分析了内蒙古锡林河流域羊草(Leymus chinensis)草原群落植物种群、功能群和群落生物量的长期变异性，以及植物功能群间的补偿作用对群落稳定性的影响，结果表明：从种群水平到功能群和群落水平，地上生物量的年度间变异性逐渐降低，而稳定性则逐渐增加。植物功能群组成对群落稳定性具有更强烈的影响，在植物生活型功能群组成中多年生根茎禾草与多年生丛生禾草和多年生杂类草功能群，在生物量的年度变化上具有补偿作用，在生态类群组成中，旱生植物与中旱生植物也具有补偿作用。植物种群多度的长期变异性可能依赖于物种对环境波动的敏感性和种间相互作用对环境波动的放大效应，生物多样性使物种对环境波动响应的多样性增加，并通过不同响应类型(功能群)间的补偿作用使群落稳定性增加。

？高寒矮嵩草(Kobresiahumilis)草地是青藏高原的主要植被类型之一，其稳定性的维持对保证高原生态屏障功能发挥具有十分重要的意义。对青藏高原高寒矮嵩草草甸稳定性的维持机制、丧失过程与恢复途径与措施，进行了综述，拟为青藏高原高寒草地的可持续利用和退化高寒草地的恢复，提供理论依据。

研究围栏封育后退化草地群落功能群的变化.在达日县典型的中度退化的嵩草草甸上建立试验样地,并进行了连续3年的观测.结果显示:随着封育年限的增加,群落盖度、多样性及生物量均在增加,其中禾本科功能群生物量增加最快,莎草科功能群次之,豆科功能群增加缓慢,而杂类草功能群生物量却逐年减少.

In order to improve the management of degraded grasslands, the characteristics of the plant communities (structure and biomass) were investigated under three grazing treatments; unrestricted grazing, 3-year enclosure and 7-year enclosure in Shenzha, Northern Tibet. The result showed that, after enclosure, vegetation height gradually increased as the duration of enclosure increased. Above-ground and below-ground biomass, vegetation coverage and community species diversity were highest in the 3-year enclosure treatment, and Pielou evenness index was the largest in the natural-grazing. Biomass and the important value of grass and sedge functional groups increased with extended enclosure time, while values for the forbs functional groups decreased significantly, indicating that enclosure promoted plant community succession. Analyzing the relationship among plant coverage, above-ground biomass, community composition and enclosure time suggested that three-five years of enclosure at a stocking rate of 1.23 sheep/ha is appropriate for the degraded alpine grasslands in this region.

针对近年来退化高寒草原的恢复和合理利用的问题,对自然放牧、封育3年和7年的藏北申扎高寒草原设置样地,采用群落调查、收割法收集地上生物量,根钻法收集地下生物量等,比较分析不同封育年限下草地群落各生态指标。结果表明,高寒草原围栏封育后,随自然放牧到3年禁牧再到7年禁牧,植被高度持续增加,地上地下生物量、总盖度、物种多样性维持性能增加再降低,Pielou 均匀度指数在自然放牧草地最大。随封育年限延长,禾草类及莎草类植物功能群生物量及重要值显著增加,杂草类功能群生物量及重要值显著降低,说明封育措施有利于群落的正向演替。但通过对群落总盖度、地上生物量及群落种类组成与封育年限间关系进行统计分析表明,藏北高寒草原封育达3到5年后以1.23只羊单位/hm 2 的放牧强度放牧为佳。

摘　要： 以内蒙古太仆寺旗地区典型克氏针茅-羊草草原为研究对象，通过调查围封6年后围栏内外典型草 原群落特征，分析围封、放牧处理下典型草原植物群落结构及地上生物量的动态变化，揭示围封放牧对植被群落结构、物种丰富度和地上生物量的影响。结果发现， 在围封6年后，各功能群物种丰富度与盖度围栏内外的空间变化趋势基本一致。群落物种丰富度和地上生物量均随坡位下降而显著增加，初步显示了物种多样性与生 态系统功能的空间变化的一致性。围栏内物种丰富度显著低于围栏外，而地上生物量却显著大于围栏外。围栏内多年生禾草、一年生植物物种丰富度显著低于围栏 外，而半灌木盖度、生物量显著高于围栏外。围栏内外在禁牧和放牧不同处理下，表现出不同的草原退化方式：在禁牧条件下，尽管生物量有所恢复，但灌木和半灌 木的增加却代表了草原的退化；放牧、刈割等人类活动增加了耐牧物种和不适口植物生长的可能，表现为草原退化指示物种增加，同样是草原退化的表现。围栏外一 年生植物盖度和生物量显著高于围栏内，而一年生植物的频数也远远大于围栏内（围栏内外频数比13：71），且独行菜、猪毛菜等仅出现于围栏外。同时，地上 生物量随着物种丰富度的增加而增加，但只有围栏外的关系达到统计显著程度，说明围封调制了生物多样性与生态系统功能的关系。本研究表明，对于干旱半干旱典 型草原的恢复，不能简单地采用长期完全禁牧措施，应当根据区域环境、植被以及社会经济情况，制定季节性放牧或者间歇性禁牧的恢复措施，从而保证草场的可持 续性恢复利用。

