Journal Article

Litter inputs and phosphatase activity affect the temporal variability of organic phosphorus in a tropical forest soil in the Central Amazon

Hofhansl, Florian, Martins, Nathielly Pires, Schaap, Karst J., Hartley, Iain P., Quesada, Carlos Alberto, Valverde-Barrantes, Oscar J., Fuchslueger, Lucia, Hoosbeek, Marcel R., Lugli, Laynara F.

2021

Overview

Purpose The tropical phosphorus cycle and its relation to soil phosphorus (P) availability are a major uncertainty in projections of forest productivity. In highly weathered soils with low P concentrations, plant and microbial communities depend on abiotic and biotic processes to acquire P. We explored the seasonality and relative importance of drivers controlling the fluctuation of common P pools via processes such as litter production and decomposition, and soil phosphatase activity. Methods We analyzed intra-annual variation of tropical soil phosphorus pools using a modified Hedley sequential fractionation scheme. In addition, we measured litterfall, the mobilization of P from litter and soil extracellular phosphatase enzyme activity and tested their relation to fluctuations in P- fractions. Results Our results showed clear patterns of seasonal variability of soil P fractions during the year. We found that modeled P released during litter decomposition was positively related to change in organic P fractions, while net change in organic P fractions was negatively related to phosphatase activities in the top 5 cm. Conclusion We conclude that input of P by litter decomposition and potential soil extracellular phosphatase activity are the two main factors related to seasonal soil P fluctuations, and therefore the P economy in P impoverished soils. Organic soil P followed a clear seasonal pattern, indicating tight cycling of the nutrient, while reinforcing the importance of studying soil P as an integrated dynamic system in a tropical forest context.

• Publisher: Springer Science + Business Media,Springer International Publishing,Springer,Springer Nature B.V
• Subject: Agriculture / Amazonia / Analysis / Annual variations / Biomedical and Life Sciences / Decomposition / Ecology / Enzymatic activity / Enzyme activity / Fluctuations / Forest productivity / Forest soils / Fractionation / Fractions / Life Sciences / Litter / Litter fall / Methods / Microbial activity / Microorganisms / Nutrient cycles / Organic phosphorus / Organic soils / ORIGINAL ARTICLE / Phosphatase / Phosphatases / Phosphorus / Phosphorus content / Phosphorus cycle / Plant communities / plant litter / Plant Physiology / Plant Sciences / Regular Article / seasonal variation / Seasonal variations / Separation (Technology) / Soil dynamics / soil organic phosphorus / Soil Science & Conservation / Soils / Tropical environments / Tropical forests / Tropical soils / uncertainty