Ecotone is a unique landscape that displays special ecology attributes and service functions. Investigation of ecotone is significantly beneficial to both exploring novel ecological laws and conserving the vulnerable environment. An increasing attention to ecotone is evidenced by the average annual publication growth rate of 57% in the last 30 years. This paper presents the concepts of and the differences among ecotones, and its related terms (ecological boundary, transitional area, environmental gradient and edge). Specifically, ecotone is a region between two ecological systems with unique ecological properties, and ecological boundary is a generic term including all kinds of interfaces, while transitional area is a description of the scope between adjacent geographic zones. Edges and environmental gradient are terms not confined to ecological discipline. Furthermore, seven basic features of ecotone are summarized in brief as: high-biodiversity, rich ecotonal species, abundant exotic species, frequent material flows, sensitive temporal-spatial dynamics, structure heterogeneity and frangibility. Then, we introduced the published principals and hypotheses about ecotone as well as originally presented Gene Hybrid Zone Hypothesis, Habitat Pressure Hypothesis, and System Successsional Hypothesis to elucidate the mechanisms of ecotone. At last, research advances are discussed in four aspects: (1) The patterns of biodiversity development in ecotones. More and more researches have been exhibiting that ecotone creates genetic diversity although its species richness is still controversial. (2) Responses and feedback to global changes. Ecotone is very sensitive to global changes (warmer climate, disturbances, and biological invasion, etc.). The changes of landscape in ecotones are presumably due to the alteration of varied material flows. (3) Ecological design and management of ecotones. Many researches are performed on the functions of conduit, filter and barrier of ecotones, particularly in land/water interface. The uptake of nutrients by ecotones functions cleaning river water. (4) The models of ecotones and its integration. The dynamic of plants movement and the relationship of plants and soil in ecotones are simulated by kinds of ecotone models. However, integrated models are still deficient. We conclude that the highlights of future research should be ecotone theories, multi-scale models and multi-variable integrated analysis of ecotone patterns to discover ecological mechanisms of ecotone.

生态交错带研究对探索自然生态规律和保护环境有重要意义。近30a来，有关生态交错带的论文数平均年增57％，显示其得到了愈来愈广泛的关注。回顾了生态交错带概念的产生与发展，区分了它与边缘、生态边界层与生态过渡带等概念的异同；简述了其7个基本属性，即高生物多样性、丰富的特有种、大量外来种、频繁的物质流动、敏感的时空动态性、结构的异质性和脆弱性；总结提炼了生态交错带的基本原理和假说；综述了生态交错带的生物多样性产生机制、对全球变化的响应与反馈、生态设计与管理以及生态交错带模型发展和整合的研究进展。提出今后需要大力发展理论研究、多尺度模型转化和多因子综合分析，以完善生态交错带理论并支持生态学机理的探索。

生态交错带变化最显著的是物种组成和植被结构, 然而植物群落与土壤养分是相互制约相互促进的两个系统。前期利用植物物种多样性变化趋势测定出退耕还林政策驱动下, 退耕撂荒地—云南松林(Pinus yunnanensis Franch)交错带宽度约9 m。假设利用土壤养分变化与前期利用植物物种多样性变化测定出的生态交错带宽度和类型一致。为验证此假设, 选取滇西北维西县永春乡退耕还林政策下形成的退耕撂荒地—云南松林交错带为研究对象, 测定其土壤养分变化趋势, 并利用移动窗口法进行交错带位置和宽度的测定。结果表明: (1)相对于云南松林, 退耕撂荒地土壤养分含量(有机质, 碱解氮, 速效钾, 速效磷)均显著偏低; (2)pH, 有机质, 碱解氮的变化趋势能更好的用于测定交错带的位置和宽度, 且SED指数优于PD指数; (3)最终测定农林生态交错带的宽度为11 m, 属于急变型交错带,  与前期利用植物多样性变化测定的结果一致。

