黑龙江省东部森林群落β多样性的研究

以连续带指数和集合环境梯度作为植物群落演替动态和环境质量的定量指标,探讨了黑龙江省东部森林群落β多样性随环境梯度和演替动态的变化规律．结果表明,森林群落中植物种的β多样性βＺ和昆虫种的β多样性βＫ都随环境梯度的增加而升高,即随着环境质量升高群落间物种更替速率降低,且βＫ的变化滞后于βＺ．βＺ和βＫ与连续带指数（ＣＩ）呈非线性相关,在演替初期群落间物种更替速率较高,在演替中后期群落间物种的更替速率最小．βＫ曲线的峰值出现滞后于βＺ曲线,说明森林昆虫群落多样性变化对植物群落多样性变化的依赖性     

荒漠景观破碎化条件下啮齿动物群落beta 多样性变化特征

2002 ～2010 年,采用夹日法对内蒙古阿拉善荒漠区禁牧、轮牧、过牧和开垦4 种不同人为干扰生境中啮齿动物群落β 多样性进行了研究,同时分析不同生境的灌木植物群落特征来探讨人为干扰下的景观破碎化。依据人为干扰下景观破碎的情况将研究区域内生境梯度的变化按照:禁牧到轮牧、轮牧到过牧、过牧到开垦、禁牧到过牧、禁牧到开垦、轮牧到开垦进行划分,分别利用Jaccard 指数、Sorenson 指数和Cody 指数分析景观破碎化条件下啮齿动物群落β 多样性变化特征。结果表明,不同生境梯度间3 种β 多样性指数差异均显著(P <0. 05),禁牧到过牧梯度β 多样性差异最大。不同干扰生境间的灌木植物群落特征差异极显著(P < 0. 01),Shannon-Wiener 指数、Simpson 指数和物种数均表现为轮牧区> 过牧区> 禁牧区> 开垦区。环境变化程度与β 多样性变化的程度一致。人为干扰是该区域景观破碎化的主要原因,特别是放牧活动,导致环境异质性显著增加。在荒漠区,这种随环境梯度造成异质性加大而增加的β 多样性,并不是由物种增加较大导致,而是由啮齿动物群落物种组成差异和变化增大所致.     

辽宁老秃顶子北坡植物群落物种多样性及其与土壤特性的相关性分析

通过沿海拔梯度的系统样方调查,利用物种丰富度、α多样性和β多样性等指标,对辽宁老秃顶子北坡植物群落木本层和草本层物种多样性随海拔梯度的变化趋势进行了研究,并对植物群落物种多样性与土壤特性之间的相关关系进行了初步探索。结果表明:木本植物物种多样性随海拔梯度的升高呈波动式降低的趋势;草本植物物种多样性随海拔梯度的变化趋势为先降低后升高;群落类型间的过渡带是植物物种替换速率较高的地区;老秃顶子北坡土壤类型以棕色森林土和暗棕色森林土为主,土壤有机质含量较高;群落物种多样性与土壤特性之间存在着一定的负相关性。     

黄土高原植物群落演替过程中的β多样性变化

采用空间代替时间的方法,以黄土高原子午岭林区6个处于不同演替阶段的植物群落为研究对象,通过β多样性的加性分解方法,揭示了群落演替过程中的β多样性及其成分(物种内嵌成分和物种更替成分)的变化规律.结果表明:在黄土高原群落演替过程中,β多样性在不同的层次呈现不同的变化规律,草本层物种呈现明显的单峰变化趋势,即随演替进展,β多样性逐渐增加,在灌丛演替到白桦群落阶段时达最大值,之后β多样性逐渐减小;灌木层β多样性随演替进展逐渐减小,而乔木层β多样性随演替进展逐渐增大;黄土高原群落演替过程中的β多样性变化由物种内嵌和物种更替2种过程共同完成,二者的相对贡献变异于不用的演替阶段和不同的物种层次,但以物种更替为主导过程;从物种多样性保护的角度考虑,应该尽可能多地保存不同的群落类型,而不是少数几个物种较丰富的群落类型.     

