基于B/S与C/S混合模式的多级征占用林地监督检查系统

从当前全国林地监督数据在管理方面存在的问题出发,以解决实际应用需求为目的,以软件工程核心思想为指导,综合.NET平台与C#语言、水晶报表技术等多种现代信息技术实现的一套面向多级用户的数字化征占用林地监督数据管理系统,为实现工作模式转变和提高工作效率和决策能力提供了解决方案.     

Use of woodland resources within and across villages in a Zimbabwean communal area

A topical issue in natural resource management is that of scale, in particular, the organizational entry-point to community-based systems of natural resource management. This study investigated access to woodland resources from the perspective of the relevance of units (traditional villages) enjoying policy attention and the nature of boundaries of resource management units as espoused in academic debates. The relevance of the boundaries was investigated from the perspective of flow of resources across boundaries of the recommended units, and resource use relations among communities residing in contiguous units. The study used questionnaire surveys, informal interviews, and personal observations to explore woodland resource use patterns within and across the villages. People acquired woodland products from both within their own villages and from adjacent ones. Most people extracted resources from within residence villages but varying proportions of the people extracted various products from other villages. In general, members of the ruling clan – those holding exclusively ancestral beliefs, those with traditional main house types – were more likely to acquire resources from neighboring villages. People extracted lighter products like wild fruits, mushrooms, and medicinal herbs from other villages compared to bulkier products like fuel wood, kraal (cattle pens) and fence posts, wall and roof poles, and brushwood. The main reasons why people did not extract woodland products from other villages were availability of the products in their own villages, the long distances to walk to gather the resources from other villages, and, to a small extent, availability of substitutes and exclusion to some products by members of other villages. Overall, people did not deny woodland resource users from other villages access to resources in their own villages, although this applied less so in the case of extraction from areas under ritual designations or extraction for commercialization. The study argues that instead of aspiring for ``hard' or ``distinct' boundaries, policy needs to recognize ``diffuse and soft' product use boundaries as a given, so as to promote resource management formulations/options that are more in phase with the operational contexts. This revised version was published online in June 2006 with corrections to the Cover Date.     

Revegetation of farmland restores function and composition of epigaeic beetle assemblages

Restoration of managed landscapes is critical for the conservation of biodiversity and function at a landscape scale. We tested effects of revegetation of grazing land formerly vegetated by eucalyptus woodland on trophic groups of epigaeic beetles, considering a restoration chronosequence (space-for-time substitution). We used paddocks (i.e. grazed pastures) as the start point, sites in two age classes (5-8 and 12-17 since years since replanting) and fenced woodland remnants to represent the desired end point. Phytophages were most common in young revegetated sites, which had reduced grazing pressure and low canopy cover. Assemblage composition of both saprophages and predators converged on those of remnants over “time”. Paddock sites had the lowest species evenness of saprophages, with two species being particularly common. Saprophage assemblages in paddocks were also more homogeneous than those in other site types i.e. between site variation in assemblage composition was low. Predators were smaller but more species-rich in sites with less coarse woody debris, canopy cover and litter, possibly responding to higher abundances of small prey. Beetle biomass did not differ across habitats. For saprophages, a greater abundance in paddocks was counterbalanced by reduced body size. Remnants did not support a significantly greater proportion of habitat-specific species. However, more species than expected were specific to treed sites. Our study supports previous findings that habitat structure is a key driver of beetle community restoration. It also suggests that epigaeic assemblages respond relatively rapidly to revegetation, probably because they do not require resources that develop over long periods of time. The similarities in biomass for all trophic groups across sites suggest that beetle-performed functions may operate similarly in different stages, reflecting high functional resilience of epigaeic beetle assemblages in this landscape.     

基于无人机影像的华南农业大学不同下垫面地表降温效益研究

以华南农业大学校园为研究对象,通过携带热成像传感器的无人机,获取了校园中心区域不同下垫面的热成像图片,分析不同下垫面的日地表温度变化,探讨其地表降温效果的影响因素。结果表明,一天中总体降温幅度从大到小的下垫面依次为水体、林地、乔-灌-草绿地/乔-草绿地、道路、建筑,水体和绿地尤其是林地的地表降温效益显著。林地的周长为0~600 m,面积为0~7000 m^(2)时,与林地的地表降温幅度呈正相关;林地的周长面积比、景观形状指数、分维数与地表降温幅度呈负相关,林地形状和边缘越简单,形状接近圆形,地表降温效益越好。