A field experiment was conducted in alpine enclosure grassland in Qinghai Lake Region, and the community features were investigated for four consecutive years. The objectives of the experiment were to reveal the dynamics of plant community structure, function and diversity of alpine grassland under enclosure and provide the basic data for the scientific management and rational utilization of grassland. With the extension of enclosure period, the community coverage and aboveground biomass significantly increased ( P P P <0.05), and the evenness index increased followed with decreased. Comprehensive considering community composition, coverage, primary productivity and species diversity, grassland can be used appropriately (mowing and grazing) after enclosuring for two years.

为了揭示禁牧封育下高寒草原的群落结构、功能和多样性动态变化规律，为草地合理利用提供基础数据，本研究对环青海湖地区高寒草原的植物群落特征进行了连续4年的调查研究。结果表明，植物群落盖度和地上生物量随着围封年限的增加表现为先显著增加后显著降低( P <0.05)，均匀度指数呈现先降后增的趋势;综合群落组成、盖度、初级生产力和物种多样性指标，在对草地进行围栏封育两年后，可对草地进行适当的利用(刈割或放牧)。

An experiment was conducted to determine the response of grassland plant community quantity characteristics to short-term enclosure in Hongsongwa Natural Reserve by monitoring the community change of grassland plant. Both enclosed measure area and continuous grazing area were studied with the quadrat method.The results showed that the basic components of plant communities inside and outside the fence did not change significantly. In both areas, the dominant species were Carex lanceolata , Polygonum viviparum , Sanguisorba officinalis and Artemisia tanacetifolia , et al . The short-term enclosure increased vegetation height, density and above-ground biomass. The species richness index( S ), dominance index ( DS and H ) and uniformity index( JP ) of tested areas were not significant difference. The similarity coefficients and Cody indexes of plant communities had similar change tendency in 2 years, and plant communities inside and outside the fence had high similarity.

为了解红松洼自然保护区植物群落数量特征对短期围栏封育的响应,以当地草原植被为研究对象,采用样方法对封育区和放牧区植被生长状况进行调查.结果表明:围栏内外植物群落的基本组成未发生明显变化,围栏内外均以披针叶苔草( Carex lanceolata )、珠芽蓼( Polygonum viviparum )、地榆( Sanguisorba officinalis )和裂叶蒿( Artemisia tanacetifolia )等植物为优势种,围栏封育措施提高了草地群落高度、密度和地上生物量.围栏内外物种丰富度指数 S 、优势度指数 DS 、Shannon-Wiener多样性指数 H 和均匀度指数 JP 差异不显著.围栏封育2年植物群落的相似性系数和Cody指数的变化趋势基本相同,围栏内外群落具有较高的相似性.

The aim of this study was to determine the effects of fencing on the productivity and structure of plant communities and on the physical and chemical properties of soil in alpine meadows. A field study was conducted in two types of degraded alpine meadows, one dominated by Kobresia pygmaea and the other dominated by Kobresia humilis , in the Qinghai Lake Basin. The results showed that the aboveground biomass of K. pygmaea and K. humilis increased by 33.8%, and 31.5%, respectively, after 2 years of exclosure. Exclosure significantly increased the proportion of aboveground biomass of sedges and members of the gramineae, and decreased the proportion of aboveground biomass of forbs. Exclosure also resulted in significant increases in plant community diversity and evenness indexes. In the K. pygmaea and K. humilis alpine meadows, grassland soil organic carbon content in the 0-10 cm soil layer increased by 10.15% and 12.74%, respectively, after 2 years of exclosure. The soil organic carbon content in the 10-30 cm soil layer did not change significantly after 2 years of exclosure. In K. humilis meadow soil, the total phosphorus content increased by 16.13% in the 0-10 cm soil layer, but was unchanged in 10-30 cm soil layer after 2 years of exclosure. In the K. pygmaea and K. humilis alpine meadows, soil bulk density increased by 6.61% and 6.25%, respectively, and pH decreased by 4.04% and 3.69%, respectively, in the 0-10 cm layer after 2 years of exclosure. In the 10-30 cm soil layers of both types of meadows, neither soil bulk density nor pH was affected after 2 years of exclosure.

