地形因子对大兴安岭北端寒温带针叶林土壤有机碳储量的影响

The Influences of Topographic Factors on Soil Organic Carbon Storage in Cool Conifer Forest in the North of Great Xing'an Mountain

为研究地形因子对寒温带针叶林土壤有机碳储量的影响,本文选取黑龙江省大兴安岭北端(122°40'52″~126°20'03″E,51°40'46″~53°20'15″N)针叶林区,按照坡位、坡向差异,对称设置20块样地,采集1 m剖面内不同发生层土样进行有机碳含量测定。结果表明,研究区1 m土壤剖面内有机碳密度范围为8.14~23.39 kg/m2,有机碳含量及密度均为中等变异(O层除外)。土壤有机碳表层聚集特征明显,大部分集中于O层和A层。地形因子(坡位、坡向、坡度)对土壤有机碳含量及密度影响明显,有机碳含量及密度表现为下坡高于上坡,阴坡高于阳坡(AB层和B层除外),A层及1m剖面土壤有机碳密度随坡度增大而减小。由于阴下坡最有利于有机碳积累,所以应更好地利用优势地形,科学引导植被高效健康生长,充分发挥其生态效能。同时也可通过该研究为我国寒温带森林地区土壤有机碳储量及分布的准确估算提供科学依据。

In order to study the influences of topographic factors on soil organic carbon storage in cool conifer forest, soil samples were synmetrically collected from 20 plots in the north of Great Xing’an Mountain in Heilongjiang Province（ 122° 40 , 52＂ - 126° 20, 03＂ E ,51.40＇ 46＂ -53° 2 0 ＇ 15＂ N） . The content of organic carbon of different soil layers were measured on the basis of the difference of aspects and positions of the slope. The result showed that the organic carbon density within one - meter soil profile ranged from 8. 14 to 23. 39 kg · m^-2 and the organic carbon content and density belong to medium mutation except for 0 layer. Most of the soil or-ganic carbon concentrated obviously in the 0 layer and A layer. Besides, the storage and density of soil organic carbon were affected significantly by the terrain factors （the positions, aspects and gradients of the slope）. Both of them at downhill were significantly high-er than those at uphill, meanwhile ones at the shady slopes were higher than those at the sunny slopes （ except for AB layer or B lay-er） .At the same time, the profile of soil organic carbon density in A layer and 1 m profile decreased with increasing slope gradient. It is better to take good advantage of the terrain and make plants flourish to let them grow ecologically since the shady slopes and down-hill are the most favorable to the accumulation of organic carbon. In addition, this study also provides scientific basis for accurately as-sessing the storage and distribution of soil organic carbon in boreal forest.