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61.
【目的】研究两种通风模式下杭州地区规模化猪场舍内环境参数及其分布规律,筛选出适合本地区推广的通风模式。【方法】选取杭州地区具有代表性的横向通风和纵向通风两种通风模式下育肥舍为研究对象,开展了早、中、晚3个不同时间点,进风口、舍中央和排风口3个不同位置的热环境参数、有害气体浓度的监测,持续监测1周。分析不同时间点和舍内不同位置对热环境参数(温度、相对湿度、风速)以及有害气体(氨气(NH3)和硫化氢(H2S))浓度的影响,并对两种模式下的热环境参数及有害气体浓度进行比较分析;采用空气沉淀法收集舍内环境中的细菌,并对细菌进行培养及统计分析,比较两种模式下育肥舍中细菌数量差异。【结果】两种通风模式下育肥舍相对湿度均低于国家标准,位置和各时间点对相对湿度影响不大,其中纵向通风舍内的相对湿度显著高于横向通风模式(P<0.05)。两种通风模式舍内平均温度没有显著性差异(P>0.05),舍内中午温度显著高于早、晚(P<0.05),位置对纵向通风舍内温度影响较大。纵向通风舍内平均风速为(1.09±0.42) m/s,符合国家标准且极显著高于横向通风模式(P<0.01),风速受舍内位置的影响,各时间点对其影响不大。两种通风模式下猪舍空气环境中有害气体浓度均在国家标准范围内,但纵向通风舍内NH3和H2S浓度均显著低于横向通风模式(P<0.05),各时间点H2S、NH3浓度差异均不显著(P>0.05),舍内不同位置对有害气体浓度分布影响较大,进风口位置有害气体浓度显著低于舍中央位置和排风口位置(P<0.05)。纵向通风舍内空气中细菌总数符合国家标准且显著低于横向通风模式(P<0.05)。【结论】纵向通风模式下育肥舍内的总体环境优于横向通风模式,在本区域生产应用中,育肥舍的设计倾向于推广纵向通风模式。  相似文献   
62.
面对伴随着城市现代化进程所带来的环境问题,宜居城乡建设是改善居住环境问题的重要举措;生态景观林带是以改善破碎化的森林斑块和绿化带、以增强森林为主体的自然生态空间的连通性、以观赏性为目的和以点、线、面相结合的景观廊道网络。生态景观林带在城乡宜居建设中发挥着改善自然环境与人文环境的双重作用,促进了城市与乡村的耦合,是城乡宜居建设的有效途径。  相似文献   
63.
通过文献分析、问卷调查和实地访谈3种方式,对CFCC森林经营认证单位综合效益、认证动力、问题与挑战进行了调研和分析。结果表明:CFCC森林经营认证在经济成本效益不高的情况下,创造了较明显的社会生态效益,市场需求不足是面临的最大问题,认证类型多样化发展为森林经营单位提供了新的服务和支持,试点项目以及CFCC与PEFC互认推动了认证类型的发展。提出了推动CFCC森林经营认证的建议,以期进一步促进CFCC森林认证健康有序地发展。  相似文献   
64.
以大字杜鹃为材料,对播种育苗技术进行研究,结果表明,种子发芽适宜的光照强度为1 000~2 000 Lx;种子最佳催芽处理方法是:种子采集调制后冷藏,播种前浸泡48 h;最适宜的播种基质为腐殖土+土沙混合,比例为2:1 ,再覆盖1 cm厚粉碎的苔藓.播种育苗适宜在温室与塑料大棚中进行,出苗率分别达到85% 和61%,当...  相似文献   
65.
