Browsing by Subject "saproxylic beetles"

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  • Hagge, Jonas; Abrego, Nerea; Baessler, Claus; Bouget, Christophe; Brin, Antoine; Brustel, Herve; Christensen, Morten; Gossner, Martin M.; Heilmann-Clausen, Jacob; Horak, Akub; Gruppe, Axel; Isacsson, Gunnar; Koehler, Frank; Lachat, Thibault; Larrieu, Laurent; Schlaghamersky, Jiri; Thorn, Simon; Zapponi, Livia; Mueller, Joerg (2019)
    Aim: Beech forests comprise a globally unique temperate forest type in Europe. The dominance of beech in these forests developed during the ongoing post-glacial northward re-colonization, concurrently with intensified forest use by humans. We investigated how these two processes together with climate shaped the patterns of functional diversity of two major species groups involved in wood decomposition and whether functional diversity is determined on the local or regional species pool level. Location: European beech forest distribution range. Taxon: Saproxylic beetles and fungi. Methods: We analysed records of 532,496 saproxylic beetles of 788 species and 8,630 records of 234 saproxylic fungal species based on sets of traits similar to both groups. We tested how space, climate and landscape composition affect trait-based functional diversity on local and regional scales. Using structural equation modelling, we tested whether functional diversity is shaped on the local or regional scale. Results: The response of local functional diversity of both saproxylic beetles and fungi followed a highly congruent pattern of decreasing functional diversity towards the north, with higher elevation and accounted for overall geographical gradients with higher temperature, while increasing with higher precipitation. Structural equation modelling revealed that local functional diversity is determined by community changes operating on the level of the regional species pool. Main conclusions: Our findings suggest that the functional diversity patterns of saproxylic organisms in European beech forests are mainly determined on the regional scale and driven by anthropogenic and biogeographical processes. To conserve the variation and hotspots of functional diversity in beech forests, activities have to focus on a broad spatial and climatic range of sites throughout Europe, including the primeval forests in the east, as started by the UNESCO World Heritage selection of "Ancient and Primeval Beech Forests of the Carpathians and Other Regions of Europe".
  • Thomssen, Pia-Maria (Helsingfors universitet, 2012)
    Old hollow trees are an important habitat for many saproxylic species. A number of threatened and rare insects are specialized on tree hollows and live in the walls of cavities or in the loose wood mould accumulating in the bottom of the hollow. In this study, I compared the species richness and composition of Coleoptera in hollow trees caught with three trap types, window, aluminium foil and pitfall traps. Furthermore, I compared the time spent handling each sample of the different trap types, when sorting all insect orders (including Coleoptera) from the material. The material was gathered in parks and mansion areas in the Helsinki metropolitan area. Window, foil and pitfall traps were placed inside cavities of Tilia cordata, Acer platanoides and Quercus robur trees. In each tree two of each trap type was placed, i.e. six traps per tree, making a total of 90 traps. The traps were emptied every third week during May to July 2006. When the samples were sorted for the first time to separate different insect orders, the duration of time spent sorting each sample was documented. A total of 3825 Coleoptera individuals from 212 species were caught, of which 3398 individuals from 121 species were saproxylic. Window traps caught 1639 individuals from 140 species, foil traps caught 1506 individuals from 134 species, and pitfall traps caught 680 individuals from 111 species. The time spent sorting each sample was on the average shortest with pitfall traps and longest with aluminium foil traps. The ?-diversity (species composition and abundance) differed between the three trap types. The ?-diversity between window and foil, window and pitfall, and foil and pitfall traps was 37%, 13% and 14% respectively. In addition for the average number of saproxylic beetle species and individuals, the average time spent sorting each sample differed statistically significantly between window and pitfall traps (p<0,05), and foil and pitfall traps (p<0,05). Window and foil traps caught, on the average, clearly more saproxylic species and individuals as compared with pitfall traps. Pitfall traps also caught, on the average, less saproxylic beetles out of total beetle individuals (59%) than window (69%) and foil traps (71%). Window traps were the most efficient conserning the average number of saproxylic beetle individuals in relation to the average time spent sorting each sample. Efficiency value (individuals/minute) for each trap type was 0,74 for window, 0,43 for aluminum foil and 0,21 for pitfall traps. Window traps have never before been used inside tree hollows, they have only been used to collect insects outside the cavities. However they functioned outstandingly inside the cavities. In this study pitfall traps were clearly outperformed by window and foil traps, still many species, even some threatened ones, would have been lost without them. To achieve as diverse a species composition as possible it is recommended to use either window or foil traps parallel with pitfall traps.
  • Burner, Ryan C.; Stephan, Jorg G.; Drag, Lukas; Birkemoe, Tone; Muller, Joerg; Snäll, Tord; Ovaskainen, Otso; Potterf, Maria; Siitonen, Juha; Skarpaas, Olav; Doerfler, Inken; Gossner, Martin M.; Schall, Peter; Weisser, Wolfgang W.; Sverdrup-Thygeson, Anne (2021)
    Aim The aim of this study was to investigate the role of traits in beetle community assembly and test for consistency in these effects among several bioclimatic regions. We asked (1) whether traits predicted species' responses to environmental gradients (i.e. their niches), (2) whether these same traits could predict co-occurrence patterns and (3) how consistent were niches and the role of traits among study regions. Location Boreal forests in Norway and Finland, temperate forests in Germany. Taxon Wood-living (saproxylic) beetles. Methods We compiled capture records of 468 wood-living beetle species from the three regions, along with nine morphological and ecological species traits. Eight climatic and forest covariates were also collected. We used Bayesian hierarchical joint species distribution models to estimate the influence of traits and phylogeny on species' niches. We also tested for correlations between species associations and trait similarity. Finally, we compared species niches and the effects of traits among study regions. Results Traits explained some of the variability in species' niches, but their effects differed among study regions. However, substantial phylogenetic signal in species niches implies that unmeasured but phylogenetically structured traits have a stronger effect. Degree of trait similarity was correlated with species associations but depended idiosyncratically on the trait and region. Species niches were much more consistent-widespread taxa often responded similarly to an environmental gradient in each region. Main conclusions The inconsistent effects of traits among regions limit their current use in understanding beetle community assembly. Phylogenetic signal in niches, however, implies that better predictive traits can eventually be identified. Consistency of species niches among regions means niches may remain relatively stable under future climate and land use changes; this lends credibility to predictive distribution models based on future climate projections but may imply that species' scope for short-term adaptation is limited.