Environmental stress can lead to a reduction in developmental homeostasis, which could be reflected in increased variability of morphological traits. Fluctuating asymmetry (FA) is one possible manifestation of such a stress, and is often taken as a proxy for individual fitness. To test the usefulness of FA in morphological traits as an indicator of environmental quality, we studied the effect of urbanisation on FA in ground beetles (Carabidae) near a Danish city. First, we performed a critical examination whether morphological character traits suggested in the literature displayed true fluctuating asymmetry in three common predatory ground beetles, Carabus nemoralis, Nebria brevicollis and Pterostichus melanarius. Eight metrical (length of the second and third antennal segments, elytral length, length of the first tarsus segment, length of the first and second tibiae, length of the proximal and distal spines on the first femurs) and one meristic (the number of spines on the second tibiae) traits were examined. Most of them showed FA but not consistently. Females generally displayed a higher level of FA than males. Finally, we examined the changes in the level of FA in bilateral morphological traits along an urbanisation gradient (forest - suburban forest - forest fragments in urban park) to test whether environmental stress created by urbanisation is reflected in FA. Ground beetles common along a Danish urbanisation gradient did not seem to indicate differences in habitat quality by their level of FA.
Digweed, S., C. Currie, H. Carcamo and J. Spence. 1995. Digging out the “digging-in effect” of pitfall traps: Influences of depletion and disturbance on catches of ground beetles (Coleoptera: Carabidae). Pedobiologia 39
A key structural component in peat bog formation is Sphagnum spp., which determines very specific associated environmental conditions. The aim of this study was to characterise some of the key factors affecting the diversity, species richness and abundance of sphagnum inhabiting ground beetles and to examine the maintenance of stable populations of cold adapted specialised peat bog species. A total of 52 carabid species were recorded by pitfall traps along six main habitats, such as the lagg zone, pine bog, hollows, hummock open bog and dome. The results are characterised by a low diversity, which vary significantly among habitat types, and include a high abundance of a few carabid species. Among the variables influencing carabid species richness and abundance were plant cover, pH and the conductivity of the Sphagnum mat water. Vascular plant cover was a key factor shaping carabid beetle assemblages in the slope and the dome, while electric conductivity affected carabid beetle assemblage in the lagg. Whereas, the water level was the most important factor for the hollows. At the same time, peat bog specialists showed low sensitivity to the gradient of the analysed variables. Most of the specialised species are protected boreal beetles in the temperate zone of Europe, and therefore Belarusian peat bogs are a significant repository of cold adapted specialised bog species and potentially represent a significant refugia for these species in the context of global warming.
Effects of forestry management were studied in the Szatmár-Bereg Landscape Protection Area (NE-Hungary). Carabid assemblages of forest stands managed by different management techniques (stand put under acorn after clearing the herbaceous and shrub layer, the other prepared for seedlings by grubbing and deep loosening) have been compared with that of a non-managed control stand using pitfall traps. The number of carabid individuals and species has been found to be the highest in the non-managed stand, followed by that of the stand which was put under acorn after clearing the herbaceous and shrub layer. The fewest individuals and species were observed in the stand managed by grubbing and deep loosening. There was no significant difference between the species richness of the control stand and the stand managed by clearing the herbs and shrubs and put under acorn, while both values were found to be significantly higher than that of the stand managed by grubbing and loosening. The composition of the carabid assemblage of the non-managed stand and that of the stand cleared and put under acorn were similar to each other, while the carabid assemblage of the stand managed by grubbing and deep loosening was considerably different from the assemblages of the two above stands. The results suggest that the grubbing and deep loosening management practice completely changes the structure and composition of the carabid assemblage, thus it is not recommended to use in protected areas. Clearing the herbaceous and shrub layer followed by putting under acorn, does not substantially change the structure and composition of the carabid assemblage, so it can be used on protected areas for forestry management.