Species‐level persistence probabilities for recovery and conservation status assessment

Recovery planning for species listed under the U.S. Endangered Species Act has been hampered by a lack of consistency and transparency, which can be improved by implementing a standardized approach for evaluating species status and developing measurable recovery criteria. However, managers lack an assessment method that integrates threat abatement and can be used when demographic data are limited. To help meet these needs, we demonstrated an approach for evaluating species status based on habitat configuration data. We applied 3 established persistence measures (patch occupancy, metapopulation capacity, and proportion of population lost) to compare 2 conservation strategies (critical habitat designated by the U.S. Fish and Wildlife Service and the Forest Service's Carbonate Habitat Management Strategy) and 2 threat scenarios (maximum limestone mining, removal of all habitat in areas with mining claims; minimum mining, removal of habitat only in areas with existing operations and high‐quality ore) against a baseline of existing habitat for 3 federally listed plant species. Protecting all area within the designated critical habitat maintained a similar level (83.9–99.9%) of species persistence as the baseline, whereas maximum mining greatly reduced persistence (0.51–38.4% maintained). The 3 persistence measures provided complementary insights reflecting different aspects of habitat availability (total area, number of patches, patch size, and connectivity). These measures can be used to link recovery criteria developed following the 3 R principles (representation, redundancy, and resilience) to the resulting improvements in species viability. By focusing on amount and distribution of habitat, our method provides a means of assessing the status of data‐poor species to inform decision making under the Endangered Species Act.     

旅游社区安全:概念及研究述评

全域旅游的兴起使得旅游社区及其安全问题日益重要,然而学术界尚未建立起旅游社区安全研究体系。旅游社区安全是以旅游为主业的社区内部协调稳定,外部健康存续,旅游业持续发展的一种状态,内涵丰富,类型多样。当前学术界主要是从旅游社区脆弱性、恢复力以及可持续发展等角度入手进行该论题的研究,且多是从目的地视角出发,并未突出社区的独立性。未来的旅游社区安全研究应首先构建起独立的研究体系,并在与国外进行比较研究的基础上,强调多样性和适宜性的研究方法和路径。     

加拿大应急管理战略规划分析研究与启示

加拿大应急管理工作起步较早,发展过程中积累了一定的实践经验。本文选取加拿大政府最新颁布实施的应急管理战略规划作为研究对象,分析了在加拿大政治体制下,面对各类灾害频发易发,应急管理工作面临的挑战。通过对规划制定的背景分析,从规划的5个方向和19个子目标着手,深入分析了加拿大应急管理未来发展的主要方向,并总结了规划的特点。根据研究,提出了进一步健全完善我国应急管理战略规划工作的参考建议。     

Creation of a Gilded Trap by the High Economic Value of the Maine Lobster Fishery

Abstract: Unsustainable fishing simplifies food chains and, as with aquaculture, can result in reliance on a few economically valuable species. This lack of diversity may increase risks of ecological and economic disruptions. Centuries of intense fishing have extirpated most apex predators in the Gulf of Maine (United States and Canada), effectively creating an American lobster (Homarus americanus) monoculture. Over the past 20 years, the economic diversity of marine resources harvested in Maine has declined by almost 70%. Today, over 80% of the value of Maine's fish and seafood landings is from highly abundant lobsters. Inflation‐corrected income from lobsters in Maine has steadily increased by nearly 400% since 1985. Fisheries managers, policy makers, and fishers view this as a success. However, such lucrative monocultures increase the social and ecological consequences of future declines in lobsters. In southern New England, disease and stresses related to increases in ocean temperature resulted in more than a 70% decline in lobster abundance, prompting managers to propose closing that fishery. A similar collapse in Maine could fundamentally disrupt the social and economic foundation of its coast. We suggest the current success of Maine's lobster fishery is a gilded trap. Gilded traps are a type of social trap in which collective actions resulting from economically attractive opportunities outweigh concerns over associated social and ecological risks or consequences. Large financial gain creates a strong reinforcing feedback that deepens the trap. Avoiding or escaping gilded traps requires managing for increased biological and economic diversity. This is difficult to do prior to a crisis while financial incentives for maintaining the status quo are large. The long‐term challenge is to shift fisheries management away from single species toward integrated social‐ecological approaches that diversify local ecosystems, societies, and economies.     

Trophic Flexibility and the Persistence of Understory Birds in Intensively Logged Rainforest

Effects of logging on species composition in tropical rainforests are well known but may fail to reveal key changes in species interactions. We used nitrogen stable‐isotope analysis of 73 species of understory birds to quantify trophic responses to repeated intensive logging of rainforest in northern Borneo and to test 4 hypotheses: logging has significant effects on trophic positions and trophic‐niche widths of species, and the persistence of species in degraded forest is related to their trophic positions and trophic‐niche widths in primary forest. Species fed from higher up the food chain and had narrower trophic‐niche widths in degraded forest. Species with narrow trophic‐niche widths in primary forest were less likely to persist after logging, a result that indicates a higher vulnerability of dietary specialists to local extinction following habitat disturbance. Persistence of species in degraded forest was not related to a species’ trophic position. These results indicate changes in trophic organization that were not apparent from changes in species composition and highlight the importance of focusing on trophic flexibility over the prevailing emphasis on membership of static feeding guilds. Our results thus support the notion that alterations to trophic organization and interactions within tropical forests may be a pervasive and functionally important hidden effect of forest degradation. Flexibilidad Trófica y la Persistencia de Aves de Sotobosque en un Bosque Lluvioso Talado Intensivamente     

