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Abstract.  1. The enormous diversity of phytophagous insects in forest canopies is hypothesised to be supported by the number of herbivorous species per host tree species or host specificity. It is therefore necessary to examine the effect of host plant species on compositional changes in the herbivore communities.
2. The lepidopteran larval communities were examined in the canopies of 10 tree species in a temperate deciduous forest of Japan. The phylogeny and leaf flush phenology of host plant species were taken into account as factors affecting the herbivore community assembly.
3. Examination of seasonal changes in the larval community structures on each tree species showed that larval species richness, abundance, and evenness decreased significantly from spring to summer. Larval species richness and abundance were characterised by family-level phylogenetic differences among tree species, whereas evenness was determined at a higher taxonomic level.
4. Compositional changes in the larval communities among tree species showed a remarkable pattern, with a phylogenetic effect at a high taxonomic level in spring, similar to evenness, but a phenological effect in summer. This suggests that host specificity could support the lepidopteran larval diversity in spring.
5. These results suggest that the differences in host utilisation of the herbivore, which reflects the phylogenetic effect of the host plants, can be important as a factor affecting the diversity of lepidopteran larval communities in temperate forests.  相似文献   

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Global biodiversity is affected by numerous environmental drivers. Yet, the extent to which global environmental changes contribute to changes in local diversity is poorly understood. We investigated biodiversity changes in a meta‐analysis of 39 resurvey studies in European temperate forests (3988 vegetation records in total, 17–75 years between the two surveys) by assessing the importance of (i) coarse‐resolution (i.e., among sites) vs. fine‐resolution (i.e., within sites) environmental differences and (ii) changing environmental conditions between surveys. Our results clarify the mechanisms underlying the direction and magnitude of local‐scale biodiversity changes. While not detecting any net local diversity loss, we observed considerable among‐site variation, partly explained by temporal changes in light availability (a local driver) and density of large herbivores (a regional driver). Furthermore, strong evidence was found that presurvey levels of nitrogen deposition determined subsequent diversity changes. We conclude that models forecasting future biodiversity changes should consider coarse‐resolution environmental changes, account for differences in baseline environmental conditions and for local changes in fine‐resolution environmental conditions.  相似文献   

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高虹  陈圣宾  欧阳志云 《生态学报》2012,32(21):6767-6775
文化林是指村民按照文化传统、风俗习惯或宗教信仰自觉保护和管理的森林,具有一定社会文化功能。目前国内外对文化林物种多样性研究主要为定性描述,缺乏对文化林和非文化林生物多样性的定量比较及差异来源分析。利用物种多样性加性分配方法,将总的Gamma 多样性分成样格内的Alpha多样性以及样格间、样方间和林型间Beta多样性,对中国亚热带地区3个村落文化林的乔木层、灌木层、草本层和藤本层进行物种多样性的多尺度分析。调查发现:(1)文化林共有维管束植物296种,以苦槠,樟和米槠为优势种,非文化林共有维管束植物189种,以杉木、马尾松和毛竹为优势种。文化林乔木层和灌木层物种数显著高于非文化林,草本层和藤本层物种数差异不显著。(2)Beta多样性随尺度增大而增加,林型间Beta多样性最高,占区域总Gamma多样性的41.9%-62.8%,其次是样方间Beta多样性(18.6%-31.9%),对区域多样性贡献最小为样格内Alpha和样格间Beta多样性。(3)林型间的多样性对区域物种多样性的贡献中,文化林占主导作用,乔木层占54.4%-81.0%,灌木层占51.2%-60.2%,草本层占42.9%-64.1%,藤本层占49.9%-62.2%。(4) 物种累积-面积曲线表明,在各个尺度上,文化林物种多样性始终高于非文化林,从而在相同面积下保护了更多的物种。加性分配模型在多个空间尺度上阐明了Alpha和Beta多样性的变化,突出了文化林对区域物种多样性的贡献,对保护对象和保护范围的决策以及生物多样性的保护与恢复具有重要意义。  相似文献   

