Effects of dung beetles on decomposition of cattle dung in spring and autumn in a Seriphi-dium-dominated desert, China.

Abstract

To understand the decomposition of cattle dung in Seriphidium-dominated desert, the changes of dung physical and chemical properties were determined by setting different stacking times (0, 7, 29, 48, 58 h) in May (spring) and September (autumn), respectively. Mesh cage with different openings (no mesh cage, opening up and down, opening up, totally enclosed) were set up to explore the effects of different ecological functional groups of dung beetles on decomposition. The results showed that species richness of dung beetles in spring was significantly higher than that in autumn, and that the abundance of dung beetles in autumn was significantly higher than that in spring. The losses of moisture, total carbon, total nitrogen and total phosphorus in dung were mainly concentrated during 0-29 h in spring, being decreased by 39.4%, 13.9%, 32.1% and 26.7% at 29 h, respectively. Neutral detergent fiber and acid detergent fiber of the dung stacked for 58 h decreased significantly by 8.0% and 16.0% respectively. In autumn, moisture, neutral detergent fiber and acid detergent fiber decreased most rapidly during 0-7 h, being decreased by 85.6%, 10.2% and 20.2% at 7 h, respectively. The concentrations of neutral detergent fiber and acid detergent fiber increased during 7-58 h by 20.0% and 13.7%, respectively. The decomposition of total carbon, total nitrogen and total phosphorus mainly concentrated during 0-29 h, being reduced by17.5%, 55.0% and 64.8%, respectively. The mesh cage with different openings effectively prevented the entering of dung beetles from the corresponding ecological functional groups. With the increases of functional groups of dung beetles, the decomposition rate accelerated, with cattle dung of no mesh cage being significantly higher than other treatments. The species richness and abundance of dung beetles and the stacking time of dung significantly affected the decomposition of cattle dung.