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201.
Abstract: Extensive habitat loss and changing agricultural practices have caused widespread declines in grassland birds throughout North America. The Flint Hills of Kansas and Oklahoma—the largest remaining tallgrass prairie—is important for grassland bird conservation despite supporting a major cattle industry. In 2004 and 2005, we assessed the community, population, and demographic responses of grassland birds to the predominant management practices (grazing, burning, and haying) of the region, including grasslands restored under the Conservation Reserve Program (CRP). We targeted 3 species at the core of this avian community: the Dickcissel (Spiza americana), Grasshopper Sparrow (Ammodramus savannarum), and Eastern Meadowlark (Sturnella magna). Bird diversity was higher in native prairie hayfields and grazed pastures than CRP fields, which were dominated by Dickcissels. Although Dickcissel density was highest in CRP, their nest success was highest and nest parasitism by Brown‐headed Cowbirds (Moluthrus ater) lowest in unburned hayfields (in 2004). Conversely, Grasshopper Sparrow density was highest in grazed pastures, but their nest success was lowest in these pastures and highest in burned hayfields, where cowbird parasitism was also lowest (in 2004). Management did not influence density and nest survival of Eastern Meadowlarks, which were uniformly low across the region. Nest success was extremely low (5–12%) for all 3 species in 2005, perhaps because of a record spring drought. Although the CRP has benefited grassland birds in agricultural landscapes, these areas may have lower habitat value in the context of native prairie. Hayfields may provide beneficial habitat for some grassland birds in the Flint Hills because they are mowed later in the breeding season than elsewhere in the Midwest. Widespread grazing and annual burning have homogenized habitat—and thus grassland‐bird responses—across the Flint Hills. Diversification of management practices could increase habitat heterogeneity and enhance the conservation potential of the Flint Hills for grassland birds. 相似文献
202.
应用遥感技术,利用长时间序列的SPOT VEGETATION NDVI数据集,结合改进的像元二分模型,对豫西山区1998年、2003年和2008年的植被覆盖度进行计算。结果表明,豫西山区植被覆盖总体上略有上升,局部地区植被覆盖度有所下降。高海拔区域植被覆盖相对稳定,退化概率较低;低海拔区域植被退化和恢复的概率都相对较高;坡度小的区域植被退化和修复的概率都较高;坡度较大的区域植被轻微退化概率增大,坡度越大,植被覆盖修复的概率越低;南坡和北坡植被覆盖度相对较高,东坡和西坡植被覆盖度较低;西南坡向的植被退化相对严重,东南坡向植被退化概率相对较低。 相似文献
203.
A vast number of prioritization schemes have been developed to help conservation navigate tough decisions about the allocation of finite resources. However, the application of quantitative approaches to setting priorities in conservation frequently includes mistakes that can undermine their authors’ intention to be more rigorous and scientific in the way priorities are established and resources allocated. Drawing on well‐established principles of decision science, we highlight 6 mistakes commonly associated with setting priorities for conservation: not acknowledging conservation plans are prioritizations; trying to solve an ill‐defined problem; not prioritizing actions; arbitrariness; hidden value judgments; and not acknowledging risk of failure. We explain these mistakes and offer a path to help conservation planners avoid making the same mistakes in future prioritizations. Seis Errores Comunes en la Definición de Prioridades de Conservación 相似文献
204.
Statistical prediction is a tool and aim in ecology and wildlife management and conservation. A prediction may either be supported by or contradicted by observations of an unknown set of observations. A contradiction occurs if the prediction is not included within the range of the unknown observations, i.e. the prediction misses the cloud of observations completely. Mixed-effects models, frequently used for statistical assessment of clustered data, carry information needed for calculating the probability of such contradictions. Here we present a new versatile statistic, the probability of contradiction (P (Contra)), that describes how often we would anticipate a new cluster of observations contradicting our predictions. Some benefits of P (Contra) are: (1) easy to calculate and intuitive interpretation, (2) comparability between datasets, (3) inclusion of residual correlation, (4) summary of the multitude of information from mixed models into one statistics, and (5) applicable to local mixed-effect models. 相似文献
205.