The issues of ecological water requirements have already been a focus of research in the context of increasingly aggravated eco-environment. The ecological water requirement is defined as the water capacity needed by the ecosystem which achieves a certain ecology level or maintains a certain dynamic balance status. The ecological water requirement would be different for different regions and different ecological objectives. Water is the most critical ecological factor over the northern farming-pastoral zones in China. The interrelations and interactions between water and the eco-environment to a large extent dictate the environmental dynamics and status of the northern farming-pastoral zones. In the present work, the authors investigated the mechanisms of the degradation of ecosystems from a perspective of ecological water shortage, with the aim to provide meaningful reference for ecological restoration and reconstruction in the northern farming-pastoral zones. The vegetation ecological water requirements for the Wuchuan County, a typical dry and semi-arid agro-pastoral transitional zone located in the middle part of the northern ecotone and facing serious ecological degradation, were calculated with the Penman-Monteith equation. In addition, the status of ecological water shortage in Wuchuan County was analyzed in detail on the basis of the experimental data of vegetation ecological water consumptions. The results showed that the major reason for degradation of vegetation ecosystems in the northern ecotone was ecological water shortage. The average water consumptions of natural grassland, shrubbery land, arbor land and cropland in Wuchuan County during growing season in 2006 were estimated to be 150.3 mm, 193.4 mm, 213.3 mm and 158.6 mm, respectively. The smallest amounts of ecological water shortage were estimated to be 93.1 mm, 38.2 mm, 251.5 mm, and 96.6 mm, respectively. It was found that vegetation of the ecosystem continued to develop towards the direction of degradation. Reasonable adjustments for the structure of plant species and reasonable allocation for limited water resources were the urgent needs for local ecological restoration and reconstruction. As to the ecological water shortage which caused the ecological degradation in Wuchuan County, the rational allocation for the limited water resource is to increase water supplies for vegetation ecosystems and to make the ecological water consumptions achieve the minimum even the optimum demands for ecological water requirements. Due to combined effects of a variety of factors, the processes of ecological degradation are quite long and complex. To this end, more comprehensive studies are needed in the future.

水是北方农牧交错带最关键的生态环境因子，水资源与生态环境之间的相互关系和相互影响很大程度上决定了北方农牧交错带的环境状况与环境动态。文章从生态缺水的角度，以内蒙古自治区武川县为例，探讨了生态系统退化机理，为北方农牧交错带的生态恢复与重建提供科学依据。研究结果表明，生态缺水是造成北方农牧交错带植被生态系统退化的主要原因。2006年武川县天然草地、灌木、乔木、农作物生长季平均耗水量分别为150.3mm、193.4mm、213.3mm、158.6mm，最小生态缺水量分别为93.1mm、38.2mm、251.5mm、96.6mm，植被生态系统继续向退化方向演替。合理调整植物品种结构，配置有限的水资源是当地生态恢复与重建的紧迫任务。

By constructing 16S rDNA clone library with PCR-RFLP, the prokaryote diversity in the seawater and groundwater of land-ocean ecotone of Zhuhai City was investigated, and the similarity and cluster analyses were implemented with the database of the sequences in Genbank. In the seawater, Proteobacteria was dominant, followed by Archaeon, Gemmatimonadetes, Candidate division OP3 and OP8, and Planctomycetes, etc.; while in the groundwater, Archaeon was dominant, followed by Proteobacteria, Sphingobacteria, Candidate division OP3, Actinobacterium, and Pseudomonas. The dominant taxa in the groundwater had high similarity to the unculturable groups of marine microorganisms. Large amount of bacteria capable of degrading organic matter and purifying water body existed in the groundwater, suggesting that after long-term evolution, the land-ocean ecotone of Zhuhai City had the characteristics of both land and ocean.

采用16S rRNA基因PCR-RFLP分析技术，对珠海市海-陆交错带的海水和地下水进行原核生物多样性分析，并将所得数据与国际基因数据库Genbank进行相似性比较及聚类分析.结果表明：海水细菌以变形菌居多，其次是古菌和芽单胞菌，以及Candidate division OP3、OP8和浮霉菌等；海陆交错带地下水细菌则以古菌居多，其次是变形菌和鞘脂杆菌，以及Candidate division OP3、放线菌和假单胞菌等.海-陆交错带地下水中大部分优势类群与源于海洋的不可培养细菌具有很高的相似性.地下水样中存在大量能降解有机质和具有净化水体潜力的细菌，说明在长期演化下，海-陆交错带兼备了海洋生态系统和陆地生态系统的特征.

