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1.
1. Global environmental change can dramatically alter the composition of floral and faunal communities, and elucidating the mechanisms underlying this process is important for predicting its outcomes. Studies on global climate change have mostly focused on statistical summaries within wide spatial and temporal scales; less attention has been paid to variability in microclimates at narrower spatial and temporal scales. 2. The microclimate is the suite of climatic conditions measured in a local area. Environmental variables at the microclimatic scale can be critical for the ecology of organisms inhabiting each area. The effect of spatial and temporal changes in the microclimate on the ecology of carabid beetle communities in three sites on Mount Odaesan, Korea was examined. 3. Carabid beetle communities and quantified site‐specific environmental factors from measurements of air temperature, air humidity, light intensity and soil temperature over 5 years (2010–2015) were surveyed. 4. It was found that microclimatic variables and the patterns of temporal changes in carabid beetle communities differed between the three sites within the single mountain system. Microclimatic variables influencing temporal changes in beetle communities also differed between the sites. Therefore, it is suggested that variation in local microclimates affects spatial and temporal variation in carabid beetle communities at a local scale. 5. The present results demonstrate the importance of regular surveys of communities at local scales. Such surveys are expected to reveal an additional fraction of variation in communities and underlying processes that have been overlooked in studies of global community patterns and change.  相似文献   

2.
Landscape heterogeneity is a major driver of biodiversity in agricultural areas and represents an important parameter in conservation strategies. However, most landscape ecology studies measure gamma diversity of a single habitat type, despite the assessment of multiple habitats at a landscape scale being more appropriate. This study aimed to determine the effects of landscape composition and spatial configuration on life-history trait distribution in carabid beetle and herbaceous plant communities. Here, we assessed the gamma diversity of carabid beetles and plants by sampling three dominant habitats (woody habitats, grasslands and crops) across 20 landscapes in western France. RLQ and Fourth Corner three-table analyses were used to assess the association of dispersal, phenology, reproduction and trophic level traits with landscape characteristics. Landscape composition and configuration were both significant in explaining functional composition. Carabid beetles and plants showed similar response regarding phenology, i.e. open landscapes were associated with earlier breeding species. Carabid beetle dispersal traits exhibited the strongest relationship with landscape structure; for instance, large and apterous species preferentially inhabited woody landscapes, whereas small and macropterous species preferentially inhabited open landscapes. Heavy seeded plant species dominated in intensified agricultural landscapes (high % crops), possibly due to the removal of weeds (which are usually lightweight seeded species). The results of this study emphasise the roles of landscape composition and configuration as ecological filters and the importance of preserving a range of landscape types to maintain functional biodiversity at regional scales.  相似文献   

3.
1. Understanding the wide-scale processes controlling communities across multiple sites is a foremost challenge of modern ecology. Here, data from a nation-wide network of field sites are used to describe the metacommunity dynamics of arable carabid beetles. This is done by modelling how communities are structured at a local level, by changes in the environment of the sampled fields and, at a regional level, by fitting spatial parameters describing latitudinal and longitudinal gradients. 2. Local and regional processes demonstrated independent and significant capacities for structuring communities. Within the local environment, crop type was found to be the primary determinant of carabid community composition. The regional component included a strong response to a longitudinal gradient, with significant increases in diversity in an east-to-west direction. 3. Carabid metacommunities seem to be structured by a combination of species sorting dynamics, operating at two different, but equally important, spatial scales. At a local scale, species are sorted along a resource gradient determined by crop type. At a wider spatial scale species appear to be sorted along a longitudinal gradient. 4. Nation-wide trends in communities coincided with known gradients of increased homogeneity of habitat mosaics and agricultural intensification. However, more work is required to understand fully how communities are controlled by the interaction of crops with changes in landscape structure at different spatial scales. 5. We conclude that crop type is a powerful determinant of carabid biodiversity, but that it cannot be considered in isolation from other components of the landscape for optimal conservation policy.  相似文献   

