不同干扰对黄土区典型草原物种多样性和生物量的影响

对黄土区典型草原进行封育+施肥(EF)、封育+火烧(EB)、封育(E)和放牧(G)处理,实地调查分析群落盖度、高度、密度、地上现存量和物种多样性,以研究不同干扰对黄土区典型草原群落物种多样性和生物量的影响.结果表明:在4种干扰类型中,施肥+封育草地群落盖度和地上生物量最高,且优势度指数最高,这与禾本科草占优势地位有关,群落均匀度指数和多样性指数最低,符合“生态位理论”;放牧地群落高度、盖度、密度和地上现存量最低,群落丰富度指数和多样性指数最高,支持“中度干扰理论”;封育地密度和均匀度指数最高;具体表现为:4种干扰类型地上生物量的变化趋势为封育+施肥＞封育+火烧＞封育＞放牧;说明长时间的封育对草地是一种严重干扰.群落丰富度指数(R和Ma)的排列顺序为放牧＞封育+施肥＞封育+火烧＞封育,群落物种多样性指数(H'和D)的排列顺序为放牧＞封育＞封育+火烧＞封育+施肥,优势度指数与多样性指数相反,群落均匀度指数(Jsw和Ea)的排列顺序为封育＞放牧＞封育+火烧＞封育+施肥.不同干扰样地群落生产力与Shannon-Wiener和Simpson 多样性指数间呈负相关关系,这个结论可以用地上/地下竞争的相互作用来解释.     

封育对高寒草甸植物群落构成及生态位特征的影响

封育是天然草地管理的一种有效措施,利于草地生产力提高和退化草地恢复。该研究通过对青藏高原高寒草甸放牧和封育草地物种多样性、植被构成、植物种生态位特征、草地演替度等分析,解析高寒草甸植物种间关系及草地演替方向。结果表明:(1)封育显著降低了草地群落植物物种数以及α和β多样性指数,显著增加了草地1年生植物种数、地面芽植物种数和地上生物量。(2)放牧草地地上生物量以莎草科(59.7%)和禾本科(23.9%)为主,封育草地地上生物量以禾本科(85.0%)为主;放牧草地优势种为矮嵩草(Kobresia humilis)和线叶嵩草(K.capillifolia),封育草地优势种为垂穗披碱草(Elymus nutans)和早熟禾(Poasp.)。(3)放牧和封育草地的群落植物种重要值均与各自的生态位宽度变化规律一致。(4)草地植物种间竞争主要发生在不同科属植物种之间,封育增加了群落植物种整体生态位重叠值和植物种间竞争。(5)草地群落演替度为封育地放牧地,封育群落处于较稳定状态。研究认为,封育促进了高寒草甸由莎草+杂类草群落向禾草+杂类草群落演替。     

高寒草甸植物群落物种多样性和生产力关系的光竞争研究

通过施肥形成的生产力由低到高的过程中,物种多样性往往降低。总体竞争假说认为对所有资源的竞争作用对多样性的影响随着生产力提高而加剧,导致物种多样性的下降;光竞争假说则认为随着生产力提高,种间竞争从低生产力时的地下竞争转向高生产力时的光竞争,是光竞争导致了物种多样性的下降。为了验证这两种假说,本文通过在甘南玛曲高寒草甸的均匀施肥实验,研究了光竞争对高寒草甸植物群落物种多样性和生产力关系的影响。结果表明：(1)随着施肥梯度的增加,大部分植物的生长速率加快,高度和叶面积增加;(2)随着施肥梯度的增加,植物群落地上总的生物量提高,叶面积指数增加,透光率降低,物种多样性减少;(3)个体大小不对称的光竞争导致了高寒草甸植物群落物种多样性随施肥梯度的增加而减少。     

半湿润常绿阔叶林次生演替阶段植物多样性和群落结构特征

以飒马场不同次生演潜阶段的半湿润常绿阔叶林为对象,测定物种丰富度、群落数量特征指标,分析植物多样性与群落结构特征之间的关系.结果表明,随着植物群落演替,物种丰富度不断增加,物种丰富度最高演替阶段的乔木层物种达到24个;植物多样性与植物个体密度间呈正相关关系;乔木层植物个体平均高与植物多样性间呈负相关关系;群落郁闭度和胸高断面积与植物多样性之间则呈对数函数关系.植物多样性与优势种个体密度和群落地上部分现存量间未呈现一致性规律.植物种-个体数间呈幂函数关系.随着植物多样性增加,种间竞争加剧.每个植物种为了维持临界最低种群,可能采取最大种群策略,导致群落植物个体数增加,密度增大,从而改变了群落结构特征.     

