title: Controls on foliar nutrient and aluminium concentrations in a tropical tree flora: phylogeny, soil chemistry and interactions among elements.
abstract: Foliar elemental concentrations are predictors of life-history variation and contribute to spatial patterns in biogeochemical cycling. We examined the contributions of habitat association, local soil environment, and elemental interactions to variation in foliar elemental concentrations in tropical trees using methods that account for phylogeny. We sampled top-soils and leaves of 58 tropical trees in heath forest (HF) on nutrient-poor sand and mixed dipterocarp forest (MDF) on nutrient-rich clay soils. A phylogenetic generalized least squares method was used to determine how foliar nutrient and aluminium (Al) concentrations varied in response to habitat distribution, soil chemistry and other elemental concentrations. Foliar nitrogen (N) and Al concentrations were greater for specialists of MDF than for specialists of HF, while foliar calcium (Ca) concentrations showed the opposite trend. Foliar magnesium (Mg) concentrations were lower for generalists than for MDF specialists. Foliar element concentrations were correlated with fine-scale variation in soil chemistry in phylogenetically controlled analyses across species, but there was limited within-species plasticity in foliar elemental concentrations. Among Al accumulators, foliar Al concentration was positively associated with foliar Ca and Mg concentrations, and negatively associated with foliar phosphorus (P) concentrations. The Al-accumulation trait and relationships between foliar elemental and Al concentrations may contribute to species habitat partitioning and ecosystem-level differences in biogeochemical cycles.
authors.affiliation: Environmental and Life Sciences Group, Faculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link, Bandar Seri Begawan, BE1410, Brunei Darussalam.
authors.forename: Faizah
authors.initials: F
authors.lastname: Metali
authors.forename: Kamariah
authors.initials: K
authors.lastname: Abu Salim
authors.forename: Kushan
authors.initials: K
authors.lastname: Tennakoon
authors.forename: David F R P
authors.initials: DF
authors.lastname: Burslem
mesh_terms: D000535:Aluminum / Q000378:metabolism*; D000704:Analysis of Variance; D002010:Brunei; D002244:Carbon / Q000378:metabolism; D017753:Ecosystem; D065928:Forests; D006863:Hydrogen-Ion Concentration; D016018:Least-Squares Analysis; D010802:Phylogeny; D018515:Plant Leaves / Q000378:metabolism*; D025341:Principal Component Analysis; D012987:Soil / Q000737:chemistry*; D014197:Trees / Q000378:metabolism*; D014329:Tropical Climate
chemical_list: D012987:Soil; D002244:Carbon; D000535:Aluminum
keywords: aluminium (Al) accumulators; foliar elemental and Al concentrations; heath forests; mixed dipterocarp forests; phylogeny; soil nutrient concentrations; tropical rain forests