聚类分析在江汉湖群典型湖泊分类中的应用

江汉湖群中的许多通江湖泊由于自然和人为原因失去了与长江及其支流的天然联系,对湖泊生态和湖区经济可持续发展造成了不利影响,重建江湖联系对湖泊生态环境改善和湖区经济发展意义重大。根据4项选择标准,选取江汉湖群中13个典型湖泊作为研究对象,以有关社会经济、生态等方面的调查统计数据为基础,利用聚类分析的方法对江汉湖群中的13个阻隔湖泊进行分类。根据所挑选的16个指标将这些湖泊划分为4大类,并对各类湖泊特点进行了分析,确定了这些湖泊的通江顺序。     

Grasslands, People, and Conservation: Over-the-Horizon Learning Exchanges between African and American Pastoralists

Abstract:  The world's grasslands and large migratory populations of wildlife have been disproportionately lost or disrupted by human activities, yet are poorly represented in protected areas. The major threats they face are land subdivision and the loss of large-scale dynamic processes such as wildlife migrations and fire. The large-scale dynamical processes and ubiquity of livestock economies and cultures across the grasslands calls for an integrated ecosystem approach to conservation to make up the shortfall in protected-area coverage. Ranchers and pastoralists will be more inclined to adopt an integrated landscape approach to conservation if they also see the threats to wildlife and grassland ecosystems as affecting their livelihoods and way of life. We arranged a series of learning exchanges between African and American pastoralists, ranchers, scientists, and conservationists aimed at building the collaboration and consensus needed to conserve grasslands at a landscape level. There was broad agreement on the threat of land fragmentation to livelihoods, wildlife, and grasslands. The exchanges also identified weaknesses in prevailing public, private, and community modes of ownership in halting fragmentation. New collaborative approaches were explored to attain the benefits of privatization while keeping the landscape open. The African–U.S. exchanges showed that learning exchanges can anticipate over-the-horizon problems and speed up the feedback loops that underlie adaptive management and build social and ecological resilience.     

Does sex affect both individual and collective vigilance in social mammalian herbivores: the case of the eastern grey kangaroo?

In several vertebrate taxa, males and females differ in the proportions of time they individually devote to vigilance, commonly attributed to sex differences in intra-specific competition or in absolute energy requirements. However, an effect of sex on collective vigilance is less often studied (and therefore rarely predicted), despite being relevant to any consideration of the adaptiveness of mixed- vs single-sex grouping. Controlling for group size, we studied the effect of sex on vigilance in the sexually dimorphic eastern grey kangaroo Macropus giganteus, analysing vigilance at two structural levels: individual vigilance and the group’s collective vigilance. Knowing that group members in this species tend to synchronise their bouts of vigilance, we tested (for the first time) whether sex affects the degree of synchrony between group members. We found that females were individually more vigilant than males and that their vigilance rate was unaffected by the presence of males. Collective vigilance did not differ between female-only and mixed-sex groups of the same size. Vigilance in mixed-sex groups was neither more nor less synchronous than in single-sex groups of females, and the presence of males seemed not to affect the degree of synchrony between females. Sixty-six percent of vigilant acts were unique (performed when no other kangaroo was alert), and only about one unique vigilant act in every three induced a collective wave of vigilance. The proportions of vigilant acts that were unique were 60% for females but only 46% for males. However, the sexes differed little in the rates at which their unique vigilant acts were copied. This limited study shows that the differences in vigilance between male and female kangaroos had no discernible effect upon collective vigilance.     

Behavioral diversification in a young species flock of pupfish (<Emphasis Type="Italic">Cyprionodon</Emphasis> spp.): shoaling and aggressive behavior

Increasing empirical and theoretical evidence supports the idea that sympatric speciation is operating, for example, in species flocks comprising several closely related fish species within one lake. Divergent natural selection (promoting spatial and food niche partitioning) and sexual selection (assortative mating) have been identified as key selection factors in intralacustric adaptive radiations. However, the evolution of social behaviors accompanying such adaptive radiations is less well understood. Using a phylogenetically young species flock of pupfish (Cyprinodon spp.) as a model, we examined differences among six sympatric species and compared their shoaling, aggressive, and territorial behaviors with that of a sister species (C. artifrons). Despite an estimated age of the species flock of less than 8,000 years, pronounced behavioral differentiation was found. C. simus, the smallest species in the flock, shoaled more than the other species and was less aggressive and less territorial than C. beltrani. F₁-hybrids between C. simus males and C. beltrani females showed an intermediate expression of shoaling and aggressive behavior. Niche partitioning among the members of this species flock appears to be accompanied by rapid divergent evolution of social behaviors. We discuss the potential role of phenotypic plasticity and within-species variation of social behaviors for such rapid behavioral diversifications in sympatric speciation processes.     

Vigilance behaviour and fitness consequences: comparing a solitary foraging and an obligate group-foraging mammal

Vigilance behaviour in gregarious species has been studied extensively, especially the relationship between individual vigilance and group size, which is often negative. Relatively little is known about the effect of conspecifics on vigilance in non-obligate social species or the influence of sociality itself on antipredator tactics. We investigated predator avoidance behaviour in the yellow mongoose, Cynictis penicillata, a group-living solitary forager, and compared it with a sympatric group-living, group-foraging herpestid, the meerkat, Suricata suricatta. In yellow mongooses, the presence of conspecifics during foraging—an infrequent occurrence—reduced their foraging time and success and increased individual vigilance, contrary to the classical group-size effect. Comparing the two herpestids, sociality did not appear to affect overt vigilance or survival rates but influenced general patterns of predator avoidance. Whereas meerkats relied on communal vigilance, costly vigilance postures, and auditory warnings against danger, yellow mongooses avoided predator detection by remaining close to safe refuges and increasing “low-cost” vigilance, which did not interfere with foraging. We suggest that foraging group size in herpestids is constrained by species-distinct vigilance patterns, in addition to habitat and prey preference.     