The landform-climate-vegetation patterns of forest-steppe ecotone on the southeast of Inner Mongolia Plateau were revealed and the result showed that vegetation distribution was affected by the combination of climate and landform. Regionally, forest community type changed along precipitation gradient from reletively humid areas to arid areas as birch, oak and popular forest, and needle leaved forest was distributed closer to forest drought limit. Locally, broad-leaved forest was distributed mostly on shady slope where evaporation was weak and soil bulk density was low and steppe on sunny slope with strong evaporation. Elm woodland was distributed on sandy land with weak capillary force and little evaporation. Based on these results, we pointed out that first, regionally when choosing tree species, their individualistic precipitation limitation should be in primary consideration; second, in microzone with the range of appropriate precipitation, considering the effects of slope aspect on soil water condition, forest should be nourished on shady slope with an angle of 10 to 40 degree; third, local species, forest density and combination of tree, shrub and grass must be taken into account on both regional and local scale, and it is inappropriate to grow dense forest on sandy land.

探讨内蒙古高原东南缘森林-草原交错带地形-气候-植被格局,表明植被分布受气候和地形综合影响,在区域尺度上,随降水量减少阔叶林逐步由桦林向栎林、山杨林转变,针叶林更为接近森林旱极;在局地尺度上,阔叶林多分布在蒸发微弱、土壤容重较小的陡阴坡,草原分布在对应的阳坡上,非地带性榆树疏林分布在毛管作用微弱、蒸发小的沙地上。交错带植被建设应在降水量允许范围内优先考虑针叶树;其次要考虑坡向、坡位对土壤水分条件的影响,森林应尽量栽植在坡度10°~40°的阴坡;在区域和局地尺度上都应注意造林密度以及乔灌草结合,沙地不宜栽植密林。

The image spectrum reflectance ( R ), spectrum reciprocal (1/ R ), the logarithm of reciprocal spectrum lg(1/ R ), first derivative reflectance spectrum ( FDR ) and spectrum band depth ( D ) of five spectral index were selected to establish soil organic matter (SOM) inversion models, and the response characteristics of TM image of Qitai county are analyzed, the F test was used to validate the model significance. It turns out that: The accuracy value of the inversion models established by the five indicators on the soil layers and different depths SOM content are various, and the order from low to high is: lg(1/ R ) R R FDR D . The model accuracy of D is the best for inversion of SOM content, and achieves a good standard for the monitoring of SOM content (10-20 cm). The model accuracy of FDR is good, and 1/ R ， R are not good. The model accuracy of lg(1/ R ) is the lowest in predicting SOM content. The precision order of the soil layers models is: 50-60 cm< 40-50 cm< 30-40 cm< 20-30 cm< 0-10 cm< 10-20 cm, and for the different soil depths models is: 0-60 cm< 0-50 cm< 0-40 cm< 0-30 cm< 0-10 cm< 0-20 cm.

选取Landsat TM影像的光谱反射率（ R ）、反射率之倒数（1/ R ）、反射率倒数之对数（lg（1/ R ））、反射率一阶导数（ FDR ）、波段深度（ D ）等5种光谱指标，分别建立了奇台县土壤有机质（SOM）含量的反演模型，并利用 F 检验来验证模型的显著性。结果表明：用各光谱指标建立的土壤各层和不同深度SOM含量的反演模型精度值由低到高的顺序均为lg（1/ R ） R R FDR D ，以 D 反演SOM含量的模型效果最好，且对10～20 cm的SOM含量的反演精度最高，适用于对研究区SOM含量的反演， FDR 的反演效果次之，1/ R 和 R 的模型精度一般，而lg（1/ R ）的模型精度最差；各层拟合模型的反演精准度由低到高的顺序为50～60 cm <40～50 cm <30～40 cm <20～30 cm <0～10 cm <10～20 cm，不同深度反演模型的优劣为0～60 cm <0～50 cm <0～40 cm <0～30 cm <0～10 cm <0～20 cm。

