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

The importance of standing dead material, including coarse woody
debris in forests, has been shown to be important in the regeneration
of forests, and critical for maintaining a variety of ecosystem
processes. 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. These
data were collected as part of the project CRN 012 examining the
effects of biodiversity on ecosystem functioning, led by Dr. Osvaldo
Sala, with collaboration from Marina Gonzalez Polo, Lucia Vivanco and
Victoria Marchesini.