bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some experiences with reafforestation of alang-alang (Imperata cylindrica L.) grassland in Indonesia
Authors: Pratiwi - , Lust N. 
Published: July 2016

In Indonesia the alang-alang grassland covers about 16-20 million hectares. It is considered unproductive land, therefore reafforestation of this grassland is very necessary. Some efforts including the policy of the Forestry Department, on national level and even in the field have been done. Some techniques to suppress the alang-alang growth have been tried out including techniques of soil preparation, species selection and maintenance of plantations. The reafforestation programme of alang-alang grassland has promising results for the increase of the forest area and will ultimately provide wood production, as well as an income for the rural people and soil protection benefits. The production of log and soft wood as raw material will increase. The knowledge of silvicultural techniques for reafforestation activities in alang-alang grassland is enough to start an action programme, but nevertheless further research has to be done to find out still more appropriate techniques and to achieve better results. The reafforestation method on the alang-alang grassland will mainly depend on the site situation and the objectives, especially the kind of wood that must be produced. Reafforestation directly with fast growing species will be carried out when soft wood will be produced. When more valuable wood should be produced, the system will be : 1. Planting fast growing species. 2. After the alang-alang is suppressed the slow growing and more demanding species is planted, while gradually the fast growing species is harvested. A choice between exotic or indigenous species for forest plantation must be done, considering very carefully the advantages and disadvantages of these species. When the value, volume and production time of an exotic and an indigenous species are comparable, the indigenous one is the preferred choice. Use of exotic species is in principle only justified when a sustainable forestry is assured. The reafforestation of alang-alang grassland will create positive socio-economic impacts as well as environmental impacts.
Heterogeneity in a poplar stand and estimation of the mean volume index
Authors: Moermans R. , Van Hecke P. , Mau F. 
Published: July 2016

For a small poplar stand of 81 Robusta trees (2 years old), contour mapping and trend surfaces are calculated. These statistical techniques can be informative for showing heterogeneity and can be helpful for estimating the mean of the parameters concerned. They can yield better estimates than random sampling in the stand. As parameter, the Volume Index is used for demonstrative purposes.
Teak (Tectona grandis L.f.) forests in Java, Indonesia: plantations, management and policy
Authors: Pratiwi - , Lust N. 
Published: July 2016

This paper gives an overview of the environmental conditions, silviculture, distribution and area of teak forests in Indonesia. As Java is a densely populated island, the population pressure is also very high. Therefore specific forest management systems are applied. The tumpangsari (taungya) system as well as daily wage system are considered as having valuable social and economic aspects for people of the area surrounding the teak forests. This way they ultimately decrease further teak forests deterioration. Indirect government policies (such as family planning and transmigration) and policies aimed directly at the teak forests, such as application of the tumpangsari and daily wage systems, could maintain teak forests and teak production in Indonesia on a sustainable basis.
Theoretische berekeningen van systematische fouten bij de bepaling van de oppervlakte van het grondvlak
Authors: Goossens R. 
Published: July 2016