Functioned as the "kidneys" of the earth, wetlands provide comprehensive eco-environmental and productive services in terms of flood mitigation, climate control, pollution prevention, soil-erosion reduction, environment beautification, biodiversity maintenance and bio-productivity protection. In China, most wetlands are distributed in the northwest part. Research on wetlands in semi arid region is very important and meaningful. Defining the location and width of interlaced zone is the basement to have quantitative study of its ecological process. In consideration of there is little research on identifying the interlaced zone boundary of semi arid area and small-scale wetland-dry grassland, this paper is based on the theory that changes of ecotone boundary can indicate the transformation of ambience in advance. Si'er Tan wetland, which is located in Yanchi county, Ningxia province, was studied by line transect methods. Four transect lines, centered on the wetland, ran into four directions: N, E, S and W respectively. These lines went through three main ecological areas including wet zone, interlaced zone and typical dry zone. Field investigations have been done every July to September during the year 2006 and 2010. In this paper, we first discussed the feasibility of using Moving Split-Window Technique in determining the interlaced zone boundary between wetland and dry grassland in semi arid area. Secondly, take Si'er Tan wetland for instance, Moving Split-Window Technique was used to identify the width and boundary of wetland and dry grassland from the year 2006 to 2010. Health condition of the whole wetland ecosystem can be known through analyzing the changes of width, boundary and vegetation of the interlaced zone during these five years. The results show that: Moving Split-Window Technique can be used to define the interlaced zone boundary. According to the dimension of investigatory scale and the visibility of ecotone transitivity, appropriate window width can be chosen especially in the selection of appropriate smallest window width. What's more, precipitation is the primary determinant factor of defining the location and width of interlaced zone but does not have substantial influence on vegetation variation. The distance between interlaced zone and the core area of the wetland can determine species richness index. By analyzing the data and making comparisons, wetland health condition shows significant differences. Owing to the built of the reserve, interlaced zone width got larger in the year 2006 and 2007, as a result, Si'er Tan wetland health condition had turned better. While from the year 2008 to 2010, the shrink of interlaced zone indicated the degradation of wetland, which as a result of railway construction disturbance. Results above prove that wetland-dry steppe alternated zone, which is always very sensible, can predict the transformation of the whole wetland ecosystem. In future development and degradation research of semi arid region wetland, we can focus on the study of interlaced zone evolvement. This method is feasible and much easier to make health evaluation for the whole wetland ecosystem. It can also provide new solutions and ideas to find and solve protection and improvement problems of wetlands in semi arid region.

鉴于目前国内对于半干旱区及小尺度上湿地-干草原交错带边界界定的研究较少,利用交错带对其周围环境变化具有提前指示作用的原理,以宁夏盐池四儿滩湿地为例,首先探讨游动分割窗技术在半干旱区湿地-干草原交错带边界判定中的可行性,其次再对2006年-2010年湿地-干草原交错带的宽度和边界进行判定,通过交错带的宽度和边界变化并结合交错带内植被的变化情况,综合对整个湿地生态系统的健康状况和湿地退化进行研究。结果表明:研究的尺度大小以及交错带过渡性是否明显将决定适宜窗口宽度的大小,这点在选择最小适宜窗口宽度时体现更为显著;降雨量是决定该区交错带的位置与宽度的最主要因素,但降雨量并不是决定该区交错带内植被变化状况的最主要因素,交错带距湿地核心区的距离是影响交错带内物种丰富度指数变化的最主要因素;由于保护区的成立,四儿滩湿地在2006年-2007年间,交错带宽度变大,湿地状况转好,2008年-2010年,由于铁路建设,湿地遭到破坏,交错带萎缩,湿地出现退化现象。湿地-干草原交错带作为一个敏感地带,它的变化情况可以对整个湿地生态系统的变化情况作出一定的提前预示;在半干旱区湿地的健康评价和退化研究中,通过交错带的变化来反映整个湿地生态系统的健康情况是一种可行的思路和方法。

