Landscape-scale crop diversity interacts with local management to determine ground beetle diversity

Crop diversification and maintenance of semi-natural habitats (grasslands and field boundaries) are suggested to enhance farmland biodiversity, but the relative importance of these factors remains poorly known. We evaluated how crop diversity and availability of semi-natural grasslands at a landscape-scale interacted with local farming management (three management types from low to high intensity: ley < winter wheat < sugar beet) in their effect on ground beetle assemblages in southern Sweden. Ground beetle diversity increased with crop diversity either independently of local management (Simpson species diversity), or only in the less intensively managed habitats (rarefied species richness). While ground beetle diversity in leys tended to increase with field boundary length, no such relationship was observed in winter wheat or sugar beet fields. In contrast, the landscape proportions of leys and semi-natural grasslands did not affect ground beetle species richness and diversity. We conclude that (a) semi-natural grasslands and leys may not function as source habitats at a landscape-scale if they comprise a low proportion of the total land-use, while (b) increasing crop diversity is correlated to ground beetle richness and diversity in agricultural landscapes dominated by arable land. The beneficial effect of landscape-scale crop diversification on farmland biodiversity may depend on the general level of agricultural intensity of a region.     

Carabid beetle (Coleoptera: Carabidae) richness and functional traits in relation to differently managed grasslands in the Alps

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

Ground beetles (Coleoptera, Carabidae)on set-aside fields in the Campine region and their importance for nature conservation in Flanders (Belgium)

Three set-aside fields of arable land on sandy soil in the Campine region of Flanders (Belgium), differently managed for nature conservation purposes, were sampled for their carabid beetle fauna during a complete year cycle by means of pitfall traps. About 3650 ground beetles belonging to 53 species were obtained. Besides this remarkably high diversity, no less than 11 Red data book species for Flanders were found. These species include three rare, two near- threatened, three vulnerable, two endangered and one critically endangered species. The most notable species were Amara tricuspidata and Harpalus froelichi. Although the results are based on a limited data set, we can conclude that, at least for ground beetles, conversion of agricultural fields to set- aside poor fields or dry grasslands has great potential with respect to regional conservation biology in the Campine region. Ordination of the data shows that each field can be characterized by a somewhat different carabid beetle community. The restricted data do not allow us to conclude which management measures seem most appropriate. The safest recommendation at this stage is to use a variety of practices on different fields, in order to enhance general diversity, and, above all, to avoid afforestation. Traditionally managed arable land thus can have a distinctive and comparatively species-rich carabid fauna, which recently has become endangered to a high degree.     

Species’ traits influence ground beetle responses to farm and landscape level agricultural intensification in Europe

Agricultural intensification may result in important shifts in insect community composition and function, but this remains poorly explored. Studying how groups of species with shared traits respond to local and landscape scale land-use management can reveal mechanisms behind such observed impacts. We tested if ground beetles (Coleoptera: Carabidae) divided into trait groups based on body sizes, wing morphologies and dietary preferences respond differently to farming practise (organic and conventional), farming intensity (measured as yield) and landscape complexity (measured as the proportion of arable land within a 1,000 m radius) across Europe. We used data from 143 farms in five regions in northern and central Europe. Organic farms did not differ in abundance or richness of any trait group compared to conventional farms. As farm scale intensity (yield) increased, overall abundance of beetles decreased, but abundances of small and medium sized beetles, as well as that of wingless beetles, were unaffected. Overall species richness was not affected by yield, whereas consideration of traits revealed that phytophagous and omnivorous beetles were less species rich on farms with high yields. Increasing the proportion of arable land in the landscape increased overall beetle abundance. This was driven by an increase in omnivorous beetles. The total species richness was not affected by an increase in the proportion arable land, although the richness of wingless beetles was found to increase. Potential effects on ecosystem functioning need to be taken into account when designing schemes to maintain agricultural biodiversity, because species with different ecological traits respond differently to local management and landscape changes.     

