Exploring the relationship between land cover and the distribution of water beetle species (Coleoptera) at the regional scale

The advent of remote-sensed satellite land cover data has provided the opportunity to assess the relationship between invertebrate species distributions and individual land cover types. Water beetle species occur in habitats within specific land cover types and the relationship between the distribution of water beetle species and land covers at the regional scale was investigated using records of 154 species from 1018 sites in north-east England. The land covers of tilled land and urban in the lowlands and of shrub heath and heath grassland in the upland areas proved to be most important in explaining the distribution of species. There were both positive and negative associations between some species and other covers such as woodland and the coast. However, a considerable number of species, generally those with a large number of records, showed no strong relationships with any land cover types. The integration of water beetle species recording data and remote-sensed land cover data as a basis for predicting and monitoring both species distribution and environmental change is discussed.     

The Distribution of Grassland Auchenorrhyncha Assemblages (Homoptera: Cercopidae, Cicadellidae, Delphacidae) in Northern England and Scotland

The distribution of Auchenorrhyncha species assemblages on 174 grassland sites in northern England and Scotland was investigated using ordination and classification techniques. Altitude appeared to be the most important environmental variable influencing assemblage distribution but the effects of altitude on soil type and moisture, and on plant composition, either herbaceous or woody, and structure were likely to have been primary influences. The main differences between sites in the eight habitat groups of the classification were products of these soil and plant variables, with the geographical position of sites in the survey area having less of an effect on site classification. A considerable number of nationally and regionally rare and scarce species were recorded. The results indicate that Auchenorrhyncha could be used in site conservation based on invertebrate species assemblages and rare species distribution but that more information is required to assess both habitat diversity and species rarity. More survey work would also be required to identify appropriate site management procedures for the conservation of Auchenorrhyncha within an overall programme for terrestrial invertebrates.     

Ground beetle species (Coleoptera, Carabidae) associations with land cover variables in northern England and southern Scotland

Distribution data concerning 172 ground beetle species derived from 1145 pitfall trap sites in northern England and southern Scotland were used to assess the relationship between species distribution and 12 satellite-derived land cover variables at the regional scale. A number of species were strongly associated with one cover type and negatively with others. The major variation was for preferences for covers in upland or lowland parts of the region. Other distinct preferences for some species were covers such as those at the coast whilst a number of common species showed no strong preference for any cover variable. The synthesis of ground beetle species distribution and satellite-derived cover data is discussed in relation to environmental assessment and change.     

An investigation into the relationship between water beetle (Coleoptera) distribution and land cover in Scotland and northeast England

Aims To determine the relationship between satellite‐derived land cover data and distribution patterns of water beetle species pools. Location A total of 687 British national grid 10 km squares in Scotland and 588 1 km grid squares in 99 10 km grid squares in northeast England. Methods Multivariate classification and constrained ordination analyses were used with water beetle species and land cover data. Results The major variation in both the Scotland and northeast England 10 km species pools was from squares with upland acid water habitats to squares with lowland fens and ponds whilst for the 1 km northeast England data it was from squares dominated by fast‐flowing streams and rivers to those with fens and ponds. The secondary variations in the 10 and 1 km analyses were the primary ones juxtaposed. Constrained ordination of the Scottish 10 km data showed upland land cover types to be most influential in determining species pool distribution whilst lowland covers were more important with both the 10 and 1 km northeast England pools. The three analyses showed that coastal cover had a relatively high influence on species pool distribution but no species pool group was dominated by coastal species. Main conclusions There were strong relationships between water beetle species pool distributions and the satellite‐derived land cover types dominating upland and lowland areas. The major variation in the northeast England species pool data differed at the two scales analysed. Results indicated that there is considerable potential for the synthesis of water beetle distribution and land cover data for use in environmental and conservation monitoring at both the regional and national scales.     

