Responses of soil nitrogen and phosphorus cycling to drying and rewetting cycles: A meta-analysis
Responses of soil nitrogen and phosphorus cycling to drying and rewetting cycles: A meta-analysis
复制标题
土壤氮磷循环对干燥和再湿润循环的响应：荟萃分析
DOI：
10.1016/j.soilbio.2020.107896
复制
发表时间：
2020-09-01
影响因子：
9.7
通讯作者：
Hagedorn, Frank
中科院分区：
文献类型：
--
作者：
Gao, Decai;Bai, Edith;Hagedorn, Frank
气候变化引起的土壤干湿变化可能影响陆地生态系统中土壤氮磷循环。土壤N和P循环的干燥和再湿润循环的反应可以与干燥-再湿润模式，实验方法，生态系统和土壤类型，从而使这些研究的综合理解机制和预测未来对气候变化的反应是必要的。在这里，我们汇编了来自79项研究的1882个观测数据，用于对土壤N和P库和通量对干燥和再湿润的响应以及这些响应如何通过实验条件进行修改进行荟萃分析。结果表明：1）实验干燥使土壤中的NH 4+、可提取有机氮（EON）和有效磷分别显着增加了22%、27%和72%。与此相反，土壤NO3-，酶活性，微生物量，净硝化作用，N2 O排放量显着下降了37，13-21，21-28，39，和93%，分别。2)在土壤复湿后，土壤EON、可提取有机磷（EOP）、净氮矿化、硝化作用、磷酸酶活性、溶解性有机氮淋溶、溶解性无机磷淋溶和N2 O排放量分别显著增加59%、27%、19%、15%、12%、60%、116%和218%。而土壤NO3-和NO3-淋溶量分别显著降低了9%和74%。土壤微生物氮和磷以及酶活性恢复干旱期间的复湿阶段。干燥和再润湿的平均效应大小一般随干燥强度的增加而增加，这可能也是实验室中观察到的效应大小大于田间试验的主要原因。我们的荟萃分析表明，有效磷的干燥和再润湿比矿物N，同意更大的影响大小比N淋失的P更强的积极响应。这表明，干燥和回湿引起的N和P之间的不平衡，这是更明显的土壤从森林比从农业系统。总的来说，这些结果意味着，干旱的频率和强度的预期增加可能会破坏磷和氮的循环，对养分的浸出和供应的植物和微生物与这些养分的后果。
Altered drying-rewetting patterns due to climate change may affect soil nitrogen (N) and phosphorus (P) cycling in terrestrial ecosystems. The responses of soil N and P cycling to drying and rewetting cycles can vary with drying-rewetting patterns, experimental methods, ecosystems, and soil types, thus making a synthesis of these studies necessary for understanding mechanisms and predicting future responses to climate change. Here, we compiled data of 1882 observations from 79 studies for a meta-analysis of the responses of soil N and P pools and fluxes to drying and rewetting and how these responses are modified by experimental conditions. Results showed that 1) experimental drying increased NH4+, extractable organic nitrogen (EON), and available P in the soil significantly by 22, 27, and 72%, respectively. In contrast, soil NO3-, enzymatic activities, microbial biomass, net nitrification, and N2O emissions significantly decreased by 37, 13-21, 21-28, 39, and 93%, respectively. 2) Upon rewetting of dried soil, soil EON, extractable organic phosphorus (EOP), net N mineralization, nitrification, phosphatase activity, dissolved organic N leaching, dissolved inorganic P leaching, and N2O emissions significantly increased by 59, 27, 19, 15, 12, 60, 116, and 218%, respectively, while soil NO3- and NO3- leaching significantly decreased by 9 and 74%, respectively. Soil microbial N and P as well as enzymatic activities recovered from drought during the rewetting phase. The mean effect sizes of drying and rewetting generally increased with drying intensity, which was probably also the main reason for greater effect sizes observed in laboratory than in field experiments. Our meta-analysis showed stronger positive responses of available P to drying and rewetting than mineral N, which agreed with greater effect sizes on P than on N leaching. This suggests that drying and rewetting induce an imbalance between N and P, which was more pronounced in soils from forests than from agricultural systems. Overall, these results imply that the expected increase in the frequency and intensity of droughts potentially decouples the cycling of P and N, with consequences for nutrient leaching and the supply of plants and microorganisms with these nutrients.