Cork-oak woodlands as key-habitats for biodiversity conservation in Mediterranean landscapes: a case study using rove and ground beetles (Coleoptera: Staphylinidae, Carabidae)

Land-use intensification in Mediterranean agro-forest systems became a pressure on biodiversity, concerning particularly the woodland sensitive species. In 2001, the effects of a land-use gradient from old-growth cork-oak forest to a homogeneous agricultural area were assessed using rove beetles as indicators in a Mediterranean landscape. The aim was to find which species were negatively affected by land-use intensification at the landscape level and whether they benefited from cork-oak patches occurring along the land-use gradient. A total of 3,196 rove beetles from 88 taxa were sampled from all landscape types. Agricultural area recorded significantly higher numbers of abundance and species richness in relation to the cork-oak mosaics, i.e. the old-growth forest and the managed agro-forest landscapes (montados). Moreover, 70% of rove beetle indicator species common enough to be tested by IndVal displayed their highest indicator value for agriculture, showing a lower number of woodland indicators in comparison to ground beetles. Nevertheless, one rove beetle taxon was considered a specialist of closed woodland mosaics while no specialist ground beetle was found for that landscape typology. Some rare rove beetle species were also important in typifying diversity patterns of old-growth cork-oak forests. Hence, future management in Mediterranean landscapes should take into account not only indicator species common enough to be tested by IndVal, but also rare and endemic species. Considering the added value of cork-oak woodland cover for sensitive rove and ground beetle diversity, the strengthening of cork-oak woodland connectivity seems to be a crucial management that is required in agricultural Mediterranean landscapes.     

Effect of land-use heterogeneity on carabid communities at the landscape scale

Carabid beetle assemblages were studied to assess how diversity and community structure varied along a gradient of land-use. This gradient was composed of six 1 km² quadrats with an increasing proportion of agricultural land reflecting the anthropogenic fragmentation and intensification of landscapes. Carabid species richness and abundance was predicted to peak in the most heterogeneous landscape, in accord with the intermediate disturbance hypothesis (IDH), and then decline as agricultural intensification increased. It was also predicted that the different landscapes would support beetle communities distinct from each other. The IDH was unsupported-in both years of this study carabid species richness and abundance was greatest in the most intensively managed, agricultural sites. Detrended correspondence analysis revealed a clear separation in beetle community structure between forested and open habitats and between different forest types. Canonical correspondence analysis revealed a significant correlation between beetle community structure and the environment, showing distinct beetle assemblages to be significantly associated with specific edaphic and botanical features of the land-use gradient. This study adds to increasing evidence that landscape-scale patterns in land-use significantly affect beetle community structure producing distinct assemblages.     

Land‐use effects on the functional distinctness of arthropod communities

Land‐use change is a major driver of the global loss of biodiversity, but it is unclear to what extent this also results in a loss of ecological traits. Therefore, a better understanding of how land‐use change affects ecological traits is crucial for efforts to sustain functional diversity. To this end we tested whether higher species richness or taxonomic distinctness generally leads to increased functional distinctness and whether intensive land use leads to functionally more narrow arthropod communities. We compiled species composition and trait data for 350 species of terrestrial arthropods (Araneae, Carabidae and Heteroptera) in different land‐use types (forests, grasslands and arable fields) of low and high land‐use intensity. We calculated the average functional and taxonomic distinctness and the rarified trait richness for each community. These measures reflect the range of traits, taxonomic relatedness and number of traits that are observed in local communities. Average functional distinctness only increased significantly with species richness in Carabidae communities. Functional distinctness increased significantly with taxonomic distinctness in communities of all analyzed taxa suggesting a high functional redundancy of taxonomically closely related species. Araneae and Heteroptera communities had the expected lower functional distinctness at sites with higher land‐use intensity. More frequently disturbed land‐use types such as managed grasslands or arable fields were characterized by species with smaller body sizes and higher dispersal abilities and communities with lower functional distinctness or trait richness. Simple recommendations about the conservation of functional distinctness of arthropod communities in the face of future land‐use intensification and species loss are not possible. Our study shows that these relationships depend on the studied taxa and land‐use type. However, for some arthropod groups functional distinctness is threatened by intensification and conversion from less to more frequently disturbed land‐uses.     