长期封育演替下典型草原植物群落生产力与多样性关系

封育是退化草地的重要恢复措施, 理解长期封育过程中草地群落生产力和植物多样性变化特征及两者间关系, 有助于草地植被的恢复管理与利用。该研究依托宁夏云雾山国家级自然保护区典型草原长期封育演替梯度, 选择持续放牧、封育9年、26年和34年的草地群落作为研究对象, 分析其地上生产力、物种多样性和功能多样性的变化特征及内在联系。结果表明, 封育显著提高典型草原植物群落的地上生产力、凋落物生物量、功能丰富度和功能离散度, 未改变草地群落的物种丰富度、Shannon-Wiener指数和功能均匀度, 但Simpson优势度指数和Pielou均匀度指数在长期封育(34年)后显著下降。此外, 封育对不同植物群落加权平均功能性状的影响存在差异。随机森林模型和方差分解结果显示, 群落加权平均功能性状对封育草地群落地上生产力变异的解释度高达70.70%, 其中植株高度是最主要的解释因子; 功能多样性的解释度为36.86%, 主要由功能丰富度贡献; 而物种多样性的解释度仅为14.72%。由此可见, 植物功能性状和功能多样性对草地群落地上生产力的贡献远高于物种多样性, 建议将其纳入植物群落恢复演替动态研究, 以便全面了解植物多样性与生态系统功能的关系, 为更好地实现生态恢复目标奠定基础。     

荒漠草原土壤种子库对草地管理方式的响应

以宁夏中部不同封育年限(封育1a、3a、5a和7a)、不同放牧方式(中等强度自由放牧、中等强度4区轮牧)、补播改良(2006年补播沙打旺Astragalus adsurgens和紫花苜蓿Alfalfa stiva)及未封育等管理方式下的荒漠草原为研究对象,采用空间梯度代替时间梯度法,于2012年3月下旬用样线法采集土壤样品,采用温室萌发法,统计土壤种子库物种组成和种子数,研究了不同草地管理方式下的种子库与地上植被相似性、多样性等特征。结果表明:1)宁夏荒漠草原土壤种子库中共出现14种植物,分属6科14属,除牛枝子(Lespedeza potanimii)为半灌木外其余均为草本植物。多年生植物占土壤种子库植物总数的65.3%,一年生植物占土壤种子库植物总数的35.7%;多年生植物种子数量随封育年限增加而表现为下降趋势,封育1a和未封育草地最多;2)不同管理方式下土壤种子库和地上植被的共有物种数为2—6种,封育时间延长导致土壤种子库物种与地上植被相似性下降,土壤种子库和地上植被共有物种数有减少趋势,自由放牧降低了土壤种子库和地上植被的共有物种数,补播恢复的草地土壤种子库中未出现补播物种;3)种子库物种多样性与管理方式无明显的相关性;种子库物种多样性指数4区轮牧草地最高,封育7a草地最低,物种丰富度指数封育1a草地最高,均匀度指数自由放牧草地最高,补播草地最低。若荒漠草原仅依靠土壤种子库恢复自然植被,则不建议封育时间过久,需间以适当的干扰(放牧);补播外来种未对荒漠草原土壤种子库产生贡献,反而对乡土种产生了一定限制。     

黄龙山林区油松林封育过程中植物物种多样性特征

对黄龙山林区不同封育年限油松林内的高等植物多样性特征进行了初步分析,结果表明:封育45a以前的油松林,群落内部各层物种丰富度随封育年限增加呈递增趋势,45a后群落内部各层物种丰富度随封育年限增加先增后减;不同封育年限的油松林,物种多样性指数表现出灌木层>乔木层>草本层的趋势,各层次的高等植物物种均匀度指数无相同的变化趋势,灌木层与草本层间各项多样性指数,乔木层与灌木层间,乔木层与草本层间的J和E存在显著差异;在乔木层物种多样性特征上,封育30a和封育75a的油松林差异显著;油松林在封育45a后,具有较高的草本植物物种多样性,但林内幼树密度大,形、质差,应进行卫生伐。     

Changes in vegetation and soil properties following 6 years of enclosure in riparian corridors

