Associations between wasp communities and forest structure: Do strong local patterns hold across landscapes?

Abstract Forest structure and habitat complexity have been used extensively to predict the distribution and abundance of insect assemblages in forest ecosystems. We tested empirically derived predictions of strong, consistent relationships between wasp assemblages and habitat complexity, using both field assessments and vegetation indices from remote sensing as measures of habitat complexity. Wasp samples from 26 paired ‘high and low’ complexity sites in two forests approximately 70 km apart, were compared with normalized difference vegetation indices (NDVIs) derived from multispectral videography of the survey sites. We describe a strong unequivocal link between habitat complexity and wasp communities, the patterns holding over coarse and fine landscape scales. NDVIs were also excellent predictors of habitat complexity and hence wasp community patterns. Sites with greater NDVIs consistently supported a greater abundance and species richness, and a different composition of wasps to sites with low NDVIs. Using vegetation indices from remote sensing to gauge habitat complexity has significant potential for ecosystem modelling and rapid biodiversity assessment.     

Using high‐resolution multi‐spectral imagery to estimate habitat complexity in open‐canopy forests: can we predict ant community patterns?

The structure and composition of arthropod assemblages are strongly associated with habitat complexity. Accurate, time efficient estimates of habitat complexity may provide insights for biodiversity management in natural systems. We obtained high-resolution (0.7 m pixel) multi-spectral aerial imagery of National Parks 20 km north and 20 km south of Sydney, Australia. We explored both the Normalised Difference Vegetation Index (NDVI) and the standard deviation of reflectance in the near-infrared spectrum (stdevR_NIR) as indicators of low and high habitat complexity in sandstone forests north of Sydney. We then tested described predictions of ant community patterns (based on a previous study) using sites selected from high-resolution multi-spectral imagery in sandstone forests south of Sydney. Ground-scored habitat complexity was positively correlated with NDVIs and, to a lesser extent, stdevR_NIR values in sandstone forests north of Sydney. As predicted, ant species richness was negatively correlated with NDVIs in forests to the south of Sydney. Also, ant species composition was different in areas with contrasting NDVIs. The ant species driving composition differences responded to habitat complexity in a similar way in forests to the north, and south, of Sydney. The strong association we detected between NDVIs and habitat complexity, most likely reflects the relatively exposed nature of the vegetative layers in the forests we sampled. Remote sensing, integrated with quantitative research testing predictive faunal responses to vegetation structure and biomass at landscape scales, may provide efficient means of estimating biodiversity for management in particular habitats.     

Relationship between land uses and diversity of dung beetles (Coleoptera: Scarabaeinae) in the southern Atlantic forest of Argentina: which are the key factors?

The loss of natural habitats is one of the main drivers of biodiversity decline. Anthropogenic land uses preserving biotic and abiotic conditions of the native ecosystem are more suitable to preserve the native biodiversity. In this study, we explored changes in species richness and composition in different land uses of the southern Atlantic forest, considering three independent factors: (1) canopy (presence–absence), (2) type of vegetation (native–exotic) and (3) livestock (presence–absence). We expected a gradient of response in the richness and composition of the native forest dung beetle community, from land uses preserving canopy and native vegetation to open land uses with exotic vegetation. Dung beetles were sampled in protected native forests and four land uses, using two potential food resources: human dung and carrion. The species richness and composition of each habitat, as well as differences in composition and the influence of factors over diversity, were then analyzed. As expected, our results showed that land uses preserving canopy and native vegetation maintain the dung beetle diversity of the native forest. Moreover, while the three factors analyzed influenced dung beetle diversity, canopy cover was the main driver of dung beetle diversity loss. The main conclusion of this study is that the conservation of canopy (either native or exotic) is determinant to preserve highly diverse dung beetle communities and subsequently, the ecological functions performed by this taxon. However, the ecophysiological mechanism behind the response of dung beetles to habitat disturbance is poorly understood.     

