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791.
Abstract:  Relocation of eggs is a common strategy for conservation of declining reptilian populations around the world. If individuals exhibit consistency in their nest-site selection and if nest-site selection is a heritable trait, relocating eggs deposited in vulnerable locations may impose artificial selection that would maintain traits favoring unsuccessful nest-site selection. Conversely, if most individuals scatter their nesting effort and individuals that consistently select unsuccessful nest sites are uncommon, then artificial selection would be less of a concern. During the 2005 nesting season of loggerhead turtles ( Caretta caretta ) at Mon Repos beach, Queensland, Australia, we measured the perpendicular distance from the original nest site to a stationary dune baseline for in situ (unrelocated) and relocated clutches of eggs. We observed the fate of in situ clutches and predicted what would have been the fate of relocated clutches if they had not been moved by mapping tidal inundation and storm erosion lines. In 2005 turtles deposited an average of 3.84 nests and did not consistently select nest sites at particular distances from the stationary dune baseline. Selection of unsuccessful nest sites was distributed across the nesting population; 80.3% of the turtles selected at least one unsuccessful nest site and when previous breeding seasons were included, 97% selected at least one unsuccessful nest site. Females with nesting experience selected more successful nest sites than females with little or no experience. Relocating eggs vulnerable to tidal inundation and erosion saves the progeny from a large percentage of the population and the progeny from individuals who may in subsequent years nest successfully. Our results suggest that doomed-egg relocation does not substantially distort the gene pool in the eastern Australian loggerhead stock and should not be abandoned as a strategy for the conservation of marine turtle populations.  相似文献   
792.
以重庆缙云山8种不同构建模式的水源涵养林及林地土壤为研究对象,用物种多样性指数(simpson指数、Shannon-Wiener指数)、均匀度指数(Pieiou指数)和物种丰富度指数(Margalef指数)以及用土壤容重、毛管孔隙度、非毛管孔隙度、pH值、有机质、全氮、全磷、全钾、速效氮、有效磷、速效钾和阳离子交换量12个指标表征土壤的物理性状和养分特征,分析了8种群落的植物多样性、土壤特征及二者的相互关系.结果表明:物种多样性以广东山胡椒(Lindera kwangtungensis)×杉木((7unninghamia anceolata)混交林最高.马尾松(Pinus massoniana)×广东山胡椒混交林次之,马尾松×柳杉(Cryptomeria fortunei Hooibrenk)混交林和毛竹(Phyllostachys pubescens)纯林最低.各模式林地土壤特征差异显著,以毛竹纯林土壤质量最差.在该地区针阔混交林对提高物种多样性和改良土壤作用显著,针叶林及纯林则较差.物种多样性指数与土壤特征因子的相关性分析表明,不同模式水源林群落植物多样性与土壤特征因子存在一定相关性,其中与土壤物理性状特征关系不显著,与养分特征关系显著.全N与全K与四个多样性指数呈显著或极显著的正相关,Shannon-Wiener指数、Simpson指数和有机质、阳离子交换量、速效P呈显著的正相关,特别是有机质和全N两因子与物种多样性关系最密切.  相似文献   
793.
The impact of copper exposure on Chinese toad (Bufo gargarizans) tadpoles was investigated in this study. First, the 96h LC50 value of copper was 8.697 μM, by means of a 4 d acute toxicity test. Second, we studied the chronic effects of copper on B. gargarizans tadpoles at control, 0.025, 0.1 and 1.0 μM concentration. Survival, body length, body weight, developmental stage, incidence of metamorphic climax, and size at metamorphic climax were determined. In tadpoles developed to metamorphic climax (stage G42), liver and thyroid gland were assessed histologically. Copper at 0.1 and 1.0 μM could inhibit tadpole growth and prolong tadpole metamorphic progress relative to controls. Tadpole size (total length and weight) at stage G42 is also affected in the 0.1 and 1.0 μM treatments. In addition, histological examinations have revealed that 1.0 μM copper could cause significant pathological changes and hepatocytes degeneration in liver. Furthermore, histomorphological measurements indicated that copper at 0.1 and 1.0 μM reduced thyroid gland size, diameter and number of follicle. In conclusion, our study suggests that Cu could damage the liver and thyroid gland, so growth and metamorphosis of B. gargarizans tadpoles were inhibited resulted of disrupting liver metabolism and THs homeostasis.  相似文献   
794.
