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1.
In this study, we compared ground-dwelling beetle assemblages (Coleoptera) from a range of different oak fragments and surrounding conifer plantations to evaluate effects of forest size and surrounding matrix habitat in a temperate forest of north China. During 2000, beetles were sampled via pitfall traps within two large oak fragments (ca. 2.0-4.0 ha), two small oak fragments (ca. 0.2-0.4 ha) and two surrounding matrices dom- inated by pine plantations (〉4 ha) in two sites of different aspects. Overall, no significantly negative effects from forest patch size and the surrounding matrix habitat were detected in total species number and abundance of ground-dwelling beetles. However, compared with small oak patches or pine plantations, more species were associated with an affinity for at least one large oak patch of the two aspects. Multivariate regression trees showed that the habitat type better determined the beetle assemblage structure than patch size and aspect, indicating a strong impact of the surrounding matrix. Linear mixed models indicated that species richness and abundance of all ground-dwelling beetles or beetle families showed different responses to the selected environmental variables. Our results suggest that more disturbed sites are significantly poorer in oak forest specialists, which are usually more abundant in large oak fragments and decrease in abundance or disappear in small fragments and surrounding matrix habitats. Thus, it is necessary to preserve a minimum size of forest patch to create conditions characteristic for forest interior, rather than the more difficult task of increasing habitat connectivity.  相似文献   

2.
The objective of this study was to examine the trait-specific response of ground beetles in terms of abundance, species richness, and composition for habitat fragmentation in temperate forests. In addition, we examined how different ecological groups and species of ground beetles responded to environmental variables. During middle May to early November in 2013, ground beetles were sampled using pitfall traps in 27 sites (18 patches and 9 continuous forests) in central Korea. A total of 51 species were identified from 17,845 ground beetles in the 27 study sites. Continuous forests had generally higher abundance and species richness of ground beetles than forest patches. Canonical correspondence analysis for ground beetles was significant, and the proportion of variance explained by environmental variables, such as patch size, elevation, organic matter (C), and soil moisture and pH, was 43.61%. In addition, species composition of ground beetles in continuous forests was grouped distinctively away from those in medium and small-sized patches. In conclusion, both small (1.1–9.6 ha) and medium patches (12.8–51.2 ha) were failed to preserve similar ground beetle biodiversity compared to continuous forests. However, our study revealed that medium-sized forest patches clearly had higher conservation value for forest specialist ground beetles than small-sized forest patches irrespective of forest type.  相似文献   

3.
Silvicultural practices are traditionally aimed at increasing forest profits; however, recent approaches to forest conservation have broadened to include nature-based silviculture for regenerating forests. In southern Ontario (Canada), originally dominated by deciduous forests, conifer plantations were established on abandoned agricultural sites. Currently, there is an increasing interest to convert these conifer stands to a state that mimics the original deciduous forest. We investigated arthropod abundance, species richness of carabid beetles, and abundance of arthropod assemblages (trophic and prey groups) under five silvicultural treatments conducted to regenerate deciduous forests (the natural forest type) from the old conifer plantations. The treatments included: (1) uniform canopy removal; (2) uniform canopy removal and understory removal; (3) group canopy removal; (4) group canopy removal and understory removal; and (5) untreated control plots (relatively pure red pine). Insects were sampled annually using sweepnets and pitfall traps. Results revealed treatment effects on the abundance of Coleoptera, Heteroptera, herbivores, and small arthropods (<3 mm) caught in sweepnet samples, where plots subjected to group shelterwood removal and understory removal supported higher abundances than the control plots. There was no treatment effect on the abundance of other arthropod groups or on the species richness and abundance of carabid beetles. The silvicultural treatments used to encourage natural regeneration did not seem to affect arthropod food availability for insectivorous vertebrates. Thus, the type of silvicultural strategy used to convert pine plantations to a stage that mimics the natural deciduous forests had little overall impact on arthropods.  相似文献   