The importance of canopy complexity in shaping seasonal spider and beetle assemblages in saltmarsh habitats

1. Habitat structure, including vegetation structural complexity, largely determines invertebrate assemblages in semi‐natural grasslands. The importance of structural complexity to the saltmarsh invertebrate community, where the interplay between vegetation characteristics and tidal inundation is key, is less well known. 2. It was hypothesised that canopy complexity would be a more important predictor of spider and beetle assemblages than simple vegetation attributes (e.g. height, community type) and environmental variables (e.g. elevation) alone, measured in two saltmarsh regions, south‐east (Essex) and north‐west (Morecambe Bay) U.K. Canopy complexity (number of non‐vegetated ‘gaps’ in canopy ≥ 1 mm wide) was assessed using side‐on photography. Over 1500 spiders and beetles were sampled via suction sampling, winter and summer combined. 3. In summer, saltmarshes with abundant spider and beetle populations were characterised by high scores for canopy complexity often associated with tussocky grass or shrub cover. Simple vegetation attributes (plant cover, height) accounted for 26% of variation in spider abundance and 14% in spider diversity, rising to 46% and 41%, respectively, with the addition of canopy complexity score. Overwintering spider assemblages were associated with elevation and vegetation biomass. Summer beetle abundance, in particular the predatory and zoophagous group, and diversity were best explained by elevation and plant species richness. 4. Summer canopy complexity was identified as a positive habitat feature for saltmarsh spider communities (ground‐running hunters and sheet weavers) with significant ‘added value’ over more commonly measured attributes of vegetation structure.     

Effects of habitat complexity on forest beetle diversity: do functional groups respond consistently?

We examined the responses of a beetle assemblage to habitat complexity differences within a single habitat type, Sydney sandstone ridgetop woodland, using pitfall and flight‐intercept trapping. Six habitat characters (tree canopy cover, shrub canopy cover, ground herb cover, soil moisture, amount of leaf litter, and amount of logs, rocks and debris) were scored between 0 and 3 using ordinal scales to reflect habitat complexity at survey sites. Pitfall trapped beetles were more species rich and of different composition in high complexity sites, compared with low complexity sites. Species from the Staphylinidae (Aleocharinae sp. 1 and sp. 2), Carabidae (Pamborus alternans Latreille), Corticariidae (Cartodere Thomson sp. 1) and Anobiidae (Mysticephala Ford sp. 1) were most clearly responsible for the compositional differences, preferring high complexity habitat. Affinities between general functional groupings of pitfall‐trapped beetles and habitat variables were not clear at a low taxonomic resolution (family level). The composition and species richness of flight‐intercept‐trapped beetles were similar in high and low complexity sites. Our study demonstrates that discrete responses of the various functional groups of beetles are strongly associated with their feeding habits, indicated by differing habitat components from within overall composite habitat complexity measures. Although habitat preferences by beetle species may often reflect their foraging habits, clarification of the causal mechanisms underpinning the relationships between habitat complexity and beetles are critical for the development of general principles linking habitat, functional roles and diversity.     

Effects of habitat complexity on ant assemblages

We investigated responses of ant communities to habitat complexity, with the aim of assessing complexity as a useful surrogate for ant species diversity. We used pitfall traps to sample ants at twenty-eight sites, fourteen each of low and high habitat complexity, spread over ca 12 km in Sydney sandstone ridge-top woodland in Australia. Ant species richness was higher in low complexity areas, and negatively associated with ground herb cover, tree canopy cover, soil moisture and leaf litter. Ant community composition was affected by habitat complexity, with morphospecies from the genera Monomorium, Rhytidoponera and Meranoplus being the most significant contributors to compositional differences. Functional group responses to anthropogenic disturbance may be facilitated by local changes in habitat complexity. Habitat complexity, measured as a function of differences in multiple strata in forests, may be of great worth as a surrogate for the diversity of a range of arthropod groups including ants.     

Invasion and retreat: shifting assemblages of dung beetles amidst changing agricultural landscapes in central Peru

