IAI-Data-CRN_012_Austin_POSIT-DEC: The importance of position of senescent material on decomposition and nutrient release

At the same time, the importance of standing dead material, and the dynamic of recycling of this senescent material in arid and semiarid ecoystems is much less well understood. In addition, the importance of abiotic factors controlling decomposition in arid zones suggests that carbon and nutrient loss from standing dead material may be fundamentally different than that driven largely by biotic degradation.

We conducted an experiment in the Patagonian steppe in southern Argentina to examine the importance of position of senescent material on decomposition and nutrient release. While the vast majority of biotic activity occurs in shrub patches, we found that the fastest decomposition occurred in litter that was elevated aboveground, exposed to wind and solar radiation. The importance of abiotic drivers and the position of senescent plant material appear to be critical in determining carbon turnover in this ecosystem.