1994—2008年河南省植被净第一性生产力及其时空变化

基于地理信息系统和卫星遥感技术,利用地面气象数据、遥感数据和土地分类等数据,根据河南省实际植被覆盖和自然地理情况,应用改进的CASA模型估算了1994—2008年间河南省植被净第一性生产力及其时空变化。结果表明：河南省植被净第一性生产力与年均温度的相关性好于植被年净第一性生产力与年降水量和年均太阳辐射之间的相关性,温度是限制河南省植被净第一性生产力的主要因子;15年来河南省植被净第一性生产力呈增加趋势,但不明显;河南省主要植被类型的净第一性生产力从大到小依次为林地、灌丛、耕地、草地、其它植被,它们随时间的变化趋势极为一致。     

Evaluation of potential topsoil productivity

A biomass productivity model based on soil properties and climate is developed from literature and used to evaluate and compare potential effects of mining and reclamation on several soils in the continental United States. Soil productivity is assumed to vary as a product of root distribution function modified by five soil properties: available water, aeration porosity, bulk density, electrical conductivity, and pH. Yield limiting property levels are derived from literature and input soil data are obtained from available USDA Soil Conservation Service information on typical profiles. Modelled values of potential productivity after mining, indicate problems and limitations to be expected. The proposed model can be used as a guide to reclamation strategy, to restore the land to premining conditions, or at times to enhance productivity of a reclaimed area.     

Wildlife and coal development: An overview

This paper briefly reviews the changes which have occurred in the past three hundred years in the public's attitudes toward our Nation's natural resources, particularly the wildlife resources. It discusses how these changing attitudes have contributed to today's surface coal mine reclamation laws which require that the disturbed land be restored to a level of productivity equal to or greater than that which occurred before mining. This paper stresses the need to manage each reclamation site on an ecosystem basis, recognizing the interrelationships of all the resource components. This paper emphasizes both the fundamental importance of the holistic approach to mine site reclamation and the responsibility that the wildlife biologist has to see to it that wildlife habitat considerations are incorporated into each phase of the reclamation plan. Brief management considerations are given to three unique reclamation habitat types; riparian, agriculture and forest.     

近50年来三江平原北部土地利用/土地覆被变化及生态效应分析

土地利用/覆被变化在全球变化中占有重要地位,对于综合模拟和评价环境问题非常重要。区域案例研究方法是土地利用/土地覆被的研究核心,以中尺度的三江平原北部作为研究区域,重建并分析了自1954年以来该地区4个时段的土地利用/土地覆被格局及其时空演化过程,在此基础上重点分析了20世纪50年代以来耕地的开发过程。结果表明1954年到2000年期间,以湿地、草地和林地转换成耕地为该区域土地利用/土地覆被变化的主要形式,耕地面积由占总面积的5.29%上升到51.81%,同时湿地占总面积的52.49%下降到15.71%,并指出人类的农垦活动是湿地减少和生态环境恶化的根本原因。     

淮河源12种园林地被植物竞争格局与过程

淮河源区处于北亚热带向暖温带过渡地带,地被植物种类繁多,选取该地区有代表性的12种典型地被植物,进行应用表现情况调查和竞争力量化评价,选用园林地被植物权重(以分布面积计)、园林地被植物养护的投入和园林地被抗杂草入侵能力三个量化指标,计算得出竞争力指数。研究表明淮河源区园林地被植物栽植后5—10年,其竞争力的强弱可充分表现出来,其中木本植物整体竞争力大于草本,而藤本植物竞争力最强。但也有少量草本如红花酢浆草,竞争力超过部分木本植物,值得大量推广运用。根据淮河源区园林地被植物群落竞争格局与过程,在进行园林工程实践中充分考虑园林地被上杂草和地被植物自身竞争力状况,降低园林工程中化学药品的使用和能源消耗,以保护生物多样性。     

Survival and growth of conservation shrubs and trees,with thin-cover reclamation on acid substrate,Iowa, USA

Many abandoned strip-mine sites in midwestern USA are highly acidic and require a separate layer of low-acidity cover materials for successful revegetation. Economics and logistics often constrain this reclamation to a very thin cover. Twenty-two species of shrubs and trees were tested for 6 years of survival and growth on a thin wedge of silt loess (up to 0.75m thick) emplaced over highly acid spoils, in south-central Iowa. No weed control or maintenance was provided. The performance of 21 of the species could be categorized into 3 groups: Group 1-consistent survival (10 species); Group 2-irregular survival and growth (6 species); Group 3-little suitability for survival (5 species). Mouldy nursery stock precluded evaluation of 1 species. For most species, the most favourable survival and growth was not on the thickest loess cover (0.75 meters) because weeds became too well established. In general, the shrubs survived severe weed competition in dwarfed form until they could break through the weed canopy. But the tree species had to penetrate the weed canopy within their first few years of growth or perish. There is evidence that if weed competition were reduced or eliminated, the species in Group 2 would probably have survival and growth equivalent to those in Group 1. The use of “tubelings” for establishing shrubs and trees on thincover reclamation sites is suggested.     

