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841.
利用ISSR分子标记技术对湖北省大贵寺国家森林公园野生青檀(Pteroceltis tatarinowii Maxim.)居群进行遗传多样性分析。用11条ISSR引物对6个青檀居群64个样品进行扩增,扩增片段长度在200bp至3000bp之间,检测到179个位点,其中多态位点165个,多态位点百分率(P)为92.14%。青檀在物种水平上的Nei基因多样性指数(胁)和Shannon信息指数∽分别为0.273和0.423,在居群水平上分别为0.225和0.343,显示出青檀有着较高的遗传多样性。居群间的遗传分化系数(Gsr)为0.192,表明青檀居群间存在着较大的遗传分化;UPGMA聚类分析表明遗传距离与海拔差距有一定的相关性,相邻海拔的青檀居群间遗传距离较近。不同海拔导致的异质生境可能是影响青檀居群遗传分化的主要原因。 相似文献
842.
Jesper Slver Schou Jesper Bladt Rasmus Ejrns Maria Nygrd Thomsen Suzanne Elizabeth Vedel Camilla Fljgaard 《Ambio》2021,50(5):1047
Policies aiming at improving biodiversity often consist of costly agri-environmental schemes, i.e. subsidized grazing or mowing of semi-natural areas. However, these practices have widely been found to be insufficient to mitigate biodiversity loss. Rewilding, i.e. restoring natural processes in self-sustaining biodiverse ecosystems, has been proposed as an alternative and is hypothesized to be a more cost-efficient approach to promote biodiversity conservation. Rewilding requires the availability of large natural areas which are not allocated for farming, forestry, and infrastructure to avoid potential conflicts over the use of the area. We perform an ex-ante private cost–benefit analysis of the establishment of four large nature reserves for rewilding in Denmark. We analyse the economic effects of changing from summer grazing in nature areas in combination with cultivated fields and forestry to the establishment of nature reserves in four case areas. We consider two scenarios involving conversion of agriculture and forestry areas into natural areas in combination with either extensive year-round cattle grazing or rewilding with wild large herbivores. In two case areas, it appears possible to establish large nature areas without incurring extra costs. Additionally, rewilding further reduces costs compared to year-round cattle grazing. Two opposing effects were dominant: increased economic rent occurred from the shift from summer grazing to year-round grazing or rewilding, while cessation of agriculture and forestry caused opportunity costs. 相似文献
843.
Karen Bailey Jonathan Salerno Peter Newton Robert Bitariho Shamilah Namusisi Rogers Tinkasimire Joel Hartter 《Ambio》2021,50(7):1351
In biodiversity hotspots, there is often tension between human needs and conservation, exacerbated when protected areas prevent access to natural resources. Forest-dependent people may compensate for exclusion by managing unprotected forests or cultivating planted woodlots. Outside Bwindi Impenetrable National Park in Uganda, household wood product needs are high and population growth puts pressure on the environment. We investigated the role of privately and collectively managed woodlots in provisioning wood products and supporting local livelihoods. We found that households relied heavily on woodlots for daily needs and as resources during time of need. We also found that locally relevant social institutions, called stretcher groups, played a role in the management of woodlots, providing shared community resources. Privately and collectively owned woodlots support local livelihoods and wood product needs in the region. Long-term management of forests in Uganda should consider the value of woodlots and the mechanisms required to support them. 相似文献
844.
叙述环境教育的产生及发展,介绍目前环境保护及环境教育还存在的问题,讨论了开展环境教育的必要性及有利条件,及在县级开展环境教育的基本作法。 相似文献
845.
本文对中国合格评定国家认可委员会能源之星实验室认可计划进行政策解读和明晰,并对能源之星实验室认可中出现的实验室比对、产品分类及检测方法,检测能力表述这三个直接影响实验室获得注册的突出关键问题进行了详细的分析和研究。为有意申请能源之星实验室认可的实验室进行指导,并为获得能源之星实验室认可的实验室最终获得美国环保署的最终注册提供借鉴。 相似文献
846.
《Environmental Communication: A Journal of Nature and Culture》2013,7(4):469-474
Ken Burns, over the course of a long and celebrated career, has developed an effective and popular formula for his documentary films, and a comfortable relationship with the Public Broadcasting System. With such a convincing, accomplished style, his work has the opportunity to tackle ecological concerns in his latest series, but Burns chooses not to do so, offering no explicit lessons to apply to current problems. While stressing the importance of the people's parks, ecological debates on land use for future citizen-owners are minimized; the conflict of conservation versus preservation policies is barely differentiated. With the skill and reputation of Burns, his researchers, and his production team, there is a singular opportunity for their films to address ecological issues, creating productive conversation using America as a microcosm of the larger global issues faced today. Nostalgia and national pride are useful, but those attributes should be channeled to look to the future. 相似文献
847.