河岸带是维持生物多样性的重要生态系统之一。然而,由于过度放牧引起的植被消耗和过度开垦等人类活动的干扰,河岸带植被多样性和植被盖度受到严重的破坏,甚至威胁了河道的稳定性。围栏封育在退化草地生态系统修复中被广泛应用,但对退化河岸带植被群落和土壤性质的影响尚不明确。本研究的目的旨在明确围封的实施是否会促进河岸带植被群落的物种组成、物种丰富度和物种多样性恢复,土壤氧分如何随围封年限的增加而变化。辽河干流自2012年起被围栏封育管理,本研究在辽河干流河岸带沿岸设置了20个草本群落长期观测样地,记录了2012–2017年样地中植被高度、盖度和个体数量等参数用于物种丰富度和物种多样性的统计分析。同时,分别测定了2012年和2017年植被群落土壤氧分含量,验证了植被群落和土壤氧分对围封的反馈,研究了2012–2017年辽河干流河岸带的围栏封育对物种多样性和土壤氧分的影响。结果表明,随着围封年限的增加,辽河干流河岸带草本群落植被丰富度和多样性显著增加。物种组成方面,菊科植物的优势度显著增加,禾本科植物优势度显著下降。围封后植被群落的恢复和禁止耕作,加速了土壤中磷和钾的消耗,表现为显著降低,土壤有机质含量对围封的响应表现的相对滞后,并没有显著变化。综上所述,本研究为河岸带植被群落物种多样性、物种组成对围封的响应提供了新的见解。     

不同干扰形式对砂生槐群落结构特征的影响

在雅鲁藏布江中游流域以放牧、封育和水淹3种不同干扰形式下的砂生槐群落为研究对象,从林分特征、物种组成、优势种种群发育状况和物种多样性等对群落特征进行对比研究,以揭示不同干扰形式对砂生槐群落结构的影响.结果显示:(1)砂生槐群落以群落A(放牧)的林分状况最好,其次为群落B(封育),群落C(水淹)最差;(2)不同干扰形式下群落中植物种类分别为群落A(13种)＞群落C(9种)＞群落B(6种);(3)优势种群生长状况说明放牧和封育形式下砂生槐生长情况基本一致,高度级和幅度级小的个体均较多,而水淹干扰下群落仅有少数生长旺盛的个体存在,种群呈衰退趋势;(4)物种多样性指数为群落A＞群落B＞群落C.研究表明:一定程度放牧干扰能够促进砂生槐种群更新,增加群落物种丰富度和物种多样性,封育可促进砂生槐种群萌蘖更新,而水淹则促使群落衰退.     

青藏高原东缘封育和退化高寒草甸种子库差异

采用幼苗萌发法研究了青藏高原东部高寒草甸封育和退化地区土壤种子库的差异.结果表明:(1)两个样地总共有10161株幼苗萌发,分属55个物种,23个科.封育样地多年生植物比例高于退化样地,禾草和单子叶植物比例在两个样地间差异不大.(2)退化样地土壤种子库种子密度((6105±1530) m-2)显著高于封育样地((3883±798) m-2),而物种丰富度差异不显著.所研究区域拥有较为丰富的种子库资源,退化地区资源更丰富,说明恢复不存在种子限制问题,土壤种子库可以成为植被恢复的潜在资源.(3)种子密度和物种丰富度在垂直分层上差异显著,且随着深度的增加而显著减小.(4)用Srensen coefficient指数计算出土壤种子库和地上植被之间的相似性在整体上较低,封育样地(45.3%)略高于退化样地(40.4%),两个样地地上植被之间的相似性为50%,而种子库之间相似性高达84.6%,说明种子库起到一个"缓冲器"的作用.(5)Shannon-Wiener多样性指数分析显示,无论在地上植被或种子库中,物种多样性都是封育样地显著高于退化样地.过度放牧不仅导致地上植被的生物多样性丧失,而且使种子库中的物种多样性降低,而封育管理可以维持地上植被和种子库中的物种多样性.     

Seed bank composition and above-ground vegetation in response to grazing in sub-Mediterranean oak forests (NW Greece)

We investigate the persistent soil seed bank composition and its relation to the above-ground flora of grazed and non-grazed sub-Mediterranean deciduous oak forests of NW Greece. Twenty-eight taxa were recorded in the soil seed bank and 83 taxa (70 taxa in plots of seed bank sampling) in the above-ground vegetation. The dominant tree species and many woodland species found in the above-ground vegetation were absent from the soil seed bank. Similarity between the soil seed bank and the above-ground vegetation decreased with grazing, and grazing led to a decrease of species richness in above-ground vegetation and soil seed bank. Beta diversity of vegetation among grazed and among non-grazed plots did not differ, but was significantly higher between grazed and non-grazed areas. Beta diversity of the soil seed bank declined with grazing. When applying classification tree and logistic regression analyses, non-grazed forest sites are clearly differentiated by the presence of Phillyrea latifolia, Euphorbia amygdaloides and Brachypodium sylvaticum. PCA ordination of above-ground species composition reflected a gradient from sites grazed by ruminants to non-grazed sites, but no clear structure was detected in the seed bank.     