白龙江干旱河谷不同坡向主要灌丛群落随海拔梯度变化的物种多样性研究

采用样方调查法,研究了白龙江干旱河谷不同坡向主要灌丛群落沿着海拔梯度的结构特征、物种多样性的变化规律,旨在了解白龙江干旱河谷不同海拔梯度植被特征和物种多样性变化,为白龙江干旱河谷区域不同海拔植被恢复提供理论依据。研究结果表明：（1）不同海拔梯度同一坡向物种数不同,同一海拔不同坡向物种数也不同,随着海拔的升高不同坡向物种数表现为先增加后减少的趋势,同一海拔梯度内不同坡向主要植被类型也不同。（2）主要灌木群落α多样性在不同坡向随着海拔梯度的升高,表现出先升高后减小的趋势。不同坡向草本群落α多样性随着海拔的升高,也表现出先升高后减小的趋势。对主要灌丛α多样性指数进行相关性分析得物种丰富度指数对物种多样性贡献率最大,表现为丰富度指数（D₁、D₂）> 生态优势度指数（SN）> 种间机遇指数（H）> 群落均匀度指数（R）。（3）不同坡向主要灌丛群落β多样性Whittaker指数沿着不同海拔梯度变化不大,最大值出现在海拔1250~1650m;Routledge和Codyβ多样性指数在海拔1450~1650m出现最大值,但是大体呈现出波形变化。草本β多样性随着海拔的升高变化较大,阳坡植物的β多样性指数在海拔1050~1250m达到最大,阴坡和半阴半阳坡在海拔区间1250~1450m达到最大,半阴半阳坡的β多样性指数均大于阳坡。白龙江干旱河谷不同坡向、不同海拔梯度物种α多样性和β多样性都不同,且不同坡向随着海拔梯度的变化物种α多样性和β多样性呈一定的相关性,说明海拔和坡向是影响生物多样性主要因子之一。     

黑龙江省东部山区森林植物物种多样性的研究

通过对黑龙江省东部山区原始阔叶红松林和次生林物种多样性的比较研究,结合定量化的群落动态和环境梯度,分析论证了演替阶段、环境梯度、生长状况及干扰与物种多样性的相关关系。结论如下：次生林物种多样性高于原始阔叶红松林,但均匀度较原始林小;物种多样性较高的群落其森林生产力中等,森林生产力较大的群落其物种多样性小;中度干扰的群落,其物种多样性较高,而重度和轻度干扰的群落,其多样性低;物种多样性指数从演替初期到中期不断增加,到演替后期逐渐下降。     

东灵山辽东栎林木本植物多样性的研究

应用α多样性和β多样性指数对东灵山地区辽东栎林在不同样地环境梯度的物种多样性进行了初步研究。结果表明:不同样地梯度的辽东栎林乔灌木物种α多样性逐步降低,但变化幅度较小,群落物种组成趋于简单。不同样地梯度内辽东栎林乔木物种的β多样性的二元属性测度与数量数据测度结果反映出乔木物种和灌木物种对整个辽东栎林多样性的影响是不同的。数量数据β多样性测度综合地考虑了物种数与物种数量对β多样性变化的影响,适于对单优群落物种多样性进行分析。在中海拔样地梯度,辽东栎林乔灌木物种各样地对之间的β多样性数值较小,表明辽东栎林内物种替代速率较低,物种组成相对稳定,总体上是比较稳定的林型。     

不同演替阶段鼢鼠土丘群落植物多样性变化研究

用空间序列代替时间序列的方法对高寒草甸不同演替阶段高原鼢鼠土丘植物群落的物种组成和多样性变化进行了研究．结果表明,不同演替阶段鼠丘植物群落的物种组成及外貌特征与原生植被(对照)之间存在较大差异．在演替的早期阶段,r对策者如萼果香薷、灰绿藜、鹅绒委陵菜、细叶亚菊等演替先锋种在群落中占相对重要地位．随着演替的进展,k对策者如长毛风毛菊、垂穗披碱草、甘肃嵩草、线叶嵩草等在群落中的比例增加．α多样性分析表明,随着演替的进展,群落物种丰富度指数(O)显著增加,其排列顺序为：阶段1<阶段2<阶段3<阶段4<原生植被;均匀度指数(Pielou均匀度指数)的变化趋势与丰富度指数相同;多样性指数(Simpson指数D和Shannon-．Wiener指数H’)按群落的演替梯度呈增加趋势．卢多样性分析表明,阶段1与原生植被及阶段1与阶段4植物群落物种组成的相似系数最小,为0．18;阶段1与阶段2植物群落物种组成的相似系数最大,为0．62．同时,群落生活型功能群组成也随鼠丘的演替进展而发生变化,反映出不同演替阶段的鼠丘植物群落和微生境都发生了改变．     

