Do tree species characteristics influence soil respiration in tropical forests? A test based on 16 tree species planted in monospecific plots

The high spatial variability of soil respiration in tropical rainforests is well evaluated, but influences of biotic factors are not clearly understood. This study underlines the influence of tree species characteristics on soil respiration across a 16-monospecific plot design in a tropical plantation of French Guiana. A large variability of soil CO(2) fluxes was observed among plots (i.e. 2.8 to 6.8 mu mol m(-2) s(-1)) with the ranking being constant across seasons. There were no significant relationships between soil respiration and soil moisture or soil temperature, neither spatially, nor seasonally. The variability of soil respiration was mainly explained by quantitative factors such as leaf litterfall and basal area. Surprisingly, no significant relationship was observed between soil respiration and root biomass. However, the influence of substrate quality was revealed by a strong relationship between soil respiration and litterfall P (and litterfall N, to a lesser extent).