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排序方式: 共有370条查询结果,搜索用时 250 毫秒
191.
Dominic Muenzel Kay Critchell Courtney Cox Stuart J. Campbell Raymond Jakub Iliana Chollett Nils Krueck Daniel Holstein Eric A. Treml Maria Beger 《Conservation biology》2023,37(2):e14008
Larval dispersal is an important component of marine reserve networks. Two conceptually different approaches to incorporate dispersal connectivity into spatial planning of these networks exist, and it is an open question as to when either is most appropriate. Candidate reserve sites can be selected individually based on local properties of connectivity or on a spatial dependency-based approach of selecting clusters of strongly connected habitat patches. The first acts on individual sites, whereas the second acts on linked pairs of sites. We used a combination of larval dispersal simulations representing different seascapes and case studies of biophysical larval dispersal models in the Coral Triangle region and the province of Southeast Sulawesi, Indonesia, to compare the performance of these 2 methods in the spatial planning software Marxan. We explored the reserve design performance implications of different dispersal distances and patterns based on the equilibrium settlement of larvae in protected and unprotected areas. We further assessed different assumptions about metapopulation contributions from unprotected areas, including the case of 100% depletion and more moderate scenarios. The spatial dependency method was suitable when dispersal was limited, a high proportion of the area of interest was substantially degraded, or the target amount of habitat protected was low. Conversely, when subpopulations were well connected, the 100% depletion was relaxed, or more habitat was protected, protecting individual sites with high scores in metrics of connectivity was a better strategy. Spatial dependency methods generally produced more spatially clustered solutions with more benefits inside than outside reserves compared with site-based methods. Therefore, spatial dependency methods potentially provide better results for ecological persistence objectives over enhancing fisheries objectives, and vice versa. Different spatial prioritization methods of using connectivity are appropriate for different contexts, depending on dispersal characteristics, unprotected area contributions, habitat protection targets, and specific management objectives. Comparación entre los métodos de priorización de la conservación espacial con sitio y la conectividad espacial basada en la dependencia 相似文献
192.
Divya Narain Laura J. Sonter Alex Mark Lechner James E. M. Watson Jeremy S. Simmonds Martine Maron 《Conservation biology》2023,37(4):e14095
Infrastructure development is a major driver of biodiversity loss globally. With upward of US$2.5 trillion in annual investments in infrastructure, the financial sector indirectly drives this biodiversity loss. At the same time, biodiversity safeguards (project-level biodiversity impact mitigation requirements) of infrastructure financiers can help limit this damage. The coverage and harmonization of biodiversity safeguards are important factors in their effectiveness and therefore warrant scrutiny. It is equally important to examine the extent to which these safeguards align with best-practice principles for biodiversity impact mitigation outlined in international policies, such as that of the International Union for Conservation of Nature. We assessed the biodiversity safeguards of public development banks and development finance institutions for coverage, harmonization, and alignment with best practice. We used Institute of New Structural Economics and Agence Française de Développement's global database to identify development banks that invest in high-biodiversity-footprint infrastructure and have over US$500 million in assets. Of the 155 banks, 42% (n = 65) had biodiversity safeguards. Of the existing safeguards, 86% (56 of 65) were harmonized with International Finance Corporation (IFC) Performance Standard 6 (PS6). The IFC PS6 (and by extension the 56 safeguard policies harmonized with it) had high alignment with international best practice in biodiversity impact mitigation, whereas the remaining 8 exhibited partial alignment, incorporating few principles that clarify the conditions for effective biodiversity offsetting. Given their dual role in setting benchmarks and leveraging private finance, infrastructure financiers in development finance need to adopt best-practice biodiversity safeguards if the tide of global biodiversity loss is to be stemmed. The IFC PS6, if strengthened, can act as a useful template for other financier safeguards. The high degree of harmonization among safeguards is promising, pointing to a potential for diffusion of practices. 相似文献
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194.
目的 研究Ni18Co9Mo5在湿热海洋环境(永兴)和亚湿热酸雨环境(重庆)下的腐蚀行为和力学性能规律。方法 通过金属粉末注塑成形方法制备Ni18Co9Mo5样品,采用力学试验机、X射线衍射分析仪、扫描电子显微镜、能谱分析仪、金相显微镜对Ni18Co9Mo5在永兴和重庆典型大气环境下暴露试验18个月的性能变化规律进行研究。结果 Ni18Co9Mo5样品的耐蚀性较差,在海洋环境和亚湿热酸雨下暴露2个月即出现明显的腐蚀现象,在平均相对湿度达到临界湿度(80%)基础上,腐蚀介质SO2(亚湿热酸雨环境)和Cl–(海洋环境)对Ni18Co9Mo5金属材料的早期腐蚀具有加剧作用。Ni18Co9Mo5在永兴试验18个月后,腐蚀产物较为疏松,且样品内外腐蚀区域均存在明显裂纹,其抗拉强度和冲击能量分别下降43%和60%左右;在重庆试验18个月后,其抗拉强度下降15%,冲击能量整体变化不明显。湿热海洋环境中侵蚀性强的Cl–导致Ni18Co9Mo5发生点蚀,甚至裂纹萌生及扩展,加剧了样品基体的腐蚀,有效承载面积减小及裂纹导致力学性能明显下降。结论 Ni18Co9M... 相似文献
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196.