4.
The effects of land-use management and environmental features at different scales on carabid beetle diversity and trait structure were assessed across olive groves in northeastern Portugal. We selected organic and integrated olive groves that were distinct in terms of specific management practices, local linear features and landscape configurations. Besides the management intensification levels, differences in carabid diversity and community traits were mainly due to local habitat and ecological linear structures at a finer spatial scale. Carabid community traits related to disturbance, namely traits of body size and species dispersal ability, responded to land-use intensity and particular olive grove features were influencing diversity patterns. Within the olive grove patches, larger and brachypterous species were associated to plots with more dense vegetation cover while macropterous and small-sized species were more associated to open areas. Also, larger carabid species benefitted from higher patch size heterogeneity within the landscape mosaics. Our findings indicate that the effects of farming system is contingent on the specific management practices, local and linear features present in agroecosystems such as olive groves. Particularly, the influence of local features on carabid diversity patterns and community traits linked to dispersal and movement may be crucial in maintaining pest control at a landscape scale.  相似文献   

5.
  1. The enhancement of pest regulation service in crops depends for a large part on the capacity of agroecological practices to increase the presence of key species or functional traits in arthropod communities within fields.
  2. We investigated the effects of undestroyed strips of winter cover crops in maize fields on carabid community composition, and on the distribution of three ecological traits: diet, wing status and body size.
  3. We found that the community composition and the distribution of ecological traits in the in-field cover crop strips had commonalities with both adjacent cropped areas and field margins. Some species were recorded mostly or only in the strips indicating that strips could support carabid species and help increase local diversity from the first year of establishment.
  4. The activity-density of Poecilus cupreus and Pterostichus melanarius was higher in the cropped proximity of the strip, and the body size was influenced by the distance from the strip.
  5. Our results suggest that carabid communities are shaped by the habitat type, but the influence of such agroecological infrastructures on communities of adjacent crops is minor beyond a distance of 10 m. However, overall species abundance was increased and thus potentially provided enhanced pest regulation.
  相似文献   

6.
In 1979–2008, serological investigation of carabid beetles as predators of the Colorado potato beetle was carried out in the fields of potato and other Solanaceae crops in nine regions of Russia, Moldova, and Ukraine. The fraction of carabid beetles feeding on the pest in the potato, tomato, and egg-plant fields grows with the duration of the pest presence in the region and is proportional to its population density.  相似文献   

7.
Å. Berg 《Bird Study》2013,60(2):153-165
CapsuleThe amount of forest (at local and landscape scales) and occurrence of residual habitats at the local scale are shown to be the major factors influencing bird community composition in farmland–forest landscapes in central Sweden.

Aims To investigate the importance of local habitat and landscape structure for breeding birds in farmland–forest landscapes in central Sweden.

Methods Breeding birds were censused at 292 points. A detailed habitat mapping was made within 300 m of the points. Within a 300–600 m radius only two major habitats (forests and arable fields) were identified.

Results Cluster analyses of bird communities identified three site types that also differed in habitat composition: (i) partially forested sites in forested landscapes; (ii) heterogeneous sites with residual habitats in mosaic landscapes; and (iii) field-dominated farmland sites in open landscapes. A total of 19 of 25 farmland bird species (restricted to farmland or using both farmland and forest) had the highest abundance in farmland sites with mosaics of forest and farmland, while only six farmland species had the highest abundance in field-dominated sites. The bird community changed from being dominated by farmland species to being dominated by forest species (common in forest landscapes without farmland) at small proportions (10–20%) of forest at the local scale. A major difference in habitat composition between heterogeneous and field-dominated sites was the occurrence of different residual habitats (e.g. shrubby areas and seminatural grasslands). These habitats seemed to influence bird community composition more than land-use, despite covering <10% of the area. Seminatural grasslands were important for bird community composition and species-richness, but grazing seemed to be less important. Among different land-use types, cereal crops were the least preferred fields. Set-asides with tall vegetation and short rotation coppices were positively associated with species-richness of farmland birds.