祁连山北坡中段植物群落多样性的垂直分布格局

利用DCCA排序和海拔高程排序相结合的方法 ,对祁连山北坡中段植物群落物种多样性垂直分布格局进行了初步研究。结果表明 :1)植物群落草本层和灌木层物种丰富度和多样性在环境梯度上呈单峰曲线变化趋势 ,乔木层的物种丰富度和多样性在环境梯度上无变化。物种丰富度和多样性对环境梯度变化敏感程度的次序是草本层 >灌木层 >乔木层 ;2 )植物群落各层次均匀度在环境梯度上没有表现出一定的变化规律 ,均匀度可能更多地受制于群落自身动态的影响 ,而独立于生境的资源水平 ;3)草地群落物种多样性在DCCA环境梯度上曲线的拟合效果优于按海拔高程排序效果 ,灌木群落则相反 ;4)低海拔、中低海拔和中海拔地带的草本层物种丰富度和Shannon Wiener多样性指数 (H′)显著高于灌木层 (p <0 .0 1) ;高海拔地带草本层仅丰富度指数显著高于灌木层 (p <0 .0 5 )。在整个海拔范围内 ,草本层和灌木层的均匀度无显著差异。就资源的可利用性而言 ,研究区域植物群落物种多样性在垂直环境梯度上的变化规律表达了物种多样性与资源生产力的单调关系内涵。     

森林-草原交错带夏季鸟类群落多样性特征

2004～2006年夏季利用样线法研究了内蒙古高原东南缘森林-草原交错带鸟类群落多样性特征及变化规律.共记录鸟类73种,隶属于13目28科56属,鸟类区系具有明显的古北界特征.鸟类群落物种数和密度年间差异不显著,α多样性随森林-草原交错带环境梯度变化而发生显著变化:在不同植被地带之间,物种数、密度、Shannon-Wiener指数和Pielou指数差异极显著、但科-属多样性差异不显著,鸟类群落α多样性各项指数表现为森林带＜交错带森林草甸区＞交错带草甸草原区＞草原带的特征与变化趋势(DG-F为交错带草甸草原区＞森林带);其中,森林草甸区是鸟类物种多样性的显著增长区,具有最高的物种数和密度,明显体现了交错区的边缘效应,草甸草原区是鸟类向草原过渡的显著变化区域、物种多样性开始显著减少.β多样性随不同植被地带逐级发生显著变化,环境差异最大的森林带-森林草甸区和草甸草原区-草原带具有最高的β多样性,物种替代速率最大;鸟类物种替代速率与环境梯度"陡度"有密切关系.鸟类优势种在各植被地带之间存在较大变化.鸟类群落的物种数、密度和物种多样性(H')与森林斑块数呈显著的正相关性,在大尺度空间上森林斑块数是影响鸟类群落多样性的最主要因素.     

Tree diversity drives abundance and spatiotemporal β‐diversity of true bugs (Heteroptera)

