Phosphorus and litter decomposability traits in tropical forest ecosystems under changing environment: A synthesis

Abstract

Tropical forests are the most productive and most vulnerable terrestrial ecosystems facing environmental changes. These ecosystems substantially control global nutrient cycling. Although our understanding of carbon and nitrogen cycling has considerably improved during the past decades, phosphorus cycling in tropical forests still remains poorly understood. Tropical forests are characterized by severe phosphorus limitation and very high productivity at the same time. This suggests that tropical plants must have the capacity to adapt to such nutrient-poor environments, which should be reflected in the nutrient concentration of plant tissues via their phosphorus resorption efficiencies and the overall phosphorus cycling. This chapter aims to provide the general patterns and mechanisms of phosphorus cycling in tropical forests. Based on the available evidence, we first overview the general nutrient cycling pattern, then highlight the mechanisms of phosphorus control, and finally discuss the possible responses to climate change. Actually, phosphorus cycling involves soil, plant biomass, and litter as the storage components, and recycling of phosphorus takes place among these components. However, due to substantial loss of nutrients, the cycling of phosphorus tends to slow down with time. Studies involving the external supply of phosphorus have suggested a considerable enhancement in the phosphorus cycle, but this enhancement could not sustain over time. Climatic factors generally control many processes of nutrient cycling; therefore, ongoing climate change has been expected to alter the phosphorus cycling in the tropical forests as well. The available evidence suggests that warm-moist conditions will favor faster litter decomposition rates, whereas seasonality in precipitation will slow down the nutrient cycling. Therefore, in this chapter, we tried to answer how litter decomposability traits and the addition of phosphorus nutrient are controlling the cycling of nutrients in the tropical forest ecosystems under changing environmental conditions.

Abhishek Kumar

Senior Research Fellow

My research interests include plant ecology, restoration ecology and soil ecology.