The natural restoration process of plant community in Grave-Soil-Taken Field which formed by road construction at different stages in the alpine steppe of Tongde county in the Three-River Source Region was studied in the present research. The combined community field survey and soil analysis were employed to investigate the natural succession of alpine steppe vegetation of Grave-Soil-Taken Field. The results showed that total above-ground biomass increased with restoration time. However, the total aboveground biomass of plant community in Grave-Soil-Taken Field had no significant difference with the control plots after 30 years of vegetation recovery. The total underground biomass in Grave-Soil-Taken Field fluctuated between 5 years and 30 years after road construction. Furthermore, the total underground biomass was significantly lower ( P P <0.05) between 5 years and 30 years after road construction. Comprehensive recovery capacity of alpine steppe decreased with recovery time increasing. The stability of plant communities increased with recovery time increasing. After 30 years of natural restoration, the plant communities were relatively stable. Changes of soil nutrients, especially organic mass and available phosphorus had significant influence on the productivity of plant community, species diversity and comprehensive recovery capacity.

本研究以三江源区同德县不同年代修建公路产生的取土场高寒草原植物群落为研究对象, 通过野外群落调查和室内土壤样品分析, 探讨自然恢复过程中植物群落的生产力、物种多样性、综合恢复能力和稳定性动态以及土壤养分变化等。结果表明, 1)植物群落的地上总生物量随恢复年限的增加呈递增趋势。但恢复年限为30年时, 取土场植物群落的地上总生物量与对照间并无显著差异( P>0.05)。地下总生物量在5～30年间波动变化。并且经过30年的恢复后, 地下总生物量仍显著低于对照(P <0.05)。2)恢复年限在5～30年期间, 植物群落物种多样性明显增加。植物群落的综合恢复力指数随恢复年限的增加而降低;植物群落的稳定性随恢复年限的增加而增加, 并且以经过30年自然恢复后的植物群落相对最为稳定。3)土壤养分的变化, 特别是有机质、速效磷的变化对植物群落的生产力、物种多样性以及综合恢复能力产生显著影响。

Ecotone is one of the important features of environmental gradient. Where there is an apparent ecotone along a gradient is a controversy existed in geography and geobotany. However, quantitative determination of its location and width is the basis for studying the ecological process of the ecotone. Transect is an effective methodology to collect non-continual gradient data and to study the structure, function and pattern variation of the ecotones. The most important characteristic of the ecotone is the vari...

生态过渡性是梯度环境的特征之一 ,过渡带的显著性是地理学和地植物学中长期争论的重要问题 ,生态交错带位置和宽度的判定是定量研究交错带生态学过程的基础。样带法是采集非连续梯度数据和研究交错带的结构、功能和格局梯度变化的有效方法。生态交错带变化最为显著的特征是植被的变化 ,包括植物种类组成和植被结构的变化 ,植被生态学群落分析中的相异系数、β多样性、梯度分析和分类排序技术等已被证明是成熟可靠的方法。介绍两种交错带定量判定的有效方法。游动分割窗技术是通过滑动求取样带上样点间相异系数 ,通过相异系数变化曲线判定交错带的位置和宽度。分割窗技术提供了敏感地定位非连续梯度的客观且有效的方法 ,它不仅可用于环境梯度上的等距离样点取样 ,而且可用于非等距离梯度样带多元变量的分析。植被的特征是对生态环境连续体的综合反应 ,植被在环境梯度上的排序参数提供了一种较好的交错带定量指标 ,样带植被数据特征参数的变异轮廓图能够反应植被沿样带的物种组成、结构和空间变化格局 ,可以反应植被沿环境梯度的 β多样性和植物群落的梯度分化 ,植被变异侧面轮廓图的间断或不连续 (突变 )区间就是群落边界的位置。

It is well known that human's living depends on plant communities, so it is very important to inquire into methods for studying plant communities stability not only in the theory but also in the practice. Based on the results of modeling community succession and comparative analysis, we proposed a method and improved M.Godron's method for studying community stability in this paper. As a sample,Daqinggou forest plant community was used to test efficiency of the above two methods.The results achieved by the two methods were similar,which showed they were suitable to study community stability,and their results could be verified each other.The Godron's method could only provide information whether community was stable, the other method combined community succession model with comparative analysis could indicate whether community was stable and what the community succession orientation and tendency were. It was effective to study community stability and useful for us to understand dynamic process of communities.