Habitat associations of epigeal spiders in upland calcareous grassland landscapes: the importance for conservation

Upland calcareous grassland landscapes are typically comprised of a matrix of calcareous grassland, acid grassland and limestone heath plant communities. This matrix of habitats is produced by a combination of underlying geology, climate and management. These landscapes are typically managed through grazing, with management targeted to maintain particular plant communities in the calcareous grassland habitat, whilst patches of acid grassland and limestone heath are not targeted by conservation management. The biodiversity value of acid grassland and limestone heath patches within the calcareous grassland matrix are unknown. This study provides the first assessment of their biodiversity value by examining aspects of epigeal spider diversity supported by these non-target habitat patches in comparison to calcareous grassland. Spiders were sampled in each habitat from April to August 2014 using pitfall traps across three upland regions in Great Britain. Spider species assemblages were distinct between limestone heath and both grassland types. Distinction in species assemblages are likely due to differences in vegetation structure and microclimate, e.g., humidity, degree of shade. Each habitat type supported several rare species (e.g., Jacksonella falconeri, Agyneta subtilis) revealing the contribution to spider fauna. The distinct spider species assemblage and presence of rare species in limestone heath patches demonstrate their importance in the upland calcareous grassland matrix. This study highlights the value of monitoring biodiversity in non-target habitats within a habitat matrix alongside those that are actively targeted by management.     

The Rove Beetles (Coleoptera, Staphylinidae) of Exposed Riverine Sediments in Scotland and Northern England: Habitat Classification and Conservation Aspects

Exposed riverine sediments (ERS) by four rivers in Scotland and northern England were sampled for beetles in 1996 and 1997. One hundred and sixty rove beetle (Staphylinidae) species lists were analysed using ordination and classification techniques in order to identify habitat groups within and between catchments and to assess which factors were affecting species assemblage distribution. There were major differences between the species assemblages of ERS by rivers of highland and lowland catchments. Within catchments, assemblage distribution was mainly influenced by the position of sites within the catchment; vegetation cover and sediment composition had less influence. The number of rove beetle habitats was not the same as those for ground and phytophagous beetle groups, indicating that conservation considerations should take into account variations in ERS habitat diversity. A considerable number of records of nationally rare and scarce rove beetle species were recorded, most on ERS by rivers and tributaries unaffected by river management or engineering.     

Large-scale terrestrial gastropod community composition patterns in the Great Lakes region of North America

Abstract: Previous ordination studies of land snail community composition have been limited to four or fewer habitat types from sites separated by no more than 300 km. To investigate the nature of large-scale patterns, North American land snail assemblages at 421 sites, representing 26 habitat types and covering a 1400 × 800 km area, were ordinated using global, nonmetric multi-dimensional scaling (NMDS). These data were then subjected to model-based cluster analysis and kmeans clustering to identify the main compositional groups and most important environmental covariables. Six primary compositional groups were identified. Three of these largely represent upland forest and rock outcrop sites, while the remaining largely represent either lowland forest, lowland grassland or upland grassland habitats. The geographical location and moisture level of sites also influences community composition. A strong compositional difference exists between sites having duff vs. turf soil surface layers. Only 8% of sites were improperly classified when soil surface architecture was used as the sole predictor variable. Fully 43% of taxa exhibited significant preferences towards one of these surface types, while only 15% of relatively common (10 + occurrence) taxa showed no preferences. Twelve groups of closely related taxa within the same genus had members that favoured different surface types, indicating that differential selection pressures have existed over evolutionary time scales. While turf faunas appeared unaffected by anthropogenic disturbance, duff faunas were strongly impacted, suggesting that their conservation will require protection of soil surface architecture.     