以青海湖流域退化的高寒草甸2个草地类型为对象,比较分析了围封2年样地植物群落生物量、群落结构和土壤理化性质的变化。结果表明, 1)围封后高山嵩草和矮生嵩草的地上生物量较放牧地分别增加了33.8%和31.5%;且禾本科植物生物量的比例显著增加,杂类草的比例降低。2)功能群多样性指数和均匀度指数显著增加。3)围封2年后,2个草地型0~10 cm土层土壤有机碳含量分别增加了10.15%和12.74%,10~30 cm土层均无显著变化;矮生嵩草草地0~10 cm土层土壤全磷含量增加了16.13%,其余无显著变化;表层土壤容重分别降低了6.61%和6.25%,pH值降低了4.04%和3.69%,10~30 cm土层均无显著变化;土壤全磷含量在各土层均无显著变化。

自20世纪70年代前,人们相信多样性比较高的群落增加生态系统的稳定性, 到倾向于物种多样性与生态系统稳定性关系的探讨至近20年间,生物多样性与生态系统功能的关系及其内在机制成为生态和环境科学的中心问题.多样性的变化始终与生态系统功能的重要表现形式--生产力密切相关,同时也与许多其他影响生产力的因素相关.人们对于这一重大课题的认识不断有新的进展,同时争论的观点也不断延伸.1)考虑空间类型来揭示由环境因子引起的多样性与生产力之间的相关性;2)考虑时间尺度上物种多样性-生态系统的功能;3)非生物因素(放牧干扰、土壤养分)等环境因子、物种多样性动态和生态系统功能之间的交互作用的实验研究不断开展;4)在注重提高资源利用率的同时,应注意引起资源的过度开采,导致生物多样性的丧失,从而降低系统生产力.

摘　要： 以宁夏盐池县四儿滩湿地-干草原为研究对象,根据四儿滩湿地植被特征,将其由湿地中心向外依 次划分为湿生带、交错带、旱生带。通过2012年7—9月份的野外调查,利用改进的M.Godron稳定性测定方法,研究其植被群落的稳定性。结果表明： （1）3条样地带的植被群落稳定性交点坐标分别为（18.39,81.61）、（24.75,75.25）、（22.85,77.15）,即湿生带植被群 落稳定性最高（欧氏平方距离为5.180 2）,旱生带次之（欧氏平方距离为16.267 7）,可见水分对植被群落稳定性有着正相关作用;而由于交错带位于湿生带和旱生带之间,同时湿地面积不断缩减,因而交错带处于不断演替的阶段,其植被群落 稳定性最低。（2）3条样带的植被种类数量表现为,交错带数量最多（23种）,旱生带次之（21种）,湿生带的种类最少（12种）,主要与旱生带土壤含水 量低,湿生带土壤盐碱化严重的现象密切相关,而交错带由于处于旱生带和湿生带之间,同时具备了土壤含水量适中,土壤盐碱化较弱的优点,故植被种类最多。整 体上,四儿滩湿地植被群落趋于稳定,且植被种类较多。这与近年来盐池县实施的草场封育措施密切相关,大大降低了放牧对湿地植被的破坏,利于植被生长和恢 复。此外,今年雨水较往年多,很大程度地提高了干旱半干旱区植被的覆盖率和多样性,提高其稳定性。

植物群落多样性与稳定性是群落生态学的核心内容,是现代生态学的热点问题,也是草地资源评价与管理的重要指标。青海湖流域是我国主要牧场之一,研究该地区草地利用现状和封育影响评价对草地可持续利用具有重要意义。本文利用Simpson,Shannon-wiener和Pielou物种多样性指数及改进后的Godron稳定性测定方法,分析了青海湖流域高寒草甸、高寒草原和温性草原三种草地群落的多样性、稳定性及二者之间的关系,比较了相同草地类型围栏内外的植物群落多样性和稳定性,及三种草地类型在围栏内外的情况。结果表明:(1)高寒草甸,多样性:围栏内>围栏外,稳定性:围栏外>围栏内;高寒草原,多样性:围栏外>围栏内,...

