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RESEARCH ARTICLE (Open Access)

Foliar trait contrasts between African forest and savanna trees: genetic versus environmental effects

Franziska Schrodt A O , Tomas F. Domingues B P , Ted R. Feldpausch A Q , Gustavo Saiz C , Carlos Alberto Quesada D , Michael Schwarz E , F. Yoko Ishida D F , Halidou Compaore G , Adamo Diallo H , Gloria Djagbletey I , Fidele Hien G , Bonaventure Sonké K , Herman Toedoumg K , Loius Zapfack K , Pierre Hiernaux J , Eric Mougin J , Michael. I. Bird L , John Grace B , Simon L. Lewis A M , Elmar M. Veenendaal N and Jon Lloyd F R S
+ Author Affiliations
- Author Affiliations

A School of Geography, University of Leeds, LS2 9JT, UK.

B School of Geosciences, University of Edinburgh, EH8 9XP­, Scotland, UK.

C Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research, 82467, Garmisch-Partenkirchen, Germany.

D Instituto Nacional de Pesquisas da Amazonia, Manaus, Cx Postal 2223 – CEP 69080-971, Brazil.

E Fieldwork Assistance, PSF 101022, 07710, Jena, Germany.

F School of Tropical and Marine Sciences and Centre for Terrestrial Environmental and Sustainability Sciences, James Cook University, Cairns, Qld 4870, Australia.

G Institut de l’Environnement et de Recherches Agricoles, 04 BP 8645, Ouagadougou, Burkina Faso.

H Centre National des Semences Forestières, BP 2682, Ouagadougou, Burkina Faso.

I Ecosystem and Climate Change Division, Forestry Research Institute of Ghana, PO Box UP 63 KNUST Kumasi, Ghana.

J Géosciences Environnement Toulouse, Observatoire Midi-Pyrénées, 14, avenue Edouard Belin - 31400 Toulouse, France.

K Plant Systematic and Ecology Laboratory, Department of Biology, Higher Teachers’ Training College, University of Yaounde, PO Box 047, Yaounde Cameroon.

L School of Earth and Environmental Sciences and Centre for Terrestrial Environmental and Sustainability Sciences, James Cook University, Cairns, Qld 4870, Australia.

M Department of Geography, University College London, WC1E 6BT, UK.

N Centre for Ecosystem Studies, University of Wageningen, PO Box 47, 6700AA, Wageningen, Netherlands.

O Present address: Max Planck Institute for Biogeochemsitry, Postfach 10 0164 , 07701 Jena, Germany and iDiv, German Centre for Integrative Biodiversity Research, Halle-Jena-Leipzig, Deutscher Platz 5e,04103 Leipzig, Germany.

P Present address: Universidade de São Paulo, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Av Bandeirantes, 3900 , CEP 14040-901 , Bairro Monte Alegre , Ribeirão Preto, SP, Brazil.

Q Present address: College of Life and Environmental Sciences, University of Exeter, EX4 4RJ, UK.

R Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL6 7PY, UK.

S Corresponding author. Email: jonathan.lloyd@imperial.ac.uk

Functional Plant Biology 42(1) 63-83 https://doi.org/10.1071/FP14040
Submitted: 31 January 2014  Accepted: 9 July 2014   Published: 6 November 2014

Journal Compilation © CSIRO Publishing 2015 Open Access CC BY-NC-ND

Abstract

Variations in leaf mass per unit area (Ma) and foliar concentrations of N, P, C, K, Mg and Ca were determined for 365 trees growing in 23 plots along a West African precipitation gradient ranging from 0.29 to 1.62 m a–1. Contrary to previous studies, no marked increase in Ma with declining precipitation was observed, but savanna tree foliar [N] tended to be higher at the drier sites (mass basis). Generally, Ma was slightly higher and [N] slightly lower for forest vs savanna trees with most of this difference attributable to differences in soil chemistry. No systematic variations in [P], [Mg] and [Ca] with precipitation or between trees of forest vs savanna stands were observed. We did, however, find a marked increase in foliar [K] of savanna trees as precipitation declined, with savanna trees also having a significantly lower [K] than those of nearby forest. These differences were not related to differences in soil nutrient status and were accompanied by systematic changes in [C] of opposite sign. We suggest an important but as yet unidentified role for K in the adaption of savanna species to periods of limited water availability; with foliar [K] being also an important factor differentiating tree species adapted to forest vs savanna soils within the ‘zone of transition’ of Western Africa.

Additional keywords: foliar cations, leaf mass per unit area, leaf physiology, nitrogen, phenology, phosphorus, potassium, plant functional traits, tropical, West Africa, zone of transition.


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