雅玛里克山植被类型及物种多样性的特征

采用典型样地法对雅玛里克山进行了植被调查，结果表明，该区的植物群落类型有14种；植物种类有223种植物．分属37科147属，植物生活型有9类；短命和类短命植物获得一定发育，旱生类型的植物占绝对优势，一年生植物占有一定比例等。     

滑坡风险图编制探讨

近20年来,滑坡风险图编制在减灾中发挥着越来越重要的作用,地理信息系统技术作为空间分析的定量方法,已日益广泛应用于滑坡风险评价.探讨了滑坡风险图编制的方法和程序,并描述了用于地理信息系统识别和定量计算不同滑坡风险分区的系统方法.以中国云南红河流域为研究区,应用地理信息系统技术成功地完成了滑坡风险图编制.研究表明,滑坡风险图可作为滑坡减灾决策的依据.     

Modeling the Effects of Land Use Change on the Water Temperature in Unregulated Urban Streams

Streams, in their natural state, are typically diverse and biologically productive environments. Streams subject to urbanization often experience degradation brought about by the cumulative effects of flow alteration, unsanitary discharge and channelization. One of the water quality parameters affected by urbanization is stream temperature. This study offers a model for predicting the impact of land use change on the temperature of non-regulated streams during extreme events. A stream temperature model was created by considering the gains and losses of thermal energy resulting from radiation, convection, conduction, evaporation and advection. A sensitivity analysis showed that out of 14 variables, shade/transmissivity of riparian vegetation, groundwater discharge, and stream width had the greatest influence on stream temperature. These same three variables are highly influenced by land use. Individual component models were developed to predict how urbanization changes stream width and baseflow discharge. Using 3-D computer modeling, a model was also developed to illustrate the effects of altering the extent and composition of riparian vegetation on streams with different orientations. By modeling these three variables as a function of urbanization, the results became inputs into the stream temperature model. The critical urban stream temperature model (CrUSTe), an aggregation of these four models, allows the prediction of stream temperature change as a result of amount, type and location of urbanization within a watershed. It has the potential to become a valuable tool for environmental managers.     

Impacts of Camping on Vegetation: Response and Recovery Following Acute and Chronic Disturbance

Experiments with controlled levels of recreational camping were conducted on previously undisturbed sites in two different plant communities in the subalpine zone of the Wind River Mountains, Wyoming, USA. The plant communities were coniferous forest with understory dominated by the low shrub Vaccinium scoparium and a riparian meadow of intermixed grasses and forbs, of which Deschampsia cespitosa was most abundant. Sites were camped on at intensities of either one or four nights per year, for either one (acute disturbance) or three consecutive years (chronic disturbance). Recovery was followed for three years on sites camped on for one year and for one year on sites camped on for three years. Reductions in vegetation cover and vegetation height were much more pronounced on sites in the forest than on sites in the meadow. In both plant communities, increases in vegetation impact were not proportional to increases in either years of camping or nights per year of camping. Close to the center of campsites, near-maximum levels of impact occurred after the first year of camping on forested sites and after the second year on meadow sites. Meadow sites recovered completely within a year, at the camping intensities employed in the experiments. Forest sites, even those camped on for just one night, did not recover completely within three years. Differences between acute and chronic disturbance were not pronounced.     

Geochemical mapping in Jamaica

A high-precision regional geochemical data base of Jamaica is being developed as a basis for a wide variety of economic and environmental applications. These include pollution studies, resource identification and management, agriculture, land use, and the relationship between geochemistry and the health of crops, animals, and man. The acquisition of analytical data is mainly by instrumental neutron activation analysis using a SLOWPOKE reactor and by energy dispersive X-ray fluorescence. Concentration ranges and means in soil are presented for 31 elements and maps illustrating the distributions of Al, Br, Co, and the -ray intensities are presented as examples. Compared with world averages the levels of many heavy metals in Jamaican soils are found to be relatively high and in the main strongly correlated with bauxite occurrences. The high content of bromine in the soils appears to reflect the impact of sea-spray.     

抚仙湖流域磷矿开采区不同植被类型水土流失的对比研究

通过对抚仙湖流域磷矿开采区内不同植被类型在同一降雨下水土流失的对比研究，筛选出磷矿开采区内水土保持能力较好的植被类型，研究表明：在所选8种植被类型中，竹林植物群落的水土保持能力最强，旱冬瓜林植物群落次之。     

元江干热河谷山地植被类型调查与恢复措施

元江干热河谷海拔1200m以下的山地残存的森林植被寥寥无几,山地严重退化,炎热、干燥的气候,旱涝、风沙灾害已成了元江县及周围山地的严重生态问题。通过对元江干热河谷山地植被类型的调查,提出了植被恢复的措施。     

Global and Regional Impacts of Stabilizing Atmospheric CO2

Among the key issues of concern to the Climate Convention is the stabilization of greenhouse gas concentrations and the minimization of impacts to global agriculture, natural ecosystems and economic development. The purpose of this paper is to couple these issues in consistent, integrated scenarios, using the IMAGE 2.0 model as an integrating tool. Scenarios of gradual stabilization of atmospheric CO₂ at 350 and 450 ppm are compared to a baseline of no policy action in which CO₂ concentration increases to 777 ppm. Under the stabilizaton scenarios substantially smaller areas of wheat and millet, as well as nature reserves, are threatened by climate change, especially in temperate regions. The amount of sea level rise is also reduced under the stabilization scenarios. However, climate continues to change under the stabilization scenarios and therefore some ‘residual’ climate impacts occur. Hence the integrated scenarios indicate that stabilizing greenhouse gas concentrations at or slightly above current levels will lessen impacts as compared to baseline levels, but not eliminate them. This revised version was published online in August 2006 with corrections to the Cover Date.     

武汉东湖水生植被现状调查及群落演替分析

对东湖水生植物的调查结果表明，东湖现存水生维管束植物共计20科25属33种，其生物量约为1.137t，分布面积仅占东湖总面积的0．7％，其中挺水植物分布面积占总面积的98％。与1957年、1962～1963年和1988～1994年相比，东湖水生植物的种类、分布面积和生物量进一步减少。认为造成东湖水生植被衰退的主要原因包括富营养化作用加剧、过度放养草食性鱼类和人类活动的影响。