Ruffed grouse brood habitat on reclaimed surface mines in West Virginia

Human-imprinted ruffed grouse (Bonasa umbellus) chicks were used to evaluate grouse brood food and cover conditions on reclaimed surface mines in northern West Virginia. Reclaimed surface-mined areas did not provide the quality of habitat for ruffed grouse chicks that unmined land provided. On the surface-mined areas, grasslegume reclamation provided the poorest cover and next to the lowest feeding rates. Of the surface-mined areas a 25-year-old reclaimed mine planted to autumn olive had canopy provided a more favorable micro-climate for insects and herbaceous vegetation was established around the edge. Planting rows of shrubs in addition to the current practice of planting grasses and legumes on surface-mined areas is suggested to create ruffed grouse brood habitat.     

Recommendations for rural abandoned mine program (RAMP) in Iowa,USA

In the last three years, twelve orphan coal surface mines in Iowa, USA, have been reclaimed under the Federal Rural Abandoned Mine Program (RAMP) by smoothing highly acid spoils, covering the spoils with a thin dirt layer and planting a cover crop. Ten years ago a test plot was designed with a wedge of loess over acid spoils. Subsequent observation suggests that on the new RAMP sites, acidified throughflow and discharge of shallow soil moisture and groundwater will gradually kill the vegetation in the lower valleys and erosion will proceed upvalley as a migrating knickpoint. The problem might be eliminated by directing the acidified throughflow beneath the cover material, in sand underdrains or tile lines in the main drainages. The discharge could either be diluted in a nearby creek, if adequate flow is available, or neutralised in a basin paved with limestone rip-rap. Vegetation which was found to be especially well adapted to thin cover sites includes native prairie grasses, crownvetch and cattails. Sphagnum mosses may also offer some possibilities for such locations. A RAMP reclamation site should be designed as an experimental area to test these methods and determine their cost. These recommendations may also be applicable in other mining areas.     

Human Impacts on Regional Avian Diversity and Abundance

Abstract: Patterns of association between humans and biodiversity typically show positive, negative, or negative quadratic relationships and can be described by 3 hypotheses: biologically rich areas that support high human population densities co‐occur with areas of high biodiversity (productivity); biodiversity decreases monotonically with increasing human activities (ecosystem stress); and biodiversity peaks at intermediate levels of human influence (intermediate disturbance). To test these hypotheses, we compared anthropogenic land cover and housing units, as indices of human influence, with bird species richness and abundance across the Midwestern United States. We modeled richness of native birds with 12 candidate models of land cover and housing to evaluate the empirical evidence. To assess which species were responsible for observed variation in richness, we repeated our model‐selection analysis with relative abundance of each native species as the response and then asked whether natural‐history traits were associated with positive, negative, or mixed responses. Native avian richness was highest where anthropogenic land cover was lowest and housing units were intermediate based on model‐averaged predictions among a confidence set of candidate models. Eighty‐three of 132 species showed some pattern of association with our measures of human influence. Of these species approximately 40% were negatively associated, approximately 6% were positively associated, and approximately 7% showed evidence of an intermediate relationship with human influence measures. Natural‐history traits were not closely related to the direction of the relationship between abundance and human influence. Nevertheless, pooling species that exhibited any relationship with human influence and comparing them with unrelated species indicated they were significantly smaller, nested closer to the ground, had shorter incubation and fledging times, and tended to be altricial. Our results support the ecosystem‐stress hypothesis for the majority of individual species and for overall species diversity when focusing on anthropogenic land cover. Nevertheless, the great variability in housing units across the land‐cover gradient indicates that an intermediate‐disturbance relationship is also supported. Our findings suggest preemptive conservation action should be taken, whereby areas with little anthropogenic land cover are given conservation priority. Nevertheless, conservation action should not be limited to pristine landscapes because our results showed that native avian richness and the relative abundance of many species peaked at intermediate housing densities and levels of anthropogenic land cover.     