Services function of ecosystem in Sanjiangyuan region, including soil conservation, water-holding, carbon dioxide fixation and oxygen production, were analyzed with geographic information system (GIS), and its ecological functions were assessed with methods of market valuation, opportunity cost and shadow engineering. The results indicated that the quantity of soil conservation, water-holding, carbon dioxide fixation and oxygen production were 1038.3million, 16469million, 141.28million, 104.01milliont·a -1 , respectively; their economic values were 1252.8million, 11034million, 10053-47798million, 36709-41605million yuanRMB·a -1 , respectively; the total ecological value of ecosystem was 59049-101690million yuanRMB·a -1 . The ecological functions and value were huge in Sanjiangyuan region, and it was very important to protect the structure and functions of its ecosystem for environment safety and sustainable development for the middle and lower reaches of rivers originating from Sanjiangyuan region.

在地理信息系统的支持下,将相关地图数字化并利用已有的地形数据库等资料,研究了三江源地区生态系统土壤保持、涵养水源、固定CO 2 和释放O 2 等4项生态功能,并利用市场价值法、机会成本法和影子工程法等评估了其生态功能的价值.研究结果表明:三江源地区生态系统土壤保持总量为1.0383×10 9 t·a -1 ,其价值总计为1.2528×10 9 元·a -1 ;植被凋落物和土壤涵养水源能力为1.6469×10 10 t·a -1 ,涵养水源能力价值为1.1034×10 10 元·a -1 ;生态系统固定CO 2 为1.4128×10 8 t·a -1 ,价值为1.0053×10 10 ～4.7798×10 10 元·a -1 ;释放O 2 为1.0401×10 8 t·a -1 ,价值为3.670 9 ×10 10 ～4.1605×10 10 元·a -1 ;4项生态功能合计总价值为5.9049×10 10 ～1.0169×10 11 元·a -1 .由此可见,三江源地区生态系统生态功能价值巨大,保护其生态系统结构和功能对我国江河中下游地区和东南亚国家生态环境安全和区域可持续发展具有重大意义.

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 using χ 2 test, Pearson’s correlation coefficient, and Spearman’s rank correlation coefficient, a quantitative study was made on the interspecific association among the 561 species pairs of 34 dominant plant species of wetland vegetation in the middle and lower reaches of Fenhe River. The χ 2 test showed that among the 561 species pairs, 178 pairs were positively while 256 pairs were negatively correlated, and the correlation ratio was 0.70. Pearson’s correlation coefficient test showed that 157 pairs were positively while 402 pairs were negatively correlated, and the correlation ratio was 0.39. Spearman’s rank correlation coefficient test showed that 216 pairs were positively while 343 pairs were negatively correlated, and the correlation ratio was 0.63. As compared with χ 2 test and Pearson’s correlation coefficient, Spearman’s rank correlation coefficient was more sensitive. Most of the total 561 species pairs did not show significant association. The results indicated that the wetland vegetation in the middle and lower reaches of Fenhe River was at the early stage of succession. According to the adaptation to the environment and the leading ecological factors, the 34 dominant species were divided into four ecological species groups.

采用 χ 2 检验、Pearson相关系数及Spearman秩相关系数检验等数量分析方法对汾河流域中下游湿地植被的34个优势种，共561个种对间的关联性进行定量研究。结果表明： χ 2 检验有178个种对呈正相关，256个种对呈负相关，正负关联比为0.70；Pearson相关系数检验有157个种对呈正相关，402个种对呈负相关，正负关联比为0.39；Spearman秩相关系数检验有216个种对呈正相关，343个种对呈负相关, 正负关联比为0.63；与 χ 2 检验和Pearson相关系数相比，Spearman秩相关系数检验具有较高的灵敏度。561个种对中负关联居多，达到极显著或显著的种对少，说明汾河流域中下游湿地植被群落处于演替初期。根据这34个优势种群对环境的适应方式和主导生态因素辅助以PCA排序，可将它们划分为4种生态种组。