实蝇类害虫是世界性检疫害虫,对福建省农作物造成为害的主要包含橘小实蝇、南亚寡鬃实蝇、瓜实蝇、具条实蝇4种。这4种实蝇类害虫给福建省水果、蔬菜带来较为严重的经济损失,并且由于防治过程中农药的使用,造成生态环境问题。本研究选取实蝇类害虫为害较为严重的福建省主要水果和蔬菜作为研究对象,从直接经济损失、防治费用和间接经济损失3个层面建立评估模型,并对2016年4种实蝇类害虫造成的经济损失进行评估,旨在通过评估经济损失情况,为今后防治政策的制定提供思路。研究结果显示,这4种实蝇类害虫对福建省造成的经济损失约为313.48亿元,其中直接经济损失约为221.74亿元,防治费用约为84.24亿元,间接经济损失约为7.5亿元。最后,本研究提出了重视有害生物灾情评估、完善经济损失评价方法,开展农户专业培训、提升防控技术水平,加强环境规制力度、发展绿色生态农业等政策建议。  相似文献   
66.
  1. The significant shortfall in global marine protection targets is likely to continue to drive rapid growth in marine protected areas (MPAs). Systematic conservation planning to fill gaps in marine protection requires sufficient knowledge of both the distribution of biodiversity and the threats to species and ecosystems. Yet such data are lacking for much of the marine environment, creating significant challenges for planning effective marine protection.
  2. In the absence of habitat mapping data, critical environmental variables associated with species' distributions can be used to model the spatial distribution of different environments. Although this approach has been used in some jurisdictions to assist MPA planners, the increased availability and resolution of spatial data now provide an opportunity to improve assessments of MPA representation.
  3. Capitalizing on advances in spatial data, this study uses a range of biological and physical environmental attributes to model the distribution of Australian marine environments. Given many Australian MPAs were implemented without knowledge of the distribution of species and benthic habitats, this Bio‐physical model is used to assess MPA coverage and equality of protection for Australian marine environments.
  4. Results of the Bio‐physical model revealed that Australian MPAs overrepresent warm, offshore waters (such as the Coral Sea) and underrepresent temperate environments. Furthermore, the distribution of protection in Australian MPAs is heavily skewed, with no‐take protection disproportionately targeting tropical environments, leaving major gaps in the protection of both temperate and nearshore habitats.
  5. Without comprehensive habitat mapping, the representativeness and adequacy of an MPA system cannot be accurately evaluated, nor can the required expansion of MPAs be planned effectively. In the interim, the biological and physical attributes chosen for this model provide useful proxies to assist in efforts to better target current and future protection based on the most up‐to‐date knowledge.
  相似文献   
67.
  1. In many parts of the world, policymakers, legislators, marine managers, and indigenous peoples have attempted to reconcile marine protected area (MPA) governance and management with indigenous peoples' ancient and ongoing traditional ownership of coastal and marine environments. This paper describes a novel approach in Australia to addressing this challenge through indigenous‐led planning and collaborative governance of holistic coastal land and sea indigenous protected areas (IPAs) based on the indigenous concept of “Country”—traditional land and sea estates and their associated cultural, environmental, and other values.
  2. To provide context to this approach, the paper explains the concept of “Sea Country” and provides an overview of the relationship between indigenous peoples and Australia's coastal and marine environments, the legal and policy recognition of Indigenous Sea Country rights and interests, and the engagement of indigenous people in the governance and management of government‐led, legislated MPAs in Australia.
  3. The paper then describes the evolution of IPAs from being specifically based on indigenous land tenure to being based more generally on Indigenous Country, across multiple tenures, including marine areas. In recent years, IPAs based on Country have enabled indigenous people to lead planning and governance of land and sea areas over which they have limited legal rights, including over existing national parks and marine parks. Using this approach, some IPAs complement existing protected area governance and management arrangements, whereas elsewhere Country‐based IPAs are adding significantly to Australia's MPA estate. The Dhimurru IPA in the Northern Territory and Girringun Region IPAs in Queensland are presented as examples of this Country‐based approach.
  4. This indigenous‐driven, collaborative, nonlegislative approach to dedicating, governing and managing coastal areas and MPAs may serve as a model in other nation states for indigenous people wishing to use a protected area governance framework to support the contemporary management of their traditional marine and coastal estates.
  相似文献   
68.
  1. The rapid degradation of freshwater habitats in southern South America may cause the extinction of the endemic species of Aegla, as well as other freshwater species and components of riverside environments related to them. Information on the distribution of species and their conservation status is essential for developing conservation strategies.
