Spiders (Araneae) associated with downed woody material in a deciduous forest in central Alberta, Canada

1 Spiders (Araneae) were collected on and near downed woody material (DWM) in a Populus-dominated forest to determine if spiders utilize wood surfaces, and to ascertain the importance of DWM habitat and wood elevation for spider assemblages. 2 Over 10 000 spiders representing 100 species were collected. Although more spiders were collected on the forest floor, spider diversity was higher in traps located on wood surfaces than on the forest floor, and 11 species were collected more frequently on wood surfaces. 3 Spiders utilized DWM at different stages in their development. Female Pardosa mackenziana (Keyserling) (Lycosidae) carrying egg sacs were caught most often on the surface of DWM, possibly to sun their egg sacs. Additionally, the proportion of immature spiders was higher on the wood surface than on the forest floor. 4 Spiders collected on logs with and without bark were compared to assemblages collected on telephone poles to assess what features of DWM habitat may be important. Web-building species were seldom collected on telephone poles, suggesting that they depend on the greater habitat complexity provided by DWM. In contrast, hunting spiders did not distinguish between telephone poles and logs. 5 Fewer spiders and a less diverse fauna utilized elevated compared to ground-level wood. Additionally, Detrended Correspondence Analysis revealed that the spider community from elevated wood was distinguishable from the spider community from ground-level wood, and from the forest floor spider community.