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581.
Wildlife managers face the daunting task of managing wildlife in light of uncertainty about the nature and extent of future climate change and variability and its potential adverse impacts on wildlife. A conceptual framework is developed for managing wildlife under such uncertainty. The framework uses fuzzy logic to test hypotheses about the extent of the wildlife impacts of past climate change and variability, and fuzzy multiple attribute evaluation to determine best compensatory management actions for adaptively managing the potential adverse impacts of future climate change and variability on wildlife. A compensatory management action is one that can offset some of the potential adverse impacts of climate change and variability on wildlife. Implementation of the proposed framework requires wildlife managers to: (1) select climate impact states, hypotheses about climate impact states, possible management actions for alleviating adverse wildlife impacts of climate change and variability, and future climate change scenarios; (2) choose biological attributes or indicators of species integrity; (3) adjust those attributes for changes in non-climatic variables; (4) define linguistic variables and associated triangular fuzzy numbers for rating both the acceptability of biological conditions under alternative management actions and the relative importance of biological attributes; (5) select minimum or maximum acceptable levels of the attributes and reliability levels for chance constraints on the biological attributes; and (6) define fuzzy sets on the extent of species integrity and biological conditions and select a fuzzy relation between species integrity and biological conditions. A constructed example is used to illustrate a hypothetical application of the framework by a wildlife management team. An overall best compensatory management action across all climate change scenarios is determined using the minimax regret criterion, which is appropriate when the management team cannot assign or is unwilling to assign probabilities to the future climate change scenarios. Application of the framework can be simplified and expedited by incorporating it in a web-based, interactive, decision support tool. 相似文献
582.
Global warming impacts the water cycle not only by changing regional precipitation levels and temporal variability, but also by affecting water flows and soil moisture dynamics. In Brandenburg, increasing average annual temperature and decreasing precipitation in summer have already been observed. For this study, past trends and future effects of climate change on soil moisture dynamics in Brandenburg were investigated, considering regional and specific spatial impacts. Special Areas of Conservation (SACs) were focused on in particular. A decreasing trend in soil water content was shown for the past by analyzing simulation results from 1951 to 2003 using the integrated ecohydrological model SWIM [Krysanova, V., Müller-Wohlfeil, D.-I., Becker, A., 1998. Development and test of a spatially distributed hydrological/water quality model for mesoscale watersheds. Ecol. Model. 106, 261–289]. The trend was statistically significant for some areas, but not for the entire region. Simulated soil water content was particularly low in the extremely dry year 2003. Comparisons of simulated trends in soil moisture dynamics with trends in the average annual Palmer Drought Severity Index for the region showed largely congruent patterns, though the modeled soil moisture trends are characterized by a much higher spatial resolution. Regionally downscaled climate change projections representing the range between wetter and drier realizations were used to evaluate future trends of available soil water. A further decrease of average available soil water ranging from −4% to −15% was projected for all climate realizations up to the middle of the 21st century. An average decrease of more than 25 mm was simulated for 34% of the total area in the dry realization. Available soil water contents in SACs were generally higher and trends in soil moisture dynamics were lower mainly due to their favorable edaphic conditions. Stronger absolute and relative changes in the simulated trends for the past and future were shown for SACs within Brandenburg than for the state as a whole, indicating a high level of risk for many wetland areas. Nonetheless, soil water content in SACs is expected to remain higher than average under climate change conditions as well, and SACs therefore have an important buffer function under the projected climate change. They are thus essential for local climate and water regulation and their status as protected areas in Brandenburg should be preserved. 相似文献
583.
