广州典型森林土壤有机碳库分配特征

 对广州2种典型森林土壤碳库分配特征进行了研究，结果表明：① 两种森林土壤有机碳（SOC）表层含量及其差异程度最高，随土壤深度增加，差异逐渐减小。马尾松林SOC密度范围为55.54～66.69 t/hm²，常绿阔叶林SOC范围为84.91～151.16 t/hm²。② 两种森林土壤活性有机碳（AOCs）含量为马尾松林<常绿阔叶林；各种AOC分配比例均随龄级增长而升高。③ 两种森林土壤的水溶性有机碳（WSC）、易氧化态碳（EOC）和微生物量碳（MBC）含量分别与SOC相关性达到极显著水平，轻组碳（LFC） 与颗粒性碳（POC）含量分别与SOC相关性达到显著水平。④ 幼龄林与中龄林的土壤碳库大于相应的地上部植被碳库，而成龄林的土壤碳库小于植被碳库；土壤碳库占森林生态系统总碳库的比例随着生物量的增长呈下降趋势。

Allocation Characteristics of Organic Carbon Pool in Typical Forest Soils in Guangzhou

Allocation characteristics of soil carbon pool for two types of subtropical forests in Guangzhou were studied in this paper. The following results were obtained(1)Soil organic carbon (SOC) contents and difference were at the highest level in soil surface layers and the difference fell off gradually downwards along the forest soil profile. SOC density of Pinus massoniana forest ranged from 55.54 t/hm² to 66.69 t/hm² while that of evergreen broad-leaved forest ranged from 84.91 t/hm² to 151.16 t/hm². (2) Active organic carbon (AOC) contents in soil surface layers were lower in Pinus massoniana forest than in evergreen broad leaved forest. Allocation ratio of all kinds of AOCs increased with the rise of age class. (3) The correlations between water-soluble carbon (WSC) and SOC, easily oxidizable carbon (EOC) and SOC, microbial biomass carbon (MBC) and SOC were all at the most significant level (P<0.01), while between light fraction carbon (LFC) and SOC, particulate organic carbon (POC) and SOC, were all at significant level (P<0.05). (4) Storage of soil carbon was higher than that of forest vegetation carbon pool in young and middle age forests, which was contrary to the conclusion in mature forest. Furthermore, the ratio of soil carbon pool/forest ecosystem carbon pool decreased with the rise of biomass.