Ground-dwelling Beetles Research Articles

Orchard and riparian habitats enhance ground dwelling beetle diversity in Mediterranean agro-forestry systems

The relative contribution of mixed orchard and riparian vegetation patches to local and regional diversity of Mediterranean landscapes dominated by cork-oak woodlands was tested in 2006–2007 using ground, rove and darkling beetles (Coleoptera: Carabidae, Staphylinidae, Tenebrionidae). Mixed orchard and riparian gallery habitats recorded higher values of abundance and species richness for overall beetle species, although most darkling beetle species were associated with the sclerophyllous cork-oak woodlands. Ground and rove beetle community structure changed from the orchard and riparian habitats to samples placed 100 m away into the surrounding cork-oak woodland, i.e., non-cork-oak patches enhanced beta diversity within the landscape mosaic. Analysis of ground beetle traits concerning moisture preferences revealed a higher proportion of hygrophilous species in mixed orchard and riparian gallery habitats while xerophilous species were dominant within the cork-oak woodlands. The results of this study suggested that land-use management promoting the maintenance of habitat heterogeneity enhances biodiversity conservation of important hygrophilous and xerophilous species, and subsequently the sustainable use of Mediterranean agro-forest mosaics.

Landscape and a political border determine desert arthropods distribution

We studied the distribution of arthropods in the Arava desert on both sides of the Israeli-Jordanian border, to assess the impact of different anthropogenic pressures on the local fauna. We examined how different landscape units, proximity to agricultural fields, and human societies, might affect the diversity of ground dwelling beetles, and spiders, using ordination and diversity estimation methods. Our results suggest that although both countries contain similar habitats, each has its own unique characteristics, probably due to different cultural practices. The immediate repercussion is that loss of a habitat on one side of the border cannot be compensated with preservation of the same habitat across the border, due to fauna dissimilarity. For example, beetle species can be assembled according to landscape units, but within each landscape unit they show dissimilarities that are based on the geopolitical location. Spiders fail to assemble according to landscape units but cluster as a unique group within Israel. Both landscape unit type and the border, were found to be important for the overall species diversity of this ecosystem and therefore “redundancy” should be carefully applied, especially across geopolitical borders.

Succession of Ground-Dwelling Beetle Assemblages After Fire in Three Habitat Types in the Andean Forest of NW Patagonia, Argentina

Wildfires are one of the major disturbances in the dynamics of forests and shrublands. However, little is known about their effects on insect communities that contribute to faunal biodiversity and play key roles in the ecosystem's dynamics. An intense and widespread fire occurred in 1999 in the Nahuel Huapi National Park in the Andean forest in northern Patagonia, Argentina. This fire affected adjacent, but different, habitat types. After the fire, beetle abundance, species richness and assemblage composition were compared among three habitats that were structurally different before the fire. These habitats were: 1) evergreen forest dominated by Nothofagus dombeyi (Mirb.) Oerst. (Fagales: Nothofagaceae), 2) a mixed forest of the evergreen conifer Austrocedrus chilensis (D. Don) Pic. Serm. and Bizzarri (Pinales: Cupressaceae) and N. dombeyi and 3) a shrubland with a diverse community of shrub species. The relationship between beetle diversity and vegetation structure was investigated over three consecutive years. Ground beetles were collected by pitfall traps, and plant species richness, vegetation cover, and height were measured. Beetle communities varied more over years between habitats during the early regeneration after fire. There was a shift in beetle assemblage composition with time after the fire in all habitat types, probably due to similar colonization rates and microclimatic conditions. Therefore, beetle succession was more influenced by recolonization and survivorship, accompanied by climatic conditions and recovery rate of plant communities over time, than it was influenced by pre-fire habitat conditions. These results suggest that in NW Patagonia, wildfire can have a substantial, short-term impact on beetle abundance and species composition. The pre-fire conditions of each habitat type determined the structure of post-fire communities of plants but not beetle assemblages. Wildfires produce simplification and homogenization of habitat types, and this was reflected by beetle diversity.

