Foliar chemistry and standing folivory of early and late-successional species in a Bornean rainforest

Abstract

Background: Few studies have investigated the chemical, morphological and physiological foliar traits and the intensity of standing folivory in a representative set of species of tropical rainforests including species of different successional stages. Aims: (i) To quantify leaf elemental composition, leaf phenolics and tannin concentrations, physical leaf traits and the intensity of standing folivory in a representative set of species of different successional stages in a Bornean tropical rainforest, and (ii) to investigate the relationships among leaf traits and between leaf traits and accumulated standing folivory. Methods: Analyses of leaf elemental concentrations, phenolics (Ph) and tannin (Tan) concentrations, leaf mass area (LMA), C assimilation rate and accumulated standing folivory in 88 common rainforest species of Borneo. Results and Conclusions: Accumulated standing folivory was correlated with the scores of the first axis of the elemental concentrations principal component analysis (mainly loaded by K and C:K and N:K ratios) with lower accumulated standing folivory at high leaf K concentrations (R = –0.33, P = 0.0016). The results show that consistent with growth rate hypothesis, fast-growing pioneer species have lower leaf N:P ratios than late-successional species, that species with higher leaf N concentration have lower LMA according with the ‘leaf economics spectrum’ hypothesis, and that species with lower leaf nutrient concentration allocate more C to leaf phenolics. This study also shows that species with different ecological roles have different biogeochemical ‘niches’ assessed as foliar elemental composition.