Conclusion In general, the composition of the landscape was important for bird community composition, although amount and distribution of forests, occurrence of residual habitats and land-use of fields at the local scale had the strongest influence on bird community composition. The possible implications of these patterns for managing farmland–forest landscapes are discussed.  相似文献   

8.
Aim Species richness in itself is not always sufficient to evaluate land management strategies for nature conservation. The exchange of species between local communities may be affected by landscape structure and land‐use intensity. Thus, species turnover, and its inverse, community similarity, may be useful measures of landscape integrity from a diversity perspective. Location A European transect from France to Estonia. Methods We measured the similarity of plant, bird, wild bee, true bug, carabid beetle, hoverfly and spider communities sampled along gradients in landscape composition (e.g. total availability of semi‐natural habitat), landscape configuration (e.g. fragmentation) and land‐use intensity (e.g. pesticide loads). Results Total availability of semi‐natural habitats had little effect on community similarity, except for bird communities, which were more homogeneous in more natural landscapes. Bee communities, in contrast, were less similar in landscapes with higher percentages of semi‐natural habitats. Increased landscape fragmentation decreased similarity of true bug communities, while plant communities showed a nonlinear, U‐shaped response. More intense land use, specifically increased pesticide burden, led to a homogenization of bee, bug and spider communities within sites. In these cases, habitat fragmentation interacted with pesticide load. Hoverfly and carabid beetle community similarity was differentially affected by higher pesticide levels: for carabid beetles similarity decreased, while for hoverflies we observed a U‐shaped relationship. Main conclusions Our study demonstrates the effects of landscape composition, configuration and land‐use intensity on the similarity of communities. It indicates reduced exchange of species between communities in landscapes dominated by agricultural activities. Taxonomic groups differed in their responses to environmental drivers and using but one group as an indicator for ‘biodiversity’ as such would thus not be advisable.  相似文献   

9.
The public promotion of renewable energies is expected to increase the number of biogas plants and stimulate energy crops cultivation (e.g. maize) in Germany. In order to assess the indirect effects of the resulting land‐use changes on biodiversity, we developed six land‐use scenarios and simulated the responses of six farmland wildlife species with the spatially explicit agent‐based model system ALMaSS. The scenarios differed in composition and spatial configuration of arable crops. We implemented scenarios where maize for energy production replaced 15% and 30% of the area covered by other cash crops. Biogas maize farms were either randomly distributed or located within small or large aggregation clusters. The animal species investigated were skylark (Alauda arvensis), grey partridge (Perdix perdix), European brown hare (Lepus europaeus), field vole (Microtus agrestis), a linyphiid spider (Erigone atra) and a carabid beetle (Bembidion lampros). The changes in crop composition had a negative effect on the population sizes of skylark, partridge and hare and a positive effect on the population sizes of spider and beetle and no effect on the population size of vole. An aggregated cultivation of maize amplified these effects for skylark. Species responses to changes in the crop composition were consistent across three differently structured landscapes. Our work suggests that with the compliance to some recommendations, negative effects of biogas‐related land‐use change on the populations of the six representative farmland species can largely be avoided.  相似文献   

10.
We studied the long-term (23-24 years) species turnover and succession of epigaeic beetle assemblages (Coleoptera: Carabidae, incl. Cicindelinae) in three remnant habitats [cottonwood (Populus spp.) and oak (Quercus spp.) stands, and old fields] that are embedded within highly urbanized areas in central Minnesota. A total of 9,710 beetle individuals belonging to 98 species were caught in three sampling years: 1980, 1981 and 2005 in pitfall traps in identical locations within each habitat. Results indicate that there were 2-3 times greater trap catches in 2005 than in 1980 (cottonwood and oak stands, and old fields) and 1.4-1.7 times greater species diversity of beetles in 2005 than in the 1980-1981 suggesting increased habitat association by beetles over time. Although there were no significant differences in catches between 2005 and 1981 (only cottonwood stands and old fields), there was a trend where more beetles were caught in 2005. At the species-level, 10 times more of an open-habitat carabid species, Cyclotrachelus sodalis sodalis LeConte, was caught in 2005 than in 1980. However, trap catches of five other abundant carabid species [Pterostichus novus Straneo, Platynus decentis (Say), Platynus mutus (Say), Calathus gregarius (Say), and Poecilus lucublandus lucublandus (Say)] did not change indicating population stability of some beetle species. These remnant habitats were increasingly colonized by exotic carabid species as Carabus granulatus granulatus Linneaus, Clivina fossor (Linneaus) and Platynus melanarius (Illiger), that were trapped for the first time in 2005. Species composition of epigaeic beetles was quite distinct in 2005 from 1980 with 39 species reported for the first time in 2005, indicating a high turnover of assemblages. At the habitat-level, greatest species diversity was in cottonwood stands and lowest was in old fields, and all habitat types in 2005 diverged from those in 1980s, but not cottonwood stands in 1981. As our sampled areas are among some of the last remnants of the original oak savanna habitats in central Minnesota, we hypothesize that conservation of these sites may be critical to maintaining epigaeic beetle assemblages under increased urbanization pressure.  相似文献   

