SOIL RESPIRATION IN THE SEASONALLY DRY TROPICS NEAR TOWNSVILLE, NORTH-QUEENSLAND

The contribution of root respiration to total soil respiration has been examined in an Australian tropical semi-arid woodland. Respiration rates were estimated by measuring CO2released from untreated soil and from soil where roots had been severed and were extensivelydecomposed. The amount of C released as CO2by soil respiration was estimated to be3800 kg ha-1year-1, and by root respiration to be 1500 kg C ha-1year-1. Soil moisture wasfound to have a major effect on soil respiration, with temperature being less significant.Consequently, most respiratory activity in the soil was confined to the relatively short wetseason, with respiration rates being much lower during the dry season. © 1990 CSIRO. All rights reserved.