辽河三角洲地区植被的地上净初级生产力格局及其制约因子

植被地上净初级生产力是监测和评价生态系统功能的重要指标之一,也是农业区划和生态资源分区管理的重要依据。通过实地调查,研究了辽河三角洲地区的植被地上净初级生产力的空间分布格局及其制约因子。2008年9月末,在辽河三角洲地区设立79个调查点,调查了植被地上净初级生产力、土壤和水文特征。借助ArcGIS软件制作了植被地上净初级生产力的分层设色等值线图,并利用简单相关分析和无条件主成分分析方法探讨了植被地上净初级生产力与环境因子的关系。结果发现：辽河三角洲地区的植被地上净初级生产力具有内部较低,外围较高的半环形分布格局。在三角洲内部,植被地上净初级生产力一般1 500 g.m-2.a-1左右;外围一般3 000 g.m-2.a-1以上。这种分布格局不仅与植被类型分布有一定的相关性,而且还与海拔高度、土壤含水量、土壤容重和土壤总磷等自然环境因子有明显的相关性。多种证据表明土壤含水量是决定辽河三角洲地区植被地上净初级生产力格局的最直接、最重要的自然环境因子。     

Development of ground vegetation under exotic tree plantations on restored coal mine spoil land in a dry tropical region of India

Restoration of mine spoil is a prime need for coal industry. The study of ground cover vegetation provides essential information about the species diversity and their successional trends during the restoration. The present study was conducted to analyze the structure and biomass accumulation of ground vegetation developing in different plantation stands of an opencast coal mine spoil in a dry tropical region. Different plantation stands showed variations in species diversities. Exotic herbs were more dominant in comparison to native herbs. Pennisetum pedicillatum, an exotic herb showed maximum Importance Value Index in most of the plantation stands. Total number of species varied between 12-18 in different plantation stands. Speces richness and evenness increased with increasing age of the plantations. Variations in total biomass accumulation of ground vegetation were also significant among different plantations. These results suggest that reforestation programme with exotic species on coal mine spoil has been successful in colonization of ground vegetation under different plantations. Gravellia pteridifolia plantations showed most successful ground cover among different plantation stands.     

Need for a global map of forest naturalness for a sustainable future

There is a growing need to assess and monitor forest cover and its conservation status over global scales to determine human impact on ecosystems and to develop sustainability plans. Recent approaches to measure regional and global forest status and dynamics are based on remotely sensed estimates of tree cover. We argue that tree cover should not be used to assess the area of forest ecosystems because tree cover is an undefined subset of forest cover. For example, tree cover can indicate a positive trend even in the presence of deforestation, as in the case of plantations. We believe a global map of forest naturalness that accounts for the bio-ecological integrity of forest ecosystems, for example, intact forests, old-growth forest patches, rewilding forests (exploited forest landscapes undergoing long-term natural succession), and managed forests is needed for global forest assessment.     

桉树人工林地力衰退防治研究──改全垦为带垦

主要讨论了桉树造林整地方式──全垦与带垦对桉树生长的影响,以及对土壤侵蚀、土壤养分和土壤物理性质的影响．研究结果表明,改全垦为带垦对防止桉树人工林地力衰退有积极作用．     

Fuel breaks affect nonnative species abundance in Californian plant communities.

We evaluated the abundance of nonnative plants on fuel breaks and in adjacent untreated areas to determine if fuel treatments promote the invasion of nonnative plant species. Understanding the relationship between fuel treatments and nonnative plants is becoming increasingly important as federal and state agencies are currently implementing large fuel treatment programs throughout the United States to reduce the threat of wildland fire. Our study included 24 fuel breaks located across the State of California. We found that nonnative plant abundance was over 200% higher on fuel breaks than in adjacent wildland areas. Relative nonnative cover was greater on fuel breaks constructed by bulldozers (28%) than on fuel breaks constructed by other methods (7%). Canopy cover, litter cover, and duff depth also were significantly lower on fuel breaks constructed by bulldozers, and these fuel breaks had significantly more exposed bare ground than other types of fuel breaks. There was a significant decline in relative nonnative cover with increasing distance from the fuel break, particularly in areas that had experienced more numerous fires during the past 50 years, and in areas that had been grazed. These data suggest that fuel breaks could provide establishment sites for nonnative plants, and that nonnatives may invade surrounding areas, especially after disturbances such as fire or grazing. Fuel break construction and maintenance methods that leave some overstory canopy and minimize exposure of bare ground may be less likely to promote nonnative plants.     

Land reclamation requirements and their estimated effects on the coal industry

This paper develops a model of the bituminous coal industry that is then used to simulate the price, output, and employment effects of land reclamation requirements in strip mining (other things equal). Our main conclusion is that a requirement to return strip-mined land to its approximate original contour and vegetative cover would have only slight effects on either sector of the industry. We estimate that such a requirement, had it been imposed in 1971, would have decreased strip-mining employment and output by 2.370, while inducing an increase in underground employment more than sufficient to offset these job losses.     

