山西中部主要森林植被类型土壤碳密度研究

Study on Soil Carbon Density under Some Main Forest Types in the Central Part of Shanxi Province

基于49个土壤剖面和411个土壤样品的实测数据,分析了山西中部7种主要森林植被类型(天然山杨林TS、天然落叶松林TL、天然侧柏林TC、天然辽东栎林TD、天然油松林TY、人工油松林RY、人工刺槐林RC)的土壤有机碳(SOC)密度及其分布特征。研究结果如下:(1)7种森林植被类型的土壤容重总体平均值变化范围为0.91～1.27 g cm-3。(2)各森林植被类型SOC含量随土层深度增加而逐渐减少,二者之间的关系可用指数函数描述(P<0.001),在30cm处的各森林植被类型SOC含量减幅最大,天然林的SOC含量均高于人工林。(3)各森林植被类型之间的SOC总密度变化范围为5.50～11.82kg m-2,表现为TL>TY>TD>TS>TC>RC>RY。(4)各森林植被类型SOC主要集中在0～50cm以上的土体中,分别占到土壤总有机碳密度的70.40%(TS)、67.19%(TL)、92.61%(TC)、66.86%(TD)、71.66%(TY)、95.63%(RY)和53.74%(RC)。天然林SOC密度均大于人工林,这也意味着人工林在提高土壤SOC密度方面还具有巨大潜力,如果对该地区人工林进行长期严格封育管理,人工林将是这一地区一个巨大的碳汇。

Based on the data of 49 soil profiles and 411 soil samples, the SOC （soil organic carbon） storage and its distribution properties of seven types of warm temperate forest in the central part of Shanxi Province were studied in the paper. The seven types of warm temperate forest were natural P. davidiana （TS）, natural L. principis-rupprechtii （TL）, natural Platycladus orientalis （Linn.） Franeo （TC）, natural Quercus liaotungensis Koidz. （TD）, natural P. tabulaeformis Carr（TY）, plantation P. ta;bulaeformis Carr （RY） and plantation Robinia pseudoacacia L （RC）. The results were as follows. （1） The average values of soil bulk density of 7 types of forest vegetation changed in the range of 0.91 - 1.27 gcm^-3. （2） For all vegetation types, there was a negative correlation between the SOC contents and soil depths, which could be described by exponential functions （/9 〈 0.001）, and the depth of 30 cm was an inflection point for the change of SOC contents. The SOC contents of natural forests were higher than that of plantation forests. （3） The total density of SOC of 7 types of forest vegetation changed in the range of 5.50 - 11.82 kg m^-2, and it ordered as TL 〉 TY 〉 TD 〉 TS 〉 TC 〉 RC 〉 RY. （4） The SOC of 7 types of forest vegetation mainly concentrated in the 0 - 50 cm depths, which were 70.40 % （TS）, 67.19 % （TL）, 92.61% （TC）, 66.86 % （TD）, 71.66 % （TY）, 95.63 % （RY） and 53.74 % （RC） of the total SOC respectively. The SOC density of Natural forest was greater than that of the plantation. This also meant that the plantation had great potential on SOC content and it would be a huge carbon sink in the central part of Shanxi Province.