Tree foliar chemistry in an African savanna and its relation to life history strategies and environmental filters

PLoS One. 2015 May 20;10(5):e0124078. doi: 10.1371/journal.pone.0124078. eCollection 2015.

Abstract

Understanding the relative importance of environment and life history strategies in determining leaf chemical traits remains a key objective of plant ecology. We assessed 20 foliar chemical properties among 12 African savanna woody plant species and their relation to environmental variables (hillslope position, precipitation, geology) and two functional traits (thorn type and seed dispersal mechanism). We found that combinations of six leaf chemical traits (lignin, hemi-cellulose, zinc, boron, magnesium, and manganese) predicted the species with 91% accuracy. Hillslope position, precipitation, and geology accounted for only 12% of the total variance in these six chemical traits. However, thorn type and seed dispersal mechanism accounted for 46% of variance in these chemical traits. The physically defended species had the highest concentrations of hemi-cellulose and boron. Species without physical defense had the highest lignin content if dispersed by vertebrates, but threefold lower lignin content if dispersed by wind. One of the most abundant woody species in southern Africa, Colophospermum mopane, was found to have the highest foliar concentrations of zinc, phosphorus, and δ(13)C, suggesting that zinc chelation may be used by this species to bind metallic toxins and increase uptake of soil phosphorus. Across all studied species, taxonomy and physical traits accounted for the majority of variability in leaf chemistry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Africa, Southern
  • Ecological and Environmental Phenomena*
  • Ecosystem
  • Geology
  • Grassland
  • Plant Leaves / chemistry*
  • Principal Component Analysis
  • Trees / chemistry*
  • Trees / physiology*
  • Tropical Climate

Grants and funding

This study was supported by the Andrew Mellon Foundation, Grantham Foundation for the Protection of the Environment, and the endowment of the Carnegie Institution for Science. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.