The vegetation composition and interspecific relationship reflect the interaction relationship of spatial distribution pattern among plant populations and communities. We analyzed the important value, diversity index of species, biomass composition, the Jaccard association index and spearman rank correlation coefficient of main species growing on patch in Polygonum viviparum alpine meadow ( P. viviparum patch) and control (CK), in order to reveal the ecological mechanism of succession process in Alpine meadow. The results indicated that number of species in P. viviparum patch was bigeer than that in CK, and the change pattern of each group was similar between important value and biomass composition. P. viviparum patch dominated mainly by forbs and grasses, accounting for 60.9% and 22.1% of the green biomass, respectively, and P. viviparum accounted for about one third of the green biomass; while it dominated mainly by grasses and forbs, accounting for 53.3% and 27.1% of the green biomass, respectively. In P. viviparum patch and CK, the significantly associated species-pairs accounted for 16.4% and 33.0% of their respective total species-pairs. The interspecific association of most species-pairs was not significant, and the independence between species-pairs was stronger. The ratios of negative and positive correlations were 0.83 and 1.40, respectively. Plant communities of P. viviparum patch was a stable stage. The formation of P. viviparum patch can strengthen community stable of alpine meadow.

群落植物种构成和种间关系反映植物种群和群落分布格局上的互作关系。通过对珠芽蓼( Polygonum viviparum )斑块及其对照区域群落植物种重要值、物种多样性指数、生物量构成及植物种种间关联Jaccard指数和Spearman秩相关进行分析,揭示高寒草甸演替过程中的生态学机制。结果表明,珠芽蓼斑块的样方物种数显著高于对照( P <0.05),二者类群生物量与其重要值构成变化规律类似。珠芽蓼斑块的植被构成以杂类草和禾草为主,其占绿色生物量的60.9%和22.1%,且珠芽蓼种群约占绿色生物量的1/3;而对照则以禾草和杂类草为主,分别占绿色生物量的53.3%和27.1%。珠芽蓼斑块及对照群落中,显著关联的种对数分别占各自总种对数的16.4%和33.0%,多数植物种对的种间联结较松散,种对间独立性较强,二者正相关与负相关种对数比分别为0.83和1.40。珠芽蓼斑块群落处于稳定阶段,珠芽蓼斑块的形成,能增强高寒草甸的群落稳定性。

作者研究了青海省甘肃马先蒿的植物学特性、群落特征及资源储量,在此基础上提出开发利用该资源植物的思路.

甘肃马先蒿(Pedicularis kansuensis)作为高寒草甸退化进程中的一种入侵毒杂草,其生长状况和繁殖特征为草地退化状况的重要指标,也是衡量高寒草甸演替进程的重要指示植物.通过比较重度退化和未退化高寒草甸的群落特征,甘肃马先蒿的生长状况与花期资源分配,结果表明:退化的高寒草甸土壤-植被系统变化明显,高寒草甸退化显著影响了甘肃马先蒿的生长状况和资源分配特征.在重度退化的黑土滩样地中,甘肃马先蒿个体形态特征如株高、根长、分叉数、叶片数、花数、总生物量都显著高于未退化高寒矮嵩草草甸样地;重度退化草甸中甘肃马先蒿花期各器官的资源投资状况,如根系投资、茎叶投资、繁殖投资分别为7.46%、48.76%、43.78%,未退化样地中甘肃马先蒿的根系投资、茎叶投资、繁殖投资分别为10.12%、54.34%、35.54%.在重度退化高寒草甸中甘肃马先蒿占据较大的生态位,长势良好,且将资源更多地用于繁殖投入.而未退化草甸中甘肃马先蒿优势度不大,更多的是将资源分配到根系和茎叶等营养器官,以期获得较多的水分、无机盐、光照等资源,增强个体竞争力.甘肃马先蒿在不同生境下资源分配的显著差异实质反映了草地退化的影响,亦是植物对外部环境改变的一种适应机制,同时也是植物可塑性的重要表现形式.

