沙漠研究 22-1, 235 -238 (2012 )"ICAL 1 / DT X"

Journal of Arid Land Studies－Refereed Paper－Effect of Grazing Pressure on the Structure of Rangeland
Plant Community in Mongolia
Sergelenkhuu JAMBAL*1), Nachinshonhor G. URIANHAI1), Takashi OTODA1), Yoshihiro YAMADA1),
Undarmaa JAMSRAN2), Keiji SAKAMOTO1) and Ken YOSHIKAWA1)
Abstract: The main cause of land degradation is overgrazing in Mongolia. The carrying capacity of rangeland is decreasing.
Under heavy grazing, remarkable changes in plant functional type was detected from the perennial and palatable plants (Stipa krylovii,Agropyron cristatum, Allium Mongolicum) to the annual and unpalatable plants (Chenopodium acuminathum, Peganum nigelastrum).
Key Words: Grazing intensity, Land degradation, Mongolia, Plant palatability

2. Materials and Methods
1. Introduction
Animal husbandry is the oldest important traditional
production in Mongolia. Currently, about 40% of herders areliving by the nomadic and traditional way of life. Mongolian
rangeland sustains a livestock activity that is the subsistence
farming, and the productivity of rangeland is a key factor forthe life and culture of Mongolia. Since the change ofMongolian economic structure from the socialistic control tothe capital marketing in 1990, livestock numbers started toincrease and became more than 45.3 million heads in 2009
(Jigjidsuren and Johnson, 2003). More than 80% of
Mongolian territory is used for pasture. Under the new
introduced economical system, herders show a tendency toaggregate around big cities, such as Ulaanbaatar, and/or mainroutes which make them easy to sell and transport livestockand by-products and to access social services. High grazingpressure in these areas seriously disturbs rangeland ecosystemand causes significant changes in vegetation structure. Over
exploitation of above and belowground biomass by heavy
grazing for long period induces indispensable degradation ofrangeland ecosystem and also decreases in carrying capacity incentral area of Mongolia. Changes in community structure
by grazing are strongly depending on plant life-form and its
palatability (Marcelo et al., 2000). Palatability of grassland
plants by livestock is the most important factor to evaluate
productivity and sustainability of rangeland. However thepalatability of each species is not so clear and is limited, notonly for introduced but also native species because of thecomplication of foraging activity.
Besides, a genotypic difference within and between plant
species was noted related to the response of plants to salt stress(Saudi et al., 2003).

During winter season, all livestock are kept at night in a
pen and every morning start from a camp to all direction
opening in front of the camp to feed on dried grass and leaves
around the camp. It is necessary to move for long distancefrom the camp to get enough amounts of dried fodder as thesettlement period progress in winter (Fig. 1).
The distance from winter camp can be considered as anindicator for grazing pressure on the vegetation, namelygrazing intensity decreases as the distance from the campincreases. Research area is the central of Mongolia from thenorth Darkhan city, N 49 24.853; E 105 58.757) to the south(Mandalgobi, N 45 47.319; E 106 10.192). It ordered from northto south with numbers from 1 to 21 included abandoned awinter camp.
Twenty one winter camps were selected as shown in Table
1. Most of all camps were located on flat or gentle south-east
facing slope of small mountains or hills.
Vegetation coverage, species composition and height ofeach species of rangeland around winter camp were recorded.
The field survey was carried out growing season, July-Autumn,
2009. Three parallel lines were set from the center of thewinter camp and seven experimental plots were establishedalong each line at 25, 50, 100, 200, 400, 800 and 1600 m fromthe origin. Total number of plots was 441. Four subplots (1 × 1m) were put within each plot, resulting totally 1764 subplots.
Seasonal changes in species composition and its
availability makes the palatability to the relative values, such aspalatable in winter (January-March), spring (April-June),summer (July-September), and autumn (October-December).
In this study, palatability of each species was classified into 5classes follows by Damiran (2005).

