Abstract:
The distribution of tropical forest biomass across the landscape is poorly understood, particularly in increasingly
common secondary tropical forests. We studied the landscape-scale distribution of edaphic properties, plant community char-
acteristics, and aboveground biomass (AGB) in secondary tropical dry forests in northwest Costa Rica. We used structural
equation modeling to examine conceptual models of relationships among these factors, with data from 84 0.1 ha plots. Stand age
and soils explained 33%–60% of the variation in community-weighted mean values of foliar traits including specific leaf area,
foliar nitrogen, phosphorus, and
!
13
C. Aboveground biomass ranged from 1.7 to 409 Mg·ha
−
1
among plots between 5
and >100 years old. Stand age alone explained 46% of the variation in AGB among plots, while a model including age, soil pH,
traits, and forest type explained 58%. Stand age was the most important variable explaining the distribution of AGB and
community characteristics in secondary forests. We speculate that plot size, landscape heterogeneity, disturbance history, and
stand dynamics contribute to the unexplained variation in AGB across the landscape.