Grazing increases functional richness but not functional divergence in Tibetan alpine meadow plant communities

Plant community diversity and ecosystem function are conditioned by competition among co-occurring species for multiple resources. Previous studies suggest that removal of standing biomass by grazing decreases competition for light, but coincident grazing effects on competition for soil nutrients remain largely unknown in Tibetan rangelands where grazing tends to deplete soil phosphorus availability. We measured five functional traits indicative of plant productivity and stoichiometry leaf carbon concentration (LCC), leaf nitrogen concentration (LNC), leaf phosphorus concentration (LPC), specific leaf area (SLA), leaf dry matter content (LDMC) for component species of plant communities in grazed and ungrazed plots in five Tibetan alpine meadows. We examined the diversity of traits singly Rao index of functional diversity (FDrao) and in aggregate functional richness (FRic), functional divergence (FDiv), and functional evenness (FEve) in response to grazing. We tested whether foliar trait diversity increases with nutrient competition but decreases with light competition when competitive exclusion is reduced by grazing. The FDrao of LPC significantly increased under grazing, but FDrao for LCC, LNC and SLA tended to decrease. The FDrao of LDMC increased at the drier site but decreased at the wettest site. There was a strong negative association between increase in FDrao of LPC and decrease in soil nutrients, especially soil phosphorus availability. The FRic for all five traits together increased with species diversity following grazing, but neither FDiv nor FEve differed significantly between grazed and ungrazed plots at most sites. Grazing in Tibetan alpine meadows tends to increase competition for soil phosphorus while decreasing competition for light, resulting in an increase in the functional richness in grazed plant communities without any significant changes in the overall functional diversity of foliar traits. Our study highlights the potential importance of grazing mediated competition for multiple resources in alpine meadow ecosystems.     

Impact of reindeer grazing on ground-dwelling Carabidae and Curculionidae assemblages in Lapland

Reindeer Rangifer tarandus L. grazing shapes forest vegetation, microclimate, and soil respiration in Lapland, especially due to grazing on lichens (Cladina). We studied how these changes and their magnitude affect ground‐dwelling species of beetle families Carabidae (predators) and Curculionidae (herbivores), by using pitfall traps to collect invertebrates from pairs of grazed and ungrazed study plots over a wide range of site types. Changes in abundance, composition, richness and diversity of beetle assemblage were tested in relation to magnitude of the impacts on vegetation. The species compositions of Carabidae and Curculionidae differed between grazed and ungrazed plots in all sites. The relative difference between grazed and ungrazed plots in the number of individuals increased linearly with the impact of reindeer on vegetation cover. Carabid beetles, as a family, were more common in grazed plots in all sites. Curculionid beetles were more common in ungrazed plots in the birch dominated sites. This difference was mainly due to the species that feeds on deciduous leaves. In the pine dominated sites with high Cladina cover and more changes in ground vegetation, the number of curculionids feeding on conifers was higher in grazed plots. Species richness and diversity (H’) of both families were higher in grazed plots. Of the total 27 species, 11 were found only in grazed plots, while not a single species was found only in ungrazed plots. The relative difference between plots in diversity and evennes (H’/H'max) had humped response to the difference in Cladina cover. The diversity values were greater in grazed plots at the intermediate levels of grazing impact, and only in sites with very low or extremely high Cladina cover difference was the diversity higher in ungrazed plots. The response of beetle diversity resembled the hypotheses suggested for the relationship between grazing and vegetation diversity: greatest positive effect at intermediate grazing intensity and negative effects at unproductive sites.     

