间伐对杉木林下地被物多样性及土壤理化性质的影响

目的]为杉木林的经营和林地地力维持提供理论依据和实践参考.方法]研究了间伐5 a后,不同强度间伐杉木人工林林下地被物多样性和土壤理化性质的动态变化.结果]抚育间伐可改变林下植被组成、植物多样性和均匀度.Margalef指数、Simpson指数和Shannon-Wiener指数以强度间伐区为最高.随着间伐强度的增加,土壤表层含水量呈增加趋势,其中强度间伐区比对照区增加了0.93％;林分土壤10 cm厚处年均温比未间伐林地提高了0.17℃以上,中度和强度间伐林分的全年极温差降低了0.35℃和0.79℃;土壤表层全C、全N、有机质、全P、有效P含量均以对照区最高,而强度间伐区仅次于对照区.从季节动态来看,夏季不同强度间伐区土壤含水量差异极显著,夏季、秋季和冬季的月平均温度比对照区均有所提高,秋季对照区全C、全N、有机质、全P、有效P的含量出现峰值,而不同强度间伐区全C、全N、有机质含量秋季最低.结论]间伐改善了土壤温、湿条件.强度间伐后,林下较高的生物多样性有利于保持土壤肥力.

The Effect of Thinning on Chinese fir Groundcover Biodiversity and Soil Physical-chemical Properties

Objective] The study provides theoretical basis and practical reference for Chinese fir forest management and forest soil fertility maintaning.Method] In this study,we discuss the seasonal dynamics of the fields biodiversity and soil properties in Chinese fir plantation after 5 year thinning.Result] The results showed that thinning can change the understory vegetation composition,plant diversity and evenness.Margalef index,Simpson index and Shannon-Wiener index were the highest in heavy intensity thinning area.With the thinning intensity increasing,soil surface moisture showed an increasing trend,which heavy intensity thinning area increased 0.93 percent than the control area,the average temperature of 10 cm forest soil was 0.17 ℃ higher than not thinning forests.Soil surface carbon,total nitrogen,organic matter,total phosphorus,effective phosphorus content were the highest in control area,and the heavy intensity thinning area behind the control area.From the seasonal dynamics view,soil moisture content of different thinning area were significant difference in summer.The annual average temperature of the summer,autumn and winter were higher than the control area.In autumn,the total C,total N,organic matter,total P,effective P content appeared peak point in control area.Total C,total N,organic matter content were the lowest in different thinning area.Conclusion] Thinning improved soil humidity conditions,and high biodiversity was helpful to maintain soil fertility after heavy intensity thinning.