摘　要： 对甘肃省天祝县4个退化梯度高寒草甸的植被特征和土壤养分特征进行了研究。结果表明,随着退化程度的加剧,草地地上生物量、植被高度、盖度、土壤有机碳、全氮、全磷和土壤含水量都显著降低（P〈0.05）,重度退化草地土壤容重显著升高（P〈0.05）。草地植物群落发生明显退化演替,矮生嵩草（Kobresia humilis）、线叶嵩草（K.capillifolia）和垂穗披碱草（Elymus nutans）的优势种地位被珠芽蓼（Polygonum viviparum）所替代,物种数由未退化样地的19种减少到重度退化样地的7种,退化指示类毒杂草生物量比例逐渐增加,由9.77%上升到62.93%。草地的退化程度会影响草地的植被特征和土壤养分特征,应根据不同退化阶段采取不同的恢复治理策略。

为研究草地植被对水淹干扰的响应,在松嫩平原羊草 (Aneurolepidium chinense)草地1998年部分遭受水淹的吉林省大安市三家甸子草场内设置了经历不同水淹强度的样带,并对这些样带的植被组成及物种多样性特征进行 了比较研究.结果表明:1)在植被的水分生态类型功能群组成中,随水淹干扰强度的增加,湿生、湿中生类植物功能群的优势度比例基本上是逐渐增加的,中生、 中旱生类植物功能群的优势度比例则逐渐减小;2)在植被的生活型功能群组成中,随水淹干扰强度的增加,一年生植物的优势度比例呈单峰型变化,地下芽植物比 例增加,地面芽植物比例减小.某些单个物种优势度比例的不规则变化和功能群组成的规则变化表明,生态补偿作用不仅仅存在于植物群落的各个功能群之间,而且 存在于同一功能群内部的不同物种之间;3)群落的物种丰富度、多样性在经历中等强度水淹干扰的样带上较高,而在未受干扰的对照样带和受干扰较为严重的样带 都较低,这有力地支持了中度干扰假说.

Spatial heterogeneity is an important feature in grassland ecosystems. Understanding spatial heterogeneity and species richness is important for determining the degree of grassland degradation and for promoting the recovery of grassland ecosystems. We conducted field surveys in a Leymus chinensis grassland, an Achnatherum splendens grassland, and an Artemisia ordosica shrub grassland in Yijinhuoluo-Qi, Ordos, China, in August 2010. First, we established study plots composed of 90 quadrats along a 45 m transect in each of the three grasslands; each quadrat was 50 cm × 50 cm and was divided into four 25 cm × 25 cm sub-quadrats. We recorded all plant species within each sub-quadrat. Then, we harvested the aboveground biomass along each transect every 5 m, classified the content by species, and weighed the oven-dried material.We analyzed vegetation data using the power law to examine characteristics such as species composition, species diversity, biomass, and spatial distribution in the three types of grassland. Our results indicated that all three types of grassland followed the power law and exhibited a strongly heterogeneous distribution of vegetation (versus a random distribution). The index values of spatial heterogeneity and species diversity for the entire community in the A. ordosica shrub grassland were higher than those for the L. chinensis grassland, and those for the L. chinensis grassland were higher than those for the A. splendens grassland. The species richness and species diversity per 50 cm × 50 cm quadrat in the L. chinensis grassland were higher than for the A. ordosica shrub grassland; the A. splendens grassland had the lowest values. The average per-quadrat biomass in the A. ordosica shrub grassland was significantly higher than that in the A. splendens grassland, whereas the values in the L. chinensis grassland did not differ significantly from the other two grassland types. The average biomass and species diversity per quadrat increased with the spatial heterogeneity for the entire community in all three types of grassland. We analyzed the species compositions in these three grassland types from the viewpoint of biological succession and found that the grasslands changed greatly after enclosure with a fence to exclude grazing for 10 years. Inside the enclosure, annuals such as Salsola collina and poisonous, harmful plants such as Cynanchum komarovii decreased greatly, while highly nutritious grasses and legumes with good palatability for livestock became the main species. This indicates that the grassland vegetation had recovered to some degree by 2010 after establishing the enclosure in Yijinhuoluo-Qi. Recently, the power law has been used widely in Japan for calculating the quantitative species composition and spatial heterogeneity of constituent plant species. However, this method has not been used much in China, which has a vast area of grassland. The power law requires only a survey to count the binary occurrence of each species in quadrats, and the survey is simple and convenient for observing many quadrats (i.e., >50-100 quadrats) in a short time. This method also avoids the destruction of vegetation during observations because it is based only on visual observation.

