Elements of regional beetle faunas: faunal variation and compositional breakpoints along climate, land cover and geographical gradients

Abstract

Summary1. Regional faunas are structured by historical, spatial and environmental factors. We studied large-scale variation in four ecologically different beetle groups (Coleoptera: Dytiscidae, Carabidae, Hydrophiloidea, Cerambycidae) along climate, land cover and geographical gradients, examined faunal breakpoints in relation to environmental variables, and investigated the best fit pattern of assemblage variation (i.e. randomness, checkerboards, nestedness, evenly spaced, Gleasonian, Clementsian). We applied statistical methods typically used in the analysis of local ecological communities to provide novel insights into faunal compositional patterns at large spatial grain and geographical extent. 2. We found that spatially structured variation in climate and land cover accounted for most variation in each beetle group in partial redundancy analyses, whereas the individual effect of each explanatory variable group was generally much less important in accounting for variation in provincial species composition. 3. We also found that climate variables were most strongly associated with faunal breakpoints, with temperature-related variables alone accounting for about 20% of variation at the first node of multivariate regression tree for each beetle group. The existence of faunal breakpoints was also shown by the 'elements of faunal structure' analyses, which suggested Clementsian gradients across the provinces, that is, that there were two or more clear groups of species responding similarly to the underlying ecological gradients. 4. The four beetle groups showed highly similar biogeographical patterns across our study area. The fact that temperature was related to faunal breakpoints in the species composition of each beetle group suggests that climate sets a strong filter to the distributions of species at this combination of spatial grain and spatial extent. This finding held true despite the ecological differences among the four beetle groups, ranging from fully aquatic to fully terrestrial and from herbivorous to predaceous species. 5. The existence of Clementsian gradients may be a common phenomenon at large scales, and it is likely to be caused by crossing multiple species pools determined by climatic and historical factors on the distributions of species.

Phylogenetic diversity of regional beetle faunas at high latitudes: patterns, drivers and chance along ecological gradients

“…Second, one cannot rule out the effects of climatic factors on the present-day distributions of beetles in our study area, and it may indeed be difficult to disentangle co-varying historical and climatic effects on beetle faunas at high latitudes (e.g. Heino and Alahuhta 2015).…”

“…Of course we do not wish to remove this effect of such predictors.'' Hence, given that both our response and predictor variables were autocorrelated owing to geographical and climate influences on provincial beetle faunas in our study area (Väisänen et al 1992;Heino and Alahuhta 2015), we considered spatial autocorrelation as a natural phenomenon that is related to the drivers of diversity. Also, Diniz-Filho et al (2003) noted that removing spatial patterns in diversity statistically may be problematic if those patterns are generated by broad-scale mechanisms.…”

“…Prior to the analyses, we merged small coastal provinces in Norway and omitted a single small Swedish island province (Gotska Sandö) to provide a better and more accurate representation of species ranges. After these modifications, the number of provinces we analyzed decreased from 101 to 79 (Heino and Alahuhta 2015). The insect faunas in the study area are relatively well-known, providing good data for many insect groups that are used infrequently in biogeographical and macroecological studies (Väisänen et al 1992;Väisänen and Heliövaara 1994).…”

“…The insect faunas in the study area are relatively well-known, providing good data for many insect groups that are used infrequently in biogeographical and macroecological studies (Väisänen et al 1992;Väisänen and Heliövaara 1994). Furthermore, use of more natural biogeographical units may be a good option over the use of grid data (Heino and Alahuhta 2015). We therefore used the 79 provinces as sampling units, where all the species recorded from each province represents a single regional assemblage.…”

Climate-induced seasonal activity and flight period of cerambycid beetles in the Zselic forests, Hungary

“…However, in close proximity of these areas, zones occur which have regained their highly diverse natural communities subsequently upon cessation of human activities (Myers et al 2000;Raupp et al 2010;Heino, Alahuhta 2015). Besides, lowland rich saproxylic communities are dependent on human-maintained habitats e.g.…”