Modelling potential impacts of climate change on the bioclimatic envelope of species in Britain and Ireland

Aim Climate change has the potential to have significant impacts on the distribution of species and on the composition of habitats. This paper identifies the potential changes in the future distribution of species under the UKCIP98 climate change scenarios, in order that such changes can be taken into account in conservation management. Location The model was applied to Britain and Ireland. Methods A model based on an artificial neural network was used to predict the changing bioclimate envelopes of species in Britain and Ireland. Fifty‐four species representing 15 habitats were modelled. Results The modelled species could be placed into three categories: those losing suitable climate space, those gaining it, and those showing little or no change. When the species were associated with habitats it was found that Arctic–Alpine/montane heath communities were the most sensitive to climate change, followed by pine woodland and beech woodland in southern England. In lowland heath, wet heath, cereal field margins, coastal grazing marsh, drought‐prone acid grassland and calcareous grassland, the species either showed little change or an increase in suitable climate space. The other eight habitats showed a mixed response. Conclusions The species show a variety of responses to climate change and thus their current habitat associations may alter. The uncertain future of some species and habitats is highlighted. Conservation policy and practice will need to be revised in the face of climate change.     

The ground beetles (Coleoptera: Carabidae) of exposed riverine sediments in Scotland and northern England

A survey of invertebrates on exposed riverine sediments (ERS) in four catchments of rivers in Scotland and northern England was carried out in 1996 and 1997 using pitfall traps. The resulting 179 lists of ground beetle species were used in ordination and classification analyses to determine the different types of habitats and the environmental factors influencing species assemblage distribution. Types of ERS habitat differed between highland and lowland catchments; there were also different numbers of habitat types in each catchment. The distribution of ERS within catchments was related to geology, position in catchment, sediment composition and the amount of vegetation. Evidence of the positive nature of river engineering was identified and the role of river management is discussed. The numbers of nationally rare and scarce ground beetle species recorded from the ERS habitats in each catchment are reported and the factors affecting their distribution discussed.     

Macroinvertebrate species and assemblages in the headwater streams of the River Tyne,northern England in relation to land cover and other environmental variables

The macroinvertebrate species and assemblages of headwater streams of the River Tyne catchment in northern England were classified and their relationship with environmental variables based on stream structure, water acidity, distance from source and land cover investigated using constrained ordination and logistic regression. Fuzzy classification of data from 322 stream sites generated five assemblages. Stream structure, quantified as an exposure index, was found to be the most important environmental variable, with water acidity also important. Distance from source and land cover had less influence on species and assemblage distribution. A considerable amount of variation in assemblage distribution was explained using a two-variable logistic regression with stream structure (exposure index) and water acidity (pH) in a template. Site structure and water acidity appeared to be related to drift, geology and topography with little anthropogenic influence. The applicability of the habitat template concept for explaining the distribution of stream macroinvertebrates is discussed.     

A phytosociological study of a mid-altitude heath in County Durham, Northern England

A phytosociological survey of Hedleyhope Fell, a mid-Durham heath, was carried out. Much of the Fell is rank Nardus grassland, with damper Juncus and Eriophorum patches. Disturbed areas to the west are covered by poor Agrostis/Trifolium/Festuca grasslands. The eastern end of the Fell forms a locally valuable area of heathland. 115 relevés were taken and 131 species of plant recorded. Classification by two-way indicator species analysis suggested the delimitation of 19 noda. The principal ordination axes, produced by detrended correspondence analysis, emphasised the importance of soil moisture gradients, organic/mineral soil gradients and levels of disturbance in determining the vegetation. The Fell, at 300 m, falls between the lowland heaths of southern England and the upland mires of the north. Indeed, its vegetation contains some assemblages and species characteristic of both habitats. The heaths of central, mid-altitude County Durham are found where the coal measures lie close to the surface and so this habitat type has suffered extensively from opencast mining activity in the recent past. Proposed opencast sites, if they go ahead, will destroy the Fell.     