11.
李超  张智  郭文超  张云慧  孙京瑞  程登发  刘怀 《生态学报》2011,31(21):6488-6494
马铃薯甲虫是一种重要的外来入侵害虫,自1993年传入我国新疆北部地区以来,迅速扩散传播,对我国马铃薯等茄科作物生产造成严重威胁。为明确马铃薯甲虫传播扩散与河流等生态因子之间的关系,结合马铃薯甲虫虫情调查,利用地理信息系统(GIS)的空间分析功能,对新疆沙湾县马铃薯甲虫发生与河流的关系进行研究。结果表明:在沙湾县内,马铃薯甲虫扩散方向与河流流向基本一致,均呈由南向北方向;不同缓冲区内,马铃薯甲虫危害级别差异极显著,缓冲区危害级别从大到小依次:缓冲区2(1-2 km)>缓冲区4(3-4 km)>缓冲区5(4-5 km)>缓冲区1(0-1 km)>缓冲区3(2-3 km);不同河流流域内马铃薯甲虫危害级别也差异极显著,危害级别排序依次是:金沟河>安集海河>玛纳斯河>西岸大渠。  相似文献   

12.
13.
Niche and neutral processes drive community assembly and metacommunity dynamics, but their relative importance might vary with the spatial scale. The contribution of niche processes is generally expected to increase with increasing spatial extent at a higher rate than that of neutral processes. However, the extent to what community composition is limited by dispersal (usually considered a neutral process) over increasing spatial scales might depend on the dispersal capacity of composing species. To investigate the mechanisms underlying the distribution and diversity of species known to have great powers of dispersal (hundreds of kilometres), we analysed the relative importance of niche processes and dispersal limitation in determining beta‐diversity patterns of aquatic plants and cladocerans over regional (up to 300 km) and continental (up to 3300 km) scales. Both taxonomic groups were surveyed in five different European regions and presented extremely high levels of beta‐diversity, both within and among regions. High beta‐diversity was primarily explained by species replacement (turnover) rather than differences in species richness (i.e. nestedness). Abiotic and biotic variables were the main drivers of community composition. Within some regions, small‐scale connectivity and the spatial configuration of sampled communities explained a significant, though smaller, fraction of compositional variation, particularly for aquatic plants. At continental scale (among regions), a significant fraction of compositional variation was explained by a combination of spatial effects (exclusive contribution of regions) and regionally‐structured environmental variables. Our results suggest that, although dispersal limitation might affect species composition in some regions, aquatic plant and cladoceran communities are not generally limited by dispersal at the regional scale (up to 300 km). Species sorting mediated by environmental variation might explain the high species turnover of aquatic plants and cladocerans at regional scale, while biogeographic processes enhanced by dispersal limitation among regions might determine the composition of regional biotas.  相似文献   

14.
Although Carabidae is among the best-studied families of beetles in Europe from the faunistic point of view, there is still a lack of available information on the ecological requirements of the particular carabid species. The habitat preferences that determine the distribution of species are largely influenced by habitat structure and microclimate. In addition to other factors, these habitat parameters are influenced by the nature of the vegetation. Therefore, our study investigated the influence of tree species on carabid beetle communities. We conducted the research at 9 stands in the Borová Hora Arboretum (Zvolen, Central Slovakia). Each studied site represents a monoculture of one of nine tree species. At each site, some soil and leaf litter attributes (pH, conductivity, and content of H, C, N and P) were evaluated. Ground beetles were collected by pitfall trapping during the vegetation periods in 2008–2011. In total, 3012 individuals of 29 species were obtained. Significant differences in the total dynamic activity and species richness of the carabid beetle communities among the compared forest stands were revealed. The results of the research confirmed statistically significant relationships among 1) the soil conductivity and both the richness and Shannon diversity of the ground beetle communities, 2) the litter and soil N content and richness, the Shannon diversity and the species composition of the ground beetle communities. The Shannon diversity and richness were negatively related to the soil conductivity and positively related with the N content. Our research showed that dominant tree species indirectly influence diversity and composition of carabid communities via the soil properties.  相似文献   

