Biotic and abiotic controls on soil respiration in a biodiversity plantation in the tropics.

摘要

The Sardinilla plantation is a long-term facility for studying the links between tree species diversity and ecosystem function. Six native tree species were planted in 2001 in plots containing 1, 3 or 6 species. Soil respiration (SR) measurements were conducted from March to December 2004 on tree pairs. ANOVAs with repeated measure on days were used to test the main effects of species (monocultures), pair (single and two-species pairs), plot (pairs in monoculture, three-, and six-species plots), and season (dry vs. early wet season). ANCOVAs were run for each effect to determine possible biotic and abiotic covariates, including root, tree, and microbial biomass, soil moisture, surface temperature, and bulk density. Significant season and pair effects accounted for 89% and 2% of the variability in SR. Driven by soil moisture, SR increased seven fold during the seasonal transition. In the dry and wet season monocultures had significantly higher SR than two-species pairs.