论文部分内容阅读
以位于亚热带丘陵区红壤的桃源县为例,通过对1979年第二次土壤普查资料和2011年实地采样分析的表层(0-20 cm)土壤有机碳数据进行对比,分析近32年来林地、稻田、旱地等几种不同利用方式土壤有机碳(SOC)的变化。结果表明,1979年研究区林地、稻田和旱地SOC含量平均值分别为13.10 g/kg、14.15 g/kg和11.17 g/kg,2011年分别为18.28 g/kg、18.89 g/kg和12.19 g/kg,近32年来稻田、林地和旱地土壤SOC含量分别增加了40%、33%和9%,以林地和稻田土壤的SOC增幅较大,而旱地土壤的增幅明显较小。林地、稻田和旱地土壤的平均SOC密度分别从1979年的32.82 t/hm~2、33.62 t/hm~2和28.99 t/hm~2增加到2011年的44.39 t/hm~2、43.50 t/hm~2和33.53t/hm~2,增长幅度分别为35%、29%和16%,增长速率分别为0.36 t/(hm~2.a)、0.31 t/(hm~2.a)和0.14 t/(hm~2.a),也是以林地和稻田土壤的增长幅度相对较高,分别是旱地土壤的2.6倍和2.2倍。可见,过去32年来亚热带丘陵区红壤不同利用方式土壤均表现为“碳汇”模式,在不同程度上贡献于该地区较强的有机碳积累,其中以林地和稻田土壤的贡献能力最强。
Taking Taoyuan County located in the red soils of subtropical hilly region as an example, the data of surface soil (0-20 cm) soil organic carbon in the second soil census data in 1979 and field sampling in 2011 were compared to analyze the changes of forest land, paddy field , Dry land and other different ways of utilization of soil organic carbon (SOC) changes. The results showed that in 1979, the SOC values of forestland, paddy field and dry land in the study area were 13.10 g / kg, 14.15 g / kg and 11.17 g / kg, respectively, and were 18.28 g / kg, 18.89 g / kg and 12.19 g / kg, SOC content of paddy field, woodland and dry land increased by 40%, 33% and 9% respectively over the past 32 years, while SOC of forestland and paddy soil increased more significantly, while dryland soil increased obviously less. The average SOC densities of woodland, paddy soil and dry land soil increased from 32.82 t / hm ~ 2,33.62 t / hm ~ 2 and 28.99 t / hm ~ 2 in 1979 to 44.39 t / hm ~ 2,43.50 t / hm ~ 2 and 33.53t / hm ~ 2 respectively, with the growth rates of 35%, 29% and 16%, respectively, and the growth rates were 0.36 t / (hm ~ 2.a) and 0.31 t / (hm ~ 2.a) 0.14 t / (hm ~ 2.a). The growth rates of forest land and paddy soil are also relatively high, which are respectively 2.6 times and 2.2 times of the dry land soil. It can be seen that in the past 32 years, the soil types under different utilization patterns of red soils in the subtropical hilly region all showed “carbon sink ” pattern, which contributed to the higher degree of accumulation of organic carbon in the region to varying extents, of which woodland and paddy soil contributed the most .