The United Nations Framework Convention on Climate Change (UNFCCC), which was signed by some 153 countries at the Earth Summit in Rio de Janeiro, Brazil in 1992, represented a singular triumph for the geographically dispersed group of island states and low-lying coastal developing countries, located in the Pacific, Atlantic and Indian Oceans, as well as in the Caribbean, South China and Mediterranean Seas, and known as the Alliance of Small Island States (AOSIS). This article focuses on the goals of AOSIS during the negotiations leading up to the adoption of the UNFCCC. For the first time in the history of the United Nations, a group of small states, hitherto relegated to the sidelines, was able to develop a specific negotiating agenda addressing areas which are of overriding concern to them and succeeded in having those concerns incorporated in a legally binding Convention of historic importance. As this article reveals, AOSIS set itself 12 negotiating goals during the negotiating rounds leading up to the UNFCCC, and 10 of these 12 goals were realized. Nevertheless, AOSIS, whose member states are most vulnerable to the possible adverse effects of climate change, was particularly concerned about those provisions of the UNFCCC that were either watered-down significantly, made largely meaningless or excluded altogether. These include: the absence of definite targets or specific timetables for the significant reduction of carbon dioxide by the industrialized countries of the North; the lack of permanent and clear financing arrangements in particular the lack of definitive financial provisions for adaptive response measures to the adverse impacts of climate change such as sea-level rise; and the absence of a specific provision for the implementation of coastal zone management schemes for those countries most vulnerable to sea-level rise. As the UNFCCC moves into the implementation phase, AOSIS should and must build on its past success. To do so, it will need to develop clearly defined initiatives aimed at strengthening the commitments for financing and insurance, and to seek inclusion of a provision to develop and finance coastal zone management schemes for the most vulnerable small states. While the article covers the AOSIS negotiating period up to and including the Earth Summit in June 1992, we nevertheless postulate some possible objectives which the AOSIS group might wish to consider in what is sure to be an intensive post-Earth Summit phase of the UNFCCC, leading up to the first Conference of the Parties of that Convention. 相似文献
584.
Jeffrey A. Bloczynski William T. Bogart Benjamin F. Hobbs Joseph F. Koonce 《Environmental management》2000,26(2):175-193
The model, a stochastic dynamic program, is used to optimize the timing and type of protective structure under a range of
management goals. A wetland can either be optimal for fish or optimal for mammals and waterfowl, but not both. Because credible
estimates of the economic values of wetland services do not exist, we treat those values as parameters in a multiobjective
analysis and show the decisions implied by alternative valuations. The model is applied to the case of Metzger Marsh, a Lake
Erie coastal wetland near Toledo, Ohio, where the decision was made in 1993 to construct an open dike. We find that the optimal
decision is robust with respect to varying assumptions about the formation of barrier beaches and the probability of climate
change, but that the decision is not robust to assumptions concerning the health of an unprotected Metzger Marsh. The most
important source of uncertainty is the biological health of an unprotected wetland. 相似文献
585.
社会-生态系统概念性框架研究综述 总被引:2,自引:0,他引:2
王琦妍 《中国人口.资源与环境》2011,(Z1)
人与自然的矛盾已成为全球性问题,可持续发展理论把人类对于生存与环境的认识推向了一个新的境界。近年来,以社会-生态系统作为研究对象,成为了可持续发展和全球变化研究的一个新视角。在社会-生态系统的概念性框架下,本文对社会-生态系统的动态运行机制和属性进行了详细的综述。社会-生态系统是复杂适应性系统,受自身和外界干扰的影响,具有不可预期性、自组织、非线性、多样性、多稳态等特点。适应性循环是一个启发性模型,有助于理解复杂系统的动态运行机制。恢复力、适应力和转化力是社会-生态系统的三个主要属性。并对社会-生态系统理论研究中面临的问题进行了展望,提出了在以后研究中可以适用的研究方法。 相似文献
586.
