Spatial and temporal variation of epigaeic beetle assemblages (Coleoptera, Carabidae, Staphylinidae) in aspen-dominated mixedwood forests across north-central Alberta

Abstract

Epigaeic beetle assemblages were surveyed using continuous pitfall trapping during the summers of 1992 and 1993 in six widely geographically distributed locations in Alberta’s aspen-mixedwood forests prior to initial forest harvest. Species composition and turnover (β-diversity) were evaluated on several spatial scales ranging from Natural Regions (distance between samples 120–420 km) to pitfall traps (40–60 m). A total of 19,885 ground beetles (Carabidae) representing 40 species and 12,669 rove beetles (non-AleocharinaeStaphylinidae) representing 78 species was collected. Beetle catch, species richness, and diversity differed significantly among the six locations, as did the identity of dominant species. Beetle species composition differed significantly between the Boreal Forest and Foothills Natural Regions for both taxa. Staphylinidae β-diversity differed significantly between Natural Regions, whereas Carabidae β-diversity differed among locations. Climate variables such as number of frost-free days, dry periods, and mean summer temperatures were identified as significant factors influencing beetle assemblages at coarse spatial scales, whereas over- and understory vegetation cover, litter depth, shade, slope, and stand age influenced beetle assemblages at finer spatial scales. Significant interannual variation in assemblage structure was noted for both taxa. Because composition of epigaeic beetle assemblages differed across spatial scales, forest management strategies based only on generalized understanding of a single location will be ineffective as conservation measures. In addition, site history and geographic variation significantly affect species distributions of these two beetle families across the landscape. Thus, we underscore Terry Erwin’s suggestion that biodiversity assessments focused on species assemblages at different spatial scales provide a sound approach for understanding biodiversity change and enhancing conservation of arthropod biodiversity.

Rapid recovery of boreal rove beetle (Staphylinidae) assemblages 16 years after variable retention harvest

“…In our study, perhaps 2009 was not conducive to mushroom growth, adversely affecting species like L. fungicola . Hammond et al (2021) reported that populations of many species of carabid and staphylinid beetles varied greatly in catch, even in successive years at the same sites. Thus, there is merit in sampling designs that include multiple years to minimize the effects of poorly understood annual variation.…”

Immediate effects of chemical and mechanical soil preparation techniques on epigaeic arthropod assemblages during reclamation of in situ oil and gas sites in northern Alberta, Canada

“…For instance, five ground beetle, nine rove beetle and 18 spider species appear to be forest specialists at these sites, and have been associated with forest stands in other studies in Alberta (Spence at al. 1997;Buddle and Draney 2004;Work et al 2004;Pinzon et al 2011;Pinzon et al 2012;Hammond et al 2018;Hammond et al 2021) The species found associated with borrow-pits fall into two categories, either true grassland species or species known to colonize recently disturbed areas. A total of 16 ground beetle, 28 rove beetle, and 30 spider species were collected almost exclusively from the borrowpits (Appendix A), however, only five species were identified as significant indicators of borrow-pits with an indicator value >0.80 (Table 2).…”

“…It seems that such biotic and structural components of the sites more directly influenced arthropod responses than did abiotic factors such as light penetration and temperature. Although abiotic environmental variables had a significant influence on epigaeic arthropod faunas when analysed at coarser spatial scales (Hammond et al 2021), such effects are often synergistic with biotic structural characteristics operating at finer spatial scales (Hammond et al 2018;Hammond et al 2021). For example, when the tree canopy and other understory elements are removed solar radiation and wind flow through the site increase, resulting in greater temperature fluctuations and moisture levels of the soil (Pearce and Venier 2006).…”