Comparing the effects of farming practices on ground beetle (Coleoptera: Carabidae) and spider (Araneae) assemblages of Scottish farmland

Multivariate techniques were used to compare and contrast the effects of land cover and farming practice on ground beetle and spider assemblages of Scottish farmland. For both ground beetles and spiders, the ordination and fuzzy clustering of sites were related to land cover rather than geographical location or year of sampling. The same four types of land cover group were identified: that is, heather moorland, semi-natural grassland, intensive grassland and arable land. The robustness of these land cover groups was tested using previously unsampled sites and it was found that 79 and 86% of sites, for ground beetle and spider assemblages respectively, were allocated to the land cover group predicted from their actual land cover. Furthermore, procrustes rotational analysis found a strong relationship between ground beetle and spider assemblages in intensively managed sites, suggesting that the assemblage structure of one group could be used to predict that of the other. The observed relationship between spider and ground beetle assemblages does not necessarily indicate that both groups were responding to agricultural practices in the same way. Indeed, the highest number of beetle species occurred in intensively managed grassland and arable sites while the highest number of spider species occurred in semi-natural grassland and heather sites. When conducting ecological assessments, one might wish to collect information on a wide range of ecologically different taxa; however, financial constraints make this unfeasible. From the results it could be concluded that spiders should be chosen in preference to ground beetles when seeking to make predictions on how farming practices influence invertebrates. However, such a conclusion would be premature since not only were spiders more numerous in the traps, but they were also more time consuming to process. In addition, the strong relationship found between the spider and ground beetle assemblages further justifies carabids as a target group when monitoring the influence of farming practices on biodiversity.     

Increasing land-use intensity decreases floral colour diversity of plant communities in temperate grasslands

To preserve biodiversity and ecosystem functions in a globally changing world it is crucial to understand the effect of land use on ecosystem processes such as pollination. Floral colouration is known to be central in plant-pollinator interactions. To date, it is still unknown whether land use affects the colouration of flowering plant communities. To assess the effect of land use on the diversity and composition of flower colours in temperate grasslands, we collected data on the number of flowering plant species, blossom cover and flower reflectance spectra from 69 plant communities in two German regions, Schwäbische Alb (SA) and Hainich-Dün (HD). We analysed reflectance data of flower colours as they are perceived by honeybees and studied floral colour diversity based upon spectral loci of each flowering plant species in the Maxwell triangle. Before the first mowing, flower colour diversity decreased with increasing land-use intensity in SA, accompanied by a shift of mean flower colours of communities towards an increasing proportion of white blossom cover in both regions. By changing colour characteristics of grasslands, we suggest that increasing land-use intensity can affect the flower visitor fauna in terms of visitor behaviour and diversity. These changes may in turn influence plant reproduction in grassland plant communities. Our results indicate that land use is likely to affect communication processes between plants and flower visitors by altering flower colour traits.     

Down‐sizing of dung beetle assemblages over the last 53 000 years is consistent with a dominant effect of megafauna losses

The ongoing down‐sizing of the global mammal communities is assumed to have subsequent effects on mutualistic species communities. Dung beetles co‐evolved with large‐sized animals since millennia and depend on the megafauna feces of an appropriate size. Mammal community down‐sizing as a result of past and ongoing megafauna losses is therefore likely to result in a down‐sizing of dung beetle communities. However, empirical evidence for this co‐down‐sizing is lacking especially on larger spatial scales and over extended periods of time. Here, we show a significant down‐sizing of European dung beetle assemblages over the last ~53 000 years by relating Quaternary fossil records with trait information on body size of beetles. This significant down‐sizing of dung beetle communities was thereby not linear, but characterized by a weak decrease until the early Holocene but a strong acceleration in the recent pre‐history, from 6–7000 years BP onwards. This acceleration of down‐sizing coincides with the completion of the Quaternary megafauna extinction and the start of major shifts in human agricultural land‐use. In contrast, assemblage mean body size of non‐coprophagous scarabids as well as ground beetles – two groups of beetles with no or weak relations to megafauna – was observed to increase towards the present with an acceleration of body size increase coinciding with the onset of late‐glacial warming (14 200 years BP). In summary, the observed late‐Quaternary down‐sizing of European dung beetle communities is consistent with an effect of pre‐historic megafauna losses, and not with the coincident general warming. Ongoing down‐sizing of mammal communities is therefore likely to result in further down‐sizing of dung beetle assemblages, with potential effects on their important role for nutrient cycling and secondary seed dispersal in natural and extensive agro‐ecosystems. Future nature management initiatives could halt or even reverse this functional diversity loss via effective protection or restoration of megafauna communities.     