Effects of fire on the vegetation of a lowland heathland in North-western Italy

This study focuses on the effect of fire on lowland heathlands at the extreme southern edge of their European distribution (Vauda Nature Reserve, NW Italy). Forty-nine plots (50 m radius) were surveyed between 1999 and 2006. Each year, fire occurrences were recorded and per cent cover of four vegetation types (grassland, heath, low shrubland, and tall shrubland) was estimated in each plot. Vascular plant species richness was also recorded in 255, 1 m² quadrats. After a fire, grassland vegetation expanded, but then declined rapidly as heath and shrubland recovered: 7 years after a fire, tall shrubland encroached on to more than 40% of the plots, and grassland declined from 50% to 20% cover. Between 1999 and 2006, Betula pendula shrubland greatly expanded, while grassland decreased over most of the Reserve, even where fire frequency was high. Tall shrubland had low plant diversity and was dominated by widespread species of lower conservation value. By contrast, early successional vegetation (grassland and low shrubland) had higher richness and more narrowly distributed species, indication that the development of tall shrubland causes significant species loss in the heathland. Italian lowland heathlands are characterized by high rates of shrubland encroachment that threatens both habitat and species diversity. Burning frequencies of once in 3–6 years seem appropriate in this habitat, but burning alone might not suffice without actions to increase herbivore grazing.     

Assessing the application of a geographic presence-only model for land suitability mapping

Recent advances in ecological modeling have focused on novel methods for characterizing the environment that use presence-only data and machine-learning algorithms to predict the likelihood of species occurrence. These novel methods may have great potential for land suitability applications in the developing world where detailed land cover information is often unavailable or incomplete. This paper assesses the adaptation and application of the presence-only geographic species distribution model, MaxEnt, for agricultural crop suitability mapping in a rural Thailand where lowland paddy rice and upland field crops predominant. To assess this modeling approach, three independent crop presence datasets were used including a social-demographic survey of farm households, a remote sensing classification of land use/land cover, and ground control points, used for geodetic and thematic reference that vary in their geographic distribution and sample size. Disparate environmental data were integrated to characterize environmental settings across Nang Rong District, a region of approximately 1300 sq. km in size. Results indicate that the MaxEnt model is capable of modeling crop suitability for upland and lowland crops, including rice varieties, although model results varied between datasets due to the high sensitivity of the model to the distribution of observed crop locations in geographic and environmental space. Accuracy assessments indicate that model outcomes were influenced by the sample size and the distribution of sample points in geographic and environmental space. The need for further research into accuracy assessments of presence-only models lacking true absence data is discussed. We conclude that the MaxEnt model can provide good estimates of crop suitability, but many areas need to be carefully scrutinized including geographic distribution of input data and assessment methods to ensure realistic modeling results.     

A Strategic Interpretation of Beetle (Coleoptera) Assemblages, Biotopes, Habitats and Distribution, and the Conservation Implications

The identification of beetle, and other invertebrate, biotopes based on the recording of species assemblages has become a regular occurrence as a result of increased survey work, with the approach expanded into classifications of grid square pooled species lists at the national scale. A reassessment of beetle biotopes and distribution has been attempted by interpreting the classifications in terms of the major environmental factors of productivity and disturbance, identified as being important drivers in work on habitat templates and strategic triangles. For grassland ground beetle biotopes, productivity was generally related to soil quality whilst disturbance was associated with land management or cover. Productivity of exposed riverine sediment ground beetle biotopes was dependent on deposited organic matter and disturbance on the effects of water flow on site structure. With both ground beetle biotopes, the distribution of assemblages was also affected by substrate water, another abiotic driver. Productivity in aquatic beetle biotopes was a function of base-status, generally reflected by pH, whilst disturbance was mainly due to water flow and wave action. However, disturbance in ditches was also the result of site vegetation management whilst another factor affecting assemblage distribution was water permanence, with temporary water having specific assemblages. For large-scale British, grid-based, classifications productivity and disturbance were interpreted from satellite-derived land cover data. At the national scale, the other important factor influencing distribution was temperature. There is a requirement for better quantification of a number of the factors influencing biotope and assemblage definition. Species strategies employed to cope with the various environmental variables were reflected in traits in such factors as morphology and life-cycles. The effects of environmental perturbations including climate change, pollution and land use are discussed in relation to the environmental variables and to the various species strategies. Biotope classifications, using standardised and reproducible survey methods, allied to a better understanding of the underlying environmental pressures, could produce a unified approach for the conservation of beetle and other invertebrate species.     

