皆伐对不同坡度及结构的林分土壤理化性状的影响

Effect of clear-cutting on soil physical and chemical properties in artificial forest lands on different slopes and forest stands

选择人工林伐区3种不同坡度和4种不同结构林分的林地作为试验地,研究分析各种林地皆伐作业前后土壤理化性状的变化情况。结果表明:皆伐后除土壤容重和结构体破坏率2项指标增大外,其余土壤理化性质指标均下降。土壤持水性能变差,孔隙度减小,养分含量降低,且土壤理化性质的变化幅度与林地坡度大小及林分结构有关。主成分分析结果表明:皆伐对不同坡度林地土壤理化性质的干扰程度,由大到小依次为30°的林地、23°的林地和16°的林地;皆伐对不同结构林分林地土壤理化性状的干扰影响,由大到小依次为短轮伐期阔叶林(尾叶桉纯林)林地、杉阔混交林林地、马杉混交林林地和杉木纯林林地。从有利于环境保护,减少采伐作业对不同坡度和不同结构林分林地土壤理化性状影响的角度,提出了相应的技术措施。

Three slope gradients and four forest stands were selected as experimental plots. Changes in soil physical and chemical properties under the forest lands were analyzed after clear-cutting. The results show a decline in soil physical and chemical properties, and an increasing in soil bulk density and soil structure degradation. Soil water-holding capacity, porosity and nutrient content generally decline after clear-cutting. The degree of change in soil physical and chemical properties is related with slope gradient and forest structure. Field slope gradients are ordered as 30° 〉 23° 〉 16° by the degree of clear-cutting disturbance effect on soil physical and chemical properties through principal component analysis, and forest stand structures are ordered as Eucalyptus urophylla plantation 〉 artificially mixed forests of Cunninghamia lanceolata and broadleaf trees 〉 artificially mixed forests of Pinus massoniana, C. lanceolata 〉 C. lanceolata plantation. Based on environmental protection and preservation of soil physical and chemical properties under different field slopes and forest structures, sustainable measures are put forward.