利用幂乘方法则模型探讨了鄂尔多斯3种不同类型草地在禁牧情况下的群落结构特征,包括物种组成、物种多样性、生物量和空间分布规律。结果表明:幂乘方法则在解析鄂尔多斯不同类型草地的空间异质性时具有很好的吻合性;羊草( Leymus chinensis )草地、芨芨草( Achnatherum splendens )草地和油蒿( Artemisia ordosica )灌丛草地均比随机分布呈现了较强的空间异质性,群落整体的空间异质性指数表现为油蒿灌丛草地>羊草草地>芨芨草草地;群落整体的物种多样性指数为油蒿灌丛草地>羊草草地>芨芨草草地;L-样方(50cm×50cm)内的平均物种数和物种多样性指数均表现为羊草草地极显著地高于油蒿灌丛草地,油蒿灌丛草地又极显著地高于芨芨草草地( P P <0.001),而羊草草地与油蒿灌丛草地以及芨芨草草地之间没有显著性差异;这3种类型的草地其L-样方内的平均生物量和物种多样性指数都随着群落整体空间异质性指数的增大而增大。

青藏高原生态系统对全球气候变化较为敏感, 系统的行为能更早地预兆全球变化, 进而影响到邻近地区乃至全球气候. 因此, 青藏高原生态系统的行为研究具有特殊重要性. 利用中国科学院海北高寒草甸生态系统定位站多年来积累观测的长时间序列数据, 运用生态系统稳定性直接分析方法, 定量分析高寒草甸生态系统的稳定性及其对环境变化的灵敏度. 结果表明, 高寒草甸生态系统的主要气候因子如年降水、年均气温都比较稳定(CV值分别为16.55%和28.82%), 而年度地上净初级生产量较降水和气温更为稳定(CV值为13.18%). 净初级生产量关于降水和气温的灵敏度或弹性分别为 E = 0.0782和0.1113, 即净初级生产量对降水和气温的波动均不敏感, 也说明高寒草甸生态系统具有较高的稳定性. 通过高寒草甸生态系统与世界其他地区5个草地生态系统的稳定性度量值横向比较, 也显示出该系统的稳定性程度较高. 结构相对比较简单的高寒草甸生态系统有较高的稳定性, 说明群落稳定性虽然与物种多样性和群落复杂性有关, 但未必成正比关系. 还有其他一些因素与生态系统稳定性密切相关, 如生物群落的外部环境稳定程度等. 高寒草甸生态系统的主要气候因子(年降水和年均气温)以3~4年的主周期随机低频振荡, 在其作用下生态系统的行为呈现同主周期、振幅比较稳定的随机波动. 高寒草甸生态系统的较高稳定性, 是较稳定的环境和系统适应环境的进化演替结果.

The relationship between species diversity and ecosystem function is one of the core problem of biodiversity research, and productivity is an important modality of ecosystem function. The species diversity of natural communities is often strongly related to their productivity. The grassland is an important component of terrestrial ecosystems and plays a significant role in the biodiversity and ecosystem function. Understanding of how to use natural vegetation to restore deteriorated grasslands is critical for protection of grassland ecosystems. Moreover, the relationship between species richness and productivity relies on scales. At some scales, productivity affects diversity, and at other scales, species diversity also affects productivity. Thus, it is necessary to know the relationship between plant functional diversity and productivity in different grassland types. In 2003 the differences in plant functional diversity, functional composition and productivity in different grassland types of alpine meadow were analyzed. Humans are modifying both the identities and the numbers of species in ecosystems. However, the impacts of such changes on ecosystem processes are still controversial. The effects of functional diversity and composition on plant community productivity were analyzed in four types of alpine meadows. The research results show:(1) the effects of the legume functional group on productivity was greater than other functional groups in Kobresia humlis meadow and Potentilla froticosa shrub. (2) Although the biomass of forbs, C3 plants and sedge functional groups account for higher proportion of community productivity in Kobresia pygmaca meadow and K. tibetica swamp meadow, differences were not significantly different, indicating that the factors influencing community productivity were not only species diversity, but also the identity of species present and environmental resources. These factors were in turn mainly affected by species diversity and evenness among functional groups. That is, differences in functional group composition have a larger effect on ecosystem processes than functional group richness alone. (3) A significant correlation was found between the coverage per functional group and the primary productivity of communities in the four types of alpine meadows. (4) Changes in productivity with number of species per functional group showed a unimodal pattern, such that the maximum community productivity occured at an intermediate level of number of species per functional group.

