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991.
江西珍稀濒危植物资源与保护 总被引:5,自引:0,他引:5
经调查统计,江西分布有国家第一批珍稀濒危保护植物74种,比《中国珍稀濒危植物》记载本省的种类(48种)增加了26种。本文论述了本省珍稀植物濒危的原因和我省自然保护的实际情况,提出了保护、发展和合理利用珍稀濒危植物资源的意见。 相似文献
992.
全球变暖影响下中国自然灾害的发展趋势 总被引:42,自引:5,他引:42
在本世纪全球与中国显著变暖和中国境内降水量有所减少影响下,结合经济发展过程中生态系统的恶化,50年代至90年代初,中国多种自然灾害包括旱灾、洪涝灾、风暴潮灾、农林生物灾害都在发展加剧,唯寒冻冰雪灾害有所减轻。自然灾害所造成经济损失80年代已比60年代成倍增长,90年代逐步损失达1000亿元至2000亿元。下世纪气候进一步变暖,如北方降水少量增加不抵蒸发量的上扬,旱灾仍将继续发展。南方雨量增加特别是暴雨和台风雨的增加,会使洪涝灾害扩大加剧。沿海地区由于海平面上升,海岸带灾害主要是风暴潮存在加剧趋势。农林病虫害也将发展,唯寒冻灾害可大幅度减轻。 相似文献
993.
Benayas JM Montaña Ede L Belliure J Eekhout XR 《Journal of environmental management》2006,79(3):279-289
A major task related to conservation is to predict if planned infrastructure projects are likely to threaten biodiversity. In this study we investigated the potential impact of planned infrastructure in Spain on amphibian and reptile species, two highly vulnerable groups given their limited dispersal and current situation of population decline. We used distribution data of both groups to identify areas of high herpetofauna diversity, and compared the locations of these areas with the locations of the planned road, high-speed train railway and water reservoir network. Four criteria were used for this identification: species richness, rarity, vulnerability, and a combined index of the three criteria. From a total of 1441 cells of 20 x 20 km, areas of high diversity were defined as those cells whose ranked values for the different criteria included either all species or all threatened species. The combined index provided the smallest number of cells needed to retain all threatened species (1.7 and 2.6% of the cells for amphibian and reptile species, respectively). Coincidences between these high diversity areas and cells including planned infrastructures-denominated 'alert planning units'-were 35.4% for amphibians and 31.2% for reptiles. Mitigation of the potential impacts would include actions such as barriers to animal access to roads and railways and ecoducts under these constructions. Our approach provides conservation authorities information that can be used to make decisions on habitat protection. A technique that identifies threats to herpetofauna before they occur is also likely to improve the chance of herpetofauna being protected. 相似文献
994.
We explore the problem of integrating some of the many factors involved in conservation planning by focusing on their effects on a common currency of conservation success, the probability of persistence. This approach has the potential to reduce many of the difficulties inherent in combining different pattern and process factors. For handling information expressed as probabilities, five area-selection methods are compared. 相似文献
995.
An Operational Model for Implementing Conservation Action 总被引:10,自引:0,他引:10
996.
MANFRED LENZEN AMANDA LANE† ASAPH WIDMER-COOPER‡ MOIRA WILLIAMS† 《Conservation biology》2009,23(2):294-306
Abstract: There is widespread agreement that biodiversity loss must be reduced, yet to alleviate threats to plant and animal species, the forces driving these losses need to be better understood. We searched for explanatory variables for threatened-species data at the country level through land-use information instead of previously used socioeconomic and demographic variables. To explain the number of threatened species in one country, we used information on land-use patterns in all neighboring countries and on the extent of the country's sea border. We carried out multiple regressions of the numbers of threatened species as a function of land-use patterns, and we tested various specifications of this function, including spatial autocorrelation. Most cross-border land-use patterns had a significant influence on the number of threatened species, and land-use patterns explained the number of threatened species better than less proximate socioeconomic variables. More specifically, our overall results showed a highly adverse influence of plantations and permanent cropland, a weaker negative influence of permanent pasture, and, for the most part, a beneficial influence of nonarable lands and natural forest. Surprisingly, built-up land also showed a conserving influence on threatened species. The adverse influences extended to distances between about 250 km (plants) and 2000 km (birds and mammals) away from where the species threat was recorded, depending on the species. Our results highlight that legislation affecting biodiversity should look beyond national boundaries. 相似文献
997.
DAVID P. EDWARDS FELICITY A. ANSELL ABDUL H. AHMAD REUBEN NILUS KEITH C. HAMER 《Conservation biology》2009,23(6):1628-1633
Abstract: The recent advent of carbon crediting has led to a rapid rise in biosequestration projects that seek to remove carbon from the atmosphere through afforestation and forest rehabilitation. Such projects also present an important potential opportunity to reverse biodiversity losses resulting from deforestation and forest degradation, but the biodiversity benefits of different forms of biosequestration have not been considered adequately. We captured birds in mist nets to examine the effects of rehabilitation of logged forest on birds in Sabah, Borneo, and to test the hypothesis that rehabilitation restores avian assemblages within regenerating forest to a condition closer to that seen in unlogged forest. Species richness and diversity were similar in unlogged and rehabilitated forest, but significantly lower in naturally regenerating forest. Rehabilitation resulted in a relatively rapid recovery of populations of insectivores within logged forest, especially those species that forage by sallying, but had a marked adverse effect on frugivores and possibly reduced the overall abundance of birds within regenerating forest. In view of these results, we advocate increased management for heterogeneity within rehabilitated forests, but we strongly urge an increased role for forest rehabilitation in the design and implementation of a biodiversity‐friendly carbon‐offsetting market. 相似文献
998.