Seasonality of a Diverse Beetle Assemblage Inhabiting Lowland Tropical Rain Forest in Australia

One of the least understood aspects of insect diversity in tropical rain forests is the temporal structuring, or seasonality, of communities. We collected 29,986 beetles of 1473 species over a 4-yr period (45 monthly samples), with the aim to document the temporal dynamics of a trophically diverse beetle assemblage from lowland tropical rain forest at Cape Tribulation, Australia. Malaise and flight interception traps were used to sample adult beetles at five locations at both ground and canopy levels. Beetles were caught throughout the year, but individual species were patchy in their temporal distribution, with the 124 more abundant species on average being present only 56 percent of the time. Climatic variables (precipitation, temperature, and solar radiation) were poorly correlated with adult beetle abundance, possibly because: (1) seasonality of total beetle abundance was slight; (2) the peak activity period (September–November) did not correspond to any climatic maxima or minima; or (3) responses were nonlinear owing to the existence of thresholds or developmental time-lags. Our results do not concur with the majority of tropical insect seasonality studies suggesting a wet season peak of insect activity, perhaps because there is no uniform pattern of insect seasonally for the humid tropics. Herbivores showed low seasonality and individual species' peaks were less temporally aggregated compared to nonherbivores. Canopy-caught and larger beetles (> 5 mm) showed greater seasonality and peaked later in the year compared to smaller or ground-caught beetles. Thus seasonality of adult beetles varied according to the traits of feeding ecology, body size, and habitat strata.     

Traits of butterfly communities change from specialist to generalist characteristics with increasing land-use intensity

Land-use intensification leads to species loss and shifts in community composition, but only few studies examine how these dynamics affect ecological and life-history traits. We thus investigated whether ecological and life-history traits differ between butterfly communities of grasslands with different land-use intensity. We conducted butterfly transect surveys in 137 grassland sites in three regions of Germany and compiled 10 species-specific ecological and life-history traits from the literature. These traits are associated with food plant specialisation, dispersal, distribution, reproduction and development. We calculated a land-use intensity gradient based on the amount of fertilise mowing frequency and grazing intensity. We analysed differences of traits characteristics between butterfly communities along the land-use intensity gradient in a fourth-corner analysis, thus considering correlations between traits. Six ecological and life-history traits changed from characteristics associated with specialists to such associated with generalists with increasing land-use intensity. These traits characteristics in intensified grasslands were: high dispersal propensity, large distribution range, low population density, more than one generation per year, hibernation in a more advanced developmental stage and a long flight period. The functional homogenisation of the butterfly communities with changes from specialist to generalist trait characteristics with increasing land-use intensity may have severe consequences for ecosystem functioning and services.     

More species,but all do the same: contrasting effects of flood disturbance on ground beetle functional and species diversity

The role of habitat disturbance on biodiversity is central as it promotes changes in ecological systems. That said, still little is known about the functional consequences of such changes. Functional diversity can be used to revealing more mechanistically the disturbance effects on communities by considering the richness and the distribution of traits among the species. Here we analyzed the response of functional and species diversity of ground beetles to flood disturbance to better understand the functioning of alluvial invertebrate communities. Ground beetles were sampled in periodically flooded grasslands along the Elbe River in Germany. We used generalized linear mixed effects models to unveil the relationships between flood disturbance, species and functional diversity, respectively. We measured different components of functional diversity (functional richness, evenness, dispersion, and divergence) and analyzed species diversity by means of rarefied species richness, abundances, evenness and Simpson's diversity. We found contrasting relationships in that most species diversity measures peaked at highest disturbance levels, while most functional diversity measures decreased with increasing disturbance intensities. Inversed relationships between species and functional diversity are rarely observed, as most studies report on positive correlations. We explain increasing species diversity with a higher amount of resources available in highly disturbed sites. Decreasing functional diversity is best explained through the convergence of species traits by flood disturbance and uneven resource exploitation in highly disturbed plots (low functional evenness), suggesting strong impacts from functionally different generalist species in floodchannels. We show that the amount of resources available, and how these resources are exploited, play major roles in the functioning of floodplain ground beetle communities.     