Individual and collective foraging decisions: a field study of worker recruitment in the gypsy ant <Emphasis Type="Italic">Aphaenogaster senilis</Emphasis>

In social insects, the decision to exploit a food source is made both at the individual (e.g., a worker collecting a food item) and colony level (e.g., several workers communicating the existence of a food patch). In group recruitment, the recruiter lays a temporary chemical trail while returning from the food source to the nest and returns to the food guiding a small group of nestmates. We studied how food characteristics influence the decision-making process of workers changing from individual retrieving to group recruitment in the gypsy ant Aphaenogaster senilis. We offered field colonies three types of prey: crickets (cooperatively transportable), shrimps (non-transportable), and different quantities of sesame seeds (individually transportable). Colonies used group recruitment to collect crickets and shrimps, as well as seeds when they were available in large piles, while small seed piles rarely led to recruitment. Foragers were able to “measure” food characteristics (quality, quantity, transportability), deciding whether or not to recruit, accordingly. Social integration of individual information about food emerged as a colony decision to initiate or to continue recruitment when the food patch was rich. In addition, group recruitment allowed a fast colony response over a wide thermal range (up to 45°C ground temperature). Therefore, by combining both advantages of social foraging (group recruitment) and thermal tolerance, A. senilis accurately exploited different types of food sources which procured an advantage against mass-recruiting and behaviorally dominant species such as Tapinoma nigerrimum and Lasius niger.     

当代公共生活面临的伦理困境研究

在当前中国社会转型时期,人们的生活方式、行为方式、价值规范和文化观念都发生了急剧的变化,使得公共生活产生了许多新的伦理问题,面临着新的伦理困境.主要表现在:一是"熟人社会"向"陌生人社会"转变,交往实践前所未有的拓宽了,信息交流产生不对称;二是社会公共生活在"情"和"理"之间矛盾增加;三是群己调适的问题凸显,在"群己"问题上更强调二者的合理性共存.参9.     

A formal model for consensus and negotiation in environmental management

Environmental management decisions typically lie at the interface of science and public policy. Consequently, these decisions involve a number of stakeholders with competing agendas and vested interests in the ultimate decision. In such cases, it is appropriate to adopt formal methods for consensus building to ensure transparent and repeatable decisions. In this paper, we use an environmental management case study to demonstrate the utility of a mathematical consensus convergence model in aggregating values (or weights) across groups. Consensus models are applicable when all parties agree to negotiate in order to resolve conflict. The advantage of this method is that it does not require that all members of the group reach agreement, often an impossible task in group decision making. Instead, it uses philosophical foundations in consensus building to aggregate group members' values in a way that guarantees convergence towards a single consensual value that summarizes the group position. We highlight current problems with ad hoc consensus and negotiation methods, provide justification for the adoption of formal consensus convergence models and compare the consensus convergence model with currently used methods for aggregating values across a group in a decision making context. The model provides a simple and transparent decision support tool for group decision making that is straightforward to implement.     

秦岭自然保护区群生态效益计量研究

秦岭自然保护区群在我国生物多样性保护方面发挥了重要作用.本研究在界定秦岭自然保护区群的概念及分析其内涵的基础上,综合运用专家咨询法及文献参考方法,建立了秦岭自然保护区群生态效益计量指标体系,利用市场价值法、等效替代法以及机会成本法等方法,对秦岭自然保护区群保护生物多样性产生的生态效益进行了经济计量及分析.结果表明:秦岭自然保护区群在保护生物多样性方面产生了巨大的生态效益,总生态效益约88.16亿元/a,其中涵养水源效益为31.77亿元;水土保持效益为17.85亿元;固碳制氧效益为3.41亿元;净化环境效益为7.56亿元;调节区域气候效益为5.32亿元;生物多样性保护效益为22.25亿元.本研究计量指标及计量方法为秦岭自然保护区群基层工作人员及类似保护区群生态效益计量及评价提供参考.     

Differences in rural landscape perceptions and preferences between farmers and naturalists

A long history of human–nature interactions mediated by agriculture, resulted in high biodiversity in Japanese rural landscapes. This diversity faces drastic decline due to the changes following the socioeconomic circumstances regarding agriculture. Rural conservation will require cooperation among major stakeholders, and knowing how preferences for and perceptions of rural landscapes differ among them can help crafting and implementing effective conservation measures. This study investigated how perceptions of rural landscapes in the Arai-Keinan region, Niigata, Japan differ among people having very different relationships to them. In a photograph-based semantic differential survey, farmers and naturalists, major stakeholders in rural conservation, rated both rice paddy and woodland landscapes. In determining preferences for rice paddy landscapes, perceptions of stewardship and openness were significantly more important for farmers, whereas those of naturalness and biodiversity were significantly more important for naturalists. Such group differences were not found for woodland landscapes. Analysis of perceptions for landscape changes suggested that farmers may have higher normative criteria for rural landscapes than naturalists. Group preferences for intensified rice paddies on sloped topography may conflict, and any rural conservation planning effort should carefully consider that farmers and naturalists consider different aspects of landscapes as important.