Distribution of ground-dwelling beetle assemblages (Coleoptera) across ecotones between natural oak forests and mature pine plantations in North China

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.

Soil dumping techniques and afforestation drive ground-dwelling beetle assemblages in a 25-year-old open-cast mining reclamation area

The open-cast lignite mine “Hambach” (NW-Germany) and the accompanying land reclamation replace a large ancient forest. Reclamation of an 1000 ha large overburden dump started 25 years ago and is still in progress. Reclamation methods comprise combinations of different topsoil dumping techniques and reclamation measures such as seeding or afforestation. In accordance with the spatial heterogeneity hypothesis, we hypothesize that beetle assemblages from sites where the topsoil was left structured are more diverse than those from sites with levelled topsoil, and that richly structured mid-successional sites harbour more heterogeneous assemblages than afforested sites. We tested the influence of environmental variables on assemblage characteristics of pitfall-trapped beetles from 17 sites on the overburden dump. The results are based on 35,588 individuals from 339 species. Species assemblages differed significantly between almost all sites. Habitat age did not affect assemblage characteristics, while species richness was significantly influenced by surface structure. Sites that were not levelled and that additionally included pits that slope down for several meters exhibited the highest species richness. Abundance of beetles increased in parallel to the canopy cover, whereas assemblage heterogeneity (MVDISP) decreased. Successional and grassland sites usually exhibited higher diversity (Fisher's α) than afforested sites, but diversity was not significantly predicted by a single environmental factor. Instead, diversity increased along with increasing MVDISP-values. Afforestations speed up the successional process and some euryecious forest species are already well established, but stenecious forest specialists have not yet been found.

Localised and regional patterns in ground-dwelling beetle assemblages in a semi-tropical arid zone environment

– Ground-dwelling beetles were sampled by pitfall traps at 304 quadrats positioned to represent the geomorphic extent and profile of the Pilbara Region, a semi-tropical arid region in north-west Western Australia. For each quadrat, 47 climatic, soil, landform, geological and vegetation attributes were determined.

Response of ground‐dwelling beetles across logging coupe edges into streamside reserves

AbstractStreamside reserves can provide important habitat reservation in forest landscapes subject to logging. Depending on the width of streamside reserves, edge effects have the potential to compromise their effectiveness for terrestrial conservation, yet edge effects into riparian environments have rarely been assessed. It would be unwise to assume that edge effects act in the same way at streamside reserves as at the non‐riparian edges of logging coupes, as interactions with riparian influences on beetles along the stream‐upslope gradient might create unique edge conditions. In this study, we assess edge effects on ground dwelling beetles at four sites, using transects of pitfall traps across logging coupe edges into streamside reserves that have only been affected by logging on one side of the stream. Edge effects were found to extend further into streamside reserves in this study than into upslope habitat at the same sites from a concurrent study. Edge effects were site specific and appeared to extend as far as the stream in most cases (23–65 m). Comparison of beetle assemblage composition with adjacent unlogged streams supported the conclusion that beetles within 10 m of streams in streamside reserves were still responding to edge effects. These results suggest that streamside reserves might not contain habitat comparable with riparian areas away from the influences of nearby clearfelling, and wider reserves are recommended to maintain core habitat not compromised by edge effects.

Are streamside buffers edge-affected habitat for ground-dwelling forest beetle assemblages?

