东北鼠兔小兴安岭亚种的分布和生境

本文通过访问调查和实地调查等方式,对东北鼠兔小兴安岭亚种的分布状况和生境特征进行调查和分析,结果表明:东北鼠兔小兴安岭亚种以点状分布的形式广泛分布于小兴安岭各林区,重点分布区包括五大连池火山岩区和伊春林管局辖区南部和北部;东北鼠兔小兴安岭亚种对生境需求较为特殊,包括生境的基质需要具有较好的孔隙结构,周围需要有草本层等植被条件,基质无浸水,基质需要具有一定的面积,不选择或很少选择蒙古栎林生境。     

Probabilistic Models for Bacterial Taxonomy

We give a survey of different partitioning methods that have been applied to bacterial taxonomy. We introduce a theoretical framework, which makes it possible to treat the various models in a unified way. The key concepts of our approach are prediction and storing of microbiological information in a Bayesian forecasting setting. We show that there is a close connection between classification and probabilistic identification and that, in fact, our approach ties these two concepts together in a coherent way.     

达日县高寒草甸土壤理化性质与物种多样性、地上生物量的关系

利用55个1m×1m的野外样方调查数据初步分析了达日县高寒草甸3种植被群落类型物种多样性与地上生物量及其同土壤理化性质的关系。结果表明:(1)土壤pH值和养分全量含量越低,其土壤有机质含量和速效养分含量越高。(2)在9个样地55个1m×1m的样方中共出现105种植物,物种丰富度最高为27种/m2,最低为4种/m2。(3)对于所有群落而言,物种多样性与地上生物量呈显著正相关关系,不同群落间,除矮嵩草群落外,小嵩草群落和山生柳+金露梅群落的物种丰富度与地上生物量呈显著正相关关系;对于Shannon-Wiener指数与地上生物量的关系,除山生柳+金露梅群落中两者呈显著正相关外,矮嵩草群落和小嵩草群落均没有表现出显著的相关性。(4)对于所有群落,土壤速效氮对物种多样性和地上生物量都有很大的影响,速效氮含量越高,物种多样性越丰富,地上生物量越高。     

Bioeconomic analysis of herpetofauna road-kills in a Florida state park

Road-kills are a major cause of mortality for a wide variety of herpetofauna, but management decisions on remediation procedures for reducing losses are based in economic realities. Because funding is finite for species conservation, bioeconomic analysis can assist in justifying, evaluating, and maximizing returns on conservation expenditures, especially for low-profile species such as herpetofauna. Here, we present a bioeconomic analysis of road-killed herpetofauna in Jonathan Dickinson State Park, Florida. Road surveys were conducted daily for four years to identify and enumerate the numbers of each reptile and amphibian species killed by vehicles. Conservative individual valuations applied to the losses formed the basis of a benefit-cost analysis aimed at identifying the thresholds at which remediation expenditures would be justified. We found an average of 64 reptiles and amphibians were killed/year, justifying conservation expenditures up to $32,000/year. However, if less conservative valuations were applied, especially for threatened and endangered species, justifiable expenditures rise dramatically.     

A Roll Call Analysis of the Endangered Species Act Amendments

Public choice economics view legislative process as a transaction in the political market. Interest groups demand regulation in their favor and lobby lawmakers. The lawmakers analyze an assortment of factors and supply legislation to the winning group, thereby maximizing their rent from the political market. This article examines Endangered Species Act (ESA) amendments from a public choice perspective. Congressional voting on the ESA amendments are assessed using a model based on political incentive and ideology. The results show that the lawmakers' voting behavior is correlated with their party affiliation, ideology, and several characteristics of their home state, such as number of endangered species, proportion of urban population, contribution of the natural resources and construction sectors in gross state product, and geographical location.     