This study examines the effects of deforestation, and the habitat value of coffee and regenerated forest for tropical dung beetles, a functionally significant insect group. Pitfall trapping was conducted at 22 sites in a montane region of central Peru during April and November/December of 2002. Sites included primary and secondary forest, shade-coffee, regenerated forest and open farms (mainly with banana, yuca, and corn). Ordination techniques indicated that beetle assemblages in forests, regenerated forest and coffee were relatively similar. However, assemblage compositions in forested areas differed even at similar altitudes under the influence of biogeographical factors, and the assemblages at disturbed sites (farms/coffee) were influenced by beetle dispersal from adjacent forests. During dry months, when beetle activity is low, communities at all habitat types tended to converge because fewer unique species were recorded in forests at that time and habitat/season generalists were dominant. Preliminary results also indicate that beetles in shady crops such as bananas responded to plant growth: as the banana canopy closed-in, producing more shade, open-habitat specialists retreated and forest/shade specialists invaded the sites. Chronosequence data at two of the sites demonstrate the rapid and dramatic changes in species richness and assemblage composition caused by deforestation. As forests become increasingly fragmented, and open farms continue to expand, dung beetles will become more restricted to the remaining fragments and reserves. In the mosaic landscape studied here, shade crops, like coffee, act as habitat and corridors for many dung beetle species. Small farm size and the consequent magnitude of edge effects, likely contributed to beetle movement between habitat types and determined the apparent generalist nature of many of the dung beetle species in this study.     

Forest edges have high conservation value for bird communities in mosaic landscapes

A major conservation challenge in mosaic landscapes is to understand how trait‐specific responses to habitat edges affect bird communities, including potential cascading effects on bird functions providing ecosystem services to forests, such as pest control. Here, we examined how bird species richness, abundance and community composition varied from interior forest habitats and their edges into adjacent open habitats, within a multi‐regional sampling scheme. We further analyzed variations in Conservation Value Index (CVI), Community Specialization Index (CSI) and functional traits across the forest‐edge‐open habitat gradient. Bird species richness, total abundance and CVI were significantly higher at forest edges while CSI peaked at interior open habitats, i.e., furthest from forest edge. In addition, there were important variations in trait‐ and species‐specific responses to forest edges among bird communities. Positive responses to forest edges were found for several forest bird species with unfavorable conservation status. These species were in general insectivores, understorey gleaners, cavity nesters and long‐distance migrants, all traits that displayed higher abundance at forest edges than in forest interiors or adjacent open habitats. Furthermore, consistently with predictions, negative edge effects were recorded in some forest specialist birds and in most open‐habitat birds, showing increasing densities from edges to interior habitats. We thus suggest that increasing landscape‐scale habitat complexity would be beneficial to declining species living in mosaic landscapes combining small woodlands and open habitats. Edge effects between forests and adjacent open habitats may also favor bird functional guilds providing valuable ecosystem services to forests in longstanding fragmented landscapes.     

Hiding Without Cover? Defining Elk Security in a Beetle-Killed Forest

Recent mountain pine beetle (Dendroctonus ponderosae; pine beetle) outbreaks in the western United States have affected nearly 18 million ha of pine (Pinus spp.) forest and are unprecedented in spatial extent, severity, and duration, yet little is known about wildlife responses to large-scale insect outbreaks. Elk (Cervus canadensis) are important wildlife whose dominant management paradigm on public lands has focused on providing security habitat to increase survival during hunting seasons and to maintain elk presence on public lands to promote hunter opportunity. To assess the effect of pine beetles and associated changes in forest structure on elk security, we used a time series to characterize canopy cover pre- and post-pine beetle outbreak, characterized relative canopy cover among the dominant forest types in the study area post-pine beetle outbreak, and used global positioning system location data from male and female elk to define habitat relationships and security during the archery and rifle hunting seasons. Our study area was within the Elkhorn Mountains of southwest Montana, USA, 2015–2017, which experienced 80% mortality of lodgepole pine (Pinus contorta) forests during a pine beetle outbreak that peaked in 2008. We observed an 8.5% reduction in canopy cover within pine beetle-infested lodgepole pine forests, yet canopy cover remained relatively high among other forest types post-outbreak. The top-ranked habitat security models contained positive relationships with canopy cover, distance to motorized routes, terrain ruggedness, and slope with few notable differences among sexes and seasons. Across sexes and seasons, 75% and 50% of elk use was within areas with average canopy cover values ≥31 ± 6.65 (SD)% and ≥53 ± 5.7% that were an average of ≥2,072 ± 187.93 m and ≥3,496 ± 157.32 m from a motorized route, respectively. Therefore, we recommend fall elk security be defined as areas that meet these criteria for minimum canopy cover and distance from motorized routes in the Elkhorn Mountains and in other landscapes with similar forest characteristics and hunting pressures. Although we observed expected reductions in canopy cover within pine beetle-infested forests, defoliation alone did not appear to negatively affect elk security or reduce canopy cover below our management recommendations. Nonetheless, because of the prevalence of standing dead trees in our study area, we recommend future work that investigates the relationships with pine beetle-infested areas post-blowdown because changes in ground structure and costs of locomotion may affect elk habitat and security. © 2019 The Authors. Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.     

