Soil carbon dynamics following land-use change varied with temperature and precipitation gradients: evidence from stable isotopes.
Soil carbon dynamics following land-use change varied with temperature and precipitation gradients: evidence from stable isotopes.
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土地利用变化后的土壤碳动态随温度和降水梯度的变化而变化：来自稳定同位素的证据。
DOI：
10.1111/gcb.12886
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发表时间：
2015
影响因子：
11.6
通讯作者：
Xiaoli Cheng
中科院分区：
文献类型：
--
作者：
Kerong Zhang;Haishan Dang;Quanfa Zhang;Xiaoli Cheng
森林砍伐后土壤有机质（SOM）的动态变化对于评估区域或全球尺度的碳（C）收支和循环至关重要。全球土地利用变化涉及不同光合途径（例如C3和C4）的植被转化，这为使用稳定同位素技术量化SOM分解速率及其对气候条件的响应提供了独特的机会。我们综合了来自131个站点（包括87个森林砍伐观测和44个重新造林观测）的结果，这些结果来自36篇文献中发表的论文以及我们在中国秦岭的观测。基于13 C天然丰度分析，研究了土地利用变化后表层土壤（0-20 cm）新旧碳的动态变化，并分析了土壤有机碳（SOC）分解速率与气候因子的关系。我们发现，SOC分解速率显着增加，年均温度和降水量的造林网站，他们没有任何气候因素的毁林网站。年平均气温对土壤有机碳分解速率的指数模型（y= 0.0014e ~（0.1395）x）解释率为56%。新土壤碳的比例随着森林砍伐和重新造林而增加，而老土壤碳则表现出相反的趋势。造林后45.4年和毁林后43.4年，新土壤碳的比例超过老土壤碳的比例。在造林地，新土壤碳积累速率随年平均降水量和温度的增加而显著增加，而在毁林地，新土壤碳积累速率仅随年平均降水量的增加而显著增加。总的来说，我们的研究提供了证据表明，SOC分解速率随温度和降水而变化，从而意味着全球变暖可能会加速SOM分解。
Knowledge of soil organic matter (SOM) dynamics following deforestation or reforestation is essential for evaluating carbon (C) budgets and cycle at regional or global scales. Worldwide land‐use changes involving conversion of vegetation with different photosynthetic pathways (e.g. C3and C4) offer a unique opportunity to quantify SOM decomposition rate and its response to climatic conditions using stable isotope techniques. We synthesized the results from 131 sites (including 87 deforestation observations and 44 reforestation observations) which were compiled from 36 published papers in the literatures as well as our observations in China's Qinling Mountains. Based on the13C natural abundance analysis, we evaluated the dynamics of new and old C in top soil (0–20 cm) following land‐use change and analyzed the relationships between soil organic C (SOC) decomposition rates and climatic factors. We found that SOC decomposition rates increased significantly with mean annual temperature and precipitation in the reforestation sites, and they were not related to any climatic factor in deforestation sites. The mean annual temperature explained 56% of variation in SOC decomposition rates by exponential model (y= 0.0014e0.1395x) in the reforestation sites. The proportion of new soil C increased following deforestation and reforestation, whereas the old soil C showed an opposite trend. The proportion of new soil C exceeded the proportion of old soil C after 45.4 years' reforestation and 43.4 years' deforestation, respectively. The rates of new soil C accumulation increased significantly with mean annual precipitation and temperature in the reforestation sites, yet only significantly increased with mean annual precipitation in the deforestation sites. Overall, our study provides evidence that SOC decomposition rates vary with temperature and precipitation, and thereby implies that global warming may accelerate SOM decomposition.