围填海的海洋环境影响国内外研究进展

围填海是通过人工修筑堤坝、填埋土石方等工程措施将天然海域空间改变成陆地以拓展社会经济发展空间的人类活动,它是当前我国海岸开发利用的主要形式。大规模围填海在产生巨大的社会经济效益的同时,也给海洋生态环境造成了深远的影响,受到了国内外学者的广泛关注。文章在系统收集了国内外围填海的海洋环境影响研究报道成果的基础上,分别从：①围填海对滨海地形地貌、湿地景观的影响研究;②围填海对近岸海域水动力环境的影响研究;③围填海对滨海湿地退化与生态功能的影响研究;④围填海对近岸海洋生态系统结构与功能的影响;⑤围填海对海洋渔业资源衰退的影响等5个方面深入分析了围填海的海洋环境影响国内外研究进展及其存在的主要问题。并剖析了加强围填海的海洋环境监测与评估,实施围填海的海洋生态环境修复与生态补偿等国际围填海研究新趋势。针对围填海的海洋环境影响国内外研究现状和发展趋势,提出加强对集中连片围填海区域的长期累积效应研究、加强围填海对海洋生态环境结构功能影响过程及机理研究、加强多学科交叉在围填海海洋环境影响方面的综合研究等相关建议。     

Response of Winter Birds to Drought and Short-Duration Grazing in Southeastern Arizona

Abstract: In a grassland–oak savanna in southeastern Arizona, we compared vegetative ground cover and bird populations between a 29-year livestock exclosure and an adjacent cattle ranch that was managed according to the principles of holistic resource management, including short-duration rotational grazing. The study took place in the winter after a 2-year drought and 1 year after the drought ended and stocking densities were reduced. During the first winter, grasses on the livestock exclosure were taller (4.4 times) and had higher basal area ground cover (2.5 times), canopy cover (2.2 times), and reproductive canopy cover (10 times) than in the grazed area. These differences persisted into the second winter but at lower levels. As a group, 19 species of ground-foraging, seed-eating birds (e.g., doves, quail, sparrows, towhees) were 2.7 times more abundant on the exclosure than on adjacent grazed grasslands during the first winter. These same species were 1.7 times more abundant on the exclosure during the second winter and were 2.9 times more abundant on both sites combined after the drought had ended. A second group of 24 avian species with different foraging ecologies (e.g., predators, frugivores, arboreal insectivores) did not differ between treatments or years. High-density, short-duration rotational grazing, coupled with a drought, left the land in a substantially denuded condition through two winters and negatively affected a variety of resident and migratory birds dependent on ground cover and seed production for over-winter survival.     

3种人工草地不同植被覆盖度实地测量方法比较

植被覆盖度是植被垂直投影面积占统计区域面积百分比;理想覆盖度实地测量方法耗时短,工具简单,结果准确,受人为因素影响小.以结缕草(Zoysia japonica)、白三叶(Trifolium repens)和雀稗(Paspalum thunbergii)人工草地为研究对象,以照相法测量值为参考,比较样线法、目估法、样针法...     

Response and resilience of <Emphasis Type="Italic">Spartina alterniflora</Emphasis> to sudden dieback

We measured an array of biophysical and spectral variables to evaluate the response and recovery of Spartina alterniflora to a sudden dieback event in spring and summer 2004 within a low marsh in coastal Virginia, USA. S. alterniflora is a foundation species, whose loss decreases ecosystem services and potentiates ecosystem state change. Long-term records of the potential environmental drivers of dieback such as precipitation and tidal inundation did not evidence any particular anomalies, although Hurricane Isabel in fall 2003 may have been related to dieback. Transects were established across the interface between the dieback area and apparently healthy areas of marsh. Plant condition was classified based on ground cover within transects as dieback, intermediate and healthy. Numerous characteristics of S. alterniflora culms within each condition class were assessed including biomass, morphology and spectral attributes associated with photosynthetic pigments. Plants demonstrated evidence of stress in 2004 and 2005 beyond areas of obvious dieback and resilience at a multi-year scale. Resilience of the plants was evident in recovery of ground cover and biomass largely within 3 y, although a small remnant of dieback persisted for 8 y. Culms surviving within the dieback and areas of intermediate impact had modified morphological traits and spectral response that reflected stress. These morphometric and spectral differences among plant cover condition classes serve as guidelines for monitoring of dieback initiation, effects and subsequent recovery. Although a number of environmental and biotic parameters were assessed relative to causation, the reason for this particular dieback remains largely unknown, however.