青海湖生态现状及影响

阐述了青海湖环湖区草原退化、沙化，湖面退缩的严重状况，提出改善青海湖生态的建议。     

Theoretical Underpinnings of Rangeland Monitoring

Monitoring of rangelands has evolved from traditional focus on plant communities and their successional status, taken from a few selected subsamples, to much broader perspectives. Rangelands, being complex biosocial systems, offer a near infinite array of possibilities for choice of variables and how to collect and interpret the data. Past monitoring approaches have inadequately considered objectives, critical definitions, and appropriate sequencing of steps taken. While management objectives should ideally have primacy in choice of variables used in inventory and monitoring, there are some countervailing advantages in employing some commonalities in monitoring protocols among tracts of rangelands. Inventories should come before monitoring. Assessment should follow collection of an adequately long time series of data which is the essence of monitoring. Trends involve judging whether the monitoring data show increases, decreases, or stable trajectories. Assessment involves an always at least partially subjective judgement of condition in relation to appropriate standards and objectives. We are no longer limited to just plant community data collected annually in a few conveniently and subjectively chosen quadrats. Geomatics (remote sensing, GIS, and GPS)opens the possibility of frequent, synoptic (everywhere, instantaneously) landscape coverage via satellite imagery. Indisputable evidence of cause(s) requires concurrent data on these influences along with similar trends from similar circumstances (replications) and controls [reference areas lacking the putative cause(s)]. Three alternatives that could replace plant succession as the underlying, dominant theory of rangeland monitoring are: risk assessment, sustainability, and desertification. Risk assessment is well proven where biophysical indicators can be employed. Politically neutral incorporation of socioeconomic considerations have yet to be demonstrated, however. Sustainability is such a broad and diffuse concept that anyone can read into it whatever he or she wishes. Desertification is the preferred macroconcept to guide us into the future, because its use can more objectively encompass both biophysical and socioeconomic features, at any scale in time and space.     

Utilization of Fodder Trees and Shrubs in the Arid and Semiarid Zones of West Asia and North Africa

Utilization of fodder trees and shrubs (FTS) in the Mediterranean arid and semi-arid zones was initiated after World War I and expanded between 1950 and 1970. A similarly slow expansion has taken place in other arid zones in the USA, South Africa, South America, and Australia. Currently in West Asian and North African (WANA) countries, the area planted with native or exotic species is about 10 6 ha. Mainly they include three categories of plant species: cacti, saltbushes, and wattles. At this time there is an expansion of hectareage and a diversi-cation of genetic material. The relative success of FTS has a number of reasons. They are tolerant to drought and have the ability to accumulate green fodder over several seasons, providing fodder reserves for times of dearth and thus permitting a switch from transhumance to sedentary husbandry. Deep rooting enables them to reach water resources unavailable to herbaceous species. Their Rain Use Efficiency (RUE) and Water Use Efficiency (WUE) rates provide productivities three to five times higher than rangelands. FTS have a positive impact on soil fertility due to their organic matter production, hence they increase microbial activity, rates of geobiogenic element cycling, and soil structure stabilization. Their above ground biomass, canopy ground cover, provides a microclimatic buffer role for wind, temperature and evapotranspiration, and their landscape roughness factor makes them efficient for erosion and desertification control. Other positive aspects include: the use on non farming land; general suitability for runo farming systems; production of valuable goods, such as food, shade, and firewood; providing wildlife shelter; and other benefits. FTS plantations are subjected, however, to constraints that limit their expansion. Their main shortcomings include the cost of establishment, often not affordable by a small farmer; required long-term planning may not be feasible, as a secure land tenure system often is nonexistent. Appropriate methods of cultivation are not being applied, management, and utilization are lacking, and availability of plant material is limited. Discipline of utilization, allowing regeneration of stands after defoliation is a problem. Identification of constraints indicates needs for research and extension activities. These include reduced-cost of establishment and improved management methods, such as ensuring availability of low-cost seeds and selection of high grade cultivars, and introduction of new high quality exotic species. Additionally, integration into economically feasible and socially acceptable production systems, including joint cultivation with cereal farming and combination with runo farming techniques, should be developed. Legal, regulatory, and administrative incentives are also needed.     