1. Spatiotemporal patterns of canopy true bug diversity in forests of different tree species diversity have not yet been disentangled, although plant diversity has been shown to strongly impact the diversity and distribution of many insect communities. 2. Here we compare species richness of canopy true bugs across a tree diversity gradient ranging from simple beech to mixed forest stands. We analyse changes in community composition by additive partitioning of species diversity, for communities on various tree species, as well as for communities dwelling on beech alone. 3. Total species richness (γ‐diversity) and α‐diversity, and abundance of true bugs increased across the tree diversity gradient, while diversity changes were mediated by increased true bug abundance in the highly diverse forest stands. The same pattern was found for γ‐diversity in most functional guilds (e.g. forest specialists, herbivores, predators). Temporal and even more, spatial turnover (β‐diversity) among trees was closely related to tree diversity and accounted for ～90% of total γ‐diversity. 4. Results for beech alone were similar, but species turnover could not be related to the tree diversity gradient, and monthly turnover was higher compared to turnover among trees. 5. Our findings support the hypothesis that with increasing tree diversity and thereby increasing habitat heterogeneity, enhanced resource availability supports a greater number of individuals and species of true bugs. Tree species identity and the dissimilarity of true bug communities from tree to tree determine community patterns. 6. In conclusion, understanding diversity and distribution of insect communities in deciduous forests needs a perspective on patterns of spatiotemporal turnover. Heterogeneity among sites, tree species, as well as tree individuals contributed greatly to overall bug diversity.     

Ecosystem engineers maintain a rare species of butterfly and increase plant diversity

We evaluated whether ecosystem engineers can accomplish two conservation goals simultaneously: (1) indirectly maintain populations of an endangered animal through habitat modification and (2) increase riparian plant diversity. We tested for effects of a prominent ecosystem engineer, the beaver Castor canadensis, on populations of St. Francis' satyr butterfly Neonympha mitchellii francisci and plant species richness and composition. We performed our test by surveying riparian vegetation communities in all stages of beaver‐influenced wetland succession. We found that beavers created wetland habitats that supported plant species not found elsewhere in riparian zones and increased plant species diversity across the landscape by creating a novel combination of patch types. Our results confirmed what others have found about engineering effects on plant diversity, but these results further demonstrated a case where ecosystem engineers indirectly maintain populations of rare animals by modifying the composition and diversity of plant communities within wetlands. Our research demonstrates how an ecosystem engineer can influence habitat availability and composition of plant communities important for an endangered insect, and maintain overall plant species diversity by increasing habitat heterogeneity.     

Spatiotemporal changes of beetle communities across a tree diversity gradient

Aim Plant and arthropod diversity are often related, but data on the role of mature tree diversity on canopy insect communities are fragmentary. We compare species richness of canopy beetles across a tree diversity gradient ranging from mono‐dominant beech to mixed stands within a deciduous forest, and analyse community composition changes across space and time. Location Germany’s largest exclusively deciduous forest, the Hainich National Park (Thuringia). Methods We used flight interception traps to assess the beetle fauna of various tree species, and applied additive partitioning to examine spatiotemporal patterns of diversity. Results Species richness of beetle communities increased across the tree diversity gradient from 99 to 181 species per forest stand. Intra‐ and interspecific spatial turnover among trees contributed more than temporal turnover among months to the total γ‐beetle diversity of the sampled stands. However, due to parallel increases in the number of habitat generalists and the number of species in each feeding guild (herbivores, predators and fungivores), no proportional changes in community composition could be observed. If only beech trees were analysed across the gradient, patterns were similar but temporal (monthly) species turnover was higher compared to spatial turnover among trees and not related to tree diversity. Main conclusions The changes in species richness and community composition across the gradient can be explained by habitat heterogeneity, which increased with the mix of tree species. We conclude that understanding temporal and spatial species turnover is the key to understanding biodiversity patterns. Mono‐dominant beech stands are insufficient to conserve fully the regional species richness of the remaining semi‐natural deciduous forest habitats in Central Europe, and analysing beech alone would have resulted in the misleading conclusion that temporal (monthly) turnover contributes more to beetle diversity than spatial turnover among different tree species or tree individuals.     

三江平原沼泽湿地群落演替系列β多样性

选择三江平原沼泽湿地4个群落演替系列,采用样方法研究其β多样性的变化.结果表明:以水分条件最充分的群落为起点,随着水分梯度递减和水平距离的增大,各群落与起始群落的相似性系数呈减小趋势.不同演替系列内群落间物种更替速率从低地向高地呈现增大趋势.各系列的基本演替趋势是物种数逐渐增多,共有种逐渐减少,群落间β多样性增大.演替机制分析支持了“初始植物区系组成说”.在三江平原沼泽湿地中,小叶章的优势地位将进一步扩大.     

