控制论在企业环境管理中的应用

在企业环境管理运用控制论实施污染防治全过程控制，来提高清洁生产水平，降低物耗，能耗，提高资源利用率，完善保护环境的自我约束机制，落实环境综合整治定量考核，以达到发展生产，提高经济效益和改善环境的目的。     

Presence–Absence versus Abundance Data for Monitoring Threatened Species

Abstract:  Effective detection of population trend is crucial for managing threatened species. Little theory exists, however, to assist managers in choosing the most cost-effective monitoring techniques for diagnosing trend. We present a framework for determining the optimal monitoring strategy by simulating a manager collecting data on a declining species, the Chestnut-rumped Hylacola ( Hylacola pyrrhopygia parkeri ), to determine whether the species should be listed under the IUCN (World Conservation Union) Red List. We compared the efficiencies of two strategies for detecting trend, abundance, and presence–absence surveys, under financial constraints. One might expect the abundance surveys to be superior under all circumstances because more information is collected at each site. Nevertheless, the presence–absence data can be collected at more sites because the surveyor is not obliged to spend a fixed amount of time at each site. The optimal strategy for monitoring was very dependent on the budget available. Under some circumstances, presence–absence surveys outperformed abundance surveys for diagnosing the IUCN Red List categories cost-effectively. Abundance surveys were best if the species was expected to be recorded more than 16 times/year; otherwise, presence–absence surveys were best. The relationship between the strategies we investigated is likely to be relevant for many comparisons of presence–absence or abundance data. Managers of any cryptic or low-density species who hope to maximize their success of estimating trend should find an application for our results.     

Water Resource Management in Botswana: Balancing Sustainability and Economic Development*

Botswana is a rapidly developing country in southern Africa. Over the last three decades, diamond mining and tourism have provided double-digit rates of economic growth. Yet most of Botswana’s land is in the Kalahari desert where the climate is subject to sustained periods of severe drought. In this environment, water resources are the most crucial of all environmental resources. Water use directly affects economic development because water utilization impacts all the major national economic sectors. A sustainable water use resource management plan must stretch several decades into the future to assure the availability of adequate supplies of water to future generations while not compromising the ability of the current generation to reasonable rates of economic development. Yet thinking about sustainability is present in Botswana water policy mostly only in rhetoric. A series of cultural traditions and political constraints, coupled with bureaucratic managerial weaknesses, serve to maintain a system of water allocation that is unsustainable in the long run and inefficient in the short-term. Unless sustainable water use patterns are adopted, the results for the short-term, as well as the long-term, will be devastating. Drawing on data obtained through a series of interviews with government officials, leaders of non-governmental organizations (NGOs), and water resource researchers, this paper explores water policy in Botswana within the larger context of sustainable natural resource management practice and the pressures of economic development. This research was partially funded under U.S. Department of State, College and University Affiliations Grant # ASCS-1095.     

企业采用自愿协议式环境管理方法的意愿调查

“企业采用自愿协议式环境管理方法的意愿调查”是欧盟资助项目“自愿协议式环境管理方法在中国工业环境管理中应用的可行性研究”的主要成果之一。调查结果表明，自愿协议式环境管理方法目前在中国只是处于初步的认知阶段，但大多数企业愿意尝试采用自愿协议式方法解决环境问题，积极性较高，且谈判式自愿协议被看好。     

Stand density index applied to timber and goshawk habitat objectives in Douglas-fir

Silvicultural guidelines are presented for the management of intermountain Douglas-fir (Pseudotsuga menziesii) stands for sawtimber production and goshawk (Accipiter gentilis) nesting habitat in the northern Rocky Mountains. Data from 14 goshawk nest stands in Douglas-fir forests on the Targhee National Forest in Idaho (Patla 1991) were used to characterize the range of stand conditions considered suitable for goshawk nesting. A density management regime is presented using Reineke's stand density index that includes a technical rotation designed to produce sawlogs with a single commercial thinning. On average timber-growing sites, stands reach goshawk habitat suitability when site height is 25 m at age 75 and provide 65 years of goshawk nesting habitat until the final harvest at age 140. Approximately 1320 m³/ha are harvested over the rotation. On higher-quality sites, rotation length declines from 140 to 85 years, of which roughly 35 years are suitable for goshawk nesting.     

Evaluating the acceptability of recreation rationing policies used on rivers

Research shows that users and managers have different perceptions of acceptable policies that ration or limit recreational use on rivers. The acceptability of seven rationing policies was evaluated using Thurstone's method of paired comparisons, which provided a rank ordering of advance reservation, lottery, first-come/first-served, merit, priority for first time users, zoning, and price. Chi-squared tests were used to determine if users and managers have significantly different levels of acceptability for the policies. River users and managers were found to be significantly different according to their evaluation of advance reservation, zoning, and merit. The results also indicated that river users collectively divide the policies into three categories corresponding to high, moderate, and low levels of acceptability, while river managers divide the policies into two levels corresponding to acceptable and unacceptable.     