Habitat distribution and conservation of land bird populations in northern Norway

About 300 km line transect censuses of breeding land birds were made in northern Norway in 1974–76. The data (1020 pairs in 26 samples) were grouped into seven major habitats: stony ground and oceanic heath (C1), continental dry heath (C2). "'2Calcarius heath", dry peatland, wet peatland (C5), meagre and average birch forest, and rich birch forest (C7). Bird density ranged from 22 pairs km⁻² (C2) to 364 pairs km⁻² (C7), but most habitats had 67–96 pairs km⁻². The bird communities are described.
Defining the Optimal habitat for a species as the maximum-density habitat, the 43 species observed were found to comprise three major groups: tundra species (optimal habitat C1), peatland species (C5) and forest species (C7). Species whose central range includes northern Norway had a broader habitat amplitude than those with a southern or a very northern distribution. A new index was devised for the evaluation of the conservational importance of a habitat or a species. From the North European standpoint. C1 is certainly the most important habitat in northern Norway, as C1 supports many species which are rare in other parts of North Europe. However, population trends should also be taken into account when conservational preferences are judged.     

Bat activity and species richness in different land‐use types in and around Chome Nature Forest Reserve,Tanzania

Bats have important ecological roles in ecosystems, but many species are threatened because of anthropogenic impacts. Tanzania has limited information on how bats respond to habitat modification. This makes it difficult to anticipate which bat species are at risk. Bat activity and species richness were assessed in five land‐use types: forest and banana–coffee (upland habitats), rice paddy, riverine and sisal estate (lowland habitats). Mist nets, harp traps and bat detectors were used to sample bats. Species richness differed between habitats. Bat activity levels were higher in lowland habitats than upland habitats. Riverine and rice paddy habitats were shown to have an important role as foraging sites for many insectivorous bats as bat species richness and activity were generally higher than other habitats. Fruit‐eating bats preferred riverine and banana–coffee habitats. We recommend using organic manure as alternatives to chemical fertilisers, and pesticide use should be avoided in rice paddies. Riparian vegetation along rivers and water bodies should be maintained as important faunal nesting, roosting and/or foraging grounds. The requirement that farming practices be at least 60 m from the river should be strictly enforced. These recommendations will help in the conservation of bats and their habitats in modified agricultural landscapes.     

Observations on the distribution, ecology, and behaviour of bats on the Galapagos Islands

The distribution of bats on five Galapagos islands was assessed using ultrasonic detectors that can identify the feeding calls of different bat species. Red bats ( Lasiurus brachyotis ) were present on Santa Cruz and San Cristobal. Hoary bats ( L. cinereus ) were present on Santa Cruz, San Cristobal, Isabela, Floreana and Santiago. Species identifications were confirmed by recordings of bat calls, observations of flying bats, and the capture of 21 red bats and three hoary bats. There was no evidence of other species of bats on the Galapagos. Body size measurements were similar to those of South American red ( L. borealis ) and hoary ( L. c. villosissimus ) bats. Species status of L. brachyotis is not supported by morphological data. Both species were active in lowland and highland habitats, and foraging activity was high around street lights. Radio telemetry was used to locate day roosts and the nightly activity areas of four red bats in lowland areas of Santa Cruz. During the day, these bats roosted singly in the foliage of nine species of plant. Nightly activity areas were 10 to 20 ha in size. The activity areas of individuals overlapped, and included their known day roost sites. Both bat species were apparently more active in lowland habitats during the cool garua season, and less active in lowland habitats during the hot season. Female red bats were more abundant in lowland habitats during the cool season than were male red bats. Mesic, upland habitat may be critical to the survival of bats in the Galapagos.     

