Response of saprophagous wood-boring beetles (Coleoptera: Cerambycidae) to severe habitat loss due to logging in an aspen-dominated boreal landscape

Logging significantly reduces the proportion of late-seral stands in managed boreal landscapes. Availability of habitat elements typical of these stand types, such as standing dead wood, decreases, and dependant species may have their abundance reduced or become locally extirpated, potentially affecting the ecosystem processes/services in which they take part. We evaluated the impact of habitat loss on saprophagous wood-boring beetles (Coleoptera: Cerambycidae) in an aspen-dominated landscape intensively logged for the past 30 years. Sixty natural snags of middle decay class were chosen along a gradient of habitat loss and disturbance age, cut down and dissected for beetle larvae. We then assessed relationships between species occurrence and percentage of residual cover and age of disturbance at spatial scales ranging from 40 to 2000 m radii. The most common species, Anthophylax attenuatus, showed no response, being abundant regardless of the intensity of habitat loss. The second most common species, Bellamira scalaris, showed a negative response, especially in sites which had been fragmented for a longer time. A third species, Trachysida mutabilis, showed an inverse trend, having a higher probability of presence where habitat loss was more severe. Our study shows that some saprophagous wood-borers do react negatively to habitat loss, but that within a relatively homogenous group the response can vary significantly between species. Saprophagous wood-borers should be considered potentially sensitive to habitat loss, and their response to fragmentation remains to be evaluated on a longer time frame.