4.
To clarify the effects of forest fragmentation in urban landscapes on the abundance, species richness, dominance, and species composition of ground beetles (Coleoptera: Carabidae and Brachinidae), we compared the beetles collected in 12 pitfall traps from April to July and from September to November between three continuous suburban forests and eight isolated urban forests (0.06–1.02 ha), most of which were in the precincts of shrines and temples in Hanshin District, Honshu, Japan. A total of 28 species and 4178 individuals of ground beetles were collected. Segregation of urban forests from continuous suburban forests has changed the species composition and resulted in the loss of some large‐sized forest species and the addition of some non‐forest species. Simpson's index of dominance (λ) also increased in the urban forests. The richness of forest species markedly decreased with the reduction in forest area but not with the distance from continuous forests, although the species richness of non‐forest species did not change with them. Also, species composition changed only with forest area. These findings indicate that continuous forests do not necessary serve as a “mainland” for urban forest species and that every urban habitat, however small in size, acts as a temporary reservoir of species. In comparison with populations of small‐sized species, populations of large‐sized forest species appeared to decline more readily during forest fragmentation.  相似文献   

5.
This paper analyzes the diversity of dung and carrion beetles (Scarabaeinae and Silphidae) in four human-induced habitats of a disturbed tropical montane cloud forest: polyspecific shade coffee plantations, monospecific shade coffee plantations, tropical montane cloud forest fragments, and clear cuts. The four habitats had similar richness, species composition, and assemblage structure of dung and carrion beetles. Differences were found in abundance and biomass levels for the four dominant species in the landscape. Dung beetles were more abundant than carrion beetles, but the biomass was higher for the latter. Carrion beetles were seasonal, while dung beetles were clearly not. When forest fragments and shade coffee plantations were compared to other similar habitats in the region, the same general pattern was observed. However, forests with high disturbance and monospecific shade coffee plantations had lower species richness than forests with low and medium disturbance and polyspecific shade coffee plantations. Thus shade coffee plantations maintain connectivity between patches of cloud forest in a landscape that is strongly affected by human activities. Protecting landscape diversity appears to ensure high species richness.  相似文献   

6.
The community structures of Mesostigmata, Prostigmata, and Oribatida in the soil of broad-leaved regeneration forests and conifer plantations of various ages were assessed alongside soil and plant environmental variables using three response metrics (density, species richness, and species–abundance distribution). The density and species richness of mites recovered swiftly after clear-cutting or replanting. Oribatid mites dominated the soil mite communities in terms of densities and species richness for both forest types. Soil mite communities in broad-leaved forests was related to forest age, the crown tree communities index, and forest-floor litter weight. In contrast, soil mite communities in the conifer plantation sites were related to various indices of understory plants. The development of the understory plants was synchronized with the silvicultural schedules, including a closed canopy and thinning. Such a conifer plantation management may affect indirectly the community of mites.  相似文献   

7.
In fragmented landscapes, ecological processes may be significantly influenced by edge effects, but few data are available for edge effects across forest–farmland edges. We investigated patterns of species richness, abundance, and species composition in ground beetles across forest–farm edges in two different agro-forest landscapes in Korea. Nine and five sites were selected from Hwaseong, a fragmented landscape, in 2011 and 2012, respectively, while eight sites were selected from Hoengseong, a relatively well-protected landscape, in 2012. Ground beetles were collected by pitfall trapping. Species richness was higher in the surrounding habitat than in the forest interior or edge in both Hwaseong and Hoengseong. However, in Hwaseong, species richness of the forest edge was similar to that of the forest interior, while in Hoengseong forest edge species richness was intermediate between that of the forest interior and surrounding areas. In addition, non-metric multidimensional scaling based on the combined data of both locations showed that the species composition of ground beetles in the forest edge was more similar to that of the forest interior than the surrounding areas, although some open-habitat species occurred at the forest edges. Three characteristic groups (forest specialists, edge-associated species, and open-habitat species) of ground beetle species were detected by indicator value analysis. In our study, ground beetle assemblages differed in the forest edges of two agro-forest landscapes, suggesting that the edge effect on biota can be influenced by landscape structure.  相似文献   