Theoretical calculation of the systematic errors made during the determination of the basal area - To prove his point, the author goes out from the supposition, that the best approximation for the basal area is an ellipse. Consequently three parameters are set up to reflect various characteristics of a given area at any moment. The first parameter (V(t)) is a measure for the form of the basal area at a moment t and is calculated from the relation between the large (a) and the small (b) axis of the ellipse. The use of a second parameter was necessary as the biological growth-centre of the tree (point M in fig. 3) does not coincide in most cases with the intersection 0 of the axes of symmetry. The distance between both points (M and 0), represented by symbol x0(t) is used as a measure for the real stem dish eccentricity. The third parameter is a measure for the size of the basal area at a moment t and is called the representative radius (r(c; t)). It is the radius of a circle with the same surface value as the considered ellipse. Going out from these three parameters, a formula was worked out up to basically calculate any r(u; t) in function of the direction u or the angle e between this radius and the maximum radius (par. 3, form. 5) of any given stem dish. As the value of x0(t) depends on the dimension of r(c; t), the concept 'relative eccentricity e(t)' is introduced (cfr. Form. 6) and it becomes thus possible to give the basic formula a definitive form (cfr. form. 7). By means of this basic formula, it is not only possible to calculate the descriptive radius at a moment t in function of V(t), e(t) and θ, but a lot of further deductions can also be made. A first possible application consists in the calculation of the procentual error Er(u; t) on any radius r(u; t) in function of V, e and their position regarding to the maximum radius (cfr. par. 4 1, form. 8). The evolution of this error in function of the mentionned parameters is given in fig. 4. In paragraph 42, the procentual error is calculated from each other on average of 12 radii, measured at a distance of 300 (form. 8). This is done in function of the relative eccentricity e and the form of the basal area. The graphic representation of this calculations is given in fig. 5. In fig. 6 the evolution of the relative distribution SRx (t) on the mentionned average is given. To calculate this distribution form. 10 was used. Paragraph 43 proves that the mentioned procentual errors only need to be duplicated to know the procentual errors on the calculated surfaces of the basal area. Finally, the position of the representative radius has been verified in function of e, and V and his evolution studied by using the formula 13 and 13' (fig. 7).
Elements of sustainable forest management
Authors: Lust N. 
Published: July 2016

Elements of the modern day vision on sustainable forest management are discussed. Some aspects of the concept are analysed, focusing on the natural definition in comparison with the ecosystem definition. The significance of ecological stability is emphasized. It is pointed out that perhaps the most important aspect of forest stability and sustainability is the ability to retain soil fertility. Attention is paid to the importance of species composition, the role of organic matter, the impact of forest use and the problems of forest engineering. In order to reach sustainable forest management, a number of strategies can be applied, based either on the market or the state. There is a need for measurable criteria and indicators for the evaluation of sustainability. Therefore new programmes of scientific sampling or even basic research are still needed. Forest sustainability provides still a dramatic lot of questions and efforts, a.o. on the potentiality of sustainable forestry.
Entwicklung mechanischer Stabilitätsmerkmale in Fichtenstangenhölzern in Oberösterreich
Authors: Huvenne P. 
Published: July 2016

In Central Europe, spruce forests play an important role in forestry and wood production and cover large surfaces. This study focuses on the mechanical stability of monocultural, evenaged spruce stands. Measurements were taken in three different forests in the Western part of Oberösterreich (Austria). Two of them belong to farmers, the third, the "Weilhartsforst" is run as a private business. In 18 plots of 20 by 20 meters, an inventory of diameter, height, crown length, social position and damage by deer was made. This data were statistically analysed on al parameters in relation to management and eld. The h/d ratio was used as main parameter, as it is in many Austrian stability studies. Generally , the mechanical stability of the spruce stands is insufficient, which is the result of the treatment. A strong thinning, by cutting neighbouring trees of all candidates will give a satisfactory h/d ratio. There was found that a first stern reduction should take place in the first 10 years, and a first thinning 5 to 7 years later. Dominant trees are the most stable ones, but also the most attractive for deer. To prevent damage, a good wildlife management is necessary. By selecting the dominant trees and following a consequent thinning, one creates a very uniform stand. This seems to be the most mechanically stable, following the results of the research, but it is known as ecologically dangerous.
Comparative study of C sequestration by new forests on former pasture lands
Authors: Lust N. , Van Camp N. , Muys B. , Nachtergale L. 
Published: July 2016