三江平原湿地典型草甸小叶章群落物种多样性的季节动态

本研究以三江平原湿地典型草甸小叶章群落为研究对象,从物种丰富度、均匀度和物种多样性指数等方面探讨其季节动态规律.典型草甸小叶章群落物种丰富度在7月份最高,生态优势度指数季节动态变化呈“V”型;多样性信息指数季节动态变化呈单峰型,6月末7月初群落群落的物种多样性最高,种类之间个体分配的均匀性最大;均匀度指数季节动态变化呈线型.群落α多样性的测度指标的季节动态变化表现出一致性.     

Biodiversity pressure and the driving forces behind

Since the UNCED Conference in Rio de Janeiro 1992, the need to actively protect biodiversity is universally acknowledged. The UN Convention on Biological Diversity (CBD) defined biodiversity as comprising ecosystem diversity, species diversity and genetic diversity, and decided for the ecosystem level as the basis for describing biodiversity. However, due to conceptual problems as much as to the lack of data, so far no comprehensive measurements of biodiversity have been developed. A single measure quantitatively describing biodiversity even seems out of reach due to the incommensurability of the three levels. This makes it impossible to directly base policy decisions on existing or future estimates of the “total size” of biodiversity. Instead, it is suggested to analyse the pressures threatening biodiversity, which can usually be measured quantitatively, and act as the interface between the socioeconomic driving forces behind them and the biological impacts. The drivers (physical primary drivers, politics and policies causing them as secondary and institutional structures as tertiary ones) do not only affect biodiversity, but a range of sustainability problems. The analysis permits to integrate biodiversity risks with broader environmental and sustainability policies, and thus to mainstream biodiversity preservation.Such an analysis is presented for Europe, naming pressures and driving forces and illustrating the close links between the causes of biodiversity pressures and other environmental problems. This way, it is possible to develop first ideas how the standard set of environmental policies must be modified and extended to cover the issue of biodiversity.     

General and specific spatial autocorrelation: Insights from country-level analysis of species imperilment

We explore the consequences of including both general and specific controls for spatial autocorrelation in country-level models of species imperilment. A general spatial autocorrelation term constructed as a binary contiguity matrix aggregates an unknown number of possible influences, some of which exert a negative impact on species imperilment in the referent country, others of which exert a positive impact. Adding spatial dependency measures that are based on specific cross-border effects can substantially change not only the size and statistical significance of the general spatial dependency term but also the size, sign, and/or statistical significance of the explanatory variables.     

大兴安岭北部林区啮齿动物种类组成及其地理区划

本文通过实地调查结合文献记录,对大兴安岭北部林区啮齿动物的种类和区系组成进行分析,结果表明:大兴安岭北部林区分布有啮齿类动物2目6科16属21种,其中鼠科5种,仓鼠科9种,鼠兔科1种,松鼠科3种,兔科2种,鼠科1种;共有10种生态地理分布型,以欧亚北方寒湿型和东北亚温型为主。     

Integrated planning for landscape diversity enhancement,fire hazard mitigation and forest production regulation: A case study in central Portugal

Forest fires and forest biodiversity are related issues of major concern in Mediterranean countries and require an integrated approach to landscape planning. The aim of this study was to develop a GIS approach for regulating forest production while promoting landscape diversity and mitigating fire hazard. A study area located in the centre of Portugal was chosen. The area was primarily occupied by maritime pine and had a high fire hazard, low tree species diversity and an extensive protection area. The classical area control method was used to assist in forest production regulation. Species suitability maps were produced for 21 recommended species for afforestation in the study area. Maritime pine management compartments were defined, and a 50-year harvesting plan was proposed. In each harvested compartment, protection areas were identified for species conversion (e.g., native oaks and/or broadleaves). Afforestation species were proposed according to the species suitability maps produced earlier. Low flammability species that produce high-quality wood, non-wood products and landscape enhancement were preferred. A comparison of the land cover in the study area in 2007 to that anticipated in 2064 via the proposed plan showed that a more fragmented landscape structure could be achieved by introducing 16 species of lower flammability than maritime pine into the study area. This study proved the usefulness of this methodological approach for guiding sustainable changes in homogeneous, unmanaged forest landscapes prone to fire. Further research is needed regarding integrated planning approaches that incorporate environmental, economic and social dimensions (e.g., human desertification of rural areas).