Dung beetle assemblages in primary forest and disturbed habitats in a tropical dry forest landscape in western Mexico

Dung beetles (Scarabaeinae) are conspicuous components in most terrestrial ecosystems, performing important ecological functions and services. Being sensitive to several types of disturbance, they have been successfully used as indicators of habitat change. Dung beetle communities in tropical rainforests have been well studied, but considerably less information is available for tropical dry forests. In this study I sampled dung beetles in two undisturbed habitats, deciduous forest and semideciduous forest, and two disturbed habitats, secondary forest and open area habitat, in the Chamela-Cuixmala region of western Mexico. Dung beetle species with high indicator value for each habitat were identified. Beetle abundance, observed species richness and estimated species richness were similar in the three forest habitats, but significantly lower in the open area habitat. A more detailed analysis of species-specific abundances in the three forest habitats revealed some differences. Transects of one of the undisturbed habitats, the deciduous forest, were more similar to the non-adjacent transects of disturbed secondary forest, than to the adjacent undisturbed semideciduous forest transects. Unlike studies in other tropical sites that have found a decrease in equitability in Scarabaeinae assemblages between undisturbed forest and disturbed habitat (particularly open habitats), in the Chamela-Cuixmala region all four habitats showed similar low equitability in community structure, with two or three very dominant species.     

The effects of reed canary grass (<Emphasis Type="Italic">Phalaris arundinacea</Emphasis> L.) on wetland habitat and arthropod community composition in an urban freshwater wetland

Reed canary grass (Phalaris arundinacea L.) is an aggressive invader that dominates wetlands throughout the US. We examined the effects of reed canary grass on wetland habitat, both vegetation canopy architecture and soil environment, and its impacts the arthropod community in an urban wetland in Portland, OR, USA. Reed canary grass dominance resulted in reduced vegetation canopy complexity through reductions in native vegetation diversity and canopy height. In addition, reed canary grass dominance significantly changed the wetland soil environment, decreasing soil organic content and increasing soil moisture. The arthropod community responded to these habitat changes, being distinct between plots dominated by reed canary grass and those dominated by native vegetation. In addition, diversity measures were significantly lower in plots dominated by reed canary grass. Variables describing both vegetation canopy complexity and soil environment were more important predictors than relative abundance of reed canary grass in multiple regression models developed for dominant arthropod taxa and community metrics. Our results suggest that the mechanism by which reed canary grass affects the wetland arthropod community is primarily indirect, through habitat changes, rather than by directly altering its food source.     

The effect of bark beetle infestation and salvage logging on bat activity in a national park

Salvage logging—the removal of dead trees in disturbed forest stands—has been controversially discussed. We investigated the impact of bark beetle attacks and subsequent salvage logging on insectivorous bats in a temperate mountain forest. We quantified bat activity (25,373?min counts; 32 plots) using batcorders during 221 all-night surveys in stands killed by bark beetles, with dead trees removed or not, and in vital, single- or multi-layered mature forest stands. We analysed the differences in activity of all bats in general and of bats of foraging guilds (open habitat, forest edge, closed habitat) in these habitats using a generalized linear Poisson mixed model, with plot and observation as random factors, and temperature and habitat as fixed factors. Only open-habitat foragers were slightly more active in salvage-logged stands than in bark-beetle-affected stands; they generally benefited from an open forest canopy, whereas closed-habitat foragers did not. Our results indicated that: (1) bats are less affected by salvage logging after a disturbance of a magnitude typical for European forests, probably because enough roosts are present in surrounding areas, (2) habitats for open foragers are improved by bark beetle infestation and (3) bats are poor bioindicators of negative impacts of salvage logging after natural disturbance in forests with a composition typical for Central Europe.     