8.
在四川卧龙国家自然保护区,以天然落叶阔叶林(约100年生)为对照,选择新种植(5年生)、幼年(15年生)和成熟(45年生)的3种落叶松种植林,采用引诱法分别在地表和地上1.5 m处取样,研究处于不同恢复阶段林地中的嗜尸性甲虫物种多样性及其变化格局。共采集甲虫标本3 066号,其中隐翅虫、球蕈甲和埋葬甲科分别占总个体数的43.71%、31.83%和17.97%。嗜尸性甲虫的多度格局呈对数正态分布,随着落叶松林树龄的增长,其分布格局更加接近天然林。物种丰富度和多样性在3种落叶松林内均显著低于天然林,且在3种落叶松林中,新种植的最低。主坐标分析排序和聚类分析表明,不同树龄的落叶松林和天然阔叶林间的嗜尸性甲虫群落组成存在显著差异。以上结果表明,落叶松种植林尚无法取代天然落叶阔叶林在维持嗜尸性甲虫物种多样性中的作用。  相似文献   

9.
Large‐scale forest restoration relies on approaches that are cost‐effective and economically attractive to farmers, and in this context agroforestry systems may be a valuable option. Here, we compared ecological outcomes among (1) 12–15‐year‐old coffee agroforests established with several native shade trees, (2) 12–15‐year‐old high‐diversity restoration plantations, and (3) reference old‐growth forests, within a landscape restoration project in the Pontal do Paranapanema region, in the Atlantic Forest of southeastern Brazil. We compared the aboveground biomass, canopy cover, and abundance, richness, and composition of trees, and the regenerating saplings in the three forest types. In addition, we investigated the landscape drivers of natural regeneration in the restoration plantations and coffee agroforests. Reference forests had a higher abundance of trees and regenerating saplings, but had similar levels of species richness compared to coffee agroforests. High‐diversity agroforests and restoration plantations did not differ in tree abundance. However, compared to restoration plantations, agroforests showed higher abundance and species richness of regenerating saplings, a higher proportion of animal‐dispersed species, and higher canopy cover. The abundance of regenerating saplings declined with increasing density of coffee plants, thus indicating a potential trade‐off between productivity and ecological benefits. High‐diversity coffee agroforests provide a cost‐effective and ecologically viable alternative to high‐diversity native tree plantations for large‐scale forest restoration within agricultural landscapes managed by local communities, and should be included as part of the portfolio of reforestation options used to promote the global agenda on forest and landscape restoration.  相似文献   

10.
Landscape and area effects on beetle assemblages in Ontario   总被引:5,自引:0,他引:5  
Dawn Burke  Henri Goulet 《Ecography》1998,21(5):472-479
We compared beetles collected from eight forest fragments in a suburban-agricultural setting and one contiguous forest in south-central Ontario. Samples were collected by pan traps from the interior of continuous forest and upland deciduous forest fragments ranging in size from 43 to 2350 ha. The pooled sample was composed of 4561 individuals from 117 species. Differences in beetle assemblages was primarily due to variation in patch isolation, although actual fragment size had a significant effect on the abundance of native and forest specializing carabid species, and the amount of forest interior habitat had a significant effect on the total number of beetle species and ground beetle species richness (family Carabidae). Fragments which were less isolated on a local scale (within a 2 km radius) had a species composition most similar to that found in continuous forest, regardless of whether the actual forest area was small or large. Marked differences in abundance and biomass were also attributed to variation in the amount of local forest cover. We suggest that a reduction in patch isolation may be an appropriate conservation strategy to improve beetle diversity and abundance in fragmented landscapes.  相似文献   

11.
Selective logging with natural regeneration is advocated as a near‐to‐nature strategy and has been implemented in many forested systems during the last decades. However, the efficiency of such practices for the maintenance of forest species are poorly understood. We compared the species richness, abundance and composition of ground‐dwelling beetles between selectively logged and unlogged forests to evaluate the possible effects of selective logging in a subtropical broad‐leafed forest in southeastern China. Using pitfall traps, beetles were sampled in two naturally regenerating stands after clearcuts (ca. 50 years old, stem‐exclusion stage: selectively logged 20 years ago) and two mature stands (> 80 years old, understory re‐initiation stage: selectively logged 50 years ago) during 2009 and 2010. Overall, selective logging had no significant effects on total beetle richness and abundance, but saproxylic species group and some abundant forest species significantly decreased in abundance in selectively logged plots compared with unlogged plots in mature stands. Beetle assemblages showed significant differences between selectively logged and unlogged plots in mature stands. Some environmental characteristics associated with selective logging (e.g., logging strategy, stand age, and cover of shrub and moss layers) were the most important variables explaining beetle assemblage structure. Our results conclude that selective logging has no significant impacts on overall richness and abundance of ground‐dwelling beetles. However, the negative effects of selective logging on saproxylic species group and some unlogged forest specialists highlight the need for large intact forested areas for sustaining the existence of forest specialist beetles.  相似文献   