Fine‐scale drivers of beetle diversity are affected by vegetation context and agricultural history

Environmental gradients have been shown to affect animal diversity, but knowledge of fine‐scale drivers of insect diversity is, in many cases, poorly developed. We investigated the drivers of beetle diversity and composition at different microhabitats, and how this may be mediated by past agricultural activities. The study was undertaken in temperate eucalypt grassy woodland near Canberra, south‐eastern Australia, with a 200‐year history of pastoral land use. We sampled beetles using pitfall traps at three microhabitats (open grassland, logs and under trees). We analysed the effects of soil properties, vegetation structure, and plant composition on beetle composition, and compared beetle responses among the microhabitats. We found that microhabitat was a strong determinant of the way beetle communities responded to their environment. Soil nutrients (C, N and P) were the strongest drivers of beetle species richness, abundance and composition at open and log microhabitat, however vegetation structure (tree basal area) was more important for beetle richness, abundance and biomass under trees. We also found significant differences in beetle composition among distinct ground‐layer plant communities at log and tree microhabitat. We show that prior agricultural land use, particularly fertilization, has altered soil and plant communities, and that these effects continue to flow through the system affecting beetle assemblages. These findings have implications for future management of microhabitat structures in temperate grassy woodlands with a history of agricultural use.     

Landscape attributes shape dung beetle diversity at multiple spatial scales in agricultural drylands

Land-use change is one of the main drivers of biodiversity loss worldwide, but its negative effects can vary depending on the spatial scale analyzed. Considering the continuous expansion of agricultural demand for land, it is urgent to identify the drivers that shape biological communities in order to balance agricultural production and biodiversity conservation in human-modified landscapes. We used a patch-landscape design and a multimodel inference approach to assess the effects of landscape composition and configuration at two spatial scales (patch and landscape) on the structure of dung beetle assemblages. We performed our study in the Caatinga, the largest dry forest in South America. We sampled 3,526 dung beetles belonging to 19 species and 11 genera. At patch scale, our findings highlight the positive relationship of forest cover and landscape heterogeneity with dung beetle diversity, which are the major drivers of beetle assemblages. Edge density, in turn, is a major driver at the landscape scale and has a negative effect on beetle diversity. Our results support the hypothesis that landscapes combining natural vegetation remnants and heterogeneous agricultural landscapes are the most effective at conserving the biodiversity of dung beetles in the Caatinga landscapes. Directing efforts to better understand the dynamics of dung beetles in agricultural lands can be helpful for policymakers and scientists to design agri-environment schemes and apply conservation strategies in tropical dry forests.     

Does wing morphology affect recolonization of restored farmland by ground‐dwelling beetles?

Revegetation of previously cleared land is widely used to increase habitat area and connectivity of remnant vegetation for biodiversity conservation. Whether new habitat attracts or supports fauna depends on the dispersal traits of those fauna as well as the structure and composition of the surrounding landscape. Here, we examined wing morphology as a key dispersal trait for beetles in a revegetated landscape and asked, first, how it was related to phylogeny (family), trophic position, and body size. Second, we asked if wing morphology of recolonizing (or persisting) beetles varied with habitat characteristics at multiple scales, from microhabitat to landscape context. Third, we examined how common winged and wingless species responded to habitat at multiple scales. We measured the wing morphology of ground‐dwelling beetles from a restoration chronosequence, including paddocks, “young” revegetation (8–11 years old), “old” revegetation (14–19 years old), and fenced remnant vegetation. We found that body size and family membership were significant predictors of winglessness, with wingless species of carabids and curculionids being larger than their winged counterparts. We found no difference in the number of sites occupied by winged and wingless species, and no relationship between the wing morphology traits represented in different locations and habitat characteristics or landscape context. Furthermore, the most abundant species of both winged and wingless ground‐dwelling beetles had relatively little affinity to any habitat successional stage. Thus, despite intrinsic differences in wing morphology among species of ground‐dwelling beetle, we found no evidence that flight‐related dispersal limitations influenced recolonization (or persistence) in this landscape.     

