柳杉人工林采伐后不同土地利用类型初期土壤有机碳变化

Antecedent Change of Soil Organic Carbon in Clear-cut Cryptomeria fortunei Plantation

运用空间代替时间的方法研究了25年生柳杉人工林(对照)采伐后形成的柳杉人工幼龄林、经济林、苗圃地、皆伐迹地、农耕地5种土地利用类型初期土壤有机碳含量和碳储量变化。结果表明,5种土地利用类型和对照的土壤有机碳含量和碳储量均随土层的加深而降低;除经济林外,苗圃地、柳杉人工幼龄林、农耕地和皆伐迹地的土壤平均有机碳含量分别比对照降低了10.8%,28.1%,37.8%,40.1%;5种不同土地利用类型土壤碳储量排序为:皆伐迹地(214.2±17.0 t C/hm2)>经济林(191.3±13.4 t C/hm2)>柳杉人工幼龄林(173.5±15.1t C/hm2)>苗圃地(171.9±9.2 t C/hm2)>农耕地(132.7±12.1 t C/hm2),分别比对照(272.9±21.8 t C/hm2)减少了21.5%,29.9%,36.4%,37.0%,51.4%。人工林采伐后形成的不同土地利用类型,土壤有机碳含量和碳储量减小的程度与采伐后紧接着采取的人为措施有关。

With the method of multi-plots, we studied the contents and storages of soil organic carbon （SOC） in 25 years Cryptorneria fortunei plantation （CP） and that cleared for the infancy Cryptomeria fortunei plantation （IP）, economics forest （EF）, nursery （NU）, clear-cut （CC） and farmland （FL） about 5 years. The results indicated that： the contents and storages of SOC in five lands and CP decreased following the soil depth increased. Related to CP, the average SOC contents in NU, IP, FL and CC decreased 10.8%, 28.1%, 37.8% and 40. 1% respectively. The SOC storages was CC（214.2±17.0 t C/hm^2）〉EF（191. 3±13.4 t C/hm^2）〉IP （173.5±15.1 t C/hm^2）〉NU（171.9±9.2 t C/hm^2）〉FL（132.7±12.1 t C/hm^2）, and decreased about 21.5%, 29.9%, 36.4%, 37.0% , 51.4% of CP （272.9±21.8 t C/hm^2） respectively. At the beginning, the content and storage of SOC in deforested lands would decrease following Cryptomeria fortunei plantation cleared. However, the decreased degree of SOC could be affected by different management strategies.