The arctic tundra ponds at the International Biological Program (IBP) site in Barrow, AK, were studied extensively in the
1970s; however, very little aquatic research has been conducted there for over three decades. Due to the rapid climate changes
already occurring in northern Alaska, identifying any changes in the ponds’ structure and function over the past 30–40 years
can help identify any potential climate-related impacts. Current research on the IBP ponds has revealed significant changes
in the physical, chemical, and biological characteristics of these ponds over time. These changes include increased water
temperatures, increased water column nutrient concentrations, the presence of at least one new chironomid species, and increased
macrophyte cover. However, we have also observed significant annual variation in many measured variables and caution that
this variation must be taken into account when attempting to make statements about longer-term change. The Barrow IBP tundra
ponds represent one of the very few locations in the Arctic where long-term data are available on freshwater ecosystem structure
and function. Continued monitoring and protection of these invaluable sites is required to help understand the implications
of climate change on freshwater ecosystems in the Arctic. 相似文献
587.
A unique long term, 49-year record (divided into three time periods 1961–1976, 1977–1992, and 1993–2009) of snow profile stratigraphy
from the Swedish sub Arctic, was analyzed with a focus on changes in snow characteristics. The data set contained grain size,
snow layer hardness, grain compactness, and snow layer dryness, observed every second week during the winter season. The results
showed an increase in very hard snow layers, with harder snow in early winter and more moist snow during spring. There was
a striking increase in the number of observations with very hard snow at ground level over time. More than twice as many occasions
with hard snow at ground level were observed between 1993 and 2009 compared to previous years, which may have a significant
effect on plants and animals. The changes in snow characteristics are most likely a result of the increasing temperatures
during the start and the end of the snow season. 相似文献
588.
Climate Warming and the Recent Treeline Shift in the European Alps: The Role of Geomorphological Factors in High-Altitude Sites 总被引:1,自引:0,他引:1
Global warming and the stronger regional temperature trends recently recorded over the European Alps have triggered several
biological and physical dynamics in high-altitude environments. We defined the present treeline altitude in three valleys
of a region in the western Italian Alps and reconstructed the past treeline position for the last three centuries in a nearly
undisturbed site by means of a dendrochronological approach. We found that the treeline altitude in this region is mainly
controlled by human impacts and geomorphological factors. The reconstruction of the altitudinal dynamics at the study site
reveals that the treeline shifted upwards of 115 m over the period 1901–2000, reaching the altitude of 2505 m in 2000 and
2515 m in 2008. The recent treeline shift and the acceleration of tree colonization rates in the alpine belt can be mainly
ascribed to the climatic input. However, we point out the increasing role of geomorphological factors in controlling the future
treeline position and colonization patterns in high mountains. 相似文献
589.
Assessments of adaptation options generally focus on incremental, homogeneous ecosystem responses to climate even though climate
change impacts can be big, fast, and patchy across a region. Regional drought-induced tree die-off in semiarid woodlands highlights
how an ecosystem crash fundamentally alters most ecosystem services and poses management challenges. Building on previous
research showing how choice of location is linked to adaptive capacity and vulnerability, we developed a framework showing
how the options for retaining desired ecosystem services in the face of sudden crashes depend on how portable the service
is and whether the stakeholder is flexible with regard to the location where they receive their services. Stakeholders using
portable services, or stakeholders who can move to other locations to obtain services, may be more resilient to ecosystem
crashes. Our framework suggests that entering into cooperative networks with regionally distributed stakeholders is key to
building resilience to big, fast, patchy crashes. 相似文献
590.
A synthesis of research on the responses of terrestrial biota (1095 effect sizes) to industrial pollution (206 point emission sources) was conducted to reveal regional and global patterns from small-scale observational studies. A meta-analysis, in combination with other statistical methods, showed that the effects of pollution depend on characteristics of the specific polluter (type, amount of emission, duration of impact on biota), the affected organism (trophic group, life history), the level at which the response was measured (organism, population, community), and the environment (biome, climate). In spite of high heterogeneity in responses, we have detected several general patterns. We suggest that the development of evolutionary adaptations to pollution is a common phenomenon and that the harmful effects of pollution on terrestrial ecosystems are likely to increase as the climate warms. We argue that community- and ecosystem-level responses to pollution should be explored directly, rather than deduced from organism-level studies. 相似文献