Temporal Dynamics of Rich Moth Ensembles in the Montane Forest Zone in Southern Ecuador1

We studied temporal dynamics of diverse moth ensembles (Arctiidae and Geometridae) in early and late succession stages of forest recovery in the montane zone of southern Ecuador. Moths were sampled using weak light sources (2 × 15 W tubes per trap) during three sampling periods (March–April 2002, wet season; October–November 2002, and August–October 2003, both “dry” seasons). Arctiid moth abundance hardly varied between sampling periods. Estimates of local diversity were lower in 2002 (wet and dry season) than in the dry season 2003, and ensemble composition was more strongly affected by sampling period rather than habitat differences. Geometridae ensembles revealed stronger temporal patterns. Geometrid abundance increased about twofold from the wet to the dry season, and temporal effects on species composition were far more pronounced that in arctiids. These differences might hint to variation in the dependence of geometrid versus arctiid larvae on ephemeral plant resources. Despite these significant temporal dynamics, in both families only a few of the more common species analyzed individually showed strong temporal changes in abundance. Almost all common species occurred as adults during all sampling periods. Therefore, even though temporal dynamics of moth ensembles are not negligible, both moth families are suitable “indicators” of community diversity and change along the succession gradient. Samples must be large enough, however, and preferably should be collated over various times of the year and in parallel, to allow for valid statements about moth diversity and species compositions in relation to habitat differences. These recommendations undermine the validity of the concept of “rapid biodiversity inventories” for speciose tropical insect communities.     

Diversity and composition of Arctiidae moth ensembles along a successional gradient in the Ecuadorian Andes

Andean montane rain forests are among the most species‐rich terrestrial habitats. Little is known about their insect communities and how these respond to anthropogenic habitat alteration. We investigated exceptionally speciose ensembles of nocturnal tiger moths (Arctiidae) at 15 anthropogenically disturbed sites, which together depict a gradient of forest recovery and six closed‐forest understorey sites in southern Ecuador. At weak light traps we sampled 9211 arctiids, representing 287 species. Arctiid abundance and diversity were highest at advanced succession sites, where secondary scrub or young forest had re‐established, followed by early succession sites, and were lowest, but still high, in mature forest understorey. The proportion of rare species showed the reverse pattern. We ordinated moth samples by non‐metric multidimensional scaling using the chord‐normalized expected species shared index (CNESS) index at various levels of the sample size parameter m. A distinct segregation of arctiid ensembles at succession sites from those in mature forest consistently emerged only at high m‐values. Segregation between ensembles of early vs. late succession stages was also clear at high m values only, and was rather weak. Rare species were responsible for much of the faunal difference along the succession gradient, whereas many common arctiid species occurred in all sites. Matrix correlation tests as well as exploration of relationships between ordination axes and environmental variables revealed the degree of habitat openness, and to a lesser extent, elevation, as best predictors of faunal dissimilarity. Faunal differences were not related to geographical distances between sampling sites. Our results suggest that many of the more common tiger moths of Neotropical montane forests have a substantial recolonization potential at the small spatial scale of our study and accordingly occur also in landscape mosaics surrounding nature reserves. These species contribute to the unexpectedly high diversity of arctiid ensembles at disturbed sites, whereas the proportion of rare species declines outside mature forest.     

Scale-specific correlations between habitat heterogeneity and soil fauna diversity along a landscape structure gradient

