燕山北部山地典型植物群落土壤有机碳贮量及其分布特征

Soil Organic Carbon Storage and Its Distribution of the Typical Communities in the North Region of Yanshan Mountain

基于36个土壤剖面的实测数据,对燕山北部地区由于不同的人类活动所形成的4种典型群落类型的土壤有机碳含量及其分布规律进行了研究。研究结果表明,处于频繁人畜干扰条件下的绣线菊灌丛各土层有机碳含量都明显低于处于封育状态下的三种群落类型(榛子灌丛、次生杨桦林、人工落叶松林)(p<0.05),而后三者之间没有显著差异(p>0.05);土壤总有机碳密度的变化也有类似的趋势,榛子灌丛、天然次生杨桦林和人工落叶松林分别为绣线菊灌丛的2.60,2.97,3.10倍;在几种群落类型中,土壤有机碳含量随土层深度的增加而呈现逐渐递减的趋势,二者之间的关系可用指数函数加以描述(p<0.01),大约40cm的土层深度是土壤有机碳含量变化的拐点;燕山北部各群落类型(绣线菊灌丛除外)土壤有机碳含量及碳密度明显高于我国相应群落类型的平均水平,也高于燕山南部及太行山中部和南部的各群落类型,但低于东北部山地。由研究结果可得出结论,燕山北部地区森林土壤具有较高的有机碳贮量,人畜干扰对土壤有机碳含量及碳贮量具有明显影响,而且影响不仅限于浅层;在排除外来干扰的情况下,不同群落类型土壤有机碳贮量差异不大,排除人畜干扰是维持该地区土壤有机碳贮量的关键因素。

Based on the datum from 36 soil profiles,the SOC（soil organic carbon） storage and its distribution properties of four types of communities from different human actives in the north region of Yanshan mountain were studied in the paper. The result showed that because of heavy disturbances from human and live-stock,the Spiraea pubescens shrub was lower than the other three types of communities under closure （including Corylus heterophylla shrub,secondary poplar-birch forest and larch plantation） in SOC content of all soil layers remarkably（p〈0.05）,and there was no remarkable difference among the latter three types of communities（p〉0.05）. Similar to the variation in SOC contents of the communities,the total SOCD（soil organic carbon density） of Corylus heterophylla shrub,secondary poplar-birch forest and larch plantation was 2.60,2.97,3.10 times as that of the Spiraea pubescens shrub respectively. For all types of communities,there was a negative correlation between the SOC content and the depth of soil,which could be described by exponential function（p〈0.01）,and the depth of about 40cm was a inflection point for the change of SOC content. The SOC content and SOCD of the communities in this region（except the Spiraea pubescens shrub）were higher than that of the corresponding communities of China in average and the south region of Yanshan mountain,middle and south part of Taihang mountain,but lower than that of northeast region of China. It is concluded that the SOC storage of the communities in the north region of Yanshan mountain is remarkable,and the disturbances from human and live-stock affect the SOC content and SOCD in the region significantly,not only in the superficial layer of soil but also in the deeper layer; when disturbances from human and live-stock are eliminated,there is no remarkable difference in the SOC content and SOCD among the different communities. Removing the disturbances can help to maintain a higher SOC storage.