张艳丽 《防灾科技学院学报》2012,14(3):88-94
清代建都北京,在这里实行特殊的行政管理制度,与之相适应,救灾组织系统也与各地不同。清代北京地区政府救灾组织系统的主要特点有三:一是旗、汉分城办理。清初实行的旗、汉分城居住政策,导致北京城市居址环境的变迁。内城八旗救灾事务由八旗都统负责,外五城救灾事务由五城察院负责。这一特点既与清代逐渐演变形成的特殊官制有关,又与中央集... 相似文献
206.
207.
A newly constructed coastal revetment at Colhuw Beach in the Glamorgan Heritage Coast, Wales, UK, was analysed using a recently
developed environmental risk assessment package (ERA). Conflict with Heritage Coast conservation objectives is apparent and
the act of building such a structure is questioned for a location where maintenance ofnatural beauty is an axiom of the coastal management philosophy. The likelyhood of revetment related environmental consequences of
significant magnitude was analysed using estimated probability values derived from Bayesian theory. The damaging impact of
the structure on the natural environment is out of all proportion to the level of storm protection afforded to the site. Analyses,
such as carried out via ERA, would have shown planners, engineers and environmentalists, the inadequacies of such an investment
and management strategy. The ERA approach can help to introduce greater clarity and consistency into decision making processes. 相似文献
208.
Integration of environmental science in society is impeded by the large gap between science and policy that is characterised by weaknesses in societal relevance and dissemination of science and its practical implementation in policy. We analyse experiences from BONUS, the policy-driven joint Baltic Sea research and development programme (2007–2020), which is part of the European Research Area (ERA) and involves combined research funding by eight EU member states. The ERA process decreased fragmentation of Baltic Sea science and BONUS funding increased the scientific quality and societal relevance of Baltic Sea science and strengthened the science-policy interface. Acknowledging the different drivers for science producers (academic career, need for funding, peer review) and science users (fast results fitting policy windows), and realising that most scientists aim at building conceptual understanding rather than instrumental use, bridges can be built through strategic planning, coordination and integration. This requires strong programme governance stretching far beyond selecting projects for funding, such as coaching, facilitating the sharing of infrastructure and data and iterative networking within and between science producer and user groups in all programme phases. Instruments of critical importance for successful science-society integration were identified as: (1) coordinating a strategic research agenda with strong inputs from science, policy and management, (2) providing platforms where science and policy can meet, (3) requiring cooperation between scientists to decrease fragmentation, increase quality, clarify uncertainties and increase consensus about environmental problems, (4) encouraging and supporting scientists in disseminating their results through audience-tailored channels, and (5) funding not only primary research but also synthesis projects that evaluate the scientific findings and their practical use in society – in close cooperation with science users − to enhance relevance, credibility and legitimacy of environmental science and expand its practical implementation. 相似文献
209.
A newly constructed coastal revetment at Colhuw Beach in the Glamorgan Heritage Coast, Wales, UK, was analysed using a recently
developed environmental risk assessment package (ERA). Conflict with Heritage Coast conservation objectives is apparent and
the act of building such a structure is questioned for a location where maintenance ofnatural beauty is an axiom of the coastal management philosophy. The likelyhood of revetment related environmental consequences of
significant magnitude was analysed using estimated probability values derived from Bavesian theory. The damaging impact of
the structure on the natural environment is out of all proportion to the level of storm protection afforded to the site. Analyses,
such as carried out via ERA, would have shown planners, engineers and environmentalists, the inadequacies of such an investment
and management strategy. The ERA approach can help to introduce greater clarity and consistency into decision making processes. 相似文献
210.
David R. Breininger Mary Jo Barkaszi Rebecca B. Smith Donna M. Oddy Jane A. Provancha 《Environmental management》1998,22(2):315-321
/ We identified and ranked 108 resident and migratory wildlife taxa on John F. Kennedy Space Center (KSC) that were vulnerable to local, regional, or global extinction. We ranked taxa based on their vulnerability to extinction, their potential role for maintaining faunal integrity, and the relevance of KSC for maintaining their populations in the United States and Florida. Several taxa, not listed by agencies, were vulnerable to regional or global extinction. Many taxa not vulnerable to global extinction were vulnerable to local and regional extinction. Top predators were vulnerable to extinction because of small population size, isolation from other populations, and road mortality. Many taxa were dependent on habitat conditions at different geographic locations so that conservation required greater collaboration among land owners, managers, and researchers at local, regional, and global scales.KEY WORDS: Biological diversity; Endangered species; Conservation 相似文献