Long-term phosphorus addition alleviates CO2 and N2O emissions via altering soil microbial functions in secondary rather primary tropical forests.
Long-term phosphorus addition alleviates CO2 and N2O emissions via altering soil microbial functions in secondary rather primary tropical forests.
复制标题
DOI：
10.2139/ssrn.4225759
复制
发表时间：
2023-02
影响因子：
8.9
通讯作者：
Jie Chen;Xiao-kun Ma;Xiankai Lu;Han Xu;Dexiang Chen;Yanpeng Li;Zhang Zhou;Yide Li;Suhui Ma;K. Yakov
中科院分区：
文献类型：
--
作者：
Jie Chen;Xiao-kun Ma;Xiankai Lu;Han Xu;Dexiang Chen;Yanpeng Li;Zhang Zhou;Yide Li;Suhui Ma;K. Yakov
热带森林土壤氮（N）丰富，但磷（P）贫乏，对全球碳（C）和氮循环有不成比例的影响。虽然氮沉降大大改变了热带森林土壤中的C和N的保留，是否P输入可以减轻这些N诱导的影响，通过调节土壤微生物功能仍不清楚。研究了海南岛热带原生林和次生林土壤微生物分类和功能性状对10年N、P添加的独立和交互效应的响应。在原始林中，氮的添加促进了贫营养细菌和磷酸酶的生长，并富集了碳、磷矿化、硝化和反硝化的相关基因，表明氮过量时，磷限制加剧。这可能会刺激P挖掘通过有机质矿化，并加强N的损失，从而增加土壤CO2和N2 O排放量的86%和110%，分别。磷和NP的添加主要是由于强化了碳限制而提高了碳采矿酶的活性，导致CO2排放量增加82%。在次生林中，P和NP的添加降低磷酸酶活性，丰富的真菌共生体和增加的微生物生物量，这表明去除营养缺乏和刺激真菌生长。同时，由于减少了有机质分解对P的吸收，增加了微生物对C、N的固定，土壤CO2排放量减少了25%，N2 O排放量减少了52-82%.总的来说，N添加加速了热带森林中C和N释放的大多数微生物过程。长期的磷添加增加C和N的保留，通过减少土壤中的CO2和N2 O的排放量在次生林，但不是主要的森林，因为强大的C限制微生物N固定。此外，在未来的研究中，应考虑在CO2和N2 O排放的季节和年度变化，以测试这些研究结果的推广和预测和模型动态的温室气体排放和C和N循环。
Tropical forests, where the soils are nitrogen (N) rich but phosphorus (P) poor, have a disproportionate influence on global carbon (C) and N cycling. While N deposition substantially alters soil C and N retention in tropical forests, whether P input can alleviate these N-induced effects by regulating soil microbial functions remains unclear. We investigated soil microbial taxonomy and functional traits in response to 10-year independent and interactive effects of N and P additions in a primary and a secondary tropical forest in Hainan Island. In the primary forest, N addition boosted oligotrophic bacteria and phosphatase and enriched genes responsible for C-, P-mineralization, nitrification and denitrification, suggesting aggravated P limitation while N excess. This might stimulate P excavation via organic matter mineralization, and enhance N losses, thereby increasing soil CO2 and N2O emissions by 86% and 110%, respectively. Phosphorus and NP additions elevated C-mining enzymes activity mainly due to intensified C limitation, causing 82% increase in CO2 emission. In secondary forest, P and NP additions reduced phosphatase activity, enriched fungal copiotrophs and increased microbial biomass, suggesting removal of nutrient deficiencies and stimulation of fungal growth. Meanwhile, soil CO2 emission decreased by 25% and N2O emission declined by 52-82% due to alleviated P acquisition from organic matter decomposition and increased microbial C and N immobilization. Overall, N addition accelerates most microbial processes for C and N release in tropical forests. Long-term P addition increases C and N retention via reducing soil CO2 and N2O emissions in the secondary but not primary forest because of strong C limitation to microbial N immobilization. Further, the seasonal and annual variations in CO2 and N2O emissions should be considered in future studies to test the generalization of these findings and predict and model dynamics in greenhouse gas emissions and C and N cycling.