对不同类型草地功能群多样性和组成与植物群落生产力之间的关系进行了探讨。结果表明:（1）在矮嵩草（ Kobresia humlis ）草甸和金露梅（ Potentilla froticosa ）灌丛中，豆科植物的作用比较明显，而其他功能群植物的作用较弱。（2）在藏嵩草（ Kobresia tibetica ）沼泽化草甸和小嵩草（ K. pygmaca ）草甸中，虽然杂类草、C3植物和莎草科植物功能群的生产力占群落初级生产力的比例较大，但二者在统计上没有显著性差异，这表明群落生产力除受物种多样性的影响外，也受物种本身特征和环境资源的影响，更主要的是受到功能群内物种密度和均匀度的影响，即功能群组成比功能群多样性更能说明对生态系统过程的影响。（3）不同类型草地群落植物功能群盖度与群落初级生产力呈显著的线性相关。（4）不同类型草地群落生产力与功能群内物种数的变化均表现为单峰曲线关系，即功能群内物种数处于中间水平时，群落生产力最高。

？以物种组成较为复杂的青藏高原东部地区典革高寒草甸植物群落为背景，从不同的时间和空间尺度水平研究了植物群落中物种丰富度与生产力（地上部生物量）关系的基本模式。结果表明：1）总体而言，高寒草甸植物群落中物种丰富度与生产力的关系呈对数线性增加关系，这实际上是空间和时间尺度放大时在时间和空间尺度的相互作用下高寒草甸植物群落中物种丰富度与生产力关系的一种总体模式；2）随着研究的时间和空间尺度的改变，物种丰富度与生产力的关系会发生一些相应的变化，但空间尺度比时间尺度对物种丰富度与生产力的关系造成的影响更为显著，这可能

研究了青藏高原退化草地常见毒杂草甘肃马先蒿地上部分水浸液对4种牧草种子萌发、幼苗生长的化感抑制作用.结果表明:甘肃马先蒿水浸液对4种牧草种子萌发和幼苗生长具有显著抑制作用,随着水浸液浓度增加,化感抑制作用不断增强;4种牧草种子萌发对甘肃马先蒿水浸液敏感性强弱顺序为:中华羊茅(Festuca sinensis)＞青牧1号老芒麦(Elymus sibiricus L.cv.Qinghai No.1)＞垂穗披碱草(Elymus nutans)＞短芒老芒麦(Elymus breviaristatus Keng F.cv.Qinhai),牧草幼苗生长对甘肃马先蒿水浸液敏感性强弱顺序为:中华羊茅＞垂穗披碱草＞青牧l号老芒麦＞短芒老芒麦;4种牧草对甘肃马先蒿化感作用的敏感性强弱顺序为:中华羊茅＞垂穗披碱草＞青牧1号老芒麦＞短芒老芒麦;4种牧草幼苗生长对甘肃马先蒿水浸液敏感性强于种子萌发.

The grassland is one of important agriculture natural resources. However, the grassland degraded seriously in China because of overgrazing. At the beginning of 21st century, enclosure was praised highly as a primary mean for grassland ecological restoration in west China. Effects of enclosure on the vegetation, soil and grassland ecosystem restoration were reviewed in this paper. It was concluded that the moderate grazing is necessary to restore degraded grassland and long-term enclosure is not as good as expected. According to the degree of grassland degradation in different regions, the enclosure should be flexibly combined with reasonable rotation grazing intensity and time to restore degraded grassland and get animal products simultaneously. It was suggested that the grassland ecological system will be sustainable and in good balance when grassland and animals are in win-win.

草地是我国重要的农业自然资源之一,但目前草地退化的现象十分严重,超载过牧是主要原因之一。本文就针对草地退化提出的围封禁牧措施对草地植被、土壤及草地生态系统恢复过程中的作用进行综述,发现适度放牧对草地恢复是必需的,但采取长期围封禁牧恢复与重建草地的做法不可取,围栏封育并非恢复退化草地的万全之计。建议在我国要因地制宜,根据草地的退化程度,采取合理的划区轮牧强度和放牧时间,与退化草地生态恢复的围封措施结合,以达到既能恢复退化草地,又可收获畜产品的双赢目的,实现草地生态系统持续平衡发展的目标。