Vertical and Horizontal Vegetation Structure across Natural and Modified Habitat Types at Mount Kilimanjaro

In most habitats, vegetation provides the main structure of the environment. This complexity can facilitate biodiversity and ecosystem services. Therefore, measures of vegetation structure can serve as indicators in ecosystem management. However, many structural measures are laborious and require expert knowledge. Here, we used consistent and convenient measures to assess vegetation structure over an exceptionally broad elevation gradient of 866–4550m above sea level at Mount Kilimanjaro, Tanzania. Additionally, we compared (human)-modified habitats, including maize fields, traditionally managed home gardens, grasslands, commercial coffee farms and logged and burned forests with natural habitats along this elevation gradient. We distinguished vertical and horizontal vegetation structure to account for habitat complexity and heterogeneity. Vertical vegetation structure (assessed as number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover) displayed a unimodal elevation pattern, peaking at intermediate elevations in montane forests, whereas horizontal structure (assessed as coefficient of variation of number, width and density of vegetation layers, maximum canopy height, leaf area index and vegetation cover) was lowest at intermediate altitudes. Overall, vertical structure was consistently lower in modified than in natural habitat types, whereas horizontal structure was inconsistently different in modified than in natural habitat types, depending on the specific structural measure and habitat type. Our study shows how vertical and horizontal vegetation structure can be assessed efficiently in various habitat types in tropical mountain regions, and we suggest to apply this as a tool for informing future biodiversity and ecosystem service studies.     

Effects of creation of open vegetation in abandoned terraced paddy fields on carabid beetle assemblages in temperate Japan

Many paddy fields in the mountainous rural areas of Japan have been abandoned since the 1960s, and forests have regenerated on these sites. In a mountainous area on Sado Island, a large number of abandoned paddies were converted into wetlands and open terrestrial vegetation. In this study, we used pitfall traps to examine the effects of the creation of open vegetation on carabid beetle assemblages by investigating 14 sites spanning five vegetation types: six sites in secondary forests (three coppice forests and three 40‐year‐old regenerating forests on abandoned paddies), three each in clear‐cuts and paddy levees, and two in grasslands. The 14 study sites were clearly separated into two groups different in the species composition of carabid beetles: secondary forest and grassland‐levee groups. The species composition of two clear‐cut sites was similar to that of secondary forests, whereas that of the remaining one clear‐cut site was similar to that of grasslands. Analyses of species responses showed various habitat preferences, e.g., for only coppice forests, for two types of secondary forests, for secondary forests and clear‐cuts, for clear‐cuts and grasslands, and for grasslands or levees, or no clear preference. There were no characteristic species in the regenerating forests. These results suggest that the 40‐year‐old regenerating forests may sustain only a limited subset of the carabid fauna found in coppice forests and that the creation of open vegetation in the abandoned paddies enhances carabid diversity at the landscape level by raising β diversity among the different vegetation types.     

Relationships between bird community and habitat structure in shelterbelts of Hokkaido,Japan

Summary The relationship between the bird community and habitat structure in wind shelterbelts of Ishikari district was examined.Breeding birds were classified into nesting guilds (hole, canopy, and bush) and also into foraging guilds (outside, canopy, and bush) Both density and species richness in the outside-foraging guild were positively related to forest age variables. On the other hand, bird density in all three nesting guilds and the other two foraging guilds (canopy and bush) was correlated with the vegetation cover of their nesting or foraging sites, and species richness was positively correlated with tree species complexity variables.Bird species diversity (BSD) was closely related to tree species complexity, but not to foliage height diversity (FHD) within woods. However, if woods were re-classified into two groups such as natural and artificial and these were separately analysed, the correlation between BSD and FHD was significant.From these results, it is concluded that both FHD and tree species complexity should be considered together in order to predict BSD within forests. A new index is proposed for this purpose, and its usefulness discussed.     

Beetle community responses to grey willow (Salix cinerea) invasion within three New Zealand wetlands

Abstract

We investigated the effects of invasion by introduced grey willow (Salix cinerea) on beetle communities within four wetland vegetation types: native vegetation, native vegetation following grey willow removal, native vegetation undergoing grey willow invasion and dense grey willow-dominated vegetation. In total, 1505 beetles from 90 species were collected using modified Malaise traps. Native wetland vegetation had significantly lower beetle species richness than willow-dominated vegetation and was dominated by herbivores, whereas detritivores characterised willow-dominated vegetation. Beetle abundance was highest in the willow-dominated vegetation and mostly comprised detritivores. In contrast, beetle abundance was lowest in native wetland vegetation, but had even proportions of herbivores and detritivores. Native wetland vegetation had a high proportion of native beetles present. As grey willows invaded, introduced beetles became more common. The beetle community composition differed significantly between grey willow-dominated vegetation and native wetland vegetation. These compositional differences were mainly due to the increasing complexity of vegetation structure following grey willow invasion. The beetle communities within restored native wetland vegetation were most similar to those within the native wetland vegetation. From a conservation perspective, these results are encouraging and suggest that, although grey willows dramatically alter the composition of beetle communities present, these communities can be restored to a beetle fauna that is similar to those found within native wetland through the removal of the willows.     