The research compares the C sequestration of on the one hand an old pasture and on the other hand two young forest stands, planted on former pasture lands. The stands are respectively ash and pin oak stands, planted 27 and 26 years ago, with a basal area of 21.3 m2 and 13.10 m2. C-content was assessed, based upon Hohenadl's model trees, for all compartments. The total C-content of the pasture land presently amounts to 128 t/ha, whereas it reaches respectively 173 t/ha and 118 t/ha for the ash and pin oak stands. The soils of the forest stands contain respectively 74 and 50 t carbon/ha. So, remarkable changes occurred in the C quantity and allocation by the afforestation. Afforestation of a rich pasture leads in the first phase to a noticeable decrease of the C content in the soil. The C content of the A1 horizon is significantly greater in the pasture than in the young forest stands. Nevertheless afforestation of a pasture considerably increases, already after 25 years, the C sequestration of the ecosystem, provided the used tree species are suitable, i.e. they should be fast growing and produce a good quality litter. This way, not only the aboveground C accumulation is useful, but also the quantity and the quality of the soil humus. Research on the evolution of the C sequestration after afforestation of agricultural lands deserves priority.
Origin and development of the Flemish Forest Decree
Authors: Lust N. 
Published: July 2016

The Flemish forest decree of 13 June 1990 is the result of 15 years intensive discussions and scrutiny by several concerned parties. The first draft was mainly the work of a small forestry group, consisting of members of the forest administration and the university. Afterwards this first draft has been thoroughly scrutinized by different pressure groups: private forest owners, local authorities, agricultural sector, nature conservation, rural planning and politicians. Finally a decree, that can be considered as a compromise, has been approved. In this decree the basic features of the first draft are still present but the influence of the pressure groups is manifest, especially from the nature conservationists and the agricultural lobby. Some articles are also rather confuse, because of controversy between the pressure groups.
Biomass of understory species of Pinus halepensis Mill. forests in the Kassandra Peninsula - Chalkidiki
Authors: Smiris P. , Maris F. , Vitoris K. , Stamou N. , Ganatsas P. 
Published: July 2016

This study deals with the biomass estimation of the understory species of Pinus halepensis forests in the Kassandra peninsula, Chalkidiki (North Greece). These species are: Quercus coccifera, Quercus ilex, Phillyrea media, Pistacia lentiscus, Arbutus unedo, Erica arborea, Erica manipuliflora, Smilax aspera, Cistus incanus, Cistus monspeliensis, Fraxinus ornus. A sample of 30 shrubs per species was taken and the dry and fresh weights and the moisture content of every component of each species were measured, all of which were processed for aboveground biomass data. Then several regression equations were examined to determine the key words.
Monitoring natural stand change in the forest reserve of Liedekerke, Flanders (Belgium)
Authors: Van den Meersschaut D. , De Cuyper B. , Vandekerkhove K. , Lust N. 
Published: July 2016

Natural stand changes in the forest reserve of Liedekerke were analysed during the period 1986-1996, using a permanent grid of circular plots. The monitoring concentrated on natural changes in species composition, using stem number and basal area as indicators, and changes in spatial distribution and colonization capacities of trees and shrubs, with special interest in the competition between exotic and indigenous species. After only a decade of monitoring important natural changes in the woody layer were detected. The pioneer forest is gradually maturing through self-thinning processes and shifts in species composition. The overall stem number decreased with 33.6%, while the basal area increased with 20.9%. Birch (Betula pendula/ pubescens) and indigenous oak (Quercus robur/petraea) remained dominant. More tolerant exotic species, like red oak (Quercus rubra) and sweet chestnut (Castanea sativa), are slowly increasing their share in the species composition and expanding their range. Pioneer species on the other hand, like aspen (Populus tremula), willow (Salix capreaicinerealaurita), alder buckthorn (Frangula alnus) and common (Alnus glutinosa) and grey alder (A. incana), strongly declined. Black cherry (Prunus serotina) seems to be slowly invading the forest due to its massive natural regeneration. Strong competition may be expected especially from rowan ash (Sorbus aucuparia), which showed similar regeneration and colonization capacities. Elder (Sambucus nigra) dramatically extented its range, though its share remains marginal. Beech remained absent most probably due to the lack of mature trees in the vacinity of the forest. Finally this change detection allowed that general predictions could be made on the future natural development and composition of this forest reserve, which could serve forest management decisions.
Challenges for the European higher education, with special reference to forestry
Authors: Lust N. , Nachtergale L. 
Published: July 2016