Due to rapid industrialization, with high population density and constraints of land, it is expected that level of risks arising from the hazardous industries will increase in India in the coming decades. However, 30 years after the Bhopal accident (1984), except a few discrete regulations, there is as yet no integrated system for assessing and managing risks arising out of these hazardous industries in India. The gravity of aspects related to the management of industrial risk still remains crucially important. In particular, there is no standard guideline on risk analysis methodology, acceptability or tolerability criteria, nor is there an accident database or a risk reduction strategy for the areas where risk levels are already high. On top of this, there are technical and legislative gaps in the institutional framework to implement any of the above mentioned issues. With the backdrop of the Bhopal gas tragedy, the objective of this paper is therefore to evaluate the effectiveness of a comprehensive risk assessment framework for the emerging economy of India, in order to control and/or to reduce the risk level that exists. In this context, regulations and policies pertaining to industrial risk assessment were reviewed. 相似文献
848.
黑龙江省各市(地)生态环境状况评价 总被引:1,自引:0,他引:1
以黑龙江省各市(地)为研究单元,通过建立生态环境评价指标体系,运用生态综合指数法对生态环境状况进行评价,初步判定出各市(地)的生态环境等级:大兴安岭地区、伊春市、牡丹江市和黑河市生态环境状况为优,哈尔滨市、鹤岗市、鸡西市、双鸭山市,七台河市、佳木斯市和绥化市生态环境状况为良,大庆市和齐齐哈尔市生态环境状况为一般。经初步分析,各市(地)生物丰度和植被覆盖程度不同是其生态环境状况差异的主要原因。而生物丰度和植被覆盖程度相差不大的市(地),其生态环境状况的差异主要是由水的丰贫程度和土地退化程度决定的。 相似文献
849.
Economic impact analysis (EIA) of outdoor recreation can provide critical social information concerning the utilization of natural resources. Outdoor recreation and other non-consumptive uses of resources are viewed as environmentally friendly alternatives to extractive-type industries. While outdoor recreation can be an appropriate use of resources, it generates both beneficial and adverse socioeconomic impacts on rural communities. The authors used EIA to assess the regional economic impacts of rafting in Grand Canyon National Park. The Grand Canyon region of northern Arizona represents a rural US economy that is highly dependent upon tourism and recreational expenditures. The purpose of this research is twofold. The first is to ascertain the previously unknown regional economic impacts of Grand Canyon river runners. The second purpose is to examine attributes of these economic impacts in terms of regional multipliers, leakage, and types of employment created. Most of the literature on economic impacts of outdoor recreation has focused strictly on the positive economic impacts, failing to illuminate the coinciding adverse and constraining economic impacts. Examining the attributes of economic impacts can highlight deficiencies and constraints that limit the economic benefits of recreation and tourism. Regional expenditure information was obtained by surveying non-commercial boaters and commercial outfitters. The authors used IMPLAN input-output modeling to assess direct, indirect, and induced effects of Grand Canyon river runners. Multipliers were calculated for output, employment, and income. Over 22,000 people rafted on the Colorado River through Grand Canyon National Park in 2001, resulting in an estimated $21,100,000 of regional expenditures to the greater Grand Canyon economy. However, over 50% of all rafting-related expenditures were not captured by the regional economy and many of the jobs created by the rafting industry are lower-wage and seasonal. Policy recommendations are given for increasing the regional retention of rafting expenditures and for understanding both the beneficial and adverse impacts that accompany outdoor recreation in rural areas. 相似文献
850.
吴雪玲 《中国人口.资源与环境》2006,16(5):135-137
“天人合一”是中国古代思想家对于天人关系的基本认识,主张遵循自然规律.实现人和自然的和谐发展.这一思想对于生态保护与天人关系的协调发展具有重要意义。经济全球化时代。探寻“天人合一”向“天人和谐”可持续发展观的现代性转化的途径,将有助于我们重瓤认识自然,正确把握环境保护与经济发展的辩证关系,培养人类的道德责任意识及科学实践精神,为现代生态伦理学的建立和可持续发展战略的实施提供帮助。 相似文献