Considerations for preserve design based on the distribution of rare plants in Great Smoky Mountains National Park,USA

Park design principles are proposed on the basis of consideration and analysis of rare plant species in Great Smoky Mountains National Park, USA. Rare species richness can be used as a simple measure of preservation success. A semilogartihmic species-area model for the Smokies was used in this analysis. Species richness would increase logarathmically with expansion of the national park area. An analysis of the relationship between species richness and the distribution of geologic and topographic features in the national park was also reported. An asymptotic relation was documented for the accumulation of newly recorded rare and endangered vascular plant species in the Smokies region up to 1978. Several multiple regression linear models predicted rare vascular plant species richness in Great Smoky Mountains National Park from area and topographic variates.Preserve design criteria can be based upon species-area, environmental gradient, and natural features distribution patterns for the specific taxa and biogeographic region under consideration. In addition, natural history characteristics for particular vulnerable species must be assessed. Rather than concentrating on the preservation of undocumented immigration and extinction processes, preserve design should be directed towards protecting geographic components and gradient patterns characteristic of a region.     

O&M SPENDING LEVELS IN THIRD WORLD IRRIGATION SYSTEMS: EXPLORING ECONOMIC ALTERNATIVES1

ABSTRACT: Third World irrigation and drainage systems have experienced major declines recently in both capability and performance. This is due initially to working them well beyond their design capaci-capacities; scouring, sedimentation, and overtopping result. Chronic O&M underfunding then adds heavily to this worsening malaise. International donors have assisted irrigation departments with rehabilitation projects and programs to improve O&M effectiveness on a grand (billions of dollars) scale. Despite their historical propensity to examine, almost fastidiously, program economic justifications (B/C, IRR, etc), the donors apparently have glossed over two basic analytic elements for (a) more spending on O&M as distinct from an equivalent spending on other means to provide farmers with an m³ of water; and (b) different levels of O&M spending on canals and drains. Surely those different levels provide differing benefits, in total, and at the margin. Which level is most economic? This paper identifies these latter analytical issues, posits methodologies key to an O&M spending level analysis, and discusses the information base. Particular attention is paid to identifying relevant costs and benefits, and to suggesting supplementary criteria for O&M spending level selection. The paper is an exercise in delineation of an imminently practical area of irrigation engineering economics.     

水平衡测试在降低钻井生产耗水量中的应用

针对石油天然气勘探钻井过程中存在的不合理用水问题，运用水平衡测试方法进行对比、分析，提出了节约用水措施，健全了用水管理制度，使钻井生产耗水量降低到合理值，有效地控制了废水的产生量。     

An evaluation of resource inventory and monitoring program used in national forest planning

The National Forest Management Act (1976) specifies that multiresource inventories be conducted to provide baseline data for development and, later, monitoring of national forest management plans. This mandate entails the most ambitious and complex resource planning effort ever attempted. In this paper we evaluate the structure and use of current inventory-monitoring programs and recommend a framework for gathering data to improve national forest planning. Current national guidelines are general and provide only basic directions to forest-level planners. Forest inventories have traditionally concentrated on timber. Although these inventories are often well designed, the questions we are now asking about forest resources have outgrown these methods. Forest management is impeded by general confusion over definitions of resources and the interactions among them. We outline a simple classification scheme that centers on identification of basic ecosystem elements that can be readily measured. Furthermore, spatial and temporal scales must be considered in the design of inventory-monitoring programs. The concept of ecological indicators is reviewed, and caution is advised in their use. Inventory-monitoring programs should be goal-directed and based on as rigorous a statistical design as possible. We also review fundamental issues of variable selection, validation, and sampling bias. We conclude by developing a flexible inventory-monitoring program that is designed to provide information on individual characteristics of the environment, rather than being based on fixed definitions of resources.     

