

B

B

Timber, Furniture, Construction

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Poles
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *4)
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Edible Fruit, Nut, Seed
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Vegetable, Edible leaves/rootsx

Medicine
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *5)
x

x

x

x

x

Fodder
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Bee forage
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Shade

Fodder Environmental factor

x

x

x

x

x

x

x

Soil conservation

Food

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Others *6)

Wood
Ornamental, Roadside tree

Description

Others *7)
x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

Live fence, Dead fence
x

x

x

x

x

x

x

x

x

Potencial of seed supply *8)
○

○

○

○

○

DANIDA

Information on seed
and seedlings *9)
KEFRI

Ecology

Tiva natural stand *10)○

Originriparian in dry areas

Azanza garckeana

Fagara usambarensis

Fagara chalybea

CoastalV. rotundata, V. tomentosa

riverine in dry areaI

E North Africa, Asia

I

I

I

I

I

I

I

I

I

I

I

E AsiaE Tropical Asia, China, Himalayas

E Central America

E Bolibia, Brazil

I

E Central and South America

I

I

I

I

I

E Madagascar

I

I

I

E India, Tropical Asia

I

I

I

I

I

Remarks

－ 78 －

*13) Fabaceae (P) = Fabaceae (Papilionaceae)*12) Fabaceae (M) = Fabaceae (Mimosaceae)*11) Fabaceae (C) = Fabaceae (Caesalpiniaceae)*10) Tiva natural stand: Tree species confirmed in the Tiva Pilot Forest, Kitui District, Eastern Province, Kenya*9) Information on seed and seedlings： Presence of leaflet information about seed and seedlings*8) Potencial of seed supply: Potencial of seed supply by the Kenya Forest Tree Seed Centre, KEFRI*7) Others: Fibre, Weaving, Rope, Thatch, Roofing, Mats, Baskets, Regin, Gum, Glue, Latex, Tannin, Dye, Ceremonial, Toothbrushes, Boundary marking, Veterinary medicine, Toxin, Insecticide, Repellent, Cosmetic, Soap, Perfume, Oil, Brooms*6) Others (Environmental factor): Mulch, Nitrogenfixation, River bank, Sand stabilization, Windbreak*5) Others (Food): Seasonings, Flavoring, Drink, Soup, Edible oil, Gum, Inner bark, Jam, Syrup*4) Others (Wood): Posts, Beehives, Tools, Tool handles, Shafts, Carvings, Utensils, Walking stick, Bow, Arrow, Farm implements*3) Firewood, Charcoal: F = for Firewood, C = for Charcoal, B = for both purpose*2) Description: Sh = Shrub, St = Small tree, Mt = Medium-size tree, Tt = Tall tree, Palm = Palm

*1) Description: D = Deciduous, E = Evergreen, SD = Semi-Deciduous, SE = Semi-evergreen (Semi-Deciduous and Semi ever green is due to the short of each period)

Remarks 4) : The information about "Information on seed and seedlings" picked up from "Tree Seed Information Leaflet", KEFRI & "Seed Leaflet", DANIDA (Danish International Development Agency)

Remarks 3) : The information about "Potencial of seed supply" picked up from "Revised Seed Catalogue", October, 2005, Kenya Forestry Seed Centre, KEFRI (Kenya Forest Research Institute)

Remarks 2) : Some information missing in the "Useful tree and shrubs for Kenya" was complemented by the information mentioned in the "Agroforestre Data Base 4.0", World Agroforestry Centre

Remarks 1) : This list has compiled based on the information from "Useful trees and shrubs for Kenya", World Agroforestry Centre. Tree species adaptable to Agro-climatic Zone IV to VII was selected.

Annex 3

Agro-climatic zone of Kenya－ 79 －

Fig. A-3-1:

Agro-climatic Zone Map of Kenya(Ministry of Agriculture, Kenya, 1980 (Organization at the time in 1980))

Published at the web site:
http://eusoils.jrc.ec.europa.eu/esdb_archive/eudasm/africa/lists/cke.htm－ 81 －

Table A-3-1: MOISTURE AVAILABILITY ZONES with an indication of rainfall, evaporation, potential for plant growth andrisk of crop failure
zon
e

r/E0
(%)

classification

average annual
potential evaporation(mm) - E0

average annual
rainfall (mm) - r

potential forplant growth

vegetation

excluding areas above 10,000 ft altitude
I

> 80

humid

1100 – 2700

1200 – 2000

moist forestII65 - 80sub-humid

1000 – 1600

1300 – 2100

III

50 - 65

semi-humid

800 – 1400

1450 – 2200

IV

40 - 50

semi-humid tosemi-arid

600 – 1100

1550 – 2200

V

25 - 40

semi-arid

450 – 900

1650 – 2300

bushlandVI

15 - 25arid

300 – 550

1900 – 2400

bushland andscrubland

VII

< 15

very arid

150 - 350

2100 - 2500

desert scrub

moist and dry
forestdry forest andmoist woodland
dry woodlandand bushlandrisk of failure of an
adapted maize

assuming that soil conditions are
not limiting
extremely low
very high(0 – 1%)very lowhigh(1 – 5%)fairly low
high to medium(5 – 10%)low
medium
(10 – 25%)highmedium to low(25 – 75%)
very highlow(75 – 95%)
extremely highvery low(95 – 100%)

Table A-3-2: TEMPERATURE ZONES with an indication of mean maximum, mean minimum and absolute minimum
temperature, night frost and altitude
mean annual
zone

temperatureclassification

○

( C)
9

less than 10810 - 12cold tovery cold
very coolmean max.

mean min.

absolute min.

temperaturetemperaturetemperature

○

( C)

○

( C)

○

( C)

less than 16

less than 4less than -4

16 - 18

4-6-4 to -2night frost

altitude (feet)

altitude (meters)

generaldescription

very

more thanmore thanAfro-Alpine

common

10000

3050

highlands

common9000 - 10000

2750 - 3050
Upper
highlands

7

12 - 14cool

18 - 20

6-8-2 to 0occasional

8000 - 9000

2450 - 2750

6

14 - 16

fairly cool

20 - 228 - 100-2

rare

7000 - 8000

2150 - 2450
Lower

5

16 - 184

18 - 203

20 - 22 *2

22 - 24 *1

24 - 30 **coolhighlands
22 - 24

10 - 122-4very rare

6000 - 7000

1850 - 2150

24 - 26

12 - 144-6

none

5000 - 6000

1500 - 1850

fairly warm

26 - 28

14 - 166-8

none

4000 - 5000

1200 - 1500

warm

28 - 30

16 - 18

8 - 10none

3000 - 4000

900 - 1200

30 - 36 **18 - 24 **10 - 16none

0 - 3000

0 - 900

temperaturewarm
temperaturefairly hot tovery hot

Midlands

Lowlands

these are averages for the whole country; for areas in and west of the Rift Valley the temperature range is one degree warmer andfor areas east of the Rift Valley one degree colder than indicated** at the Coast 28 - 31 and 20 - 23 resp.

－ 82 －

Japan International Forestry Promotion
and Cooperation Center (JIFPRO)
Rinyu Bldg. 3F, 1-7-12 Koraku, Bunkyo-ku,
Tokyo 112-0004, JAPANE-mail: jifpro@jifpro.or.jp
Website: http://www.jifpro.or.jp

Kenya Forest Research Institute (KEFRI)
P.O Box 20412-00200 Nairobi, Kenya
E-mail: director@kefri.org
Website: http://www.kefri.org