Leafing patterns and leaf exchange strategies of a cerrado woody community

Abstract

The deciduousness of tropical trees and communities depend on ecosystems characteristics such as plant species diversity, and strength of the dry season. Based on seven years of phenological observations, we provide the first long-term description of leafing patterns of a woody cerrado community, aiming to investigate (1) the leaf exchange strategies considering the interannual variation in the degree of deciduousness of individuals and species and quantify the community deciduousness; (2) the relationship between interannual patterns of leaf fall and leaf flush according to the species’ leaf exchange strategies and climate; (3) the onset of cerrado growing season and its relation to climate seasonality. To detect seasonality and leafing onset we applied circular statistics and to understand the relationships between environmental predictors and leaf exchange strategies, we used generalized additive models. From 106 species observed, we classified 69 as deciduous (26 species), semi-deciduous (25) or evergreen (18) and defined the studied cerrado as a semi-deciduous vegetation. Leaf phenology was markedly seasonal and similar among years. Leaf fall peaked in the dry season, and leaf flush in the dry-to-wet transition. Leaf fall patterns related to temperature and leaf flush to day length and rainfall. Semi-deciduous and deciduous species were more constrained by climate than the evergreen ones. The cerrado growing season started in the dry-to-wet season transition. Interannual variations in rainfall and temperature affected the individuals’ and, consequently, species’ degree of deciduousness, highlighting individual and species variability, and suggesting that cerrado leafing patterns are likely susceptible to future climate change scenarios.