湘中丘陵区不同经营类型毛竹林土壤有机碳垂直分布与季节动态

Vertical Distribution and Seasonal Dynamics of Soil Organic Carbon of Phyllostachy edulis Forests Under Different Managing Patterns in the Hilly Region of Central Hunan Province,Southern China

研究了湘中丘陵区不同经营类型毛竹笋用林(Ⅰ)、笋材兼用林(Ⅱ)、材用林(Ⅲ)土壤有机碳质量分数、储量的垂直分布、季节动态及与土壤温度、湿度的关系。结果表明:笋用林、笋材兼用林和材用林土壤平均土壤有机碳(SOC)质量分数分别为15.06～28.26、15.18～28.22和14.04～28.95 g.kg-1,储量为95.42～178.35、104.43～193.55和84.00～173.63 t.hm-2;在垂直分布上,不同类型毛竹林有机碳质量分数、碳储量随土壤深度增加而下降,0～20 cm土层是土壤有机碳的主要分布区;在季节动态上,不同类型毛竹林有机碳质量分数、碳储量均以1月最高,7月最低;在一定范围内,土壤温度上升、湿度增加将加速土壤有机碳的分解和矿化进程,土壤有机碳与土壤温度、湿度均呈现显著负相关性;土壤温度、湿度对土壤有机碳的影响符合对数模型,两者的耦合作用符合线性关系。

Based on the plot data of shoot utilizing （I）, shoot and timber utilizing （II） ＂and＂ timber utilizing （III） of Phyllostachy edulis forests located at the hilly region in central Hunan, a research was conducted to investigate vertical distribution, seasonal dynamics and relationship with soil temperature and moisture of soil organic carbon （SOC）. The average SOC contents of type I, II and III are 15.06-28.26 g · kg^-1 , 15.18-28.22 g · kg^-1 and 14.04-28.95 g · kg^-1 , respectively, and the storages are 95.42-178.35 t· hm^-2 , 104.43-193.55 t · hm^-2 and 84.00-173.63 t · hm^-2 , respectively. The vertical distribution shows that SOC contents and storages decrease with the increasing of the soil depth in three for- ests. The soil layer of 0-20 cm is the main distribution layer for SOC. For seasonal dynamics, SOC content and storage are the highest in January and the lowest in July. SOC is negatively related with the soil temperature and moisture, their rela- tionship can be described well by the logarithm model and the coupling effects of temperature and moisture on the SOC accord with the linear relation.