Linking perceived land and water resources degradation,scarcity and livelihood conflicts in southwestern Tanzania: implications for sustainable rural livelihood

In Africa, the land and water resources quality are key factors for sustainable development. The degradation of the quality of these resources leads to scarcities and conflicts, which together threaten the sustainability of rural livelihoods. This work investigated and analysed the livelihoods conflicts over the land and water resources and their scarcities, policies that contributed to the land and water scarcities and the livelihood conflicts and linkage of the conflicts to the resources scarcities and degradation. Implications of degradation of the resources, development policies and livelihoods conflicts on sustainable development are discussed. Literature study, visits and discussions, participatory assessments, observations and questionnaire survey were used tools to collect data. Interviews of the 266 households revealed that, those experiencing the land and water scarcities and conflicts over these resources are significantly (p < 0.001) higher than those not experiencing the scarcities and conflicts. Crop-livestock competition, over the land and water resources causes prominent conflicts. A significant, (p < 0.05) associations of livelihoods conflicts to water shortage and period of water shortage for crop and livestock production were found. Improved accessibility to soil and water management technologies, wildlife–livestock co-existence, recognition of needs and land rights for pastoralists are recommended to minimize scarcities and herders versus farmers’ conflicts.     

祁连山北麓生态移民的生计风险与应对策略选择——以武威市为例

生计风险作为移民社会整合的标尺,已成为研究生态移民生计及可持续发展的重要视角。以祁连山北麓的武威市为例,利用Binary Logistic模型分析了移民生计风险对其应对策略的影响机制,以期为制定有效的生计风险防范体系提供科学支撑。结果表明：（1）武威市生态移民的生计类型以非农户为主,纯农户比例不足10%,生计多样化指数仅为1.74且存在显著的区域差异。（2）67.44%的移民面临着多重风险,以经济风险为主,生活开支大、新分棚圈耕地质量差、返贫是主要的风险要素。（3）应对策略主要为向亲朋借钱、银行贷款、外出打工和减少开支,后顾生计则多选择扩大养殖、长期打工和维持现状,不同县区移民的策略选择略有不同。（4）政策、福利和经济风险会显著影响移民对“向银行贷款”“减少开支”及“外出打工”等应对策略的选择,而后顾生计的选择更多受制于生计资本储量,而政策及经济风险的影响较低。移民户的类型对策略选择影响显著,非农型兼业户更倾向于选择“向银行贷款”和“扩大养殖”。     

基于神经网络综合建模的区域城市群发展脆弱性评价——以滇中城市群为例

城市脆弱性是评价城市发展韧性状况的有效测度。目前我国对于城市脆弱性的研究以运用统计学方法评价特殊城市为主,尚未形成对区域城市群具有普遍适用性的科学客观评价方法。以滇中城市群为例,从环境系统、经济系统、社会系统三个方面综合构建城市脆弱性评价体系,采用熵值法和BP神经网络综合建模方法,对2007—2016年10年间滇中城市群的城市脆弱性进行评价。结果表明：滇中城市群的城市脆弱性总体呈现下降趋势,但城市组团之间差异较大,呈现出发展中的不均衡性。评价结果对滇中城市群韧性发展规划具有重要指导意义,为区域城市群发展脆弱性研究提供一种科学评价方法。     

农地整治对农户生计策略的影响分析——基于PSM-DID方法的实证研究

论文先对农户生计策略类型进行细分,利用倾向得分匹配-双重差分方法（Propensity Score Matching-Difference in Differences,PSM-DID）排除其他混杂因素,探讨农地整治在生计资本差异下对农户生计策略的影响效用,并运用多种匹配方法和反事实检验法对估计结果进行稳健性检验。结果表明：1）农地整治的实施能够显著改变二兼型农户的生计策略,但并不能显著改变专业型或多兼型农户的生计策略;2）农地整治对传统兼业型、现代兼业型、非农兼业型农户生计策略有显著影响,传统兼业型、现代兼业型农户比重显著增加,而非农兼业型农户比重显著减少,说明农户能够通过调整自身生计策略适应农地整治带来的变化,农地整治促进了农户生计多样化;3）通过多种匹配方法及反事实法开展稳健性检验,证实论文主要估计结果是稳健的。建议针对不同类型农户家庭需求制定差别化的鼓励政策;充分利用当地产业特色,依托农地整治与现代农业政策,带动现代兼业型农户发展区域特色农业或休闲农业。     

农牧交错区农户生计分化及其对耕地利用的影响——以宁夏盐池县为例

农户生计与耕地利用之间的关系已经成为理解人地关系的重要切入点。论文以宁夏盐池县为例,在可持续生计框架下,从农户生计资本和生产要素配置两个角度,探讨农户生计分化及其对耕地利用的影响。结果表明：1）盐池县兼业户与非农就业户合计占调查农户的58%,农户非农化现象普遍;2）劳动力越多、人均耕地越少的农户,其家庭非农收入占比越高,生计资本是农户生计分化的“推力”;3）务农机会成本越高的农户其生计分化程度越高,务农机会成本是农户生计分化的“拉力”;4）随着生计分化程度的增加,耕地利用的生产要素投入强度呈递减态势,但是兼业户的耕地利用效率高于纯农户和非农就业户。农牧交错区同时面临着生态保护、农牧业生产、脱贫攻坚等挑战,政策制定需充分考虑当地农户的生计特征与人地关系的演变规律,加强非农就业引导,鼓励农户土地流转,促进农户生计多样化,实现生态、经济、社会效益“共赢”发展。