Impact of grazing and atmospheric nitrogen deposition on the vegetation of dry coastal dune grasslands

Abstract. A five-year experimental study was carried out to examine the combined effects of grazing and atmospheric nitrogen deposition on the vegetation of three dry dune grasslands: one short species-rich, one short species-poor, and one predominated by tall graminoids. Additional fertilization with nitrogen had no significant effect, neither in grazed nor in non-grazed plots. Exclusion of grazing by rabbits resulted in an increase in the frequency of perennial graminoids and a decrease in the frequency of annual graminoids and herbs. Nevertheless, species diversity remained the same in the species-rich grassland. During the experiment, the above-ground biomass increased in all nongrazed plots and the amount of bare soil and mosses decreased. The vegetation changes occurred mainly within one year after the exclusion of grazing. An exception is the grass-dominated site where the amount of Calamagrostis epigejos increased gradually from ca. 20 % in the first two years to about 50 % in the fourth and fifth year. Grazing by rabbits seems essential to prevent graminoids to become predominant in the dry dunes. If graminoids are dominant, grazing by horses can be an appropriate method to restore the original grassland vegetation. After six months of grazing by horses the grass-dominated site showed a decrease of the frequency of perennial graminoids, from 95 % to 80 %, and an increase of the frequency of perennial herbs, from 2.5 % to between 13 and 20 %.     

Interacting effects of fertilization,mowing and grazing on plant species diversity of 1500 grasslands in Germany differ between regions

The relationship of different types of grassland use with plant species richness and composition (functional groups of herbs, legumes, and grasses) has so far been studied at small regional scales or comprising only few components of land use. We comprehensively studied the relationship between abandonment, fertilization, mowing intensity, and grazing by different livestock types on plant diversity and composition of 1514 grassland sites in three regions in North-East, Central and South-West Germany. We further considered environmental site conditions including soil type and topographical situation. Fertilized grasslands showed clearly reduced plant species diversity (?15% plant species richness, ?0.1 Shannon diversity on fertilized grasslands plots of 16 m²) and changed composition (?3% proportion of herb species), grazing had the second largest effects and mowing the smallest ones. Among the grazed sites, the ones grazed by sheep had higher than average species richness (+27%), and the cattle grazed ones lower (?42%). Further, these general results were strongly modulated by interactions between the different components of land use and by regional context: land-use effects differed largely in size and sometimes even in direction between regions. This highlights the importance of comparing different regions and to involve a large number of plots when studying relationships between land use and plant diversity. Overall, our results show that great caution is necessary when extrapolating results and management recommendations to other regions.     

The maintenance of offspring diversity in response to land use: sexual and asexual recruitment in an alpine meadow on the Tibetan Plateau

Human activities have caused dramatic land use changes, impacting plant community composition, diversity and function. Fertilization and grazing are the two most common land use modes in grasslands. To understand the effects of grazing and fertilization on sexual and asexual recruitment in alpine grasslands, we conducted a demographic field investigation of species recruitment in an alpine meadow on the Tibetan Plateau. Grazing and fertilization had different effects on the quantity and diversity of sexual and asexual recruitment. Sexual recruitment increased significantly in grazed plots, but decreased significantly in fertilized plots. Asexual recruitment increased significantly in fertilized plots, but decreased significantly in grazed plots. For functional groups, grazing significantly reduced offspring recruitment of graminoids, but significantly increased offspring recruitment of forbs and legumes; fertilization significantly reduced offspring recruitment of forbs and legumes, but significantly increased offspring recruitment of graminoids. Furthermore, offspring diversity from sexual recruitment was significantly higher than from asexual recruitment in grazed plots, and as compared to non‐grazed and fertilized grasslands. Our studies indicate that moderate grazing disturbance has positive effects on seedling recruitment and offspring diversity, and fertilization has negative effects on offspring diversity, but may significantly increase asexual recruitment.     

Root-shoot competition interactions cause diversity loss after fertilization: a field experiment in an alpine meadow on the Tibetan Plateau

Aims A decrease in species diversity after fertilization is a common phenomenon in grasslands; however, the mechanism causing it remains highly controversial. The light competition hypothesis to explain loss of diversity has received much attention. The aim of the present paper was to test this hypothesis.Methods Fertilization was used to control above- and belowground resources simultaneously, while shade was used to control aboveground resource in an alpine meadow on the Tibetan Plateau. Univariate general linear models was used to estimate the effects of fertilization and shade on above- and belowground vegetation characteristics, including photosynthetically active radiation (PAR) in the understory, aboveground biomass, belowground biomass, R:S ratio, species richness and Simpson's diversity index.Important findings PAR was similar in the understory of shaded and fertilized plots, but only fertilization reduced species richness and diversity, suggesting that light competition alone could not explain diversity loss after fertilization. The root biomass and R:S ratio had a significant increase in shaded plots, but the richness and diversity did not change, suggesting that root competition alone also could not explain diversity loss after fertilization in this community. Our results illustrated that the root–shoot competition interactions, investigated from a functional groups perspective, should be the most reasonable explanation leading to the diversity loss due to fertilization.     