15.
Assembly of fungal communities remains poorly understood in part because of the daunting range of spatial scales that may be involved in this process. Here, we use individual leaves as a natural sampling unit, comprising spatially distinct habitat and/or resource patches with unique histories and suites of resources. Spatial patterns in fungal beta diversity were tested for consistency with the metacommunity paradigms of species sorting and neutral dynamics. Thirty senesced leaves were collected from the forest floor (O horizon) in replicate upland forest, riparian forest and vernal pool habitats. We quantified spatial distance between leaves, and fungal community composition was assayed by terminal restriction fragment length polymorphism. Significant distance‐decay relationships were detected at all but one upland site. This is the first study where changes in fungal community composition were quantified across discrete adjacent habitat patches, providing evidence that fungal distance decay is operational at a scale of centimetres. Although leaves of differing lignin contents were sampled from each site, leaf type was not consistently important in explaining variation in fungal community composition. However, depth of a leaf within the forest floor significantly influenced community composition at five of six sites. Environmental heterogeneity associated with depth could include moisture gradients, relative influence of soil or spore colonization, and impact of forest floor biotic community (i.e. collembola and earthworms). Because the influence of spatial distance and depth on fungal community composition could not be disentangled, both species‐sorting and neutral processes may be embedded within the distance‐decay relationships that we found.  相似文献   

16.
Species richness, composition, and functional traits of carabid beetle assemblages (Coleoptera: Carabidae) were studied in relation to different grassland management. Carabid beetles were sampled during the summers 2008 and 2009 by 165 traps located in 11 sites in the central-eastern Italian Alps. Using mixed effect models to account for potential spatial bias, we found that mown grasslands had significantly more species, a lower proportion of wingless species and a lower proportion of species with long larval development than grazed and natural grasslands. Within grazed and mown grasslands, neither cattle density nor number of cuts had any significant effect neither on species richness nor on any of the traits. The influence of grassland management can be summarised as follows: (1) grazing does not change community structure and functional traits compared to natural grasslands; (2) mowing negatively affects the carabid beetle assemblages; (3) the intensity of grazing and of cutting may not affect the structure of species assemblages of ground beetles. Our results support the hypothesis that agroecosystem practices in alpine grasslands influence carabid beetle communities. Specifically, the species with traits typical of undisturbed habitats (low dispersal abilities and long larval development) are more sensitive to perturbations (e.g. cutting). Our suggestion for agricultural and environmental planning and for conservation schemes is that the preservation of natural grasslands (e.g. forest gaps) and the implementation of grazing should be promoted during the planning of agroecosystem mosaics.  相似文献   

17.
农田边界植草带是农田系统各斑块间生物物种迁移和群落演替、物质和能量交换的主要区域,对维持农业生物多样性及提高农田生产力具有重要意义。基于作物-害虫-天敌互作有机整体对植草带宽度的响应,选取不同宽度植草带(2 m、4 m、6 m)及其比邻农田并以对应宽度作物边界作为对照,采用地表陷阱法对蜘蛛和步甲进行取样调查,探究植草带宽度对蜘蛛和步甲种群结构、迁移扩散规律以及对农田害虫控制潜力的影响。结果表明:植草带内蜘蛛和步甲个体数均显著高于对照条带,4 m、6 m植草带的蜘蛛和步甲多度显著高于2 m植草带,且物种丰富度和多度显著高于其对照条带。此外,不同宽度植草带蜘蛛和步甲群落存在较高的异质性,蜘蛛和步甲群落结构差异显著;在4 m和6 m植草带及其比邻玉米田内,蜘蛛和步甲多度在植草带和植草带与比邻玉米田交界处显著高于农田内部,且随距离的增加,蜘蛛物种多度呈显著降低趋势,植草带宽度和距离共同决定蜘蛛和步甲的空间分布;Monte Carlo检验结果表明,植草带宽度、植被Margalef指数对农田中蜘蛛和步甲群落结构的影响均达到显著水平,蜘蛛主要优势科和步甲主要优势种主要分布在6 m植草带比邻玉米田内;4 m、6 m植草带比邻的玉米田中蜘蛛和步甲对玉米害虫的益害比显著高于2 m植草带比邻的玉米田,且4 m、6 m植草带显著增加了玉米籽粒的百粒重及比邻农田的玉米总产量。本研究对植草带涵养捕食性天敌预防害虫发生的最适宽度进行探索,综合考虑植草带耕地占用、天敌涵养和生物控害潜力等因素,确定4 m宽度植草带是具有推广价值的农田边界模式。  相似文献   