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Species richness and abundance are the two most important diversity variables. Species abundance is additive when aggregated across spatial scale, whereas species richness is non-additive. This study analyzes the effect of spatial scale and site on species abundance and richness in a 25-ha temperate forest plot in the Changbai Mountains, northeastern China. The result shows that species abundance and richness are not only dependent on spatial scales, but also dependent on site. Species abundance responds linearly to changes of spatial scale with no intersection in different sites of the study area. However, although species richness also increases with the increase of spatial scale, there are some intersections for the different sites, suggesting that a species-rich site does not always have a high value if the spatial scale is changed. In all, with respect to additive variables, it is relatively easy to extrapolate them from one spatial scale to another spatial scale, as they and the spatial scale usually form a linear relationship. In contrast, non-additive variables are difficult to extrapolate across spatial scales, because they often respond nonlinearly to spatial scale changes. In order to extrapolate these non-additive variables across spatial scales, it is necessary to estimate the relationships between them and spatial scales. As a result, extrapolation of information among spatial scales may be possible, but very difficult, especially for non-additive variables. Because the 25-ha Changbai plot is very small compared to the extent of the world temperate forests, and the vegetation is a relatively uniform type, more such studies in other ecosystems are needed before theories and generalization about scaling effects can be formulated.  相似文献   

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The vertical stratification of lepidopteran and coleopteran communities in a cool-temperate deciduous forest in Japan was examined to evaluate the hypothesis of an expected uniform distribution of mobile flying insects between the canopy and understory of temperate forests. Lepidopteran and coleopteran insects were trapped using light traps at three sites in each of the canopy and understory for three consecutive nights each month from April to October 2001. For Lepidoptera, species richness, abundance, and family richness were significantly higher in the understory than in the canopy. For Coleoptera, only abundance was larger in the canopy relative to the understory; species and family richness did not differ between the strata. The beta diversity of the lepidopteran community was larger between the strata than among sites, but the coleopteran community showed an inverse pattern. These results imply the presence of vertical stratification within the lepidopteran community, but not within the coleopteran community, in the temperate forest. The understory contributes more than the canopy to lepidopteran diversity in the temperate forest, although this stratification may be relatively weak because, in contrast to the situation in tropical forests, the canopy and understory assemblages share many species.  相似文献   

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We investigated plant species diversity as it related to stand structure and landscape parameters in abandoned coppice forests in a temperate, deciduous forest area of central Japan, where Fagus crenata was originally dominant. The species occurring in the study plots were classified into habitat types based on a statistical analysis of their occurrence bias in particular habitats (e.g., primary forest, coniferous plantation) in the landscape studied. The relationships between stand structure, which reflected the gradient of management, and forest floor plant species diversity (H and J) and richness (number of species per unit area) were not significant. However, these factors did influence the forest floor plant composition of the different types of habitat. According to the multiple regression analysis, species diversity and the richness of forest floor plants was affected by landscape parameters rather than by stand structure. For trees, species richness was mainly affected by the relative dominance of F. crenata, which is one of the stand structure parameters that decreases with intensive management. This is probably because many of the tree species that are characteristic of coppice forests increase after F. crenata have been eliminated by management; these species are not dominant in the original forest, where they are suppressed by F. crenata, the shade-tolerant dominant species. The species diversity (H and J) of trees was positively correlated with some landscape parameters, including the road density around the study plot, which may be associated with the intensity of management activity. The number of disturbance-tolerant species increased with increasing road density. Stand structure mainly affected disturbance-intolerant forest floor plant species and disturbance-tolerant tree species. Thus, the species diversity responses differed between forest floor plants and trees. The impact of forest management on species diversity was more prominent for forest floor plants.  相似文献   