JONATHAN V. HIGGINS‡ MARK T. BRYER† MARY L. KHOURY THOMAS W. FITZHUGH‡ 《Conservation biology》2005,19(2):432-445
Abstract: Freshwater biodiversity is highly endangered and faces increasing threats worldwide. To be complete, regional plans that identify critical areas for conservation must capture representative components of freshwater biodiversity as well as rare and endangered species. We present a spatially hierarchical approach to classify freshwater systems to create a coarse filter to capture representative freshwater biodiversity in regional conservation plans. The classification framework has four levels that we described using abiotic factors within a zoogeographic context and mapped in a geographic information system. Methods to classify and map units are flexible and can be automated where high-quality spatial data exist, or can be manually developed where such data are not available. Products include a spatially comprehensive inventory of mapped and classified units that can be used remotely to characterize regional patterns of aquatic ecosystems. We provide examples of classification procedures in data-rich and data-poor regions from the Columbia River Basin in the Pacific Northwest of North America and the upper Paraguay River in central South America. The approach, which has been applied in North, Central, and South America, provides a relatively rapid and pragmatic way to account for representative freshwater biodiversity at scales appropriate to regional assessments. 相似文献
999.
The machair sand dune systems of the Outer Hebrides of Scotland are a unique habitat, which is rare within both a global and
European context. Unusually, the machair habitat also represents an agricultural resource that is very important to the Hebridean
people, having been subject to both grazing and cultivation throughout the historical period. Following designation as an
Environmentally Sensitive Area (ESA) in 1988, the machairs of South Uist have been studied with the aim of understanding the
links between agricultural practice and their plant community and ecosystem dynamics. This research focused primarily on the
effects of cultivation practices and their role in maintaining plant species richness and community and ecosystem stability.
Within two carefully selected areas, the successional plant communities of machair at different stages of recovery following
ploughing and cultivation of cereals and potato patches or ‘lazy beds’ were identified at both a macro- and micro-level. Investigations
of the vegetation recovery processes on turves taken from newly ploughed land indicated that the initial stages of recolonization
are characterized primarily by rapid vegetative reproduction and growth, although re-vegetation by seeds is also an important
factor. The implications of these findings for the long-term management of machair plant communities are discussed and in
particular the need to maintain old cultivation practices such as shallow ploughing. The need for more detailed research into
both seed banks and seed rain and into processes of vegetative reproduction is stressed. 相似文献
1000.
We examined the physiological and morphological response patterns of plains cottonwood [Populus deltoides subsp. monilifera (Aiton) Eck.] to acute water stress imposed by groundwater pumping. Between 3 and 27 July 1996, four large pumps were used
to withdraw alluvial groundwater from a cottonwood forest along the South Platte River, near Denver, Colorado, USA. The study
was designed as a stand-level, split-plot experiment with factorial treatments including two soil types (a gravel soil and
a loam topsoil over gravel), two water table drawdown depths (∼0.5 m and >1.0 m), and one water table control (no drawdown)
per soil type. Measurements of water table depth, soil water potential (Ψs), predawn and midday shoot water potential (Ψpd and Ψmd), and D/H (deuterium/hydrogen) ratios of different water sources were made in each of six 600-m2 plots prior to, during, and immediately following pumping. Two additional plots were established and measured to examine
the extent to which surface irrigation could be used to mitigate the effects of deep drawdown on P. deltoides for each soil type. Recovery of tree water status following pumping was evaluated by measuring stomatal conductance (g
s
) and xylem water potential (Ψxp) on approximately hourly time steps from before dawn to mid-afternoon on 11 August 1996 in watered and unwatered, deep-drawdown
plots on gravel soils. P. deltoides responded to abrupt alluvial water table decline with decreased shoot water potential followed by leaf mortality. Ψpd and percent leaf loss were significantly related to the magnitude of water table declines. The onset and course of these
responses were influenced by short-term variability in surface and ground water levels, acting in concert with physiological
and morphological adjustments. Decreases in Ψpd corresponded with increases in Ψmd, suggesting shoot water status improved in response to stomatal closure and crown dieback. Crown dieback caused by xylem
cavitation likely occurred when Ψpd reached −0.4 to −0.8 MPa. The application of surface irrigation allowed trees to maintain favorable water status with little
or no apparent cavitation, even in deep-drawdown plots. Two weeks after the partial canopy dieback and cessation of pumping,
g
s
and Ψxp measurements indicated that water stress persisted in unwatered P. deltoides in deep-drawdown plots. 相似文献