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Linkages between changes in land use, biodiversity and land degradation on the slopes of Mount Kilimanjaro, Tanzania Полный текст
2003
Misana, S.B. | Majule, A.E. | Lyaruu, H.V.
Linkages between changes in land use, biodiversity and land degradation on the slopes of Mount Kilimanjaro, Tanzania Полный текст
2003
Misana, S.B. | Majule, A.E. | Lyaruu, H.V.
Linkages between changes in land use, biodiversity and land degradation on the slopes of Mount Kilimanjaro, Tanzania
2003
Misana, S.B. | Majule, A.E. | Lyaruu, H.V.
Biodiversity, Urban Areas, and Agriculture: Locating Priority Ecoregions for Conservation Полный текст
2003
Taylor Ricketts | Marc Imhoff
Urbanization and agriculture are two of the most important threats to biodiversity worldwide. The intensities of these land-use phenomena, however, as well as levels of biodiversity itself, differ widely among regions. Thus, there is a need to develop a quick but rigorous method of identifying where high levels of human threats and biodiversity coincide. These areas are clear priorities for biodiversity conservation. In this study, we combine distribution data for eight major plant and animal taxa (comprising over 20,000 species) with remotely sensed measures of urban and agricultural land use to assess conservation priorities among 76 terrestrial ecoregions in North America. We combine the species data into overall indices of richness and endemism. We then plot each of these indices against the percent cover of urban and agricultural land in each ecoregion, resulting in four separate comparisons. For each comparison, ecoregions that fall above the 66th quantile on both axes are identified as priorities for conservation. These analyses yield four "priority sets" of 6-16 ecoregions (8-21% of the total number) where high levels of biodiversity and human land use coincide. These ecoregions tend to be concentrated in the southeastern United States, California, and, to a lesser extent, the Atlantic coast, southern Texas, and the U.S. Midwest. Importantly, several ecoregions are members of more than one priority set and two ecoregions are members of all four sets. Across all 76 ecoregions, urban cover is positively correlated with both species richness and endemism. Conservation efforts in densely populated areas therefore may be equally important (if not more so) as preserving remote parks in relatively pristine regions.
Показать больше [+] Меньше [-]Indigenous livelihood systems in industrial tree-plantation areas in West Kalimantan, Indonesia: Economics and plant-species richness Полный текст
2003
Tyynelä, T. | Otsamo, R. | Otsamo, A.
An integrated tree plantation approach combining indigenous livelihoods and industrial wood production is being implemented in West Kalimantan, Indonesia. In this study the economics of land-use was investigated in villages within the plantation scheme. The effect of three alternative land-use scenarios and costs and benefits of each land-use type were studied using linear programming. The scenarios were based 1) on the current land-use, 2) on the integrated tree plantation system with incentives and government regulations, and 3) on a financially optimal land-use distribution. Additionally, plant species richness in different land-use types was surveyed. The scenarios had different kinds of effects on villages varying in respect to their possibilities for land-use intensification. In villages with extensive land use, establishment of tree plantations without any land-use regulations increased the potential economic return on land, resulting in conversion of natural and man-made semi-natural forests into swidden fields. In villages with more sedentary agriculture, the plantation scheme did not create pressures towards remaining forests even in the case of financially optimal land-use distribution. Incorporation of land-use regulations prevented further deforestation but also decreased households' economic returns. The results also showed that conversion of Imperata grasslands to any other land-use increased species richness. Incentives, restrictions or regulations aiming at conserving natural and semi-natural forests are needed to ensure conservation of biodiversity and long-term improvements in local livelihoods. It can be concluded that tree plantations can be combined with other land-use practices: They can improve the economic return on land without further degradation of the environment.
Показать больше [+] Меньше [-]Traditional farming and plant species diversity in agricultural landscapes of south-western Uganda Полный текст
2003
Eilu, Gerald | Obua, Joseph | Tumuhairwe, Joy K. | Nkwine, Charles
An effort was undertaken in Bushwere Parish (Mbarara district, south-western Uganda) between 1999 and 2000 to develop sustainable and participatory approaches to plant biodiversity conservation at the farm level. One hundred farmers were interviewed on their socio-economic profiles and plant use strategies. Plant diversity was assessed in 400 plots of established in 53 field types of seven land-use categories. The most species-rich land-use category was under annual crops (149 plant species) while the most species-rich field type was planted with bananas (118 species). Shannon diversity and Sørensen’s similarity indices were used to compute species diversity and similarity, respectively, between field types and land-uses. The most plant diverse land-use was natural woodland, the least fallow. Canonical correspondence analysis (CCA) showed that occurrence of species, field type or land-use depended upon environmental factors such as elevation, position on the slope and soil type. Redundancy analysis (RDA) showed that species utility and occurrence were related to the socio-economic status of farmers. Plant species were most diverse in land-uses located on hill tops and steep slopes. Farmers should therefore be advised on how to maintain plant diversity in agricultural landscapes.
Показать больше [+] Меньше [-]Rewards for ecological goods--requirements and perspectives for agricultural land use Полный текст
2003
Gerowitt, B. | Isselstein, J. | Marggraf, R.
This paper focuses on the possibilities to reward ecological goods and services of agriculture. Ecological goods in agriculture are achieved by various types of agricultural land use either creating resources or buffering resource consumption. From an economic point of view, positive consequences will result from rewarding the agricultural sector for the production of ecological goods according to market principles. A rewarding system can be developed according to market principles when results instead of actions are rewarded, producer and consumer surpluses are created, demand can be expressed and supply can be provided. Ecological goods are public goods, therefore the expression of demand is up to the community. However, the purchasing of such ecological goods is up to the authority administrating public finances. Establishing regional markets is necessary, since regional differences are evident. Principally, the price of an ecological good should be determined by its value to the public, not by the cost of production. With respect to the various ecological goods achieved by the agricultural sector, the contribution of agricultural land use to biodiversity, and more specifically to plant biodiversity seems to be the most appropriate for a market-orientated rewarding system. A framework for establishing such a market is outlined in this paper. Deviation from standard economic principles regarding prices for ecological goods are considered to be necessary during an introductory period. Finally based on both, ecological and economical considerations, and regarding the intrinsic and extrinsic characteristics of "plant biodiversity connected with agricultural land use", it seems worth the effort to further examine and develop this concept.