The value of the trackway system within a lowland plantation forest for ground-active spiders

European forest management guidelines include conservation and enhancement of biodiversity. Within plantation forestry, trackways provide contiguous permanent open-habitat with potential to enhance biodiversity. We examined the ground-active spider assemblage in the trackway network of Thetford Forest, Eastern England, the largest lowland conifer forest in the UK, created by afforestation of heathland and farmland. Results are relevant to other forests in heath regions across Europe. We used pitfall trapping to sample the spider assemblage of trackways within thicket-aged stands (n = 17), mature stands (n = 13) and heathland reference sites (n = 9). A total of 9,314 individuals of 71 species were recorded. Spider assemblages of the trackway network were distinct from those of the heathland reference sites; however, trackways were found to support specialist species associated with grass-heath habitats, including nationally scarce species. Richness of grass-heath species was similar for trackways in thicket-aged forest and heathland reference sites, although the abundance of individuals was three times greater in the reference sites. Trackways in mature stands had lower grass-heath species richness and abundance than both thicket trackways and heath reference sites. Wide trackways within thicket stands contained greater richness and abundance of specialist xeric species than narrower trackways. However, fewer xeric individuals were found in trackways compared to heathland reference sites. Either inferior habitat quality in trackways or poor dispersal ability of specialist xeric species may largely restrict these to relict areas of heathland. Targeted widening of trackways to allow permanent unshaded habitat and creating early successional stages by mechanical disturbance regimes could improve trackway suitability for specialist species, helping to restore connectivity networks for grass-heath biodiversity.     

The relevance of non-farmland habitats, uncropped areas and habitat diversity to the conservation of farmland birds

Use of non-farmland habitats by species generally perceived as 'farmland birds' is common, yet these habitats are not always considered in conservation strategies aimed at population recovery. At the national scale, many farmland species occur in landscapes not dominated by farmland. An analysis of distribution atlas data coupled with remotely sensed habitat data showed that for 16 out of 28 farmland species, less than half of the breeding range was associated with high cover of lowland farmland. However, with a few exceptions, populations breeding in non-farmland habitats are likely to depend on farmland at some time in the year. Within farmland landscapes, uncropped areas and patches of non-farmland habitat can provide nesting, foraging or roosting resources. Habitats that are scarce on farmland and that provide potential supplementary or complementary resources to those available within the productive areas of farmland include ruderal vegetation, rough grassland and scrub. Enhancing habitat diversity through provision of modest quantities of these habitats will benefit farmland birds. Complete knowledge of year-round habitat requirements and patterns of resource use at all scales is needed if robust national conservation plans are to be developed for farmland species. Similarly, interactions between the farmland and non-farmland sections of populations need to be determined.     

A method for assessing evergreen habitats using phytodiversity and geospatial techniques in tropical rain forests of Southern Western Ghats (India)

We have used data generated using remote sensing and geographical information systems to categorize habitats, and then determined the relationship between the habitat categorizations and species-distribution patterns. A biologically rich hotspot—Kalakad-Mundanthurai Tiger Reserve, located at Southern Western Ghats, India, was chosen for this study. In order to spatially delineate areas of high species richness/diversity and endemic habitat zones, we have identified evergreen habitats in conjunction with landscape metrics, species assemblage, micro-habitats like slope, topography, species endemism, and proportion of core and edge species. A total of 236 species and 2,920 individuals were recorded using systematic stratified plots of 0.1 ha covering 47 plots. Hierarchical cluster analysis was done using Ward’s method. Plot information was used to identify clusters based on species density. The analysis showed five species assemblages that are quite distinct from each other in terms of dominant species. The distribution of endemic and edge species, land cover heterogeneity, and continuity of patches in these clusters were evaluated to understand the degree of disturbance and intactness at landscape scale. Integration of species assemblages and topography brought out four major elevation-slope complexes. Information on species composition (robust field survey) with spectral (hybrid classification) properties has shown 72% overall accuracy and distinguished four evergreen sub-groups and other land cover classes. The developed approach assumes great importance in the assessment of biodiversity and prioritizing the areas of conservation.