Fazhu Zhao, Jiao Sun, Chengjie Ren, Di Kang, Jian Deng, Xinhui Han, Gaihe Yang, Yongzhong Feng, Guangxin Ren
1] College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi, China [2] The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100 Shaanxi, China.
College of Life Science, Northwest A&F University, Yangling, 712100 Shaanxi, China.
Sci Rep. 2015 May 19;5:10195. doi: 10.1038/srep10195.
Changes in land use might affect the combined C, N and P stoichiometry in soil. The Grain-to-Green Program (GTGP), which converts low-yield croplands or abandoned lands into forest, shrub, and/or grassland, was the largest land reforestation project in China. This study collected the reported C, N and P contents of soil in GTGP zones to achieve the factors driving the changes in the C:N, C:P, and N:P values. The results showed that the annual average precipitation exerted significant effects on the C:P value, and on the N:P value became significant 20 years after the change in land use. The annual average temperature was the main factor affecting the C:N value during the first 10 years, while the annual average precipitation strongly affected this value afterwards. In addition, "Redfield-like" interactions between C, N, and P in the soil may exist. A linear regression revealed significant positive correlations between the C:N, C:P, and N:P values and the restoration age, temperature, and precipitation after a change in land use. Therefore large-scale changes in land use under the 'GTGP' program might significantly affect the C:N, C:P and N:P ratios in soil.
土地利用变化可能会影响土壤中碳、氮、磷的化学计量比。退耕还林工程是中国最大的土地造林项目，该工程将低产农田或荒地转变为森林、灌木和/或草地。本研究收集了退耕还林工程区域土壤中已报道的碳、氮、磷含量，以找出驱动碳氮比、碳磷比和氮磷比变化的因素。结果表明，年平均降水量对碳磷比有显著影响，而土地利用变化20年后，年平均降水量对氮磷比的影响变得显著。在最初的10年里，年平均气温是影响碳氮比的主要因素，而此后年平均降水量对该比值有强烈影响。此外，土壤中碳、氮、磷之间可能存在“类雷德菲尔德”相互作用。线性回归分析表明，土地利用变化后，碳氮比、碳磷比和氮磷比与恢复年限、温度和降水量之间存在显著正相关。因此，退耕还林工程下的大规模土地利用变化可能会显著影响土壤中的碳氮比、碳磷比和氮磷比。
