Rational forest productivity decline

A whole forest optimisation model was employed to examine economic behaviour as it relates to long term, forest productivity decline in the boreal forests of Ontario, Canada. Our productivity investment model(PIM) incorporated a choice between productivity decline as representedby a drop in forest Site Class, and a fee to 'maintain' site productivity. Sensitivity analysis was used to determine the point at which these fees exceeded the value of the differential in timber volume between upper and lower site classes. By varying discount rate, 'productivity investment frontiers' were constructed, which highlight the effects of the magnitude in productivity decline, maintenance fees, and harvest flow constraints upon the occurrence and schedule of productivity declines. In presenting this simple approach to exploring the effects of economic choice upon forest productivity decline, the phenomena of 'natural capital divestment' within forestry is described.     

Social goals and the valuation of natural capital

Valuation ultimately refers to the contribution of an item to meeting a specific goal or objective. Conventional economic valuation is based on the goal of allocative efficiency. But other social goals may be equally, if not more, important. For example, the goals of social fairness and ecological sustainability have been identified as being at least of the samelevel of importance as allocative efficiency. This paper looks atthe role of social goals in determining the basis for valuation ofnatural capital and ecosystem services, and sketches the characteristics of a system of valuation that would give equal weight to all three of the major social goals mentioned above. It also places these goals within a more comprehensive conceptualmodel of the economy and its relationship to the ecological lifesupport system in which it is embedded.     

Measuring the wealth of nations

The sustainability of development is closely linked to changes intotal per capita wealth. This paper presents estimates of the wealth of nations for nearly 100 countries, broken down into produced assets, natural resources and human resources. While thelatter is the dominant form of wealth in virtually all countries,in low income natural resource exporters the share of natural resources in total wealth is equal to the share of produced assets. For low income countries in general, cropland forms thevast majority of natural wealth. The analysis suggests the process of development can be viewed as one of portfolio management: sustainable development entails saving the rents fromexhaustible resources, managing renewable resources sustainably,and investing savings in both produced assets and human resources.     

论人地关系变化对湖北省自然灾害的影响

人口增长及其引发的人地关系失调导致并加重了一系列自然灾害.人地关系恶化致使湖北省“灾种增多、频率加快、灾情趋重“.因此,湖北省的防灾减灾工作,不仅要重视水利工程、生态工程等减灾措施的作用,更要重视人地关系变化对自然灾害的影响,从调整人地关系入手,进行生态减压,从而达到从根本上防灾减灾的目的.     

中国救灾物资代储点优化布局研究

优化国家救灾物资代储点布局的目标是要提高我国的自然灾害应急响应能力和救灾时效性.构建了自然灾害发生过程中交通应急响应能力的评价指标和模型,包括陆地综合通行能力指数、空运通达时间和陆地交通通达时间,编制了相应的数字地图.结果表明:全国陆地交通综合通行能力在地域上是不平衡的,东南地区远远大于西北地区,其中以环渤海、长三角、珠三角地区最大;从通达时间来看,要以现有的10个代储点为中心来覆盖全国,空运至少需要7h,陆地交通运输至少需要48h,这使得许多地区的交通应急响应能力因运输时间过长而降低.最后,提出了国家救灾物资代储点的优化布局方案,建议新增6个代储点,以此实现灾中空运3h,全国各地均可送达救灾物资;陆运6h,全国近90%的地区可送达救灾物资.     

基于活化能指标的煤自燃倾向性及发火期研究

在煤的自燃及热分析动力学的基础上,结合对神东矿区3种煤样进行了热重实验,运用热重分析手段对煤从常温到燃点之间的氧化热解过程进行了研究。运用不同动力学机制模型函数分别对热重分析数据进行了处理和相关性分析,结果表明煤炭氧化热解过程符合一级化学反应动力学机制,据此求出活化能等动力学参数。对基于活化能指标的煤的自燃倾向性及自然发火期进行了初步研究。经过研究发现,该方法是科学的、客观的。     

Integrity and Rights of Plants: Ethical Notions in Organic Plant Breeding and Propagation

In addition to obviating the use of synthetic agrochemicals and emphasizing farming in accordance with agro-ecological guidelines, organic farming acknowledges the integrity of plants as an essential element of its natural approaches to crop production. For cultivated plants, integrity refers to their inherent nature, wholeness, completeness, species-specific characteristics, and their being in balance with their (organically farmed) environment, while accomplishing their “natural aim.” We argue that this integrity of plants has ethical value, distinguishing integrity of life, plant-typic integrity, genotypic integrity, and phenotypic integrity. We have developed qualitative criteria to ethically evaluate existing practices and have applied these criteria to assess whether current plant breeding and propagation techniques violate the integrity of crop plants. This process has resulted in a design of a holistic, scientific approach of organic plant breeding and seed production. Our evaluation has met considerable criticism from mainstream (crop) scientists. We respond to the following questions: (1). Can ethics be incorporated into objective crop sciences? (2). What is the nature of the intrinsic value of plants in organic farming? We argue that criteria to take integrity into account can only be assessed from a holistic perspective and we show that a holistic approach is needed to design such ethical notions in a consistent way. The ethical notions have been further elaborated by formulating human responsibility and respect towards crop plants. Responsibility and respect can only be shown by providing crop plants the right to be nurtured and to express natural behavior at all levels of integrity.     

灾害易损性研究的回顾与展望

近十余年来,易损性研究成为灾害学术研究和国际社会发展减灾策略的一个主题.本文概述了易损性研究的历史发展过程,评述了易损性的三类概念,总结了易损性的四个性质,阐述了易损性识别和测量的一些基本理念和方法,指出了易损性分析在灾害研究和减灾防灾中的积极意义.     

2003年重大自然灾害回顾

2003年是全球自然灾害重灾年.根据收集到的全球自然灾害记录的数据,客观地对全球主要自然灾害的特征和分布特点进行了分析,并对其成因和发展趋势进行了初步探讨.     

Reference Conditions of Alpine Streams: Physical Habitat and Ecology

Natural and near-natural streams are rare in the densely populated areas of the Alps. A variety of anthropogenic impacts have resulted in the alteration and sometimes even complete destruction of these systems. Nowadays it is difficult to find un-impacted streams that are strongly needed to define the natural variability and ecosystem processes. The results from freshwater inventories and habitat assessments conducted in protected areas in Austria (Nationalpark Hohe Tauern) and Italy (Naturpark Rieserferner-Ahrn) were used to develop a comprehensive typology of Alpine streams. Three different levels were used to discriminate between the distinct stream/river types: source (glacial vs. non-glacial), hierarchy (i.e. location within the stream system) and topography/ channel morphology. Important characters defining the structure and function of these stream types are gradient, substrate composition, flow pattern and riparian vegetation. Benthic fauna assemblages from 99 near-natural stream segments in glacial and non-glacial systems demonstrated the effect of glaciation on abundance levels of the total macroinvertebrate fauna, EPT taxa (Ephemeroptera, Plecoptera and Trichoptera) and the chironomid subfamily Diamesinae in different altitudes. A general decrease of abundances with increasing altitude was found. While stream segments with a degree of glaciation >10% primarily showed reduced abundances at all altitudes, lower (<10%) or no glaciation did not influence invertebrate abundances at lower reaches. Due to the near-natural conditions of the selected stream segments, a valuable definition of reference conditions of Alpine streams based on habitat characteristics is available. As a basis it offers excellent opportunities to conduct holistic interdisciplinary studies in protected areas in the future.