Increasing native, but not exotic, biodiversity increases aboveground productivity in ungrazed and intensely grazed grasslands

Species-rich native grasslands are frequently converted to species-poor exotic grasslands or pastures; however, the consequences of these changes for ecosystem functioning remain unclear. Cattle grazing (ungrazed or intensely grazed once), plant species origin (native or exotic), and species richness (4-species mixture or monoculture) treatments were fully crossed and randomly assigned to plots of grassland plants. We tested whether (1) native and exotic plots exhibited different responses to grazing for six ecosystem functions (i.e., aboveground productivity, light interception, fine root biomass, tracer nitrogen uptake, biomass consumption, and aboveground biomass recovery), and (2) biodiversity-ecosystem functioning relationships depended on grazing or species origin. We found that native and exotic species exhibited different responses to grazing for three of the ecosystem functions we considered. Intense grazing decreased fine root biomass by 53% in exotic plots, but had no effect on fine root biomass in native plots. The proportion of standing biomass consumed by cattle was 16% less in exotic than in native grazed plots. Aboveground biomass recovery was 30% less in native than in exotic plots. Intense grazing decreased aboveground productivity by 25%, light interception by 14%, and tracer nitrogen uptake by 54%, and these effects were similar in native and exotic plots. Increasing species richness from one to four species increased aboveground productivity by 42%, and light interception by 44%, in both ungrazed and intensely grazed native plots. In contrast, increasing species richness did not influence biomass production or resource uptake in ungrazed or intensely grazed exotic plots. These results suggest that converting native grasslands to exotic grasslands or pastures changes ecosystem structure and processes, and the relationship between biodiversity and ecosystem functioning.     

Grazing as a mediator for maintenance of offspring diversity: Sexual and clonal recruitment in alpine grassland communities

To understand the effects of grazing on grassland plants sexual and clonal recruitment, we conducted a demographic field investigation of species recruitment along a grazing gradient in the Tibetan alpine grassland. Grazing intensity had significant effects on quantity and diversity of sexual and clonal recruitment. Sexual recruitment increased significantly, but clonal offspring production decreased significantly with increased grazing intensity. Grazing intensity had different, significant effects on offspring recruitment of the various functional groups in the community, grasses (GG), sedges (SG), legumes (LG) and forbs (FG). Higher grazing intensity reduced offspring recruitment of GG and SG; it increased offspring recruitment of LG and FG. Seedlings were significantly more abundant in lightly grazed, moderately grazed and heavily grazed meadows than in non-grazed grasslands. Offspring diversity from sexual recruitment was significantly higher than that from clonal recruitment in grazed than in non-grazed grasslands. Our studies indicate that moderate grazing had positive effects on seedling recruitment and offspring diversity, but heavy gazing may alter community succession by affecting recruitment patterns among the four plant functional groups.     

放牧强度对短花针茅荒漠草原甲虫群落分布格局的影响

放牧对脆弱的荒漠草原生态系统有着重要影响,且随放牧强度及持续时间不同而变化。鞘翅目昆虫是环境监测与生物多样性变化的指示生物。利用巴氏罐诱法对短花针茅荒漠草原不同放牧强度草地的甲虫群落组成和多样性进行调查,探究放牧对荒漠草原甲虫群落的影响。结果表明:(1)步甲科、金龟科为短花针茅荒漠草原甲虫群落优势类群,埋葬甲科、芫菁科、拟步甲科和花金龟科为常见类群。(2)放牧强度增加不利于维持更多的捕食性甲虫;对照和轻度放牧样地可维持更多的腐食性甲虫。(3)甲虫数量随放牧强度增加而递减;群落多样性以重度放牧草地最大,轻度放牧草地最小;群落优势度为对照、中度、重度显著高于轻度放牧草地。各甲虫类群在不同放牧强度草地出现时间、高峰期均不同。(4)对照、轻度、重度放牧样地的甲虫优势类群群落结构不同于其他生境,但均与中度放牧样地存在相似性。轻度、中度、重度放牧样地的甲虫稀有类群群落结构不同于其他生境,但均与对照样地存在相似性。(5)甲虫群落个体数与植物群落物种丰富度、盖度、植物平均高度、生物量呈显著正相关。Shannon-Wiener多样性指数、Margalef丰富度指数均与植物群落物种丰富度、生物量显著负相关。研究结果为荒漠草原甲虫多样性保护提供参考依据。