Tree growth periodicity in the ever‐wet tropical forest of the Americas

作者：Jorge A. Giraldo, Jorge I. del Valle, Sebastian González‐Caro, Diego A. David, Tyeen Taylor, Conrado Tobón, Carlos A. Sierra · 发表于：Journal of Ecology · 年份：2023 · DOI：10.1111/1365-2745.14069 · 被引用次数：29 · 研究领域：Tree-ring climate responses、Plant Water Relations and Carbon Dynamics、Geology and Paleoclimatology Research

Abstract The occurrence of annual growth rings in tropical trees—the result of the seasonal activity of vascular cambium—has been explained by seasonal water deficit or flooding periods. However, little is known about the drivers of annual tree‐ring formation under tropical hyper‐humid conditions without clear seasonal dry periods or flooding (ever‐wet conditions). Shelford's law states that the deficit or the excess of environmental resources limits plant growth. Accordingly, we hypothesize that excess soil moisture, a slight seasonal reduction of precipitation and a reduction in light availability determine rhythmic growth in ever‐wet tropical forests. We first assessed the occurrence of rhythmic growth in 14 tree species from the Biogeographic Chocó Region (annual rainfall 7200 mm) using three methods: Radiocarbon ( 14 C) dating (all studied species), tree‐ring synchronization (4 species that have replicates) and automatic dendrometers (two species). Then, we assessed the effect of environmental drivers (rainfall, short‐wave radiation, temperature and soil moisture) on tree growth based on tree ring and dendrometer observations. We present evidence of annual tree‐ring formation in all 14 studied tree species. Depending on the tree species, we observed positive and negative correlations between growth, water availability and light availability. These relationships suggest that both excess or deficit of environmental resources may explain the seasonal pattern of tree growth....