Effect of land management on soil microbial N supply to crop N uptake in a dry tropical cropland in Tanzania

In Sub-Saharan Africa, conservation of available soil N during early crop growth, when N loss by leaching generally occurs, is important to improve crop productivity. In a dry tropical cropland in Tanzania, we assessed the potential role of soil microbes as a temporal N sink-source to conserve the available soil N until later crop growth, which generally requires substantial crop N uptake. We evaluated the effect of land management [i.e., no input, plant residue application before planting (P plot) with or without fertilizer application, fertilizer application alone, and non-cultivated plots] on the relationship between soil N pool [microbial biomass N (MBN) and inorganic N] and crop N uptake throughout the ∼120-d crop growth period in two consecutive years. In the P plot, MBN clearly increased (∼14.6-29.6 kg N ha⁻¹) early in the crop growth period in both years because of immobilization of potentially leachable N, and it conserved a larger soil N pool (∼10.5-21.2 kg N ha⁻¹) than in the control plot. Especially in one year in which N leaching was critical, increased MBN maintained a larger soil N pool in the P plot throughout the experimental period, and a delay of increased MB C:N ratio and a substantial decrease in MBN was observed, indicating better soil microbial N supply for crop N uptake during later crop growth. Therefore, plant residue application before planting should enhance the role of soil microbes as a temporal N sink-source, leading to the conservation of potentially leachable N until later phase of crop growth, especially in years in which N leaching is relatively severe. Although further studies are necessary, our results suggest that plant residue application before planting is a promising option to achieve better N synchronization.     

Responses of plant, insect and spider biodiversity to local and landscape scale management intensity in cereal crops and grasslands

The aim of this study was to determine the relative effects of landscape scale management intensity, agroecosystem type, local management intensity and edges on diversity patterns of functional groups of plants, carabid beetles, spiders and grasshoppers. Nine landscapes were selected differing in percent intensively used agricultural area (IAA), each with a pair of organic and conventional winter wheat fields and a pair of organic and conventional mown meadows. Within fields, plants were surveyed in the edge and in the interior. Carabid beetles and spiders were captured by funnel traps, while grasshoppers were sweep-netted in the meadows. Diversity patterns of study organisms were affected both by local variables (local management, agroecosystem type and within-field position) and by landscape scale management intensity. Species richness of grasses, presumably because of sowing low-diversity mixtures, and hunting spiders decreased with percent cover of IAA. Meadows differed from wheat fields in that they had higher species richness of forbs and grasses, as well as higher densities of hunting spiders. In contrast, more carabid individuals, especially of non-carnivore species, were captured in wheat fields. In field edges with their reduced management intensity and increased immigration, species richness of plants, carabids and spiders was higher than in the interiors regardless of agroecosystem type and management. Organic management enhanced forb richness and cover in both agroecosystem types. Organic management also increased grass cover in wheat fields, but not in meadows, and promoted species richness of non-carnivore carabids and hunting spiders, but not grasshoppers. The results show that agri-environmental management needs to be targeted to the agroecosystem's field size, because higher edge area led to higher species richness. Organic management affected several functional groups positively (forbs, non-carnivore carabids, hunting spiders), while lower landscape scale management intensity only increased species richness of grasses and spiders. The great differences in responses of functional groups to local cereal and grassland as well as landscape management suggest implementing more scale and group specific targets for agri-environmental schemes to improve their efficiency.     

耕地资源非市场价值评价方法的研究进展与述评

论文系统梳理了国内外耕地资源非市场价值评价方法的研究进展,指明了今后该领域研究的努力方向。研究结果表明:国内评价耕地资源非市场价值的方法主要是CVM,研究方法单一,缺少同时运用其他非市场价值评价方法来对CVM的研究进行比较的案例,从而无法清晰辨识CVM的缺陷,并对其加以改进;而且,CVM方法本身存在一些不足,大多数CVM的应用尚停留在实施CVM实验并报告结果的初级阶段,对CVM的有效性与可靠性方面的相关研究不够。国外非市场价值评价方法表现出两个特点:一是研究方法不断拓展,Mixed Logit逐步得到应用;二是研究方法不断深化,对CVM的研究从调研内容与结果的报告,向检验结果的有效性、可靠性方向转变,进而转向CVM的经济学理论的探讨和研究;对CVM与预期不相符合的原因进行深入研究;对问卷的设计进行深入研究;并将非市场价值评价模型和方法与空间分析相结合。在此基础上,建议将CE模型引入中国的耕地资源非市场价值评价研究;加强耕地资源非市场价值的空间分异特征与分异规律,以及耕地资源非市场价值形成的空间分异机理和动态演变规律的研究;尝试调查问卷设计中的可视化研究。     

基于ESDA的京津冀地区草地变化空间分异

论文以县域为基本研究空间单元,借助GIS软件与Geoda空间统计分析软件,利用ESDA方法,对京津冀地区县域草地资源数量变化的总体与局域空间差异进行了分析。结果表明:①1980-2000年京津冀地区草地动态变化系数的Global Moran’s I为0.184 4,α = 0.05时呈显著的空间正相关,草地变化呈现出较明显的空间集聚特征;②时段Ⅰ(1980-1995年)到时段Ⅱ(1995-2000年)的全局Moran指数有所增加,表明草地变化在空间分布上集聚的趋势在增强;③各县域Local Moran’s I的Grid图反映了京津冀地区草地变化在局域空间上的均质性,尤其是高值区域与低值区域的集聚特征十分显著;④LISA集聚4种类型中,正相关的"H-H"类型区、"L-L"类型区占主体部分,二者约占总数的70%以上,其中,在时段Ⅱ,"H-H"关联的县域主要聚集在西北部山区,而中部的平原区域则表现出明显的"L-L"关联特征。