Reservation of forest in riparian buffers is common practice in commercial forestry areas worldwide, potentially providing valuable habitat for biodiversity dependent on mature forest. However, the habitat value of narrow reserve corridors can be compromised by edge effects. We investigated the habitat value of streamside buffers in wet eucalypt forest for ground-dwelling beetles in Tasmania, Australia. Beetles were collected with pitfall traps in five replicates of four habitats: unlogged corridors of mature forest in streamside reserves (buffers) with clearfelling-derived logging regeneration either side; continuous mature upslope forest; continuous mature riparian forest; and <20-year-old upslope clearfelling-derived logging regeneration. Streamside reserve widths on each side of the stream were on average 40 ± 6 m (±95% CI) from reserve edge to stream. Beetle assemblages in logging regeneration differed substantially from those in the unlogged habitats, including the streamside reserves. Streamside reserve assemblages nevertheless differed from those of the continuous unlogged areas. Assemblage composition in streamside reserves was most similar to that in continuous mature riparian forest, although beetle diversity was higher in the reserves. Our results suggest that although streamside reserves provide habitat for the majority of commonly collected beetle species occurring in continuous mature forest, wider reserve corridors in the wet eucalypt forests of Tasmania may be required to provide habitat that is not edge-affected.

Conserving ground-dwelling beetles in an endangered woodland community: Multi-scale habitat effects on assemblage diversity

Patterns of biodiversity are influenced by habitat features at multiple spatial scales, yet few studies have used a multi-scale approach to examine ground-dwelling beetle diversity patterns. We trapped and quantified ground-dwelling beetle assemblages at two spatial scales: (1) microhabitat elements, represented by open ground, ground under trees and ground next to logs and (2) macrohabitat, represented by three vegetation types in a box-gum grassy woodland in south-eastern Australia. Species richness and evenness was highest at samples from under trees and lowest at samples in the open. At the macrohabitat scale, species richness and evenness did not differ among vegetation types. Assemblage composition was significantly different between trees, logs and open elements. Assemblage composition was different only between vegetation types with contrasting high and low shrub cover. Estimation of true species richness indicated assemblages at logs may have a higher number of species compared to trees and open elements, and implied greater spatial heterogeneity in assemblages at logs. Significant spatial autocorrelation in beetle assemblages was detected for logs at up to 400 m, but not for ground under trees or in the open. In agreement with previous studies, a mix of vegetation types at the macrohabitat scale is important for beetle conservation. Assemblage composition, however, appears to be more closely linked with habitat elements at the microhabitat scale, where logs support a high diversity of beetle species. This strongly supports the idea that restoring logs to box-gum grassy woodlands would be useful for increasing beetle species richness and assemblage heterogeneity.

Composition and spatial distribution pattern of ground-dwelling beetle communities in Yeyahu Wetland, Beijing

Composition and spatial distribution pattern of ground-dwelling beetle communities in Yeyahu Wetland, Beijing

Ground-dwelling beetle community in beech forests of Sado Island, Japan: comparison with the mainland

Island ecosystems differ from mainland ecosystems in their long-term isolation. On Sado Island, Japan, cattle grazing in the past gradually changed forests into grasslands, thereby altering the diversity of indigenous insects. We compared ground-dwelling beetle diversity on Sado Island to that on the nearby mainland. Contrary to previous reports, the island isolation effect resulted in lower γ and β diversity than on the mainland, because of the low species richness of beetles with low dispersal abilities. Few flightless beetles could invade Sado Island, even when the beech forests on the island were relatively adjacent to those on the mainland. Such a history of ecosystem formation could be the general pattern for continental-island mountain forests that were never connected to those of the mainland. We did not observe low α diversity of ground-dwelling beetles, suggesting that the cattle grazing history of the island has not changed environmental conditions for ground-dwelling beetles enough to reduce their diversity. In addition, cattle grazing increases the abundance of merdivorous insects by increasing the abundance of their food resource.