12.
Economic and biological consequences are associated with exotic ambrosia beetles and their fungal associates. Despite this, knowledge of ambrosia beetles and their ecological interactions remain poorly understood, especially in the oak-hickory forest region. We examined how forest stand and site characteristics influenced ambrosia beetle habitat use as evaluated by species richness and abundance of ambrosia beetles, both the native component and individual exotic species. We documented the species composition of the ambrosia beetle community, flight activity, and habitat use over a 2-yr period by placing flight traps in regenerating clearcuts and older oak-hickory forest stands differing in topographic aspect. The ambrosia beetle community consisted of 20 species with exotic ambrosia beetle species dominating the community. Similar percentages of exotic ambrosia beetles occurred among the four forest habitats despite differences in stand age and aspect. Stand characteristics, such as stand age and forest structure, influenced ambrosia beetle richness and the abundances of a few exotic ambrosia beetle species and the native ambrosia beetle component. Topographic aspect had little influence on ambrosia beetle abundance or species richness. Older forests typically have more host material than younger forests and our results may be related to the amount of dead wood present. Different forms of forest management may not alter the percent contribution of exotic ambrosia beetles to the ambrosia beetle community.  相似文献   

13.
The effects of commercial forestry harvest and regeneration practices (clearfelling and slash-burning) on the lucanid fauna of the wet sclerophyll forests of southern Tasmania and the dry sclerophyll forests of eastern Tasmania were examined using pitfall catches. Lucanids are saproxylic beetles, dependent on dead, moribund and decaying wood. Samples taken from old-growth forest and from a chronosequence of sites regenerating after logging, in each forest type, were used to compare the species richness and abundance of the lucanid assemblages. In both forest types, species richness and abundance was highest in the youngest regeneration sites (1–3 year), reflecting the species richness of the original and adjacent unlogged forest, lowest in the older (20–25 year) sites, and variable in the old-growth sites. TWINSPAN cluster analysis showed no clear distinction between regeneration and old-growth forest. The post-harvest slash and stump residue provided an important refugium and initial habitat, but our research indicates that some species may not maintain populations in the long term. Our results suggest that most species of lucanids will find a continuous supply of suitable habitat only in old-growth forests; and such species may become less common as clearfell harvesting leads to a replacement of heterogeneous old-growth forest with single-aged monospecific stands. Continuity of supply of wood in all decay stages, the maintenance of sufficient source areas, and biological connectivity between old-growth stands to enable dispersal, are all likely to be essential to maintain lucanid beetle community integrity. If similar principles apply to other saproxylic species of invertebrate, then clearfelling and slash-burning may cause a gradual extinction of an important element of the forest biota.  相似文献   

14.
This paper studied edge effects resulting from logging to reforestation on the distribution of ground-dwelling beetles (Coleoptera) across ecotones between natural oak forests and mature pine plantations established after harvesting of natural forests. Using pitfall traps, ground-dwelling beetles were investigated at three replicated plots (ecotones) with three sampling positions of slope (lower, middle and upper) for each plot. Rarefaction estimates of species richness indicated that traps on natural forests and transition zones had more species than mature plantations did, and traps on the middle slope had more species than on the lower and upper slopes did. Results of an ANOVA analysis, which used forest type and slope position as factors and number of species and individuals as the response variables, showed a significant effect of forest type and slope position, and a significant interaction between forest type and slope position. Multivariate analyses (DCA and CCA) showed that beetles of transition zones were more similar to those of natural forests than to those of mature plantations, and that some environmental characteristics, i.e., proportion of broad-leaved trees, canopy cover and elevation (slope position), significantly affected species abundances. We conclude that the logging of natural oak forests and the reforestation of pine plantations can result in subtle variation in the composition and distribution of beetle assemblages at a local scale and such variation should be taken into account when conservation issues are involved.  相似文献   