Показать больше [+] Меньше [-]Traditional farming and plant species diversity in agricultural landscape of South-Western Uganda. Полный текст
2003
Eiru, Gerald | Obua, Joseph | Tumuhairwe, Joy K. | Nkwiine, Charles
An effort was undertaken in Bushwere Parish (Mbarara district, south-western Uganda) between 1999 and 2000 to develop sustainable and participatory approaches to plant biodiversity conservation at the farm level. One hundred farmers were interviewed on their socio-economic profiles and plant use strategies. Plant diversity was assessed in 400 plots of 5 m X 5 m established in 53 field types of seven land-use categories. The most species-rich land-use category was under annual crops (149 plant species) while the most species-rich field type was planted with bananas (118 species). Shannon diversity and Sørensen’s similarity indices were used to compute species diversity and similarity, respectively, between field types and land-uses. The most plant diverse land-use was natural woodland, the least fallow. Canonical correspondence analysis (CCA) showed that occurrence of species, field type or land-use depended upon environmental factors such as elevation, position on the slope and soil type. Redundancy analysis (RDA) showed that species utility and occurrence were related to the socio-economic status of farmers. Plant species were most diverse in land-uses located on hill tops and steep slopes. Farmers should therefore be advised on how to maintain plant diversity in agricultural landscapes.
Показать больше [+] Меньше [-]Technological change and biodiversity in the rubber agroecosystem of Sumatra Полный текст
2003
l joshi
Large areas of the humid tropics have land use patterns that do not fit into a simple culture/nature or agriculture/forest dichotomy and thus the term 'deforestation' refers to a gradual loss of forest functions, rather than an abrupt change. The term â??agroforestâ??, as defined by de Foresta and Michon (1996) captures the mixed heritage of the â??wildâ?? and the â??domesticatedâ?? aspect of these systems, or as an intermediate stage between natural forest and agricultural plantations. Outside perspectives on these systems have focussed on either side of the coin: poorly managed, low productivity, because â??too wildâ?? or interesting biodiversity but not like a real forest, because â??too domesticatedâ??. Yet, these land use systems should be understood from a farmers/managers perspective if we want to understand what scenarios exist for their future development. Can farmers increase productivity (and/or profitability) while maintaining current biodiversity of the system? Or, will any intensification beyond current practices lead to a further decrease of biodiversity values, which in the past were largely derived from the natural forest context of the system. In this chapter we will discuss these perspectives on the basis of ongoing research by ICRAF and partners in Jambi, one of the main rubber producing provinces in Sumatra (Indonesia) | L Joshi, 'Technological change and biodiversity in the rubber agroecosystem of Sumatra', In: Vandermeer J, (eds). Tropical agroecosystems: new directions for research. Boca Raton, Florida: CRC Press, pp.133-157, 2003
Показать больше [+] Меньше [-]Conservancy
2003
Brewer, Richard
"Brewer's book, the first comprehensive treatment of land trusts, combines a historical overview of the movement with more specific information on the different kinds of land trusts that exist and the problems they face. The volume also offers a "how-to" approach for people and institutions interested in donating, selling or buying land. | Discusses four major national land trusts (The Nature Conservancy, Trust for Public Land, American Farmland Trust, and Rails-to-Trails Conservancy); and gives a generous sampling of information about the activities and accomplishments of smaller, local trusts nationwide. | Brewer's information on the how and why of protecting land is enriched by his intimate knowledge of ecological systems, biodiversity, and the interconnectedness on human and non-human life forms." "Conservancy is a must-read volume for people interested in land conservation - including land trust members, volunteers, and supporters - as well as anyone concerned about land use and the environment."--Jacket.
Показать больше [+] Меньше [-]An assessment of restoration of biodiversity in degraded high mountain grazing lands in northern Ethiopia Полный текст
2003
Asefa, D.T. | Oba, G. | Weladji, R.B. | Colman, J.E.
Loss of biodiversity is the single most important threat to the conservation and sustainable use of drylands in northern Ethiopia due to many centuries of cultivation and heavy livestock grazing pressure. The current study assessed the restoration of biodiversity in highly degraded areas in eastern Tigray, northern Ethiopia using area enclosures (AEs). The study assessed whether the differences in biodiversity between AEs and open management schemes and time of land abandonment influenced diversity of plant life forms (i.e. herbs, shrubs and trees). Changes in biodiversity were compared using the state-and-transition model. Management types and time since abandonment (hereafter called age) had a significant effect on herbaceous plant species abundance but not in shrub species, while site factors had a greater effect on diversity of plant life forms in general. Herbaceous species richness increased with age of restoration, reaching a maximum after three years of rest and declined thereafter, most probably as a result of hay harvesting and replacement of annual species by perennial grass species. Tree species richness increased gradually with age of land abandonment up to the maximum age of eight years. Four vegetation states and seven possible transitions that could guide management were identified. The vegetation states differed in terms of diversity of herbs and tree species but not those of shrubs. Promotion of tree species states will require longer periods of rest, while promotion of herbaceous species richness will need shorter periods. The state-and-transitional model could, therefore, be used to guide future management by promoting vegetation states that are desired by land users.
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