Changes of dung beetle communities from rainforests towards agroforestry systems and annual cultures in Sulawesi (Indonesia)

Little is known about how tropical land-use systems contribute to the conservation of functionally important insect groups, including dung beetles. In a study at the margin of Lore Lindu National Park (a biodiversity hotspot in Central Sulawesi, Indonesia) dung-beetle communities were sampled in natural forest, young secondary forest, agroforestry systems (cacao plantations with shade trees) and annual cultures (maize fields), each with four replicates (n = 16 sites). At each site we used 10 pitfall traps, baited with cattle dung, along a 100 m transect for six 3-day periods. The number of trapped specimens and species richness at the natural forest sites was higher than in all land-use systems, which did not significantly differ. Each land-use system contained, on average, 75% of the species richness of the natural forest, thereby indicating their importance for conservation. However, a two-dimensional scaling plot based on NESS indices (m = 6) indicated distinct dung beetle communities for both forest types, while agroforestry systems and annual cultures exhibited a pronounced overlap. Mean body size of dung beetles was not significantly influenced by land-use intensity. Five of the six most abundant dung beetle species were recorded in all habitats, whereas the abundance of five other species was significantly related to habitat type. Mean local abundance and number of occupied sites were closely correlated, further indicating little habitat specialisation. The low dung beetle diversity (total of 18 recorded species) may be due to the absence of larger mammals in Sulawesi during historical times, even though Sulawesi is the largest island of Wallacea. In conclusion, the dung beetle fauna of the lower montane forest zone in Central Sulawesi appears to be relatively robust to man-made habitat changes and the majority of species did not exhibit strong habitat preferences.     

Sampling beetle communities: Trap design interacts with weather and species traits to bias capture rates

Globally, many insect populations are declining, prompting calls for action. Yet these findings have also prompted discussion about sampling methods and interpretation of long‐term datasets. As insect monitoring and research efforts increase, it is critical to quantify the effectiveness of sampling methods. This is especially true if sampling biases of different methods covary with climate, which is also changing over time. We assess the effectiveness of two types of flight intercept traps commonly used for beetles, a diverse insect group responsible for numerous ecosystem services, under different climatic conditions in Norwegian boreal forest. One of these trap designs includes a device to prevent rainwater from entering the collection vial, diluting preservatives and flushing out beetles. This design is compared to a standard trap. We ask how beetle capture rates vary between these traps, and how these differences vary based on precipitation levels and beetle body size, an important species trait. Bayesian mixed models reveal that the standard and modified traps differ in their beetle capture rates, but that the magnitude and direction of these differences change with precipitation levels and beetle body size. At low rainfall levels, standard traps catch more beetles, but as precipitation increases the catch rates of modified traps overtake those of standard traps. This effect is most pronounced for large‐bodied beetles. Sampling methods are known to differ in their effectiveness. Here, we present evidence for a less well‐known but likely common phenomenon—an interaction between climate and sampling, such that relative effectiveness of trap types for beetle sampling differs depending on precipitation levels and species traits. This highlights a challenge for long‐term monitoring programs, where both climate and insect populations are changing. Sampling methods should be sought that eliminate climate interactions, any biases should be quantified, and all insect datasets should include detailed methodological metadata.     

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.     

The relationship between the classification of Scottish ground beetle assemblages (Coleoptera, Carabidae) and the National Vegetation Classification of British plant communities

A sufficiently large body of knowledge on British ground beetle (Carabidae) communities now exists to allow investigation of whether habitats may be classified or described on the basis of their ground beetle communities, in the same way that the National Vegetation Classification (NVC) describes British plant communities. A data set of ground beetle abundances from pitfall traps at 481 sites in a range of natural, semi-natural and agricultural habitats throughout Scotland was available for analysis. Multivariate analysis (detrended correspondence analysis and fuzzy cluster analysis) was carried out on proportional catch data of 156 species of ground beetle from 444 of these sites and the results related to the NVC of the sites.
Initial analysis classified the sites into five broad categories: 1) peatlands, 2) calcifugous, 3) mesotrophic, 4) dry river sediments and 5) damp river sediments. Further analysis identified 15 ground beetle assemblages, each corresponding to a relatively well defined vegetation type within one of these broad categories. The major environmental factors appearing to determine the distribution of ground beetle assemblages were substratum type, disturbance and soil moisture, all of which are also important determinants of the distribution of plant communities. The presence and absence of relatively stenotopic species were important discriminants of certain habitats such as wetlands and river sediments but the relative abundances within assemblages of more eurytopic species provided good indications of a relationship between ground beetle assemblages and NVC categories.