在群落演替预测研究的基础上,结合比较分析,提出群落稳定性的测度方法,并对M .Godron法进行改进。以大青沟森林植物群落为例,探讨了上述两种方法在群落稳定性研究中的有效性。2种方法得出较为一致的结果,说明它们都适于森林植物群落稳定性的研究,可互相验证。但M .Godron法结果仅能提供群落稳定与否的信息,而演替与比较分析相结合的方法还可以说明群落的演替方向及趋势。因此,它有助于理解群落的动态过程,是研究森林植物群落稳定性较为有效的方法。

By secret plots method, species composition, flora character, living form, growth form, water ecotype and species diversity of harvesting on Pinus tabulaeformis inter forest grassland in Lingkong Mountain were analy. The result indicated that: 1)There is a significant difference between clear cutting and intermediate cutting forest grassland on the geographical composition in the family and species level. The areal types of genera is largely affected by the harvesting time. 2)Therophytes more easily survive in the clear cutting than intermediate cutting forest grassland, cryptophytes may be more suitable growth under the woods environment. 3)The quantity and type of growth and water ecotype are more abundant of clear cutting forest grassland than intermediate cutting. 4)Except Carex lanceolata and Chrysanthemum chanetii , the dominant species in three plots are not the same; Due to the different harvesting time and the degree, species diversity of complex appear: plotⅠ＞plot Ⅲ＞plotⅡ.

采用记名样方,对不同采伐方式油松林林间草地群落的草本植物区系及其生态生活型和物种多样性进行了比较分析。结果表明,皆伐后林间草地的草本植物科、属、种数均高于间伐,不同时间间伐的物种数变化不大。在种水平上的区系地理成分都是以温带分布为主和植物生活型以地面芽、隐芽植物为主。皆伐方式下的各生长型种数比间伐方式下多,一年生草本所占比例也较大。不同采伐方式下的水分生态型差异不明显,以中生和旱中生植物为主。重要值统计结果表明,不同采伐方式下草本群落除共优种大披针苔草( Carex lanceolata)、小红菊(Chrysanthemum chanetii )外,均存在不同的优势种。物种多样性指数随采伐方式和时间不同呈现出皆伐＞间伐、采伐晚的＜采伐早的。

Aims Human disturbance, such as overgrazing have resulted in widespread declines in biodiversity and ecosystem functioning and services in arid and semiarid grasslands worldwide. This study is aimed to examine the effects of grazing intensity, topography and precipitation fluctuation on plant diversity across three levels of organization (i.e., plant species, functional group, and community) in a typical steppe of the Inner Mongolia grassland. Methods Based on a long-term grazing experiment maintained for eight years with seven levels of grazing intensity and two topographic systems in a typical steppe of the Inner Mongolia grassland, the effects of grazing intensity, topography (flat vs. slope), and precipitation fluctuations (wet vs. normal years) on plant diversity (i.e. α, β and γ diversity) and their controlling mechanisms were examined. Important findings Our results showed that: (1) The diversity-grazing intensity relationship differed between two topographic systems and over two years (wet vs. normal years). The α, β, and γ diversity in the wet year (2012) were higher than those in the normal year (2011). The effect of topography on plant diversity was dependent on precipitation, with higher α diversity in the slope system and normal year and higher α and γ diversity in the flat system and wet year. There was no significant effect of topography on β diversity. (2) The α diversity decreased with increasing grazing intensity in both the flat and slope systems. The α diversity response to grazing differed substantially among the dominant species, common species, and rare species in the two topographic systems, with the highest negative response for rare species, intermediate negative response for common species, and the weakest response for dominant species. (3) In the flat system, γ diversity declined with increasing grazing intensity, while it firstly decreased and then increased at the intermediate level of grazing intensity in the slope system. (4) The β diversity decreased with increasing grazing intensity in the flat system due to grazing-induced species convergence, while it did not show any tendency in the slope system. Our results suggest that the topography and precipitation are two key factors governing the relationship between plant biodiversity and grazing intensity in the arid and semiarid grasslands. The loss of species in the dry year was greater in the flat system than in the slope system, while the opposite result was found in the wet year. The rare species plays an important role in maintaining species diversity. These findings provide a better understanding of the biodiversity-grazing intensity relationship in the context of different precipitation and topographic conditions in the semiarid steppe and beyond.

