Shi Li-jiang, Zheng Li-bo, Mei Xue-ying, Yu Li-zhong, Jia Zheng-chang
Department of Geography, Taiyuan Normal University, Taiyuan 030012, China.
Ying Yong Sheng Tai Xue Bao. 2010 Sep;21(9):2279-87.
By the methods of field sampling and laboratory analysis, this paper studied the variations of soil organic carbon (SOC) and total nitrogen (TN) contents and SOC density under different land use types in Shanghai. Significant differences were observed in the test parameters among different land use types. The SOC density was the highest in paddy field (3.86 kg x m(-2)), followed by in upland (3.17 kg x m(-2)), forestland (3.15 kg x m(-2)), abandoned land (2.73 kg x m(-2)), urban lawn (2.65 kg x m(-2)), garden land (2.13 kg x m(-2)), and tidal flat (1.38 kg x m(-2)). The assessment on the effects of three types of land use change on the test parameters showed that the conversion of paddy field into upland resulted in a significant decrease of SOC and TN contents and SOC density; the abandonment of farmland was not an effective way in improving SOC storage in the Yangtze Delta region with abundant water and heat resources, high soil fertility, and high level of field management; while the 4-5 years conversion of paddy field into artificial forestland decreased the SOC and TN contents and SOC density, suggesting that in a short term, the soil carbon sequestration effect of the conversion from paddy field to forestland was at a low level, due to the limitation of vegetation productivity.
通过野外采样和实验室分析方法，研究了上海不同土地利用类型下土壤有机碳（SOC）、全氮（TN）含量及SOC密度的变化。不同土地利用类型间的测试参数存在显著差异。SOC密度在水田中最高（3.86 kg·m⁻²），其次是旱地（3.17 kg·m⁻²）、林地（3.15 kg·m⁻²）、荒地（2.73 kg·m⁻²）、城市草坪（2.65 kg·m⁻²）、园地（2.13 kg·m⁻²）和潮滩（1.38 kg·m⁻²）。对三种土地利用变化对测试参数影响的评估表明，水田转变为旱地导致SOC和TN含量及SOC密度显著下降；在水热资源丰富、土壤肥力高且田间管理水平高 的长江三角洲地区，弃耕农田并非提高SOC储量的有效方式；而水田转变为人工林地4 - 5年后，SOC和TN含量及SOC密度下降，这表明短期内，由于植被生产力的限制，水田转变为林地的土壤碳固存效应处于较低水平。