15.
The rapid and extensive conversion of Neotropical rain forests to a landscape consisting of pasture lands and other agricultural habitats has meant the local disappearance fragmentation and isolation of vertebrate populations To avoid further losses in biodiversity in Neotropical rain forests, it is imperative to determine how the different species that constitute the different vertebrate communities have responded to the anthropogenic alterations of their natural habitats To provide data in this direction we sampled non flying mammals in 35 forest fragments, in six disturbed forest sites in 12 regenerating forests, in 20 arboreal agricultural habitats (cacao coffee, mixed, citrus and allspice), in four live fence sites and in four pasture sites at Los Tuxtlas, Veracruz Mexico Sampling indicated that area of forest fragments and isolating distance were important variables influencing species richness Disturbed forest had fewer species and individuals present and supported a lower non flying mammal biomass than undisturbed and regenerating forests Shaded plantations (cacao coffee and mixed) were richer in species and in individuals than unshaded ones (citrus, allspice) Species richness in forests and agricultural habitats were associated to horizontal plant diversity and vertical foliage diversity Pasture habitats were the poorest man-made habitats in non flying mammal species Live fences supported a higher biomass and species of non flying mammals than pastures and were similar to forest and shaded man-made habitats in species assemblages  相似文献   

16.
The Chaco is the largest dry forest biome in South America and one of the regions most threatened by agricultural intensification. As a consequence, in several areas Chaco forests persist as forest remnants of different sizes embedded in an agricultural matrix. Ants are social insects that have key roles in ecosystem functioning, and the effects of this ongoing land use change process on ant communities are little known for this region. In the present study, we assessed the consequences of land use replacement by monocultures and forest fragmentation on ant communities. Particularly, we assessed whether patch size, patch isolation and edge effect affect species richness and composition of ground‐dwelling ants in fragmented landscapes of Chaco forests. We collected ants by combining hand collecting and pitfall traps in 17 forest fragments and the surrounding matrix from two sites in Córdoba, Argentina. Patch size and patch isolation had no effect on ant richness; however, patch isolation and, to a lesser extent, patch size altered ant species composition. The ant community was not affected by edge but it was negatively affected by the crop matrix, which reduced richness and altered species composition. These results indicate that monoculture matrices severely affect ant communities in the Chaco forests, and that the effects of other indicators of habitat fragmentation (patch size and edge effect) are subtler and less relevant. In the present context of land use change, even small fragments could have an important value for the conservation of ant diversity.  相似文献   

17.
In many temperate terrestrial forest ecosystems, both natural human disturbances drive the reestablishment of forests. Succession in plant communities, in addition to reforestation following the creation of open sites through harvesting or natural disturbances, can affect forest faunal assemblages. Wild bees perform an important ecosystem function in human-altered and natural or seminatural ecosystems, as they are essential pollinators for both crops and wild flowering plants. To maintain high abundance and species richness for pollination services, it is important to conserve and create seminatural and natural land cover with optimal successional stages for wild bees. We examined the effects of forest succession on wild bees. In particular, we evaluated the importance of early successional stages for bees, which has been suspected but not previously demonstrated. A range of successional stages, between 1 and 178 years old, were examined in naturally regenerated and planted forests. In total 4465 wild bee individuals, representing 113 species, were captured. Results for total bees, solitary bees, and cleptoparasitic bees in both naturally regenerated and planted conifer forests indicated a higher abundance and species richness in the early successional stages. However, higher abundance and species richness of social bees in naturally regenerated forest were observed as the successional stages progressed, whereas the abundance of social bees in conifer planted forest showed a concave-shaped relationship when plotted. The results suggest that early successional stages of both naturally regenerated and conifer planted forest maintain a high abundance and species richness of solitary bees and their cleptoparasitic bees, although social bees respond differently in the early successional stages. This may imply that, in some cases, active forest stand management policies, such as the clear-cutting of planted forests for timber production, would create early successional habitats, leading to significant positive effects for bees in general.  相似文献   