发展生态建筑已经成为当今社会发展的主题,同时也是顺应建筑全球化潮流,提升人居环境健康性和舒适性的迫切需要.必须不断转变建筑在设计和建设方面的思维方式,才能逐步缓解资源紧缺和环境污染的现状.该文对生态建筑定义以及设计原则两方面进行研究,通过对台湾水滴塔和新加坡展览塔楼这两座典型生态建筑案例进行了分析,再从生态建筑材料和生态建筑节能技术两方面予以阐述,得出生态建筑作为当今社会的发展趋势,其还有很多方面需要通过实践去探索.  相似文献   
795.
Conservation and development initiatives have been widely promoted in protected areas (PAs) in developing countries despite ongoing challenges inherent in their capacity to protected biodiversity and alleviate poverty. Bhutan’s vast PA network is becoming increasingly affected by the rapid expansion of conservation and development activities. This paper examines important challenges that PA stakeholders face during socio-political change, and assess how these challenges might impact stakeholder relations in a remote Asian PA. Multiple methods were used to explore the gap between expectations and delivery of two development projects and provide insights through issues of local capacity, indigenous culture and incompatible priorities. Perceived impacts indicated flaws in project design, strong local cultural norms yet weak local ownership, trust and accountability concerns, tensions between modernization and traditional lifestyles, and prospective trade-offs. Suggestions for stronger projects and PA management include having greater internal leadership, adopting realistic timelines, and openly negotiating trade-offs and hard choices.  相似文献   
796.
The prosperity and well-being of human societies relies on healthy ecosystems and the services they provide. However, the biodiversity crisis is undermining ecosystems services and functions. Vultures are among the most imperiled taxonomic groups on Earth, yet they have a fundamental ecosystem function. These obligate scavengers rapidly consume large amounts of carrion and human waste, a service that may aid in both disease prevention and control of mammalian scavengers, including feral dogs, which in turn threaten humans. We combined information about the distribution of all 15 vulture species found in Europe, Asia, and Africa with their threats and used detailed expert knowledge on threat intensity to prioritize critical areas for conserving vultures in Africa and Eurasia. Threats we identified included poisoning, mortality due to collision with wind energy infrastructures, and other anthropogenic activities related to human land use and influence. Areas important for vulture conservation were concentrated in southern and eastern Africa, South Asia, and the Iberian Peninsula, and over 80% of these areas were unprotected. Some vulture species required larger areas for protection than others. Finally, countries that had the largest share of all identified important priority areas for vulture conservation were those with the largest expenditures related to rabies burden (e.g., India, China, and Myanmar). Vulture populations have declined markedly in most of these countries. Restoring healthy vulture populations through targeted actions in the priority areas we identified may help restore the ecosystem services vultures provide, including sanitation and potentially prevention of diseases, such as rabies, a heavy burden afflicting fragile societies. Our findings may guide stakeholders to prioritize actions where they are needed most in order to achieve international goals for biodiversity conservation and sustainable development.  相似文献   
797.
随着国家政策导向提出实现生物多样性整体性、系统性保护的要求,新时期背景下的生物多样性保护除了注重实现生物多样性在自然生态系统、生物物种、遗传资源(基因)三方面的协同性整体性保护以外,还强调了实现自然生态系统平衡、维护国家安全等总体性目标。在此背景下,本文建议,生物多样性保护法律体系也应当在推动立法实践、提升国家安全治理能力、整合现有立法资源等方面发挥其应有价值。从系统性的角度出发,明确法律体系贯彻生物多样性整体性保护理念、执行国家战略部署以及平衡多元化利益的应有定位,并在此基础上从整体性目标的树立、网格联动性的体系构建、合理配置现行法律制度等方面探寻系统性法律体系的构建路径,将有效发挥我国生物多样性保护法律体系在服务社会需求、回应国家政策导向等方面的制度支撑价值。  相似文献   
798.