Habitat heterogeneity contributes to the maintenance of diversity, but the extent that landscape-scale rather than local-scale heterogeneity influences the diversity of soil invertebrates—species with small range sizes—is less clear. Using a Scottish habitat heterogeneity gradient we correlated Collembola and lumbricid worm species richness and abundance with different elements (forest cover, habitat richness and patchiness) and qualities (plant species richness, soil variables) of habitat heterogeneity, at landscape (1 km²) and local (up to 200 m²) scales. Soil fauna assemblages showed considerable turnover in species composition along this habitat heterogeneity gradient. Soil fauna species richness and turnover was greatest in landscapes that were a mosaic of habitats. Soil fauna diversity was hump-shaped along a gradient of forest cover, peaking where there was a mixture of forest and open habitats in the landscape. Landscape-scale habitat richness was positively correlated with lumbricid diversity, while Collembola and lumbricid abundances were negatively and positively related to landscape spatial patchiness. Furthermore, soil fauna diversity was positively correlated with plant diversity, which in turn peaked in the sites that were a mosaic of forest and open habitat patches. There was less evidence that local-scale habitat variables (habitat richness, tree cover, plant species richness, litter cover, soil pH, depth of organic horizon) affected soil fauna diversity: Collembola diversity was independent of all these measures, while lumbricid diversity positively and negatively correlated with vascular plant species richness and tree canopy density. Landscape-scale habitat heterogeneity affects soil diversity regardless of taxon, while the influence of habitat heterogeneity at local scales is dependent on taxon identity, and hence ecological traits, e.g. body size. Landscape-scale habitat heterogeneity by providing different niches and refuges, together with passive dispersal and population patch dynamics, positively contributes to soil faunal diversity. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Importance of scale,land‐use,and stream network properties for riparian plant communities along an urban gradient

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Feedback effects between plant and flower-visiting insect communities along a primary succession gradient

Primary successions of glacier forelands are unique model systems to investigate community dynamics and assembly processes. However, successional changes of plant and insect communities have been mainly analysed separately. Therefore, changes in plant–insect interactions along successional gradients on glacier forelands remain unknown, despite their relevance to ecosystem functioning. This study assessed how successional changes of the vegetation influenced the composition of the flower-visiting insect assemblages of two plant species, Leucanthemopsis alpina (L.) Heyw. and Saxifraga bryoides L., selected as the only two insect-pollinated species occurring along the whole succession. In addition, we investigated the links between reproductive output of these plants and pollinator abundance through experimental exclusion of pollinators. Plant community structure changed along the succession, affecting the distribution and the abundance of insects via idiosyncratic responses of different insect functional groups. L. alpina interacted with ubiquitously distributed pollinators, while S. bryoides pollinators were positively associated with insect-pollinated plant species density and S. bryoides abundance. With succession proceeding, insect assemblages became more functionally diverse, with the abundance of parasitoids, predators and opportunists positively related to an increase in plant cover and diversity. The reproductive output of both plant species varied among successional stages. Contrary to our expectation, the obligate insect-pollinated L. alpina showed a reproductive output rather independent from pollinator abundance, while the reproductive output of the self-fertile S. bryoides seemed linked to pollinator abundance. Observing ecological interactions and using functional traits, we provided a mechanistic understanding of community assembly processes along a successional gradient. Plant community diversity and cover likely influenced insect community assembly through bottom-up effects. In turn, pollinators regulate plant reproductive output through top-down control. We emphasise that dynamics of alpine plant and insect communities may be structured by biotic interactions and feedback processes, rather than only be influenced by harsh abiotic conditions and stochastic events.     

Effects of anthropogenic habitat disturbance on local pollinator diversity and species turnover across a precipitation gradient

Anthropogenic habitat disturbance can have profound effects on multiple components of forest biotas including pollinator assemblages. We assessed the effect of small-scale disturbance on local richness, abundance, diversity and evenness of insect pollinator fauna; and how habitat disturbance affected species turnover across the landscape and overall diversity along a precipitation gradient in NW Patagonia (Argentina). We evaluated the effect of disturbance on overall pollinator fauna and then separately for bees (i.e. Apoidea) and non-bee pollinators. Locally, disturbed habitats had significantly higher pollinator species richness and abundances than undisturbed habitats for the whole pollinator assemblage, but not for bees or non-bees separately. However, significant differences in species richness between habitats vanished after accounting for differences in abundance between habitat types. At a local scale Shannon–Weaver diversity and evenness did not vary with disturbance. A β diversity index indicated that, across forest types, species turnover was lower between disturbed habitats than between undisturbed habitats. In addition, rarefaction curves showed that disturbed habitats as a whole accumulated fewer species than undisturbed habitats at equivalent sample sizes. We concluded that small patches of disturbed habitat have a negligible effect on local pollinator diversity; however, habitat disturbance reduced β diversity through a homogenization of the pollinator fauna (in particular of bees) across the landscape.