The ongoing discussion about the future of the forestry education can be considered as a part of the present intensive discussion on the European Higher Education System. Both the Sorbonne and the Bologna declarations are calling for the harmonisation of the higher education systems in Europe. The reality, however, is that the existing structures show an extreme complexity and diversity of curricular and degree structures, due to major differences in several key factors. Forestry education in Europe reflects quite well the features of the Higher Education in Europe. Curricula strongly differ, forestry as a science has thoroughly evolved during the last decades, foresters are faced to new challenges and the labour market offers other opportunities. As a result, there is both the need for harmonisation and for increased mobility, meaning that there are several reasons for changing forestry curricula. Fundamental changes in the field of profession and didactic requirements are major reasons to revise the forestry curricula. The shift from developing mainly the professional qualifications of the students to a stronger emphasis on the formation of the personal qualifications are considered as the main general issue in the changes of the forestry curricula.
Einfluss der Naturschutzgesetzgebung auf die Forstgesetzgebung in Flandern
Authors: Lust N. , Nachtergale L. , Serbruyns I. 
Published: July 2016

Gegenstand dieser Untersuchung ist der Einfluss der Naturschutzgesetzgebung auf die Forstgesetzgebung in Flandern. Von großer Bedeutung hierfür ist zunächst das erste Naturschutzgesetz von 1973. Die Forstverwaltung hat dieses grob vernachlässigt und sah sich mit den entsprechenden Konsequenzen konfrontiert. 1990 wurde das erste Flämische Forstgesetz erlassen, in dem der ökologische Wert der Wälder bereits stark betont wurde. Das Flämische Naturschutzgesetz von 1997 hat jedoch den Einfluss des Naturschutzes auf den Wald noch wesentlich verstärkt. Und schliesslich haben die Änderungen des Flämischen Waldgesetzes von 1999 die Ökologie noch stärker gewichtet. Die allgemeinen Schlussfolgerungen bezüglich des Verhältnisses zwischen Naturschutzgesetz und Waldgesetz sind offensichtlich. Es gibt eine Reihe von Überlappungen zwischen dem Waldgesetz von 1990, revidiert im Jahre 1999, und dem Naturschutzgesetz von 1997. Durch das Waldgesetz wird der Naturschutzwert des Waldes sehr stark betont. Der Einfluss des Naturschutzes auf die Forstpolitik, die Forstgesetzgebung und die Waldbewirtschaftung ist groß. Dabei kann das Naturschutzgesetz in Zukunft einen noch viel grösseren Einfluss auf die Waldbewirtschaftung ausüben. Durch die Naturschutzgesetzgebung gibt es zahlreiche Konfliktquellen zwischen dem Waldsektor und dem Naturschutzsektor. Sie können zu einer scharfen Auseinandersetzung zwischen beiden Gruppen führen, von der vor allem die Privatwaldbesitzer betroffen wären. Konflikte zwischen den Sektoren werden unvermeidlich zu einer Demotivation der Waldeigentümer und damit auch zu einem verminderten Wert des Waldbesitzes führen.
Impact of small-scale variability of soil pH on the vegetation composition in a mixed hardwood stand, East-Flanders Belgium
Authors: Zahedi GH. , Lust N. , Van Meirvenne M. , Nachtergale L. , Muys B. 
Published: July 2016

1 Soil pH of the forest stand varies widely for the different depths and is very important in determining the forest vegetation types. Main aim of the study was to examine the correspondence between forest vegetation composition and small-scale heterogeneity in pH by several statistical methods. 2 Ordination using DCA (Detrended Correspondence Analysis) found clear distinction in the vegetation structure and pointed pH differences as the main factor explaining the variability (Eigenvalue= 0.76 for the first three axis). 3 Clustering analysis by TWINSPAN resulted into four major vegetation groups. Most of these divisions were explained by differences in pH. 4 The spatial dependence of the pH at ectorganic and top mineral layers was examined by geostatistics analysis. All variograms showed a similar well-defined structure. The structure of variograms accounted for 95 - 100 % of the spatial dependence for the pH at all depths. All variograms represented the same range of 50 m for the pH at ectorganic horizons, but the distance of 65 and 72 m was calculated respectively for the pH at 0 - 5 and 5 -15 cm depth. All variograms increased to the maximum lag over which they were calculated. 5 The raster image of pH variability resulting from Kriging interpolation coincided significantly with the raster image of vegetation composition. It was concluded that it is possible to predict the pH value based on the vegetation composition or vice versa. Predicting the vegetation type from pH value is only possible for the range of the distance of the pH variogram.
Structure and development patterns analysis of the Ostrya carpinifolia pure and mixed stands in the western part of Nestos valley
Authors: Milios E. 
Published: July 2016