草本植物在荒漠化治理、高速公路绿化以及铁路护坡中的作用

介绍了几种常见的草本植物,它们在荒漠化治理、高速公路以及铁路护坡方面发挥着十分重要的作用。百喜草、香根草、紫花苜蓿、狗牙根等是治理江河水土流失的较理想的草本植物。赖草、野牛草、披碱草、茅香、虎尾草、草地早熟禾、异穗苔草、草木樨,特别是碱草属的广泛生于盐碱地的植物,都有抗盐、泌盐或稀盐的功能,是治理盐渍地的良好植物。另外,结缕草、香根草有吸收土壤中重金属或去除塘泥中悬浮固形物、净化土壤的功能。狗牙根、结缕草、百喜草等是南方高速公路生物防护的优良地被。扁穗冰草、青岛结缕草等在铁路护坡方面应用较广。     

Land restoration by fodder shrubs in a semi-arid agro-pastoral area of Morocco. Effects on soils

The present study assesses the effects of Atriplex nummularia Lindl. growth on soil chemical properties in a semi-arid area. The area is located in the Marrakech province (Morocco), in a degraded agropastoral region subjected to soil restoration actions based on fodder shrub plantations.     

科尔沁不同沙地土壤饱和导水率比较研究

用Guelph入渗仪对科尔沁沙地不同沙漠化阶段土壤不同层次的土壤饱和导水率(Kfs)进行测定,分析研究了Kfs与沙地类型、土层厚度、沙丘坡位及土壤理化性质的关系.结果表明:(1)草地(潜在沙漠化)、固定沙丘(轻度沙漠化)和流动沙丘(严重沙漠化)的Kfs依次增大,平均值分别为2.15、4.79和5.89 mm min-1,呈现出土壤入渗能力随沙漠化程度的增强而增强的趋势;三种沙地间Kfs差异显著,沙丘不同坡位Kfs也有较大差异,表明科尔沁沙地Kfs具有较高的空间异质性;(2)三种沙地Kfs随深度的变化规律差异较大,草地Kfs随深度呈抛物线状变化,而固定沙丘Kfs随深度呈指数函数变化;(3)通过逐步回归分析发现对Kfs影响较大的土壤理化性质是土壤有机质含量、土壤细砂含量、黏粉粒含量和粗砂粒含量,并且Kfs与前三个因素呈显著的负相关关系,与最后一个因素呈显著的正相关关系.     

奈曼旗沙地32年来的沙漠化进程浅析

选取位于科尔沁沙地腹地的奈曼旗为研究对象,分析了研究区1977到2009年沙漠化进程情况.研究结果表明：沙地面积从1977年开始呈上升趋势,1989年后有所减少.研究发现年降水量和耕地面积的变化对沙地面积的影响较大,退耕还林还草和禁牧政策的提出对沙漠化防治起到了积极作用.     

开垦草原导致荒漠化的物理过程

对照国内外有关草原荒漠化的研究,说明了在我国开垦草原导致草原荒漠化的基本途径有两条:(1)开垦草原→植被减少和表土露出→土壤风蚀、水蚀→土壤沙化、盐碱化;(2)用地下水灌溉→造成土地盐碱化。     

Soil microarthropods as indicators of exposure to environmental stress in Chihuahuan Desert rangelands

 We studied soil microarthropod communities along livestock grazing disturbance gradients, inside and outside grazing exclosures, and on areas subjected to restoration efforts (herbicide and bulldozing) in order to test the suitability of mites as indicators of rangeland soil quality. We found that mite numbers generally increased with decreased grazing disturbance. Soil microarthropods appeared to respond to a complex of factors including soil compaction, depth to an impervious soil layer, below-ground vegetative biomass, and residual effects of herbicide. All of our study plots, except those that had been herbicide treated, were dominated by microbivorous mites of the family Nanorchestidae. The numerical responses of mites, especially nanorchestids, appeared to provide a sensitive indicator of ecosystem health in a Chihuahuan Desert grassland. Received: 29 December 1997     

分布式信息系统的设计及其在环境动态监测中的应用

利用ArcIMS客户端与服务器机制、ArcXML语言及面向对象的开发策略,设计可以集成多方面观测信息和遥感信息,并能实现环境监测的分布式信息系统。通过在内蒙古中南部的应用表明,该系统提供了有效集成分布式采集到的环境信息及实时发现典型环境问题的途径。