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The effect of P addition on organic C and N mineralization in soils (0~10 cm) from three forest types, pine (pinus massoniana) forest (PMF), pine and broad-leaved mixed forest (PBMF) and monsoon evergreen broad-leaved forest (MEBF), in Dinghushan, southern China, was studied based on indoor incubaiton. Soils were incubated at 25℃ for 28 wk or 1 wk. The results showed that the total CO2-C cumulative amount in the 28 wk incubation from PMF, PBMF and MEBF soil treated with100 mg P was 82.4％, 84.4％ and 102.8％of that from their control, respectively, and the amount treated with 2000 mg P was 107.2％, 101.2％和109.1％of that from their control, respectively; The CH4 cumulative amount from PMF, PBMF and MEBF soil treated with100 mg P was 69.9％, 102.7％ and 66.3％of that from their control, respectively, and the amount treated with 2000 mg P was -57.4％, 25.3％ and 22.4％of that from their control, respectively. The addition of P led to a short-term increase in CO2 and CH4 emission after P application, and the responses of CO2-C and CH4 evolution to P addition related to the added P concentration and forest types. The addition of P inhibited significantly organic N mineralization and N nitrification. The available N net production in the 1 wk incubation from PMF, PBMF and MEBF soil treated with100 mg P was less 37.06％, 39.60％ and 28.62％ than that from their control, respectively, the production treated with 2000 mg P was less 70.97%, 84.14% and 187.97％than that from their control, respectively; The nitrate net production from PMF, PBMF and MEBF soil treated with100 mg P was less 48.06％, 40.45％ and 28.03％than that from their control, respectively, the production treated with 2000 mg P was less 254.09%,115.32% and 238.50％ than that from their control, respectively. We suggested that the sorption of P to soil minerals must to be taken into account in the future research.
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