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141.
本文在界定耕地总量动态平衡是由耕地数量、耕地质量和耕地生态环境三者组成的整体平衡的基础之上 ,对耕地总量的评价方法进行了初步研究 ,并以启东市为例 ,构建了耕地生产力总量动态平衡规划模式。  相似文献   
142.
本文以现代生态法文化观念为理论导引,在对传统生态法理论进行检视和对三江源区的生物多样性保护与生态裣机制进行尝试考评的基础上,以理论分析与实证调研相结合的方法,提出了具有建设性和可行性的法律对策。  相似文献   
143.
对云南个旧市乍甸镇农田土壤和农作物重金属污染现状进行了野外调查及评价。结果表明:农田土壤Pb、Zn、Cu、Cd、As质量比均超出GB 15618—1995《土壤环境质量标准》二级标准,Hg未检出,该地区农田呈现以As、Cd为主多种重金属复合污染。Pb、Zn、Cu、Cd、As土壤有效态质量比与土壤全量呈极显著正相关(p<0.01)。农作物中Cu、As质量比与土壤有效态Cu、As质量比无显著相关,Zn质量比与土壤有效态Zn呈极显著负相关(p<0.01),Cd、Pb质量比与土壤有效态Cd、Pb呈显著正相关(p<0.05)。89%的农作物As超标,油菜籽(Brassica napusL.)As质量比最高,均值达(23.04±14.33)mg/kg(鲜重,下同)。Pb超标率达72%,油菜籽Pb质量比最高,平均为(5.55±2.53)mg/kg。Zn、Cd超标率均为11.11%,超标最严重的油菜籽Zn质量比为(46.65±13.61)mg/kg,Cd质量比为(0.24±0.10)mg/kg。Cu超标率为5.55%,油菜籽Cu质量比最高,达(16.02±2.75)mg/kg。油菜籽对As、Pb、Zn、Cu、Cd的转移系数(农作物可食部分重金属质量比(鲜重)与土壤重金属质量比的比值)远高于其他作物。农作物对Pb、Zn、Cd、As的转移顺序依次为果实类、叶菜类、根茎类,对Cu的转移顺序为果实类、根茎类、叶菜类。农作物以As、Pb污染为主,总体属重度污染。聚类分析得出:油菜籽、青蒜(Allium ampeloprasumL.)和生菜(Lactuca sativaL.var.ramosaHort.)重金属污染严重,不适合在该地区继续种植和食用。  相似文献   
144.
Air pollution is one of the primary concerns of our society for its effect on human health and the environment. Among the policy measures that can be put in place to limit air pollutant emissions, end-of-pipe technologies and/or regulatory instruments may be implemented through legislative acts. Also, equally important are behavioural measures, requiring citizens’ active involvement. The success of any measure to limit pollutant emissions requires the acceptance by the citizens that, in turn, implies a correct perception of the main pollutant emission drivers. We present here the comparison between the public perception of air pollution sources and the real-world situation through a survey carried out in seven European countries and involving 16 101 respondents. Our study shows a dramatic underestimation of the contribution of the agri-food sector to air pollution. This result is common to all respondents in the seven countries examined and only to a small extent depends on gender, age and socio-economic status of the respondents.  相似文献   
145.
Amid a growing global agenda, biodiversity conservation has embraced gender equity as a pillar of equitable and effective practice. Gender equity has become enshrined in the global environment and development agenda through global commitments, policy and funding. However, for various reasons, conservation biodiversity often takes a simplistic view of gender as synonymous with women or as a dualism between women and men. This narrow view risks promoting inequitable processes and ineffective outcomes. Deeper engagement with feminist theory, and feminist political ecology in particular, could help advance biodiversity conservation's approach to how gender is understood, framed and integrated. Engaging with lessons from feminist political ecology can help advance gender equity in conservation through attention to power dynamics, intersectionality, and subjectivity.  相似文献   
146.