The study was conducted in Ostrya carpinifolia (pure and mixed) stands in the slopes of the western part of Nestos valley (in the region of Xanthi). In order to analyze the structure and the development patterns of our stands, 41 plots were established, trees were cut, increment cores were taken, and stem analysis was conducted in 3 couples of dominant (competitive) trees. The main results of this research indicate that a) O. carpinifolia (pure and mixed) stands origin, initiation, development patterns, structure and spatial distribution were strongly affected by anthropogenic disturbances. b) The development patterns and structures (today) of O. carpinifolia structural types were also affected by three other important factors: the growth ecology of each species, their regeneration mechanisms and the quality of the site. c) O. carpinifolia and F. ornus trees, until the age of 80 - 100 years old, dominate in the upper storeys, exhibiting similar height growth patterns, whereas C. orienta lis trees usually are stratified in the lower storeys. d) The site sensitivity classification of the three main species, in O. carpinifolia mixed stands, is as follows O. carpinifolia &gt; F. ornus &gt; C. orientalis. This site sensitivity difference between the main species of our mixed stands has a significant effect in the formation of their structure. We observe a gradual alteration of the species contribution, in the total basal area of the stand, in relation to site quality. e) O. carpinifolia trees maintain a high sprouting capacity in medium ages (around 50 years old), whereas the most vigorous 30 years old stump sprouts, have high growth rhythms that are greater than those which had the seed origin standards in the first 30 years of their lives. f) The main silviculture objective is to convert almost all stands in seed origin stands. Furthermore, forest practice must favor multiple species mixed stands. Their composition must be determined in relation to site quality.
Dynamics and development patterns of Pinus sylvestris L. - Fagus sylvatica L. stands in Central Rhodope
Authors: Milios E. 
Published: July 2016

The study was conducted in second growth stands in the central Rhodope mountains and (specially) in the region of Xanthi. In order to determine the dynamics and the development patterns of Pinus sylvestris - Fagus sylvatica stands, 39 plots were established, trees were cut, increment cores were taken, and stem analysis was conducted in 4 couples of dominant (competitive) pine and beech trees. The main results of this research indicate that a) The population structures, the regeneration and development patterns are strongly influenced by human and natural disturbances and species 'life history characteristics'. b) The difference in site quality between site types results in differences in the duration of beech invasion (under pine) and in species basal area distribution. c) In good site qualities when individual dominant beech and Scots pine (competitive) trees with a small age difference grew together, the beech trees, in some cases, have almost the same height growth as the pines and the pine trees showed a delayed (for the species) culmination in current annual volume increment which is not followed by a abrupt fall. d) The process of secondary succession is influenced by disturbances regime, environment, propagule availability and species biology.
The mixed forests of Greece
Authors: Zagas T. , Tsitsoni T. , Hatzistathis A. 
Published: July 2016

Greece is a mountainous Mediterranean country characterised by a variety of microenvironments. As a result, a great number of mixed forest types appear. These stands are natural by unevenaged stands with a lot of ecological and social advantages (as resistance against biotic and abiotic factors) high biodiversity and aesthetical beauty. For this reason, these forests must be protected and managed in a sustainable way, in order to fulfil their valuable services. This paper is dealing with the most important and representative mixed-species stands of Greece beginning from those existing in the lower elevations (zone of evergreen broadleaves) and continuing to the higher ones (zone of boreal conifers).