Tuesday, August 7, 2007

PS 24-28: Fine root decomposition in ponderosa pine forests

Valerie J. Kurth1, Kevin C. Grady2, and Stephen C. Hart1. (1) Northern Arizona University, (2) University of California - Davis

Fine root dynamics are notoriously difficult to study, but knowledge of them is imperative to our understanding of nutrient cycling and carbon allocation patterns in forest ecosystems.  We assessed relative rates of fine root decomposition using trenched plots in forest stands that had previously undergone management treatments (unmanaged, thinned, thinned/burned, and wildfire).  Fine root biomass and microbial carbon were compared inside and outside of the trenches after 5 and 27 months.  Significant trench and stand treatment effects were observed in fine root biomass and microbial carbon.  Relatively high rates of fine root decomposition compared to foliage suggest that fine root turnover is important to nutrient availability in these ecosystems.