电解法处理高含硫气田水

本文详细介绍了川南矿区含硫气田水电解法处理的试验情况，用自己研制的电解反应器对电解时间、pH值、电流密度等工艺条件进行了考察，提出了电解法处理含S~(2-)200mg／L的气田水的最佳工艺条件。试验结果表明：该方法是成功的，它可以使气田水中硫化物的脱除率达99％以上，达到国家排放标准（GB8978—88：S~(2-)＜5mg／L）。该方法的主要特点是投加处理药剂少，操作简便，设备小型，占地面积小，特别适用于产水量不大的井站使用。     

对由制定抗震救灾工作预案引起地震误传的平息与启示

本文概述了在制定和部署抗震救灾工作预案时，所引起地震误传事件的经过、对社会造成的影响，以及采取的对策和所汲取的教训。     

A dynamic model for intertemporal allocation of old-growth forests in the Pacific Northwest

Across the globe, continued policy debates regarding the management of old-growth forests center around the difficult task of balancing economic and ecological considerations. Though the forests of the Pacific Northwest United States are among the most studied old-growth ecosystems, ecological and economic analyses have yielded public land management directives that remain controversial. Specifically, the recently adopted Northwest Forest Plan lacks explicit goals for maintaining intergenerational equity for the use of forest resources and the diversity of old-growth ecosystems. Unlike previous studies which rely on monetary quantification of costs and benefits, this study develops and applies a conceptual framework for evaluating socially optimal Pacific Northwest old-growth forest utilization strategies. Conditions for the optimal management of old-growth forests are derived using dynamic programming. The objective function synthesizes relevant biological and economic attributes of the old-growth allocation problem. Results in the form of extraction paths are compared given social pressure for consumptive and non-consumptive benefits, as well as different planning horizons, rates of social time preference, and environmental variance. Lengthening the planning horizon results in a vast divergence of optimal policies in the absence of discounting. Extraction rates appear to approach zero as the planning horizon approaches infinity. While higher rates of social time preference increase the rate of extraction, forest stocks remaining at the terminal time period equal levels remaining with a lower discount rate. Increasing environmental variance results in a higher level of stock remaining at the terminal time period. This analysis, while specific to the old-growth controversy of the Pacific Northwest, does provide general guidelines for addressing similar problems of multiple uses of natural areas, particularly where such uses are mutually incompatible, or where one use may be irreversibly destructive to another.     

Preparation and implementation of seven ecological compensation plans for Dutch highways

First-generation compensation plans (CPs) for Dutch highway projects have been evaluated with respect to implementation of the compensation principle (1993), which aims to counterbalance the adverse ecological impacts of large-scale development projects. Decision-making on the seven projects took place between 1993 and 1995. Specifically, we considered: (a) the processes employed to prepare and implement the compensation plans; (b) the methods used to identify, plan, and execute the compensation measures; and (c) the results yielded by these methods. We conclude that the CPs were prepared fairly uniformly, particularly in terms of the processes and methodologies used to derive compensation measures. Five of the seven CPs had become operational by 2001 and initial experience is now being gained on land acquisition and transfer of compensation sites to nature conservation trusts. Further progress of CPs is likely to be seriously hampered by growing demand for land for development in general and associated increases in real estate prices. Several problems are addressed and recommendations made with respect to: (a) developing a legal basis for the compensation principle; (b) the relationship with re-allotment projects; (c) estimation of compensation costs; (d) an annual bias of CP budgets to account for rising costs; (e) contingency measures; and (f) criteria for CP (ex-post) evaluation.     

Biomethanation of plant materials and agricultural residues using dung samples as wild population of microbes and also with isolated methanogens

Recycling of plant materials and agricultural residues for biomethanation was attempted in vials. The methanogenic activities of certain sewage samples have also been tested. Both sterilized and non-sterilized biomasses were used. Biomethanation was carried out with dung samples (cow, goat, buffalo, piggery wastes and poultry wash) as wild populations of microbes and in combination with other microbial isolates (isolated in the laboratory).Biomethanation had been observed to be good in most cases and particularly with the sterilized biomass. Mixed inoculum (dung samples and poultry wash) was found to be best for biomethanation. Of the microbe isolates, isolates from buffalo, pig and paper mill wastes appear to be most effective. Pretreated sawdust and rice straw were found to be good subtrates for biomethanation. Of the different plant biomass used Spirogyra (algae), Ipomea and water hyacinth were most effective whereas Jatropa gossypifolia and Parthenium sp. were the least effective. Biomethanation of Spirogyra was carried out both in anoxic and oxic conditions. Though methane production decreased enormously under oxic conditions, definite methane production continued indicating that the biomethanation process is not exclusively anoxic. Similarly, biomethanation of sewage samples from different sewage treatment plants were carried out with and without isolated methanogens and methane production was found to be moderate.