18.
Wood-boring beetles in the family Cerambycidae (Coleoptera) play important roles in many forest ecosystems. However, increasing numbers of invasive cerambycid species are transported to new countries by global commerce and threaten forest health in the United States and worldwide. Our goal was to identify effective detection tools for a broad array of cerambycid species by testing some known cerambycid attractants and a pheromone in different trap designs placed across a range of habitats. We compared numbers and species richness of cerambycid beetles captured with cross-vane panel traps and 12-unit Lindgren multiple-funnel traps, placed either at ground level (1.5 m high) or canopy level (approximately 3-10 m high), at eight sites classified as either residential, industrial, deciduous forest, or conifer forest. We captured 3,723 beetles representing 72 cerambycid species from 10 June to 15 July 2010. Species richness was highest for the subfamilies Cerambycinae and Lamiinae, which accounted for 33 and 46% of all species captured, respectively. Overall, the cross-vane panel traps captured approximately 1.5 times more beetles than funnel traps. Twenty-one species were captured exclusively in traps at one height, either in the canopy or at ground level. More species were captured in hardwood sites (59 species) where a greater diversity of host material was available than in conifer (34 species), residential (41 species), or industrial (49) sites. Low numbers of beetles (n < 5) were recorded for 28 of the beetle species. The number of species captured per week ranged from 49 species on 21 June to 37 species on 12 July. Cross-vane panel traps installed across a vertical gradient should maximize the number of cerambycid species captured.  相似文献   

19.
Species loss caused by anthropogenic disturbance threatens forest ecosystems globally. Until 50 years ago, the major sources of boreal forest disturbance in western Canada were a combination of forest wild fire events, pest insect outbreaks, and forest timber harvesting. However, in the 1960s, when the oil boom started in Alberta, oil and gas development along with oil sands mining quickly became another major forest disturbance agent. In this case study we report the effects of operational oil sands mine reclamation on terrestrial arthropod communities and compare them with nearby burned and mature forest sites as a way to provide a benchmark from which to understand the long-term trajectory of recovery for these groups. During the summer of 2016 over 6700 epigaeic beetles were collected using pitfall traps. A total of 43 species of ground beetles and 118 species of rove beetles were collected. Epigaeic beetle assemblages differed between the reclaimed, burned, and mature forest sites. Partitioning of beta diversity in the reclaimed, burned areas and mature forests indicated that species turnover formed the largest component of diversity. Species richness patterns were similar among sites; however, cluster analysis indicated that epigaeic beetle assemblages were only 20% similar between the reclaimed and natural sites. Although ground beetles of the reclaimed area showed positive spatial autocorrelation among treatments, both ground and rove beetles showed responses to the reclamation treatments. The reclaimed areas were dominated by small- to medium-sized open-habitat eurytopic species, whereas the fire and mature forest sites were dominated by larger forest species. The reclaimed area of this case study constitutes a novel, reconstructed ecosystem that is clearly not equivalent in species assemblage to burnt stands of similar age or to mature forest stands.  相似文献   

20.
In the humid warm-temperate zone of southwestern Japan, old-growthforests have been seriously fragmented to small remnants due to traditionalagriculture and coppicing as well as recent rapid plantation with conifers.Assemblages of longicorn beetles (Coleoptera: Disteniidae and Cerambycidae) werecompared among old-growth forests, second-growth forests and conifer plantationsusing collision traps baited with chemical attractants. Species richness oflongicorn beetles was poorer in second-growth forests and conifer plantationsthan in old-growth forests. It was proved by multidimensional scaling(MDS) that the beetle assemblages of old-growth forests were distinct from thoseof conifer plantations, while those of second-growth forests were intermediatebetween them. Further analysis showed that a number of species, including manyPidonia spp., were specific to or closely associated withold-growth forests, and the results were largely supported by the indicatorvalue (IndVal) approach. It is likely that many of such old-growth forestspecies in the larval and pupal stages require large broad-leaved trees standingor fallen with thick bark. At the same time, the flower-visiting adults wouldplay an important role in pollinating various herbaceous and woody plants.Regional forest management for the conservation of insect biodiversity is alsodiscussed.  相似文献   

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