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1.
Conservation of Biological Diversity in Paraguay   总被引:1,自引:0,他引:1  
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A Conservation Gap Analysis of Brazil''s Amazonian Vegetation   总被引:4,自引:0,他引:4  
Vegetation types lacking protection in the existing conservation units of the nine states in the Brazilian Legal Amazon were identified, and locations were noted where these vegetation types could be protected. Maps of vegetation, protected areas, and semi-protected areas, such as Amerindian and forestry reserves, were digitized and overlaid using a geographic information system. There are 28 natural vegetation types in the Brazilian Legal Amazon. Locations of new areas for protection were selected using a minimum criterion of protecting at least one example of each vegetation type in each state (here called "vegetation zones"). There are 111 vegetation zones in the Legal Amazon, of which only 37 (33%) have some portion of their area protected. There are few protected areas in the most heavily deforested states along the southeastern fringe of the forest. In Maranhão, where 60% of the original forest had been lost by 1990, only one of 10 vegetation types is protected. Negotiating agreements with indigenous tribes, and to a lesser extent with extractivists who harvest nontimber products from the forest, represents a major opportunity to increase significantly the area and representativeness of the conservation units. Additional conservation units need to be established quickly before rapidly increasing deforestation and land prices preclude this opportunity; otherwise, some vegetation types may virtually disappear.  相似文献   

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基于1 458个自然保护区的实地考察资料、总体规划和公开发表的相关文献,通过建立自然植被就地保护评价指标体系,分析了我国自然植被的就地保护现状,查明了保护空缺。根据评价指标体系,将我国自然植被就地保护水平划分为有效保护、较好保护、一般保护、较少保护、保护状况不明、未受保护和不予评价7个等级。评价结果显示,全国583种自然植被类型中,不予评价的有4种。受评的579种中,522种已经受到不同程度保护。有效保护的自然植被有58种,占全国自然植被类型总数的9.9%;较好保护、一般保护和较少保护的自然植被分别有154、110和200种,分别占全国自然植被类型总数的26.4%、18.9%和34.3%。另外,我国自然植被的保护空缺包括保护状况不明和未受保护的植被类型,分别有38和19种,两者合计占全国自然植被类型总数的9.8%。总体来说,我国绝大部分自然植被已得到就地保护,但保护力度有待加强;对于存在保护空缺的植被类型,亟须加强调查研究以确定其位置、范围和保护价值等,并通过进一步完善保护区网络将其纳入自然保护体系内。  相似文献   

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The nature of conservation challenges can foster a reactive, rather than proactive approach to decision making. Failure to anticipate problems before they escalate results in the need for more costly and time‐consuming solutions. Proactive conservation requires forward‐looking approaches to decision making that consider possible futures without being overly constrained by the past. Strategic foresight provides a structured process for considering the most desirable future and for mapping the most efficient and effective approaches to promoting that future with tools that facilitate creative thinking. The process involves 6 steps: setting the scope, collecting inputs, analyzing signals, interpreting the information, determining how to act, and implementing the outcomes. Strategic foresight is ideal for seeking, recognizing, and realizing conservation opportunities because it explicitly encourages a broad‐minded, forward‐looking perspective on an issue. Despite its potential value, the foresight process is rarely used to address conservation issues, and previous attempts have generally failed to influence policy. We present the strategic foresight process as it can be used for proactive conservation planning, describing some of the key tools in the foresight tool kit and how they can be used to identify and exploit different types of conservation opportunities. Scanning is an important tool for collecting and organizing diverse streams of information and can be used to recognize new opportunities and those that could be created. Scenario planning explores how current trends, drivers of change, and key uncertainties might influence the future and can be used to identify barriers to opportunities. Backcasting is used to map out a path to a goal and can determine how to remove barriers to opportunities. We highlight how the foresight process was used to identify conservation opportunities during the development of a strategic plan to address climate change in New York State. The plan identified solutions that should be effective across a range of possible futures. Illustrating the application of strategic foresight to identify conservation opportunities should provide the impetus for decision makers to explore strategic foresight as a way to support more proactive conservation policy, planning, and management.  相似文献   

