祁连山青海云杉(Picea crassifolia)林浅层土壤碳、氮含量特征及其相互关系

为阐明祁连山青海云杉(Picea crassifolia)林分布带对其土壤碳、氮含量的影响,以分布在祁连山东段和西段的典型青海云杉林为研究对象,通过野外取样和室内分析,论述了青海云杉林浅层土壤碳、氮含量特征及其相互关系。结果表明:(1)祁连山东、西段土壤剖面有机碳含量均随土壤深度的增加而减小,但不同土层差异显著性不同,0~40cm含量分别为73.57±17.17g·kg-1和45.85±11.93g·kg-1;东、西段土壤剖面有机碳储量没有明显的变化规律,0~40cm有机碳储量分别为205.51±39.44t·hm-2和134.93±25.80t·hm-2。(2)祁连山东、西段土壤全氮含量随土层深度变化和不同土层差异显著性变化规律同土壤有机碳含量,0~40cm全氮含量分别为4.56±0.88g·kg-1和2.81±0.66g·kg-1;东、西段土壤全氮储量亦同土壤有机碳储量变化规律,0~40cm储量分别为12.77±2.08t·hm-2和8.38±1.56t·hm-2。(3)祁连山东、西段土壤剖面不同土层C/N比差异显著性变化规律相同,其C/N值分别为15.92±1.24和16.10±2.07;C/N比值大小主要取决于有机碳含量;线性分析表明,土壤有机碳与全氮含之间呈极显著的正相关关系,可用乘幂曲线模型Y=aXb较好地描述(p0.01)。上述研究结果可为祁连山水源涵养林建群种青海云杉林的经营和管理提供理论依据和数据支撑。

Characteristics and Interrelation of Shallow Soil Organic and Total Nitrogen of Picea crassifolia Forest in the Qilian Mountain,Gansu, China

In order to clarify distribution areas of Picea crassifolia forest impact on its soil carbon and nitrogen in the Qilian Mountain through horizontal scale, we selected typical P. crassifolia forest which lives in the eastern and western of the Qilian Mountain as research objects. Through field sampling and laboratory analysis, this paper discussed characteristics and coupling relationships of shallow soil organic and total nitrogen of P. crassifolia forest in the Qilian Mountain. The results showed that: (1)Organic carbon content decreases with the increasing depth of soil profile in the eastern and western of the Qilian Mountain, but significant differences between the soil layers are not identical. The organic carbon content of the soil layer were 73.57±17.17 g·kg^-1 and 45.85±11.93 g·kg^-1 at 0-40 cm. The organic carbon reserves of soil profile had no obvious changes rule in the eastern and western of the Qilian Mountain, the organic carbon reserves of the soil layer were 205.51±39.44 t·hm^-2 and 134.93±25.80 t hm^-2 at 0-40 cm. (2) Soil total nitrogen content change with soil depth and different soil and the significant change rule is the same with the soil organic carbon content changes rule. The total nitrogen content of the soil layer were 4.56±0.88 g·kg^-1 and 2.81±0.66 g·kg^-1 at 0-40 cm. The soil total nitrogen reserves change rule is the same with the soil organic carbon reserves change rule. The total nitrogen reserves of the soil layer were 12.77±2.08 t·hm^-2 and 8.38±1.56 t·hm^-2 at 0-40 cm. (3) Different soil layer C/N ratio with different significant change rule is the same in the eastern and western of the Qilian Mountain. The C/N values were 15.92±1.24 and 16.10±2.07 and the C/N ratio size mainly depends on the organic carbon content. The linear analysis showed that the soil organic carbon and total nitrogen content were significant positive correlation relationship between them, the regression model Y=aX^b(p<0.01) could be used to depict their correlations. The results are expected to provide theoretical basis and data to support the management and administration of water conservation forests edificators, P. crassifolia in the Qilian Mountain.