A comparison of saproxylic beetle occurrence between man-made high- and low-stumps of spruce (Picea abies)

The making of high-stumps in today's forestry is becoming more and more common and several studies of these have shown their high conservation value for many wood living species, especially saproxylic beetles. However, the amounts of dead wood and bark surface on high-stumps are small compared to the amount on the ordinary cut stumps and further there have been no studies on the fauna of ordinary cut stumps.By sieving bark from ordinary (low) stumps and high-stumps (at ground level and at breast height) of Norway spruce we investigated whether there were differences in the saproxylic beetle community between low-stumps, high-stumps at ground level and high-stumps at breast height. We also tested whether beetle species showed preferences for any of the three substrate types.A total of 10,984 saproxylic beetle individuals divided into 67 species, were collected from 128 low- and high-stumps on 16 clear-cuts in southern Sweden. The number of species found in high-stumps at ground level (53) was significantly higher than the numbers found in high-stumps at breast height (38) and low-stumps (39). Many of the caught species showed substrate preferences and an ordination showed that there are different beetle communities at the tree different substrate types.