Soil Changes in Model Tropical Ecosystems: Effects of Stand Longevity Outweigh Plant Diversity and Tree Species Identity in a Fertile Volcanic Soil

摘要: Plant or community longevity can strongly influence soil fertility, yet it is seldom among the functional traits considered in studies of biodiversity and ecosystem functioning. For 11 years we tracked influences plant longevity, life-form richness, tree species identity on 12 chemical properties model ecosystems an allophanic Andisol humid lowlands Costa Rica. The design employed three levels longevity: 1 year 4 years (trees cut without biomass removal replanted to same species), uncut; two diversity (tree alone, plus palm giant perennial herb); eudicot, non-nitrogen (N)-fixing species. site’s proved remarkably resistant treatment-induced loss fertility. Although magnitude changes was low, most declined during early phases growth, then stabilized increased. greatest declines occurred stands shortest life span, where organic matter inputs were low leaching rates high. In contrast, massive depositions every sustained augmented surface-soil cation concentrations, pH, carbon (SOC), extractable phosphorus (P). An increase from one form led more SOC calcium (Ca), whereas potassium (K) decreased due a effect: high K uptake by herb. notable tree-species effects concerned P: It increased under that had highest litterfall may facilitate apatite weathering; tissue-N concentrations. Through its exposure returns, exerted greater than either identity.