* Corresponding Author: seegii_hustai@yahoo.com
1-1-1, Tsushima-naka, Kita-ku, Okayama, 700-8530, Japan
1) Graduate School of Environmental Science, University of Okayama, Japan

2) Center of Ecosystem Study, Mongolian State University of AgricultureFig. 1. A winter camp in the rangeland of Mongolia.
Table 1 Location of research sites.
No.

EN

Altitude (m)1105058.757'

49024.853'

786

Darkhan Uul

Prefecture

DarkhanCounty2105055.258'

49021.042'

785

Darkhan Uul

Khongor3

105 28.429'

47046.423'

1152

Tov

Lun

4

105028.425'

47046.413'

1150

Tov

Argalant

5106049.905'

47033.610'

1435

Tov

Sergelen

6106045.679'

47031.954'

1463

Tov

Sergelen

7106043.607'

47028.988'

1509

Tov

Sergelen

8106044.500'

47027.264'

1583

Tov

Sergelen

9106031.958'

47006.452'

01508

Tov

Bayantsagaan

10105 58.753'

47003.002'

1283

Tov

Bayan-O'njuul

11106023.647'

46046.347'

1419

Tov

Bayantsagaan

12106027.768'

46041.596'

1388

Tov

Delgertsogt

13106024.894'

46037.106'

1332

Tov

Bayantsagaan

14106026.284'

46033.322'

1372

Dundgobi

Delgertsogt

15106023.858'

46031.196'

1336

Dundgobi

Delgertsogt

16105039.915'

46029.122'

1486

Dundgobi

Adaatsag000

17

106 05.684'

46 14.220'

1504

Dundgobi

Adaatsag

18106011.166'

46010.228'

1508

Dundgobi

Sain tsagaan

19106013.058'

46009.673'

1458

Dundgobi

Sain tsagaan

20106 06.630'

45049.954'

1500

Dundgobi

Sain tsagaan

21106010.192'

45047.319'

1470

Dundgobi

Sain tsagaan

0Each winter camp, number of livestock, composition ofthem and duration of rangeland utilization were recorded byinterview to the owner and neighbor. The soil type inMongolian rangeland steppe is the mostly typical Kastanozems(Haase, 1983).
The meteorological data was provided from Mongolian
Institute of Meteorology and Hydrology, Ministry of Natureand Environment, in 2009. The climate condition of study
sites was shown in Table 2.
These 4 meteorological stations data can show thecondition of climate in our sites. The precipitation is decrease
and air temperature increase from north to south.

3. Results and Discussion
Eighty two species of 53 genus and 24 families wererecorded throughout the study sites. According to thesespecies composition sites are characterized by typical steppeand dry steppe vegetation, which dominated by the feather
grass (Stipa spp) genus, shrubs (Caragana spp) andwormwood (Artemisia spp) species on the chestnut soils. Inaddition, Achnatherum splendens, Chenopodium acuminatum,
Cleistogenes squarrosa, Artemisia adamsii, A.frigida, Carex
duriusculla and Leymus chinensis are common in these areas.
Plant palatability should be taken into account in order toestimate correctly or monitor precisely the foraging resourcesof the Mongolian rangeland.
3.1. The changes of vegetation by grazing intensity withgrazing gradientAccording to the result all species with north and south
areas were classified by 4 relationship types with grazing
distance from the winter camps such as negative, positive,independent and temporal (Fig. 2).

Table 2. Climate information of nearby meteorological stations from research sites.
Air temperature (0 C)

Locationave.

49 0 28.148'N
105 0 57.464'E

ave.

Relative humidity (%)

max.

ave.

min.

Precipitation (mm)

max.

-33.9

16.2

1.9

8.8

60.7

44.4

81.6

338.9

31-29.8

12.3

2.5

7.2

54.7

38.6

71.8

332.4

30.5

-27.9

13.4

3.1

10.3

55.1

3974.8

261

34.2

-24.3

19.7

5.3

12.2

4427.566

86.4

105 0 34.820'E
106 0 56.970'E

Wind velocity (m/s)

max.

36.2

47 0 38.855'N
47 0 42.428'Nmin.