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During the period fromlate May through December 1981, tree-dwelling beetles were regularly surveyed at three deciduous oak and two evergreen forests in the vicinity of Gifu City. Chrysomelidae and Curculionidae were abundant in these forests. The species diversity and the seasonal succession of species were most apparent in May and June. The three deciduous oak forests, with many species and high equitability, showed more diverse community structure, but fewer individuals, when compared with the two evergreen forests. Furthermore, the species compositions of the deciduous oak forests were seasonally and spatially more heterogeneous than those of the evergreen forests. A few dominant species, however, had a strong influence on the community structure. The relationship between the diversity index and sample size was examined. The diversity index changed with the sample size, and the range of the variation diminished as the sample size increased. However, equilibrium was not reached even in the largest sample size used in this study (20 samples). There was a significantly high correlation (P<0.001) in diversity index between the smaller sample sizes (5, 10, 15) and the largest. It was, therefore, shown that community structures can be compared on the basis of the diversity indices from samples of constant size, even when the samples are small. Contribution No. 108 from Lab. Ent., Fac. Agr., Gifu Univ.  相似文献   

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The floristic diversity of Mexican tropical deciduous forests (TDF) is of critical importance given the high species richness (alpha diversity), species turnover (beta diversity), and the intense deforestation rates. Currently, most TDF landscapes are mosaics of agricultural land, secondary vegetation, and patches of relatively undisturbed primary vegetation. Here we illustrate how both primary forest remnants and secondary vegetation patches contribute to the floristic diversity of TDF in a landscape of volcanic origin in central Veracruz, Mexico. Our objectives were to assess sampling efficiency and inventory completeness, to compare mean and cumulative species richness between primary forest and secondary vegetation sites, and to analyze beta diversity between vegetation types. In an area of 12,300 m2 we recorded 105 families, 390 genera, and 682 species. Species inventories for both vegetation types were about 80% complete. Secondary vegetation is more alpha diverse than primary forest, both in terms of cumulative and mean species richness. We found a remarkably high beta diversity between vegetation types (75% of complementarity, 91.60% of mean dissimilarity). We also identified the species that contribute the most to similarity within vegetation types and to dissimilarity between vegetation types. Our results support the idea that assessing biodiversity on the landscape scale is an appropriate way to ascertain the impact of human activities. For this land mosaic, conservation of the flora would not be possible by focusing solely on primary forest remnants. We propose the implementation of a network of small conservation areas with a flexible structure, following the “archipelago reserve” model.  相似文献   

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Aims The relative roles of ecological processes in structuring beta diversity are usually quantified by variation partitioning of beta diversity with respect to environmental and spatial variables or gamma diversity. However, if important environmental or spatial factors are omitted, or a scale mismatch occurs in the analysis, unaccounted spatial correlation will appear in the residual errors and lead to residual spatial correlation and problematic inferences.  相似文献   

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Aims Despite wide consensus that ecological patterns and processes should be studied at multiple spatial scales, the temporal component of diversity variation has remained poorly examined. Specifically, rare species may exhibit patterns of diversity variation profoundly different from those of dominant taxa. Location Southern Finland. Methods We used multiplicative partitioning of true diversities (species richness, Shannon diversity) to identify the most important scale(s) of variation of benthic macroinvertebrate communities across several hierarchical scales, from individual samples to multiple littorals, lakes and years. We also assessed the among‐scale variability of benthic macroinvertebrate community composition by using measures of between‐ and within‐group distances at hierarchical scales. Results On average, a single benthic sample contained 23% of the total regional macroinvertebrate species pool. For both species richness and Shannon diversity, beta‐diversity was clearly the major component of regional diversity, with within‐littoral beta‐diversity (β1) being the largest component of gamma‐diversity. The interannual component of total diversity was small, being almost negligible for Shannon index. Among‐sample (within‐littoral) diversity was related to variation of substratum heterogeneity at the same scale. By contrast, only a small proportion of rare taxa was found in an average benthic sample. Thus, dominant species among lakes and years were about the same, whereas rare species were mostly detected in a few benthic samples in one lake (or year). For rare species, the temporal component of diversity was more important than spatial turnover at most scales. Main conclusions While individual species occurrences and abundances, particularly those of rare taxa, may vary strongly through space and time, patterns of dominance in lake littoral benthic communities are highly predictable. Consequently, many rare species will be missed in temporally restricted samples of lake littorals. In comprehensive biodiversity surveys, interannual sampling of littoral macroinvertebrate communities is therefore needed.  相似文献   