Effects of some macrobiota on the Weipa Bauxite, northern Australia

Bioturbation of the Weipa bauxite is effected primarily by termites and tree roots. Termite galleries extend into the Plasmic Zone to a depth of 20 m. Termite nests are constructed from the surrounding soil (averaging 30% kaolinite) and also from kaolinite derived from below the bauxite, with some parts of the nest containing 75% kaolinite. Measurement of termite nest volume from two 1 ha areas indicates nest materials amount to as much as 5 t/ha and that termites bring kaolinite to the surface to the extent of perhaps 10 kg/ha annually. Roots of Eucalyptus tetrodonta, the main forest tree of the region, penetrate the 3–6 m thickness of the bauxite at least as far as the top of the Mottled Zone and commonly some distance further. Penetrating roots displace the loose pisolithic bauxite, and eventually provide channels through the bauxite down which material may fall, thus tending to homogenise the deposit. Evidence of their effect on local redox conditions is revealed in mine faces by zones of variable ferruginous colouration. Tree-fall, mainly the result of cyclones, disturbs the soil and upper bauxite: about 0.5% of a 1 ha area is estimated to have been affected by tree-fall. Small nodules scattered throughout the bauxite, prolate ellipsoidal in shape, averaging 28 × 21 mm, are interpreted as the fossilised pupal cases of ground-dwelling beetle larvae, probably scarabs or weevils.

Reliability of a Higher‐Taxon Approach to Richness, Rarity, and Composition Assessments at the Local Scale

A promising shortcut for quantifying species patterns is to use genera and families as surrogates of species. At large spatial scales, concurrence between patterns of richness, rarity, and composition of species and higher taxa is generally high. Only a few researchers, however, have examined this relationship at the local scale, which is frequently the relevant scale in land-use conflicts. We investigated the reliability of the higher-taxon approach in assessing patterns of species richness, rarity, and composition at the local scale. We studied diversity patterns of three commonly used surrogate taxa: vascular plants, ground-dwelling beetles, and moths. We conducted year-round field surveys for these taxa in the Jerusalem Mountains and the Judean foothills, Israel. Richness and composition of species were highly correlated with richness and composition of genera for all taxa. At the family level, correlations with richness and composition of species were much lower. Excluding monotypic genera and families did not affect these relations. Rarity representation based on higher taxa varied considerably depending on the taxon, and rarity scale and was weaker compared with richness and composition representation. Cumulative richness curves of species and genera showed similar patterns, leveling off at equivalent sampling efforts. Genus-level assessments were a reliable surrogate for local patterns of species richness, rarity, and composition, but family-level assessments performed poorly. The advantage of using coarse taxonomic scales in local diversity surveys is that it may decrease identification time and the need for experts, but it will not reduce sampling effort.

Identification of a Widespread Monomolecular Odor Differentially Attractive to Several Delia Radicum Ground-dwelling Predators in the Field

Dimethyl disulfide (DMDS) was identified as a major volatile constituent of Brassica napus roots heavily infested by Delia radicum, the cabbage root fly. Attractiveness of this widespread compound was tested in the field in a naturally complex odorous environment. By using an original setup especially designed for ground dwelling beetles, different concentrations of the pure molecule as well as attractiveness of the natural blend emitted by the rotten part of infested roots were tested simultaneously. The use of general linear model (GLM) statistics permitted us to finely discriminate the responses among the different treatments. The main predators of D. radicum (i.e., two staphylinids Aleochara bilineata and Aleochara bipustulata and carabid beetles of the genus Bembidion) were significantly attracted by DMDS, but responded in different ways to the natural blend and to the different concentrations tested. The dose-response curves were similar for the two staphylinids. However, whereas A. bilineata was more attracted by the natural volatile blend than by its preferred DMDS concentration, A. bipustulata was attracted as much by the natural blend as by its preferred DMDS concentration. Carabid beetles exhibited a different response. They were not attracted by the natural blend, but responded to a wider range of DMDS concentrations that included low concentrations that did not attract the staphylinid beetles. These results are discussed according to the potential resources searched by each taxon studied and their specificity for the resources. The possible use of DMDS for enhancing biological control of D. radicum is mentioned.