Wet grassland populations of wading birds in the United Kingdom have declined severely since 1990. To help mitigate these declines, the Royal Society for the Protection of Birds has restored and managed lowland wet grassland nature reserves to benefit these and other species. However, the impact of these reserves on bird population trends has not been evaluated experimentally due to a lack of control populations. We compared population trends from 1994 to 2018 among 5 bird species of conservation concern that breed on these nature reserves with counterfactual trends created from matched breeding bird survey observations. We compared reserve trends with 3 different counterfactuals based on different scenarios of how reserve populations could have developed in the absence of conservation. Effects of conservation interventions were positive for all 4 targeted wading bird species: Lapwing (Vanellus vanellus), Redshank (Tringa totanus), Curlew (Numenius arquata), and Snipe (Gallinago gallinago). There was no positive effect of conservation interventions on reserves for the passerine, Yellow Wagtail (Motacilla flava). Our approach using monitoring data to produce valid counterfactual controls is a broadly applicable method allowing large-scale evaluation of conservation impact.  相似文献   
799.
Conflicts between the interests of agriculture and wildlife conservation are a major threat to biodiversity and human well-being globally. Addressing such conflicts requires a thorough understanding of the impacts associated with living alongside protected wildlife. Despite this, most studies reporting on human–wildlife impacts and the strategies used to mitigate them focus on a single species, thus oversimplifying often complex systems of human–wildlife interactions. We sought to characterize the spatiotemporal patterns of impacts by multiple co-occurring species on agricultural livelihoods in the eastern Okavango Delta Panhandle in northern Botswana through the use of a database of 3264 wildlife-incident reports recorded from 2009 to 2015 by the Department of Wildlife and National Parks. Eight species (African elephants [Loxodonta africana], hippopotamuses [Hippopotamus amphibious], lions [Panthera leo], cheetah [Acinonyx jubatus], African wild dogs [Lycaon pictus], hyenas [Crocuta crocuta], leopards [Panthera pardus], and crocodiles [Crocodylus niloticus]) appeared on incident reports, of which 56.5% were attributed to elephants. Most species were associated with only 1 type of damage (i.e., either crop damage or livestock loss). Carnivores were primarily implicated in incident reports related to livestock loss, particularly toward the end of the dry season (May–October). In contrast, herbivores were associated with crop-loss incidents during the wet season (November–April). Our results illustrate how local communities can face distinct livelihood challenges from different species at different times of the year. Such a multispecies assessment has important implications for the design of conservation interventions aimed at addressing the costs of living with wildlife and thereby mitigation of the underlying conservation conflict. Our spatiotemporal, multispecies approach is widely applicable to other regions where sustainable and long-term solutions to conservation conflicts are needed for local communities and biodiversity.  相似文献   
800.
When evaluating the impact of a biodiversity conservation intervention, a counterfactual is typically needed. Counterfactuals are possible alternative system trajectories in the absence of an intervention. Comparing observed outcomes against the chosen counterfactual allows the impact (change attributable to the intervention) to be determined. Because counterfactuals by definition never occur, they must be estimated. Sometimes, there may be many plausible counterfactuals, including various drivers of biodiversity change and defined on a range of spatial or temporal scales. Here, we posit that, by definition, conservation interventions always take place in social-ecological systems (SES) (i.e., ecological systems integrated with human actors). Evaluating the impact of an intervention in an SES, therefore, means taking into account the counterfactuals assumed by different human actors. Use of different counterfactuals by different actors will give rise to perceived differences in the impacts of interventions, which may lead to disagreement about its success or the effectiveness of the underlying approach. Despite that there are biophysical biodiversity trends, it is often true that no single counterfactual is definitively the right one for conservation assessment, so multiple evaluations of intervention efficacy could be considered justifiable. Therefore, we propose calculating the sum of perceived differences, which captures the range of impact estimates associated with different actors in a given SES. The sum of perceived differences gives some indication of how closely actors in an SES agree on the impacts of an intervention. We applied the concept of perceived differences to a set of global, national, and regional case studies (e.g., global realization of Aichi Target 11 for marine protected areas, effect of biodiversity offsetting on vegetation condition in Australia, and influence of conservation measures on an endangered ungulate in Central Asia). We explored approaches for minimizing the sum, including a combination of negotiation and structured decision making, careful alignment of expectations on scope and measurement, and explicit recognition of any intractable differences between stakeholders.  相似文献   
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