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Vertical and seasonal distributions of flying beetles were investigated in asuburban temperate deciduous forest in Kanazawa, Japan using water pan traps to determine the abundance and composition among vertical strata, change in the abundance and composition through seasons and determinant factors in generating the distributions. Traps were placed at three levels (0.5 m, 10 m, and 20 m above ground) on a tower. Samplings were carried out seasonally from May to November in 1999 and 2000. Variations in the abundance of flying beetles were observed from different layers. The results showed that the abundance and composition of flying beetles varied among strata and seasons. In both 1999 and 2000,Elateridae was consistently most abundant in the bottom layer, while Attelabidae and Cantharidae were most abundant in the upper layer. In 1999, Eucnemidae and overall scavengers were most abundance in the bottom layer, but results were not consistent with those in 2000. In general, the abundance of herbivores reaches a peak in the early season(May/June) and decreases in the following months. Peaks of abundance in predators vary vertically. In the bottom layer a peak was observed in the early season (May/June), while in the upper layer this was observed in July. Scavengers had two peaks, in May/June and September. These patterns indicated that vertical distributions in the abundance of differentfeeding guilds varied through seasons.  相似文献   

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胡芳  曾馥平  杜虎  彭晚霞  张芳  谭卫宁  宋同清 《生态学报》2018,38(17):6074-6083
物种多样性的空间分布格局及其与尺度的关系研究对于了解群落物种多样性形成机制具有重要意义。为了探讨喀斯特地区物种多样性空间分布格局的尺度效应,以喀斯特常绿落叶阔叶混交林25 hm~2样地的(胸径DBH≥1)木本植物为研究对象,分析了6个空间尺度(5 m×5 m,10 m×10 m,20 m×20 m,50 m×50 m,100 m×100 m,250 m×250 m)上的多度、物种丰富度、Shannon-Wiener指数、Simpson指数以及Pielou均匀度指数的变化规律。结果表明:物种多样性指数的空间分布均表现出较高的空间异质性;物种多样性指数的方差随取样尺度增加呈现单峰分布特征,并且在100 m×100 m尺度上达到最大值;物种多样性指数的变异系数随尺度的增加呈线性下降趋势,其中,Shannon-Wiener指数、Simpson指数以及Pielou均匀度指数均在5 m×5 m至20 m×20 m尺度上明显减小;在大于50 m×50 m的尺度上,物种丰富度与多度的正相关性不显著(P0.05)。喀斯特常绿落叶阔叶混交林物种多样性的空间分布格局与不同空间尺度密切相关,深入解析物种多样性随空间尺度的变化模式,需要在类似的森林生态系统做更多的研究。  相似文献   

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Environmental heterogeneity is regarded as one of the most important factors governing species richness gradients. An increase in available niche space, provision of refuges and opportunities for isolation and divergent adaptation are thought to enhance species coexistence, persistence and diversification. However, the extent and generality of positive heterogeneity–richness relationships are still debated. Apart from widespread evidence supporting positive relationships, negative and hump‐shaped relationships have also been reported. In a meta‐analysis of 1148 data points from 192 studies worldwide, we examine the strength and direction of the relationship between spatial environmental heterogeneity and species richness of terrestrial plants and animals. We find that separate effects of heterogeneity in land cover, vegetation, climate, soil and topography are significantly positive, with vegetation and topographic heterogeneity showing particularly strong associations with species richness. The use of equal‐area study units, spatial grain and spatial extent emerge as key factors influencing the strength of heterogeneity–richness relationships, highlighting the pervasive influence of spatial scale in heterogeneity–richness studies. We provide the first quantitative support for the generality of positive heterogeneity–richness relationships across heterogeneity components, habitat types, taxa and spatial scales from landscape to global extents, and identify specific needs for future comparative heterogeneity–richness research.  相似文献   

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