Warming drives sustained plant phosphorus demand in a humid tropical forest

Abstract

Phosphorus (P) is often one of the most limiting nutrients in highly weathered soils of humid tropical forests, which may regulate the responses of carbon (C) feedback to climate warming. Based on a 7-year continuous field warming experiment conducted by translocating microcosm forest ecosystems from a high-elevation site to low-elevation sites, we detected changes in the ecosystem P cycle in response to warming. We report that warming drives sustained plant P demand by increasing P uptake and thus decreasing foliar N:P. This increased plant P content is supplied by multiple processes including enhanced plant P resorption, soil P mineralization and dissolution without changing litter P mineralization and leachate P. These findings suggest that warming may alleviate initial P deficiency and/or limitation of plant growth and contribute to sustaining plant C fixation in these tropical forests.