Response of ground-dwelling beetle (Coleoptera) assemblages to giant knotweed (Reynoutria spp.) invasion

Giant knotweeds (Reynoutria spp.) are highly productive and aggressive invaders in riparian wetlands of Europe and North America. We sampled ground-dwelling beetles by pitfall traps from six sites comparing monotypic Reynoutria stands with the invaded native Urtica-dominated stands. Three sites were located in a semi-natural softwood forest and three sites were on a ruderal embankment. The analyses are based on a total of 13,244 individuals from 218 species. Location and site significantly influenced beetle assemblages. Moreover, there were pronounced differences between vegetation stands. The monotypic Reynoutria stands exhibited lower beetle abundance, species richness and rarefaction diversity irrespective of location. However, the negative effect on species richness, abundance and assemblage similarities were stronger on the transformed ruderal embankment than in the semi-natural softwood forest. Reynoutria invasion seems to influence microclimatic conditions. We found a higher abundance of silvicolous and a lower abundance of xerophilous ground beetles in the Reyountria stands than in the Urtica-dominated stands. Feeding guilds reacted differently to Reynoutria invasion that reduced the abundance of predators and herbivores but enhanced that of detritivores. Detritivores assumingly profit from the perennial presence of the large quantities of Reynoutria litter. We conclude that highly productive invaders pauperise the arthropod fauna and alter link strengths in trophic cascades shifting primary producer-based food webs to detritus-based food webs.

Distribution of ground-dwelling beetles in fragmented tropical habitats

The conservation of biodiversity is increasingly dependent on human-altered habitats. In a fragmented forest landscape in northern Costa Rica within the Mesoamerican Biological Corridor, an area of great conservation importance, we compared the diversity and composition of ground-dwelling beetle communities in five habitat types along a gradient of increasing disturbance: primary forest, logged forest, secondary forest, plantation (Gmelina arborea) and pasture. Using pitfall trapping we captured a total of 1,877 beetles (Coleoptera), comprising 422 morphospecies in 26 families. The plantation sites had the lowest number of species followed by secondary forest and pasture. Multivariate analysis separated the beetle fauna according to land use, and suggested that only the logged forest maintains a similar species assemblage to primary forest. However, each habitat harboured a number of unique species indicating the conservation value of the mosaic of habitats found in fragmented landscapes. Our results suggest that to maintain forest beetle species diversity it is essential that areas of natural forest are conserved. However, other land uses also provide beetle habitats and in fragmented areas active management to maintain a mosaic of land uses will contribute to the conservation of beetle diversity.

Estimating edge effects on ground-dwelling beetles at clearfelled non-riparian stand edges in Tasmanian wet eucalypt forest

Edge effects potentially have negative consequences for biodiversity in logging areas. In Tasmanian wet eucalypt forest, ground-dwelling beetle assemblages responded to habitat edges between mature unlogged forest and young regeneration following clearfelling. Transects of pitfall traps extended 100 m into unlogged forest and 10 m into the felled area firebreaks at four study sites (4 sites × 3 transects × 8 traps/transect = 96 traps). The depth of edge influence extended between 10 m and 25 m into mature forest, and the beetle assemblage was estimated to be 95% similar to interior forest at approximately 22 m from the edge. The species composition of beetles changed gradually with distance from the edge, but for practical purposes we distinguished three zones of edge response: mature forest interior extending ≥22 m into unlogged forest, firebreak habitat at the edge of the coupe that extends 1 m into unlogged forest, and an edge-affected mature forest zone in between. Individual species known to be characteristic of mature and young forest were of greatest indicator value in mature forest interior and firebreak habitat, respectively. Choleva TFIC sp 01 (Leiodidae), Decilaus nigronotatus, D. lateralis and D. striatus (all Curculionidae) were identified as indicator species characteristic of mature forest interior. No species were found to be characteristic of the habitat edges. These results are relevant to current management practices in Tasmanian wet eucalypt forest, in particular to the efficacy of linear reserve networks. One hundred metre wide wildlife habitat strips, when bounded by recently harvested forest, are estimated to contain a little over 50% of interior habitat not compromised by edge effects. Small patches of forest (<1 ha) retained in variable retention harvesting are predicted to contain little or no uncompromised interior habitat for ground-dwelling beetles.