Giant panda (Ailuropoda melanoleuca) conservation is a possible success story in the making. If extinction of this iconic endangered species can be avoided, the species will become a showcase program for the Chinese government and its collaborators. We reviewed the major advancements in ecological science for the giant panda, examining how these advancements have contributed to panda conservation. Pandas’ morphological and behavioral adaptations to a diet of bamboo, which bear strong influence on movement ecology, have been well studied, providing knowledge to guide management actions ranging from reserve design to climate change mitigation. Foraging ecology has also provided essential information used in the creation of landscape models of panda habitat. Because habitat loss and fragmentation are major drivers of the panda population decline, efforts have been made to help identify core habitat areas, establish where habitat corridors are needed, and prioritize areas for protection and restoration. Thus, habitat models have provided guidance for the Chinese governments’ creation of 67 protected areas. Behavioral research has revealed a complex and efficient communication system and documented the need for protection of habitat that serves as a communication platform for bringing the sexes together for mating. Further research shows that den sites in old‐growth forests may be a limiting resource, indicating potential value in providing alternative den sites for rearing offspring. Advancements in molecular ecology have been revolutionary and have been applied to population census, determining population structure and genetic diversity, evaluating connectivity following habitat fragmentation, and understanding dispersal patterns. These advancements form a foundation for increasing the application of adaptive management approaches to move panda conservation forward more rapidly. Although the Chinese government has made great progress in setting aside protected areas, future emphasis will be improved management of pandas and their habitat.  相似文献   
147.
In temperate regions, winter presents animals with a number of challenges including depressed food abundance, increased daily energy requirements, higher frequency of extreme weather events and shortened day length. Overcoming these constraints is critical for overwintering survival and scheduling of future breeding of long-lived species and is likely to be state dependent, associated with intrinsic abilities such as food acquisition rates. We examined the relationship between environmental and intrinsic factors on overwintering foraging and subsequent breeding phenology of the European shag Phalacrocorax aristotelis, a diurnal marine predator. We tested a range of hypotheses relating to overwintering foraging time and location. We found that individuals greatly increased their foraging time in winter to a peak of more than 90% of available daylight at the winter solstice. The seasonal patterns of foraging time appear to be driven by a combination of light levels and weather conditions and may be linked to the availability of the shag's principal prey, the lesser sandeel Ammodytes marinus. There was no evidence that shags dispersed south in winter to increase potential foraging time. Foraging time decreased after the winter solstice and, crucially, was correlated with subsequent breeding phenology, such that individuals that spent less time foraging in February bred earlier. The relationship was much stronger in females than males, in line with their more direct control of timing of breeding. Our results demonstrate that pre-breeding intrinsic foraging ability is critical in determining breeding phenology.  相似文献   
148.
To investigate the role of template plasticity in shaping nest-mate recognition processes in ants, we constructed experimental mixed-species groups of Manica rubida with either Myrmica rubra, Tetramorium bicarinatum or Formica selysi. Selecting Ma. rubida as the focal species, we observed the behaviour within mixed-species groups and the transfer rates of cuticular hydrocarbons (CHC) onto the focal ants, and we also tested the aggression of the focal species reared either alone or in association with each of the three different species. We show that Ma. rubida workers were always amicable towards their mixed group members, as towards members of the respective parental colonies, irrespective of the associated species. They did, however, express different levels of aggression towards single-species groups of the other species tested, depending on the species with which they were reared. The study suggests that similarity in CHC profiles in two species leads to a narrow template in mixed groups, while dissimilarity is followed by lower levels of aggression (a broader template), at least against species with similar CHC compound compositions (i.e. both a broader template in the focal ants and familiarity with the compound groups of the tested individuals operate together). This refutes the hypothesis that ants reared in mixed-species groups are systematically more tolerant. It also demonstrates that heterospecific information is not treated equally during development. We suggest that post-imaginal learning, template reforming and decision making are more precisely tuned when the two species' chemical complexes are similar.  相似文献   
149.
根据对河西走廊中部荒漠植被的调查,对荒漠植被进行了分类及生态学描述,重点讨论了荒漠植被对改善河西走廊中部农村生态环境的作用,提出了保护和利用荒漠植被的措施及改善生态环境的途径。  相似文献   
150.
A model of rainfall redistribution in terraced sandy grassland landscapes   总被引:5,自引:0,他引:5  
A simple model of rainfall redistribution within a terraced sandy grassland landscape has been developed. The model assumes that rainfall redistribution is driven by rainfall impulses and is controlled by characteristic field capacity of soils. When the rainfall intensity is large enough to render soil water content greater than its characteristic field capacity, the excessive soil water can drain very quickly by means of large amounts of non-capillary pores of sandy soils or by means of surface runoff. Exponential distribution of rainfall impulses was assumed and tested with measured daily rainfall at two meteorological stations in the sandy grassland area of north China. The model was solved to give the equivalent rainfall at each terrace in the landscape.  相似文献   
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