人类活动干扰对生物多样性和生态系统功能的影响机制是近年来生态学研究的一个热点问题。该研究以内蒙古锡林郭勒草原生态系统国家野外科学观测研究站的大型放牧控制实验为平台, 系统地研究了不同降水(丰水年份和平水年份)和地形(平地和坡地)条件下, 放牧对典型草原不同空间尺度植物多样性(α、β和γ多样性)的影响。研究发现: (1)降水和地形条件及其交互效应对植物多样性有明显的影响, 丰水年份的α、β和γ多样性均高于平水年份; 降水和地形条件存在交互效应, 平水年份坡地系统的α多样性高于平地系统, 丰水年份平地系统的α和γ多样性高于坡地系统, 而地形对β多样性并没有显著影响; (2)随着放牧强度的增加, 平地和坡地的α多样性均呈逐渐下降的趋势, 不同植物群落成员型(优势种、常见种和稀有种)对放牧的响应及其对α多样性的贡献不同, 其中稀有种对α多样性的贡献最大, 常见种次之, 优势种最小; (3) γ多样性对放牧强度的响应受地形条件的影响, 随着放牧强度的增加, 平地γ多样性呈逐渐下降的趋势, 而坡地γ多样性呈现先减少后增加的趋势; (4)平地β多样性随放牧强度的增加而逐渐减小, 而坡地并没有明显的规律。该研究表明, 植物多样性对放牧的响应受降水和地形因素的调控, 平地对放牧的缓冲能力强于坡地, 干旱会加剧过度放牧对生物多样性的影响; 稀有种对于草地生态系统的多样性维持具有重要意义。因此, 在确定合理的放牧强度时, 应结合降水和地形条件。在平水年份需加强平地系统植物多样性的保护, 而在丰水年份需加强坡地系统植物多样性的保护, 从而实现草地资源的可持续性利用。

To measure the eco-tone width is fundamental to the quantitative study on the ecological processes of eco-tone.In this study,Moving Split-Window Technique (MSWT) was used to measure the eco-tone width between mountain agro-ecosystem and forest ecosystem.Four indices (Species richness,Cody,Dissimilarity coefficient and Important value) had been selected,which could reflect the change of species biodiversity in eco-tone transect gradients.In addition,Squared Euclidean distance (SED) was better than Bray-Curtis percent dissimilarity (PD) for quantifying the change of species biodiversity in the eco-tone of agricultural-forest ecosystem.The results showed that the species richness was consistent with issimilarity coefficients in the eco-tone transect.It was also indicated that the width of eco-tone of agricultural-forest ecosystems was a sharp type which spanned about 9 m.

生态交错带宽度的测定是定量研究其生态过程的基础,研究利用移动分割窗技术,对退耕还林工程影响下的山地农业生态系统和森林生态系统间的生态交错带宽度进行测定.首先以对生态交错带生物多样性分布趋势有较好体现的4个多样性指数(物种丰富度、Cody指数、群落相异性系数( β J 和 β S ))和能体现群落本质特征的重要值为指标,取平方欧氏距离(SED)和Bray-Curtis系数(PD)为距离系数,采用移动分割窗技术分析比较.结果表明,物种丰富度,群落相异性系数 β J 和 β S 曲线趋势具有很好的重合性,同质区间也体现得较为明显,说明这3个指标生态学意义明显,有较高的实用价值;与PD相比,SED函数划分的结果要好.然后选取物种丰富度、群落相异性系数 β J 和 β S 作为指标以及SED作为距离系数对交错带的宽度进行测定.撂荒地-云南松林交错带位置约在样带序列25~36 m处,宽度为9 m,属于急变型交错带.