  2. The updated distribution of Aegla in its southernmost distribution was analysed in order to prioritize freshwater ecoregions, applying biogeographical, phylogenetic and conservation status and complementarity approaches.
  3. The distributions of the species of Aegla were delineated on maps and plotted against freshwater ecoregions. A data matrix of areas versus species was constructed and a taxon–area cladogram was created. Ecoregions were ranked, based on their species richness and using a complementarity criterion, to create a list of those considered important for conservation. The conservation status of Aegla species was assessed on the basis of the categories and criteria of the International Union for Conservation of Nature (IUCN) to produce a decreasing order of the risk of species extinction. These assessments were combined to define a consensus ranking of the priority areas for conservation.
  4. The areas of maximum species richness and endemicity, and consequently highest priority of conservation, were the Lower Parana and Patagonia ecoregions. The Cuyan Desaguadero and Mar Chiquita Salinas Grandes ecoregions were the areas of second priority, and the Chaco and Lower Uruguay ecoregions were the areas with the third priority for conservation. Ten out of the 20 species analysed fall within the threat categories of the IUCN. Sixty per cent of the species of Aegla analysed have at least one population contained in protected areas.
  5. The results obtained may be used to design strategies for implementing conservation policies on freshwater species, generate biogeographical atlases and contribute to selecting Ramsar sites.
  相似文献   
69.
  1. Amphidromy is the most prevalent type of diadromous migration. Despite this, the conservation and management of amphidromous species is exceptionally challenging because this life history type, with larval development in a pelagic habitat (usually marine) and adult development in fresh water, is poorly resolved.
  2. The chronological properties of otoliths, together with a spatial and temporal analysis of post‐larval migration traits and adult reproductive traits, were used to reconstruct the life history of a widespread, yet declining amphidromous galaxiid, Galaxias maculatus, and to explore relationships between marine and freshwater life phases.
  3. A wide range of post‐larval migration traits were observed over the peak migratory period. Post‐larvae were smaller and younger at inward migration late in the migration season (November) and were derived from winter spawning events. Earlier migrants (September) were larger, older and derived from autumn spawning events.
  4. Age estimates confirmed that G. maculatus is largely an annual species, but back‐calculated hatch dates showed that spawning times are more extensive than previously known.
  5. Growth reconstructions revealed that winter‐hatched larvae were faster growing during marine and freshwater life and attained sexual maturity at a younger age than autumn‐hatched fish. However, no differences in body size or reproductive investment were detected between autumn‐ and winter‐hatched larvae.
  6. The first 50 days of marine growth were inter‐dependent, indicating that early larval growth may be the critical link to understanding intra‐ and inter‐annual recruitment variations of inward migrating post‐larvae. Furthermore, growth after 60 days of larval life propagated through to adult freshwater development, highlighting linkages between late marine and adult freshwater life.
  7. This study highlights the value of studying the marine and freshwater life phases of amphidromous species in tandem. This interconnected understanding must ultimately be achieved for the conservation and management of species with this poorly understood life history type.
  相似文献   
70.
  1. The population of bottlenose dolphins in eastern Scotland has undergone significant range expansion since the 1990s, when a Special Area of Conservation was established for the population.
  2. Distribution of this population is well described within areas of its range where intensive work has been carried out, such as the inner Moray Firth, St Andrews Bay and the Tay estuary area. However, elsewhere in their range, habitat use is less well understood.
  3. In this study, a large‐scale and long‐term passive acoustic array was used to gain a better understanding of bottlenose dolphin habitat use in eastern Scottish waters, complementing and augmenting existing visual surveys.
  4. Data from the array were analysed using a three‐stage approach. First, acoustic occupancy results were reported; second, temporal trends were modelled; and third, a spatial–temporal‐habitat model of acoustic occupancy was created.
  5. Results from the acoustic occupancy are in agreement with visual studies that found that areas near known foraging locations were consistently occupied. Results from the temporal trend analysis were inconclusive. Habitat modelling showed that, throughout their range, bottlenose dolphins are most likely to be detected closer to shore, and at a constant distance from shore, in deeper water.
  相似文献   
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