Composition and Abundance of Ground-Dwelling Coleoptera in a Fragmented and Continuous Forest

The structure of the ground-dwelling beetle community at two forested sites in northern Delaware was compared by examining composition and abundance at the species or genus level for five target families and at the family level for all other Coleoptera. The beetle communities at an isolated 15-ha woodlot and a nearby plot of relatively continuous forest were sampled using pitfall traps during 2000 and 2001. The results showed an absence or reduced abundance of many beetle taxa in the isolated woodlot relative to the continuous forest site and elevated abundances of a few taxa. Most notably, the species richness of poorly dispersing species of carabid beetles was lower in the isolated woodlot, with 12 of 19 brachypterous species completely absent from pitfall samples. Although this study does not constitute a test of habitat fragmentation hypotheses, the data do suggest that the beetle community in the woodlot may be suffering from isolation effects. The estimated response to fragmentation was correlated with body size for the 19 most common carabid species caught, suggesting that body size may be a useful predictor of vulnerability to forest fragmentation. At least in Carabids, larger body size seems to be associated with greater susceptibility to fragmentation. A number of staphylinid beetle taxa were also significantly less abundant or absent in the isolated woodlot, as were some beetles in other trophic groups, including carrion beetles (Silphidae) and geotrupid beetles (Geotrupidae). Although it retains some faunal similarity with nearby continuous forest, the woodlot may be too isolated to sustain populations of some beetle taxa, especially large, poorly dispersing forest species.

Composition and Abundance of Ground-Dwelling Coleoptera in a Fragmented and Continuous Forest

The structure of the ground-dwelling beetle community at two forested sites in northern Delaware was compared by examining composition and abundance at the species or genus level for five target families and at the family level for all other Coleoptera. The beetle communities at an isolated 15-ha woodlot and a nearby plot of relatively continuous forest were sampled using pitfall traps during 2000 and 2001. The results showed an absence or reduced abundance of many beetle taxa in the isolated woodlot relative to the continuous forest site and elevated abundances of a few taxa. Most notably, the species richness of poorly dispersing species of carabid beetles was lower in the isolated woodlot, with 12 of 19 brachypterous species completely absent from pitfall samples. Although this study does not constitute a test of habitat fragmentation hypotheses, the data do suggest that the beetle community in the woodlot may be suffering from isolation effects. The estimated response to fragmentation was correlated with body size for the 19 most common carabid species caught, suggesting that body size may be a useful predictor of vulnerability to forest fragmentation. At least in Carabids, larger body size seems to be associated with greater susceptibility to fragmentation. A number of staphylinid beetle taxa were also significantly less abundant or absent in the isolated woodlot, as were some beetles in other trophic groups, including carrion beetles (Silphidae) and geotrupid beetles (Geotrupidae). Although it retains some faunal similarity with nearby continuous forest, the woodlot may be too isolated to sustain populations of some beetle taxa, especially large, poorly dispersing forest species.

Site effects outweigh riparian influences on ground-dwelling beetles adjacent to first order streams in wet eucalypt forest

In wet eucalypt forest with a rainforest understorey the vegetation adjacent to first order streams does not form a distinct riparian strip. This study investigated the riparian response of terrestrial ground-dwelling beetles adjacent to four such streams in Tasmania, Australia. Beetle assemblages varied more between the four sites than they did with distance from stream within sites, where they exhibited a measurable but subtle riparian response. The extent of the riparian zone varied between the four study sites, with a 1-5 m riparian zone at three sites and a gradually changing community up to 50-100 m upslope at one site. There was a trend for greater between plot variability immediately adjacent to the streams, possibly because this is a more highly disturbed environment. None of the habitat variables measured were consistently associated with riparian or upslope assem- blages of beetles, probably explaining the subtlety of the beetles' riparian response. Forest conservation efforts for terrestrial species should not necessarily be focused on the riparian zone in preference to upslope areas.