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Strategies to mitigate climate change can protect different types of cool environments. Two are receiving much attention: protection of ephemeral refuges (i.e., places with low maximum temperatures) and of stable refugia (i.e., places that are cool, have a stable environment, and are isolated). Problematically, they are often treated as equivalents. Careful delineation of their qualities is needed to prevent misdirected conservation initiatives; yet, no one has determined whether protecting one protects the other. We mapped both types of cool environments across a large (~3.4M ha) mixed‐use landscape with a geographic information system and conducted a patch analysis to compare their spatial distributions; examine relations between land use and their size and shape; and assess their current protection status. With a modest, but arbitrary, threshold for demarcating both types of cool environments (i.e., values below the 0.025 quantile) there were 146,523 ha of ephemeral refuge (62,208 ha) and stable refugia (62,319 ha). Ephemeral refuges were generally aggregated at high elevation, and more refuge area occurred in protected areas (55,184 ha) than in unprotected areas (7,024 ha). In contrast, stable refugia were scattered across the landscape, and more stable‐refugium area occurred on unprotected (40,135 ha) than on protected land (22,184 ha). Although sensitivity analysis showed that varying the thresholds that define cool environments affected outcomes, it also exposed the challenge of choosing a threshold for strategies to address climate change; there is no single value that is appropriate for all of biodiversity. The degree of overlap between ephemeral refuges and stable refugia revealed that targeting only the former for protection on currently unprotected land would capture ~17% of stable refugia. Targeting only stable refugia would capture ~54% of ephemeral refuges. Thus, targeting one type of cool environment did not fully protect the other. Evaluación de la Distribución y Estado de Protección de Dos Tipos de Ambientes Fríos para Facilitar su Conservación bajo el Cambio Climático  相似文献   

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城市绿化中选择净化空气的植物配植   总被引:3,自引:0,他引:3  
文章叙述了在城市绿化中选择净化空气的植物配植的方法、原则,介绍了几种对大气污染吸收净化能力强的植物种类,和室内选择净化空气的花草。  相似文献   

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Abstract:  Optimization of resource use is necessary for efficient conservation planning. Many reserve-selection algorithms aim to identify representative but inexpensive networks, which may lead to selecting small sites due to their lower costs and collectively higher species richness. Nevertheless, larger sites would be preferable regarding species' long-term persistence. An area-based refinement can be used to overcome this problem. We used a reserve-planning framework in which continuous benefit functions valued representation (numbers of populations), and differential species weights were based on a species' local rarity and threatened status. We introduced a refinement based on the species-area relationship that provides relatively higher values for larger sites. We applied the proposed method to rich fen vegetation in southern Finland. The species-area refinement resulted in a network of significantly larger sites with minor trade-offs with representation (numbers of populations). Giving endangered species higher weights ensured that the trade-off occurred mostly between site size and representation of low-priority species. We recommend using a species-area refinement for practical, maximum-coverage conservation planning.  相似文献   

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Abstract:  Selecting suitable nature reserves is a continuing challenge in conservation, particularly for target groups that are time-consuming to survey, species rich, and extinction prone. One such group is the parasitoid Hymenoptera, which have been excluded from conservation planning. If basic characteristics of habitats or vegetation could be used as reliable surrogates of specific target taxa, this would greatly facilitate appropriate reserve selection. We identified a range of potential habitat indicators of the species richness of pimpline parasitoid communities (Hymenoptera: Ichneumonidae: Pimplinae, Diacritinae, Poemeniinae) and tested their efficiency at capturing the observed diversity in a group of small woodlands in the agricultural landscape of the Vale of York (United Kingdom). Eight of the 18 vegetation-based reserve-selection strategies were significantly better at parasitoid species inclusion than random selection of areas. The best strategy maximized richness of tree species over the entire reserve network through complementarity. This strategy omitted only 2–3 species more (out of 38 captured in the landscape as a whole) than selections derived from the parasitoid survey data. In general, strategies worked equally well at capturing species richness and rarity. Our results suggest that vegetation data as a surrogate for species richness could prove an informative tool in parasitoid conservation, but further work is needed to test how broadly applicable these indicators may be.  相似文献   

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Determining which vegetation types organisms perceive similarly and classifying these types into groups that function as similar habitats are necessary steps toward expanding the focus of conservation strategies from single species to ecosystems. Therefore, the methods used to determine these habitat classifications are crucial to the successful design and implementation of these conservation strategies. Typically, this process has been accomplished through best professional judgement. We used quantitative techniques to group vegetation types into habitats based on the occurrence of breeding wildlife species ( n = 420) in Oregon. After calculating faunal similarities among all regional vegetation types ( n = 130), we used cluster analysis to group vegetation types into wildlife habitats. We classified the original 130 vegetation types into 30 wildlife habitat types that we believe function similarly. We tested this classification to assess whether vegetation types could be correctly classified into habitat types based on wildlife species composition. Discriminant analysis correctly classified 95% of the vegetation types into their wildlife habitat types, strengthening our confidence in this approach. This approach for classifying habitat types allows consistent development of conservation strategies at coarse resolutions and aids in identifying vegetation types where additional biodiversity surveys are needed. Finally, this approach can be refined continuously as the precision of vegetation mapping and our understanding of organism-habitat associations improve.  相似文献   