045 45.942'N
106 0 16.500'E

Table 3. Representative species of relation groups.
Negative

Positive

Independent

T emporal

Chenopodium acuminatum

Stipa Krylovii

Artemisia Adamsii

Convolvulus Ammanii

Salsola collina

Agropyron cristatum

Carex pediformis

Heteropappus hispidus

Artemisia scoparia

Artemisia frigida

Kochia prostrata

Thermopsis dahurica

Potentilla bifurca

Cleistogenes squarrosa

Cymbaria dahurica

Peganum nigellastrum

Table 4. Plant palatability and life form.

80

negative

positive6040Coverage (%)

Life form
Palatability

AnnualPerennial
GrassHerb

Shrub

0Preferred-

45130Desirable

1582

Undesirable

5-133Not consumable

5-7210T oxic--2-

0No data--

21Unknown

2212-

T otal (82)131149920

independent

temporal

20

0500

1000

1500

2000 0500

1000

1500

2000

Distance from winter camp (m)Fig. 2. Relationship types between plant cover and grazing gradient.

The representative species of each relation group were shownin Table 3.
We focused on important relationship with positive andnegative effects. These species can show any tendency ofchanges species coverage with grazing distance from thewinter camp.
3.2. The relationships of plant palatability and life form
As shown in Table 4, plants sought by particular species ofanimal and made up a major part of the diet or consumed far inexcess were classified into preferred (P), plants sought andreadily eaten but to a lesser portion than preferred plants wereclassified into desirable (D), plants eaten but usually made up
only a minor part of the diet or consumed in a much smallerproportion than occurred on the rangeland were classified intoundesirable (U). Moreover, plants not eaten intentionally, andplants with toxic substances were classified into notconsumable (N) and toxic (T) respectively.
Most of annual plants were undesirable or not consumablespecies. On the other hand, most of grasses such as Stipa

Table 5. Species relation with grazing distance from winter camp.
(P: Palatable species, UP: Unpalatable species).
Relation
Negative
Positive
Independent
Temporal
Total (82)

AnnualP
11UP272
11GrassPUP
1632120PerennialHerbP
UP
15
6
20
10242721

Shrub
UP
314
237P

krylovii, Agropyron cristatum and Cleistogenes squarrosa werepreferred or desirable species as shown in Table 4.
Comparison between species relation with distance fromthe winter camp and species life forms classified into groups ofpalatable (P + D) and unpalatable (U + N + T), most
unpalatable species shown the negative relation and palatablespecies shown the positive relation with grazing distance fromthe winter camp (Table 5).
As shown in Figure 2 and Table 4, most annuals andunpalatable species were with independent relation and grasses
and palatable species were with positive relation within thegrazing distance from the winter camp. According to thegrazing intensity, the structure of rangeland plant community is
becoming from palatable and grass species to unpalatable andannuals species by the grazing intensity.
In our results, that nearby the winter camp are coincidedwith Zhang et al. (2001), who showed that continued heavy
grazing changed species composition and decreased species
richness of plant community in Inner Mongolia. However inour studied case, seasonal use of winter camp gives plantcommunity a rest time in grown season by release fromgrazing pressure. It has been suggested that management ofgrazing intensity among dimensions of time and space have an
important role to the sustainability of steppe vegetation
resources and livestock industry itself in the Mongolian
plateau.

References
Damiran D. (2005): Palatability of Mongolian Rangeland
Plants. Eastern Oregon Agricultural Research Center.
Haase G. (1983): Akademie Ved. In Geograficky Ustav eds.,
Physisch-geographische Studien in Asien. Brno, pp.
230-367.
Jigjidsuren S, Johnson A. (2003): Forage plants in Mongolia,Ulaanbaatar.
Sternberg M., Gutman M., Perevolotsky A., Eugene D. (2000):
Ungar and Jaime Kigel Vegetation response to grazing
management in Mediterranian herbaceous community:
functional group approach. Journal of Applied Ecology, 37:224-237.
Zhang Tonghui, Zhao Halin, Li Shenggong, Zhou Ruilian(2004): Grassland changes under grazing stress in Horqin
sandy grassland in Inner Mongolia, China. New Zealand
Journal of Agricultural Research, 47: 307-312.