关于武汉市园林草坪建设的思考

通过对武汉市公共绿地草坪种植的情况进行初步调查，分析了近两年绿化草坪在武汉市流行的原因，探讨了武汉园林绿化建设中草坪种植过多的弊端，并进一步阐明武汉市科学建植草坪应该采取的措施。     

城镇土地定级中结点评价方法的探讨

目前我国的城镇土地定级工作已拉开序幕,随着城镇土地定级工作的不断发展,必然会出现许多新的理论问题和技术问题,研究和解决这些问题对于不断充实和完善城镇土地定级工作的方法理论体系,不断提高城镇土地定级工作的效率,质量和水平都具有十分重要的意义。本文针对单元评价中遇到的一些实际问题,提出了结点评价的粗浅看法,希望有助于这方面研究工作的继续深入和发展。     

Effects of forest patch size on avian diversity

The effects of landscape patchiness on the diversity of birds of the Georgia Piedmont were investigated during 1993. Birds were sampled along line transects within relatively large (10–13.25 ha) and small (less than 3.25 ha) forest patches located within nonforest agricultural landscapes. Patterns of habitat use in these patches were compared to those in contiguous forest patches larger than 13.25 ha. Analysis of variance revealed significant differences in diversity between large and small woodlots and between contiguous and fragmented landscapes, especially in terms of the numbers of edge and interior species and winter-resident, summer-resident, and year-round birds observed.     

福建农村信用社盈利能力的因素分析

选择主成分分析法,并在充分调研、专家咨询的基础上,本着定性指标和定量指标兼顾,绝对指标、相对指标和平均指标相结合的原则,确定了能够用来衡量农村信用社盈利能力的若干指标。认为农村信用社要实现可持续发展的长远战略目标,必须从现在起把能力建设作为重要战略基点,谋求在农村金融领域中的规模和优势,进行技术创新、制度创新、人力资源能力建设、外部环境培育。     

Human-mediated vegetation switches as processes in landscape ecology

Switches are processes in which there is positive feedback between vegetation and environment. Landscape features can be created and modified by switches. The concept has previously been used with physical factors and non-human animals as the switch mediator, i.e. the factor which the vegetation modifies and which in turn affects the vegetation. Here, the switch concept is extended to include some types of human behaviour as possible switch mediators. With this extension, the switch concept can explain the impact on the landscape of some types of human behaviour. Examples are given of the behaviour of mower drivers, mowing up to a boundary which they create and/or maintain, and of walkers trampling tracks which they create and/or maintain. Other possibilities are discussed briefly. It is concluded that the concept of a human-mediated switch can unify the study of human behaviour, vegetation processes and landscape ecology.     

我国农村社会保障体系建设研究

分析了我国农村社会保障体系目前面临的困境和挑战,阐述了加快建立农村社会保障体系的必要性和紧迫性,并提出了建立和完善农村社会保障体系的思路与对策。     

Metapopulation theory and habitat fragmentation: a review of holarctic breeding bird studies

Metapopulations are conceived as spatially structured populations consisting of distinct units (subpopulations), separated by space or barriers, and connected by dispersal movements. Metapopulations characteristically demonstrate a turnover of local populations going extinct and becoming re-established, resulting in a distribution pattern that shifts over time. Metapopulation theory is used to analyse the effects of habitat fragmentation on birds in the temperate zone, integrating various explanations for the paucity of species in isolated ecotopes.There is some evidence that turnover of local populations occurs in fragmented systems. A few studies based on time series demonstrate the local extinction rate to be related to the size of the habitat fragment, whereas the recolonization rate depends on the degree of isolation. Most evidence comes from short-term pattern studies in which the probability of occurrence was found to depend on the size of habitat fragments, on their relative position in the landscape and on the density of corridors lowering the landscape resistance. These data are consistent with predictions from metapopulation theory. However, almost all investigations consider wood fragmentation in agricultural landscapes, and there is a great need for studies in naturally fragmented landscapes as well as for studies focussing on other, less predictable, habitat types.     

Can place names be used as indicators of landscape changes? Application to the Doñana Natural Park (Spain)

This work broaches the possibility of using place names as indicators of original landscapes that have been much transformed. The reconstruction of landscape elements from place names is commonly disputed because such daring notion is impossible to demonstrate. The present case avoids this by making a preliminary study of changes in the landscape using conventional methods. With the knowledge gained from objective and reliable sources, the possibility is analyzed of whether place names are a reflection of landscape changes taking place over a considerable period of time (the last few centuries). It is concluded that, for the present case study, in natural areas with a high rate of change of land use (Doñana Natural Park), place names indicate not only changes in the landscape, but also how such changes are perceived. In the study area, this is especially clear regarding the fens.     

Quantifying habitat specificity to assess the contribution of a patch to species richness at a landscape scale

Assessing and predicting the species richness of a complex landscape remains a problem because there is no simple scaling function of species richness in a heterogeneous environment. Furthermore, the potential value of an area for biodiversity conservation may depend on which, rather than how many, species the area contains. This paper shows how we can objectively evaluate the contribution of an area, e.g., a habitat patch, to larger-scale plant species richness, e.g., a landscape composed of patches of several habitat types, and how we can test hypotheses that attempt to explain this contribution. We quantified the concept of habitat specificity to assess the proportion of each observed plant population that is concentrated within a given spatial element. A case study of a biodiversity-monitoring program in the Swiss Canton of Aargau showed that the relative contribution of the three main types of land use to the overall species richness differed strongly between higher taxa (vascular plants and molluscs). However, the type of data, i.e., presence-absence or abundance, was not important. Resampling of the plant data suggested that stratification provided an unbiased estimate of relative specificity, whereas unstratified sampling caused bias even for large samples. In a second case study of vascular plants in an agricultural landscape in central Switzerland, we tested whether the type, size or shape of a landscape element can predict its contribution to the species richness of the landscape. Habitat types that were less frequently disturbed contributed more per m² to landscape species richness than more frequently disturbed ones. Contrary to expectation, patch size was negatively correlated to specificity per m² for arable fields, whereas patch shape appeared to be unrelated to the specificity per m² both for arable fields and for meadows. The specificity approach provides a solution to the problem of scaling species richness and is ideally suited for testing hypotheses on the effect of landscape structure on landscape species richness. Specificity scores can easily be combined with measures of other aspects of rarity to assess the contribution of a spatial element to conservation goals formulated at regional, national or global level.