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Abstract:  Populations at the periphery of a species' range are of interest to conservation biologists because they can show marked genetic differentiation from populations at the center of a range and because of potential hybridization among rare and common species. We examined two closely related Cyclamen species. One is a narrow endemic, and the other is more geographically widespread (both protected by law in continental southern France). We used floral traits and genetic variability to test for hybridization among the species in peripheral populations of the rare species. The species co-occurred on Corsica in a disjunct, peripheral part of the distribution of the endemic species and in an ecologically marginal area for the widespread species. The two species have hybridized and the endemic species showed high levels of introgression with its widespread congener. Genetic and floral variability in sites with both species was markedly higher than in sites with a single species. Our results highlight the need for a conservation strategy that integrates hybrid populations because they represent a source of novel diversity that may have adaptive potential.  相似文献   

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辽宁东部山区几种主要森林植被类型土壤渗透性能研究   总被引:6,自引:0,他引:6  
沿辽河水系设置临时标准地 ,对辽宁东部山区具有代表性的油松林、落叶松林、红松林、柞木林、杂木林及灌丛 6种植被类型的土壤水分的入渗性能进行了研究。结果表明 ,辽东山区 6种植被类型下土壤都表现出较强的渗透性能。A层的初始入渗率 (f0 /mm·min- 1) 1 2 .8~ 6 1 .1 ,平均值为 38.7,B层 1 6 .8~4 1 .7,平均值为 2 7.0 ,C层 2 9.2~ 38.2 ,平均值为 2 4 .4 ;A层的稳定入渗率 (fc/mm·min- 1) 2 .6~ 4 .2 ,平均值为 3.5 ,B层 2 .2~ 4 .1 ,平均值为 2 .9,C层 1 .1~ 3.3,平均值为 2 .2 ;A层的饱和导水率 (k10 /mm·min- 1)1 .5 3~ 2 .2 3,平均值为 1 .86 ,B层 0 .77~ 2 .0 5 ,平均值为 1 .2 7,C层 0 .5 0~ 1 .2 8,平均值为 0 .79。不同植被类型下不同土壤发生层次的入渗能力差异显著 :一般地 ,阔叶林下土壤的入渗性能明显好于针叶林 ,榛丛下土壤也表现出很好的渗透性能 ;不同土层入渗性能大小为A层 >B层 >C层。林龄差异在 2个龄级以上时 ,林龄越大 ,土壤初渗性能越好。用Horton方程拟合土壤饱和渗透过程 ,模拟结果与实测结果相近。  相似文献   

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Abstract:  Freshwater ecosystems are declining in quality globally, but a lack of data inhibits identification of areas valuable for conservation across national borders. We developed a biological measure of conservation value for six species of Pacific salmon ( Oncorhynchus spp.) in catchments of the northern Pacific across Canada, China, Japan, Russia, and the United States. We based the measure on abundance and life-history richness and a model-based method that filled data gaps. Catchments with high conservation value ranged from California to northern Russia and included catchments in regions that are strongly affected by human development (e.g., Puget Sound). Catchments with high conservation value were less affected by agriculture and dams than other catchments, although only 1% were within biodiversity reserves. Our set of high-value areas was largely insensitive to simulated error, although classification remained uncertain for 3% of catchments. Although salmon face many threats, we propose they will be most likely to exhibit resilience into the future if a complementary mosaic of conservation strategies can be proactively adopted in catchments with healthy salmon populations. Our analysis provides an initial map of where these catchments are likely to be located.  相似文献   

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Abstract:  Rapid biodiversity assessment and conservation planning require the use of easily quantified and estimated surrogates for biodiversity. Using data sets from Québec and Queensland, we applied four methods to assess the extent to which environmental surrogates can represent biodiversity components: (1) surrogacy graphs; (2) marginal representation plots; (3) Hamming distance function; and (4) Syrjala statistical test for spatial congruence. For Québec we used 719 faunal and floral species as biodiversity components, and for Queensland we used 2348 plant species. We used four climatic parameter types (annual mean temperature, minimum temperature during the coldest quarter, maximum temperature during the hottest quarter, and annual precipitation), along with slope, elevation, aspect, and soil types, as environmental surrogates. To study the effect of scale, we analyzed the data at seven spatial scales ranging from 0.01° to 0.10° longitude and latitude. At targeted representations of 10% for environmental surrogates and biodiversity components, all four methods indicated that using a full set of environmental surrogates systematically provided better results than selecting areas at random, usually ensuring that ≥90% of the biodiversity components achieved the 10% targets at scales coarser than 0.02°. The performance of surrogates improved with coarser spatial resolutions. Thus, environmental surrogate sets are useful tools for biodiversity conservation planning. A recommended protocol for the use of such surrogates consists of randomly selecting a set of areas for which distributional data are available, identifying an optimal surrogate set based on these areas, and subsequently prioritizing places for conservation based on the optimal surrogate set.  相似文献   

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