Two transects were set up to study the Lespedeza potaniniiArtemisia ordosica community boundary in south edge of Maowusu Desert. The squared Euclidean distance coefficients of sampling plots along ecotone transect were applied in the moving splitwindow technique for edge influence of landscape boundary position and width in the area across the community. The result showed that while the split form was in size of 4 and 6 units of plots, the curves dramatically varied and the identification of landscape boundary was interfered. While the minimum size of splitwindow was 8 plots the landscape boundary could be properly identified. The emerging peaks appeared between plot 20 and plot 25 in Transect A and B. Therefore, moving splitwindow technique was an effective method for edge influence of landscape boundary and community classification and it was a satisfactory method to show the peaks and widths of communities in small scale.

采用样带法，以毛乌素沙地南缘牛枝子Lespedeza potaninii-黑沙蒿Artemisia ordosica群落界面为研究对象。以样带上样地间的平方欧氏距离系数为指标，采用游动分割窗技术判定了牛枝子-黑沙蒿群落界面的位置和宽度。结果表明：当分割窗体大小在4个和6个样地单位时，曲线波动大，干扰了界面的判定。而最小窗体大小为8个时，能很好地进行界面的判定。样带A和样带B在样地2025都出现了波峰。游动分割窗技术是景观界面影响域判定和群落划分的有效方法，并在小尺度研究中能够较好地解释群落水平界面的边界和宽度。

The distance coefficients of sampling plots along on ecotone transect were applied in the moving split-window technique for determining ecotone position and width in the area across the Abies faxoniana timberline ecotone in Balang Mountain, on the southeast edge of the Qinghai-Tibetan Plateau. The result showed that distance coefficients, such as Bray-Curtis percent dissimilarity, relative Euclidean distance, chord distance, squared Euclidean distance, coincide in peaks and width in the transect. Among them, the squared Euclidean distance is the best one to show the variation of ecotone in the moving split window. The peaks and widths of space coefficients are sensitive indicators for those of ecotones. Therefore, moving split-window technique is an effective method for ecotone determination and community classification.

以样带上样方间的距离系数为指标，采用游动分割窗技术辨析了岷江冷杉(Abies faxoniana)林线附近交错带的位置和宽度。结果表明，Bray-Curtis距离、相对欧氏距离、弦距离与平方欧氏距离的峰值和峰宽具有很好的重合性，上述距离系数均能作为判定林线交错带群落的边界和宽度的优良指标，其中，平方欧氏距离更能直观和准确地反映交错带植被的变异。样带上距离系数的峰值区和峰宽对生态交错带的位置和宽度有较为敏感的指示意义，游动分割窗技术是交错带判定和群落划分的有效方法。以样带上样方间的距离系数为指标，采用游动分割窗技术辨析了岷江冷杉(Abies faxoniana)林线附近交错带的位置和宽度。结果表明，Bray-Curtis距离、相对欧氏距离、弦距离与平方欧氏距离的峰值和峰宽具有很好的重合性，上述距离系数均能作为判定林线交错带群落的边界和宽度的优良指标，其中，平方欧氏距离更能直观和准确地反映交错带植被的变异。样带上距离系数的峰值区和峰宽对生态交错带的位置和宽度有较为敏感的指示意义，游动分割窗技术是交错带判定和群落划分的有效方法。

A field survey was conducted to investigate the quantitative characteristics of alpine vegetation among grazing area and fenced area. The results of this study showed that the fence obviously increased the coverage, height and biomass of alpine vegetation, proportion of palatable forage group, which included grasses, sedges and other forages, and decreased the proportion of unpalatable forage. Meanwhile, the fence changed the community composition structure and dominant values of plant species, indicating that the fence increased plant diversity and the important values of some palatable forage, and decreased the important values of some unpalatable forage.

对青海湖地区高寒草地围栏内外植被进行调查分析。结果显示，围栏封育措施使高寒草地植被的盖度、高度、生物量均明显增加，从不同经济类群分析，其禾草、莎草等可食牧草比例增加，而不可食牧草比例相对下降。围栏封育措施对群落组成结构及植物种的重要值产生不同程度的影响，主要表现在生物多样性增加，一些可食牧草的重要值增加，而不可食牧草的重要值相对下降。