TY - JOUR
T1 - Litter inputs and phosphatase activity affect the temporal variability of organic phosphorus in a tropical forest soil in the Central Amazon
AU - Schaap, Karst J.
AU - Fuchslueger, Lucia
AU - Hoosbeek, Marcel R.
AU - Hofhansl, Florian
AU - Martins, Nathielly Pires
AU - Valverde-Barrantes, Oscar J.
AU - Hartley, Iain P.
AU - Lugli, Laynara F.
AU - Quesada, Carlos Alberto
PY - 2021
Y1 - 2021
N2 - 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.
AB - 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.
KW - Amazon
KW - Hedley fractionation
KW - Leaf litter
KW - Lowland tropical forest
KW - Phosphatase activity
KW - Phosphorus cycle
U2 - 10.1007/s11104-021-05146-x
DO - 10.1007/s11104-021-05146-x
M3 - Article
AN - SCOPUS:85117224968
SN - 0032-079X
VL - 469
SP - 423
EP - 441
JO - Plant and Soil
JF - Plant and Soil
IS - 1-2
ER -