伏牛山南北坡针阔混交林土壤养分对比分析

Contrastive analysis of soil nutrients in coniferous and broad-leaved mixed forest on southern and northern slope of Funiu mountain

研究秦岭东段伏牛山南坡和北坡针阔混交林土壤的养分状况,有助于对该区森林土壤的保护及改良提供理论基础。在伏牛山南坡的宝天曼和北坡的白云山设置样地,分层采集土样,对比分析土壤有机质、全氮、速效磷、速效钾、pH值的分布特征及变异情况。结果表明:(1)伏牛山北坡土壤肥力水平高于南坡,除pH值小于南坡外,北坡的有机质、全氮、速效磷和速效钾平均含量分别比南坡高1.91 g/kg、0.41 g/kg、16.97 mg/kg、7.62 mg/kg;南坡和北坡土壤养分垂直分布均呈现出表聚性特征。(2)土壤pH值随土层的变化不明显,但略有上升。(3)各层土壤养分均表现为中等变异,变异系数在13%~69%之间。0~20 cm土层养分的变异系数相对较小。(4)伏牛山南坡和北坡的土壤养分含量与土层深度之间有着较显著的回归关系,R2在0.472~0.692之间。土壤pH值与土层深度之间的回归关系不显著。(5)相关分析表明,有机质与全氮呈极显著正相关,且与速效磷、速效钾之间存在不同程度的正相关关系,土壤养分与土壤pH值之间多呈负相关关系。

It is helpful to study the soil nutrient status in coniferous and broad-leaved mixed forest on the southern and northern slope of Funiu mountain, located in the eastern part of the Qinling mountains, which can provide a theoretical basis for the protection and improvement of forest soil in this area. Set up plots in Baotianman nature reserve on the southern slope and Baiyun mountain on the northern slope of Funiu Mountain, collecting soil samples. The distribution characteristics and variation of soil organic matter, total nitrogen, available phosphorus, available potassium and pH were analyzed and compared. The results showed that： The soil fertility level of the northern slope of Funiu Mountain was higher than that of the southern slope. Except for the pH value, the average contents of organic matter, total nitrogen, available phosphorus and available potassium in the northern slope were 1.91 g/kg, 0.41 g/kg, 16.97 mg/kg, 7.62 mg/kg higher than the southern slope respectively. The vertical distribution of soil nutrients on the southern slope and the northern slope showed a phenotypic characteristics. Soil pH did not change significantly with the soil layer, but increased slightly. The soil nutrient of each layer showed moderate variation, and the coefficient of variation was between 13%-69%. The coefficient of variation of 0-20 cm soil layer was relatively small. There was a significant regression relationship between soil nutrient content and soil depth on the southern slope and northern slope of Funiu Mountain, R2 was between 0.472-0.692. The regression relationship between soil pH and soil depth was not significant. Correlation analysis showed that organic matter was positively correlated with total nitrogen, and there was a positive correlation with available phosphorus and available potassium, and there was a negative correlation between soil nutrients and soil pH.