Ground-dwelling spiders (Arachnida, Araneae) in fragmented old forests and surrounding managed forests in southern Finland

We studied the structure of spider assemblages in fragments of old coniferous forest in the southern Finnish taiga We sampled spiders with pitfall traps in the interiors and in the edges of the old-forest patches and in the surrounding managed forests We surveyed assemblages of ground-dwelling spiders and the relation of species to formerly mentioned three forest-habitat categories We analysed spider assemblages in relation to vegetation structure as well As in forest spiders there are no habitat specialists, no strict old-forest species were found However, the spider assemblages of old forests were different from those in the surrounding managed forests The difference was attributable to habitat differences, mainly to reduced tree-canopy cover in managed forests Large hunting-spider species (Gnaphosidae, Lycosidae) benefitted from clearcutting and other management measures, whereas the catches of small forest-living species (Linyphiidae) decreased in plantations and open forests The hunters colonized the edges of old-forest fragments, and were seldom found in the interior of old forest Size of old-forest fragment did not affect significantly the spider assemblage The results indicate that a buffer zone of mature forest with closed canopy should be left to surround the old-growth reserves in order to minimize the edge effect in the fragments     

Response of beetles (Coleoptera) at three heights to the experimental removal of an invasive shrub, Chinese privet (Ligustrum sinense), from floodplain forests

Chinese privet (Ligustrum sinense Lour.), an invasive shrub from Asia, is well established in the southeastern United States where it dominates many floodplain forests. We used flight intercept traps to sample beetles at three heights (0.5, 5 and 15 m) in ~2 ha plots in which L. sinense had (by chainsaws or mulching machine) or had not been removed from forests in northeastern Georgia. Removing L. sinense, particularly by machine, increased the richness and diversity of beetles and affected composition near the ground (0.5 m) but not in the forest canopy (15 m). There were no differences among treatments above the L. sinense canopy (5 m) aside from Xylosandrus crassiusculus, an exotic ambrosia beetle from Asia, dominating the beetle community at that height in control plots. Removing the L. sinense layer greatly increased beetle richness near the ground, resulting in vertical distribution patterns more similar to those observed in areas of forest devoid of L. sinense. We suspect that even organisms in the canopy will benefit from privet removal in the long term given that tree regeneration is nearly impossible in forests in which L. sinense has become well established.     

Forest cover and heterogeneous pastures shape the diversity of predatory rove beetles in tropical riparian habitats

In tropical landscapes, forest remnants have been reduced to narrow strips of vegetation along rivers and streams surrounded by agricultural land that affects biodiversity, depending on the habitat and landscape characteristics. To assess the effect of riparian forest loss on the diversity of Staphylininae predatory rove beetles, we considered two habitat conditions (river sites with riparian vegetation and sites with heterogeneous pastures) within two micro-basin types (with >70% and <40% forest cover) in a tropical montane cloud forest landscape, Mexico. Beetles were collected using baited pitfall traps during the rainy season of 2014. No differences were found between micro-basin types and, although species richness (⁰D) was similar between habitat conditions, when the diversity of common (¹D) and dominant (²D) species was considered, sites with heterogeneous pastures were almost twice as diverse as those with riparian vegetation. All diversity measurements were greater in sites with heterogeneous pastures of either micro-basin type. Air temperature and canopy cover were the environmental variables that best explained the variation in beetle species composition. The greatest environmental differences related to species composition were detected between habitat conditions and were more evident in sites with heterogeneous pastures and low forest cover in the surroundings. The results suggest that replacing riparian vegetation with heterogeneous pastures, within micro-basins that lost between 30% and 60% of their forest cover, does not significantly reduce the diversity of predatory rove beetle but rather modifies the beetle composition. Effective formulation of management strategies to mitigate the impact of land use modification therefore requires an understanding of the interaction between vegetation remnants and landscape characteristics.