Soil greenhouse gas fluxes and C stocks as affected by phosphorus addition in a newly established Acacia mangium plantation in Indonesia

摘要

A 2-year-long monitoring experiment was conducted to determine the effects of phosphorus (P) addition on nitrous oxide (NO) emission, methane (CH) uptake and carbon (C) sequestration and decomposition in a newly established Acacia mangium plantation in South Sumatra, Indonesia. We established three large plots and prepared six control sub-plots and four sub-plots with P added in each large plot. Gas emissions were measured using a chamber method. We also measured selected physical and chemical parameters for soil, fresh leaves, litter layers, and the aboveground biomass of Acacia trees. Mean daily NO flux was reduced (0.42mgN mpodayp#) by P addition. The reduction in NO emissions resulting from P addition was likely to be due to the stimulation of root uptake of soil N and water, as suggested by the soil N and WFPS dynamics and correlations with NO fluxes. P addition significantly increased (25.6Mghap# 20monthsp#) the Acacia biomass, contributing to an increase (46.9Mg CO-e hap#) in C sequestration. P addition also stimulated soil C decomposition. Soil total C (TC) decreased significantly (0.14kgCmpo) in the second year of P addition; CO emissions from soil were also stimulated (0.29g C mpo dayp#) by P addition. P addition reduced (0.15mgC mpo dayp#) CH uptake significantly, although the difference was small.