18.
《Acta Oecologica》2002,23(6):361-374
Oribatid mite and Carabid beetle communities were investigated at five sites in the ‘Pietraporciana’ and ‘Lucciolabella’ Nature Reserves (central Italy). In this part of southern Tuscany many attempts have been made to encourage the regeneration of native habitats and to preserve existing ones. Human-induced changes in the original forest landscape have had a direct impact on mite and carabid populations. Significant differences in species diversity and abundance among different sites were revealed throughout the sampling period. Species richness, abundance and diversity of oribatid mites decrease from woodland sites to open habitats where evenness was high. There is an inverse trend between the number of species and richness of carabid beetles and those of oribatid mites. Canonical correspondence analysis (CCA) of oribatid and carabid beetle compositions discriminated the sites, demonstrating how even small areas with different vegetation, composition, structure, environment and microclimate were characterised by distinct edaphic populations.  相似文献   

19.
Multi-species indicators are often used to assess biodiversity trends. By combining population trends across several species they summarise trends across a community. Composite indicators such as these are useful for examining general temporal patterns and may suggest important drivers of biodiversity change. However, they may also mask substantial spatial variation in population trends, particularly when they are calculated over large spatial regions. We produced spatially-explicit indicators for farmland and woodland bird communities in the UK and further separate these into trends for generalist and specialist species within each group. We found considerable spatial variation in the indicators, which is masked by indicators calculated at the national level. The farmland community indicator showed mostly positive trends in western areas and extensive declines in south-east England. The woodland community indicator showed a north–south divide, with increases in Scotland and northern England and stability in the southern regions. For both communities, indicator trends for specialist species were more negative than those for generalists. We found no significant difference in farmland community indicators between arable land and improved grassland. Woodland specialists had significantly more negative trends in broadleaf compared to coniferous woodlands, suggesting habitat-type is one of the drivers of changes in the woodland community. These spatial patterns in bird population trends may be used to highlight regional conservation priorities and identify where those may differ from the national scale. In combination with information about other environmental changes, they may also be used to develop hypotheses about potential drivers of change. We advocate that this approach is adopted for other taxa and geographical areas.  相似文献   

20.
We investigated the composition and structure of dung beetle communities (Coleoptera, Scarabaeidae, Scarabaeinae) inhabiting areas of forest fragments next to either conventional or Bt-transgenic maize crops. The purpose of the study was to examine possible impacts of transgenic plants on non-target organisms associated with mammals through their food chain. In February 2011, we collected a total of 1502 beetles belonging to 33 species in Campos Novos, Santa Catarina state (SC), Brazil. Beetles were captured using 200 pitfall traps distributed among 20 forest fragments, 10 fragments in each site type (adjacent to conventional vs. Bt crops). In the fragments adjacent to conventional maize, 805 dung beetles from 27 species were collected. In the fragments adjacent to Bt-transgenic maize, 697 dung beetles from 27 species were caught. Dung beetle community composition was affected by fragment size and environmental complexity, and by distance between fragments. However, it did not explain the differences related to the two crop types, i.e., the functional group of dwellers was significantly over-represented in the fragments surrounded by transgenic maize. Hence, the dweller species Eurysternus francinae and Eurysternus parallelus were more frequent and abundant in fragments located near the transgenic maize, while the tunneler species Onthophagus tristis, Uroxys terminalis, Ontherus sulcator and the roller species Canthon lividus seminitens were more frequent and abundant in fragments surrounded by conventional maize. This observed impact of transgenic crops on functional group dynamics within dung beetle communities could potentially lead to impaired capacity for feces removal, seed dispersal, edaphic aeration, and incorporation of organic matter in the soil in these areas, as such ecosystem services are not performed by the dominant functional group (i.e., dwellers).  相似文献   

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