Md. Rashed Chowdhury P.-S. Chu Thomas A. Schroeder Xin Zhao 《Journal of Coastal Conservation》2008,12(2):93-104
The objective of this study is to provide an improved climatology of sea level extremes on seasonal and long-term time scales for Hawaii and the U.S-Trust islands. Observations revealed that the Hawaiian and U.S.-Trust islands, by and large, display a strong annual cycle. For estimating the statistics of return period, the three-parameter generalized extreme value (GEV) distribution is fitted using the method of L-moments. In the context of extremes (20- to 100-year return periods), the deviations in most of the Hawaiian Islands (except at Nawiliwili and Hilo) displayed a moderate sea-level rise (i.e., close to 200 mm), but the deviations in the U.S.-Trust islands displayed a considerably higher rise (i.e., more than 300 mm) in some seasons due to typhoon-related storm surges. This rise may cause damage to roads, harbors, and unstable sandy beaches. Correlations between the El Niño-Southern Oscillation (ENSO) climate cycle and the variability of seasonal sea level have been investigated. Results show that correlation for the station located west of the International Date Line (DL) is strong, but it is moderate or even weaker for stations east of the DL. The skill of SST-based Canonical Correlation Analyses (CCA) forecasts was found to be weak to moderate (0.4–0.6 for Honolulu, Kahului, Hilo, and Wake, and 0.3 or below for Kahului, Mokuoloe, and Johnston). Finally, these findings are synthesized for evaluating the potential implications of sea level variability in these islands. 相似文献
197.
火焰原子吸收光谱法测定苏州开发区26种蔬菜中铜锌铁锰镍 总被引:6,自引:0,他引:6
用火焰原子吸收光谱法测定了苏州开发区26种蔬菜中的铜、锌、铁、锰和镍的含量。蔬菜样品用硝酸高氯酸混合酸进行消解。4次测定值的相对标准差<5%,加标回收率在92%~107%之间。26种蔬菜中铜、锌、铁、锰、镍的含量基本均在世贸组织规定的范围内。 相似文献
198.
Heather Welch Stephanie Brodie Michael G. Jacox Steven J. Bograd Elliott L. Hazen 《Conservation biology》2020,34(3):589-599
Spatial management is a valuable strategy to advance regional goals for nature conservation, economic development, and human health. One challenge of spatial management is navigating the prioritization of multiple features. This challenge becomes more pronounced in dynamic management scenarios, in which boundaries are flexible in space and time in response to changing biological, environmental, or socioeconomic conditions. To implement dynamic management, decision-support tools are needed to guide spatial prioritization as feature distributions shift under changing conditions. Marxan is a widely applied decision-support tool designed for static management scenarios, but its utility in dynamic management has not been evaluated. EcoCast is a new decision-support tool developed explicitly for the dynamic management of multiple features, but it lacks some of Marxan's functionality. We used a hindcast analysis to compare the capacity of these 2 tools to prioritize 4 marine species in a dynamic management scenario for fisheries sustainability. We successfully configured Marxan to operate dynamically on a daily time scale to resemble EcoCast. The relationship between EcoCast solutions and the underlying species distributions was more linear and less noisy, whereas Marxan solutions had more contrast between waters that were good and poor to fish. Neither decision-support tool clearly outperformed the other; the appropriateness of each depends on management purpose, resource-manager preference, and technological capacity of tool developers. Article impact statement: Marxan can function as a decision-support tool for dynamic management scenarios in which boundaries are flexible in space and time. 相似文献
199.
以实际生活污水为研究对象,在序批式活性污泥反应器中探究了Ni2+对活性污泥形态及生物除磷性能的影响。实验结果表明,Ni2+能够抑制生物除磷,当Ni2+质量浓度由0 mg/L增加至10.0 mg/L时,PO43--P去除率由93%下降至12%。机理研究结果表明:Ni2+能抑制聚磷微生物的厌氧释磷和好氧吸磷,并能抑制内聚物聚羟基烷酸酯(PHA)的合成;当Ni2+质量浓度为10.0 mg/L时,PHA的最大含量仅为2.4 mmol/g (以单位质量挥发性悬浮物所含PHA中C的物质的量计),远低于空白组中PHA的含量。此外,Ni2+还对微生物群落的组成产生影响,并促进活性污泥中聚糖微生物的增殖。 相似文献
200.
Improving Community-Based Conservation Near Protected Areas: The Importance of Development Variables
Balint PJ 《Environmental management》2006,38(1):137-148
Community-based conservation projects implemented in conjunction with protected area management often struggle to meet expectations.
This article argues that outcomes will improve if project leaders pay closer attention to four development indicators—rights,
capacity, governance, and revenue—that are often taken for granted or considered beyond the scope of local conservation projects.
I make the case for focusing on these variables in four steps. First, I distinguish community-based conservation linked to
protected area management from community-based institutions studied by scholars of the commons. Second, I draw on the theory
and practice of international development to highlight the central relevance of the variables highlighted in this article
to development projects at all levels. Third, I discuss the four variables in some detail, considering problems of definition
and measurement and reviewing possible interactions among them. Fourth, to illustrate the influence of the variables in particular
cases, I review outcomes from community-based conservation projects implemented near protected areas in El Salvador and Zimbabwe. 相似文献