Research

Saproxylic Biodiversity:

• Collected 8,679 specimens, including nearly 300 species in 50 families

  • 254 species were deemed to be obligate or facultative saproxylics

• Most diverse beeltle families collected (includes non-saproxylics)

  • Staphylinidae (56 spp., excluding Aleocharinae)

  • Latridiidae (26 spp.)

  • Cryptophagidae (23 spp.)

  • Leiodidae (20 spp.)

  • Carabidae (18 spp.)

  • Elateridae (18 spp.)

  • Curculionidae (17 spp.)

  • Nitidulidae (17 spp.)

• Most abundant beetle species

  • the staphylinid, Eusphalerum pothos Mannerheim, (368 individuals)

  • a novel species of monotomid, Rhizophagus n.sp. 1, (347 individuals; near R. pseudobrunneus Bousquet, identity confirmed by Y. Bousquet)

  • two latridiid species, Cortinicara gibbosa Herbst, (334 individuals) and Melanophthalma pumila (LeConte), (278 individuals)

  • a nitidulid, Epuraea flavomaculata Mäklin, (242 individuals)

  • the curculionid ambrosia beetle, Trypodendron retusum (LeConte), (229 individuals)

• 47 new provincial records for Alberta

• 7 new species to science (to be described)

Results Summary - Deadwood Size:

• Species richness patterns vary depending on standardization method (as estimated from Mao-Tau interpolations of species density)

  • increased with diameter of log (per sample)

  • equal across various diameters (7 cm - 43 cm) of logs (per unit surface area)

• Species composition differed significantly by size class

• Saproxylic species were positively associated with large (≥ 25 cm) diameter logs

  • more indicator species

  • use of large logs greatly disproportionate to their availability in the study stands

• Large (≥ 25 cm) diameter logs had a lower density of predaceous beetles than smaller diameter logs

à Large diameter substrates provide unique habitats (possible refuge from predation pressure, longer habitat persistence, more stable microclimate, different fungal communities/decay dynamics, increased heterogeneity of microhabitats)

à Size of deadwood substrate is important for maintaining saproxylic beetle biodiversity

Results Summary - Deadwood Type & Decay:

• Beetle ssemblages from live trees, dead trees (snags), and logs were distinct

  • Live trees: 5 indicator species

For e.g., Epuraea terminalis, E. flavomaculata, E. truncatella, Phloeostiba lapponica

• • Snags: 33 indicator species

For e.g., Clypastraea lugubris, Cossonus pacificus, Megatoma perversa, Hemicoelus carinatus

• • Logs: 9 indicator species

For e.g., Cucujus clavipes, Corticaria elongata, Agonum retractum, Lathrobium washingtoni

• Beetle assemblages diverge (are more dissimilar) as logs and snags advance through the decay sequence

Results Summary - Collection Methods for Sampling Saproxylic Beetles:

• Collection methods vary greatly in performance across variables examined

  • species accumulation

  • targetted catch (saproxylic : non-saproxylic)

  • number of unique species caught

  • catch of mature beetles (adults : immatures)

  • diversity of feeding guilds represented

  • substrate specificity (ecological patterns detectable at substrate-scale)

  • setup costs (materials, person-hours)

• All methods contributed at least one unique species

• Saproxylic beetle assemblage structure depends greatly on Collection Method

à Studies need to select sampling methods carefully and appropriately

à There is much value in employing multiple methods (particularly those that sample different portions of the saproxylic community)