桂西北红椎次生林生长及土壤的理化性质

The Growth of Castanopsis hystrix Secondary Forest and the Soil Physicochemistry Properties in the Northwest of Guangxi

对桂西北12～15年生红椎次生林分的生长量、林地枯枝落叶现存量及其养分含量以及土壤理化性质等进行测定,并与相似立地条件的杉木人工林(15年生,中坡)进行比较分析。结果表明:(1)不同立地红椎次生林分的平均胸径、平均树高及平均蓄积量显示出中坡和下坡林分最大,是上坡林分的1.6～4.0倍;(2)不同立地红椎次生林分枯枝落叶现存量及其最大持水量和主要养分(N、P、K)含量测定结果中,中坡林分比相应杉木人工林高;(3)不同立地红椎次生林分土壤理化条件也比相应杉木人工林略好;(4)不同立地红椎次生林分土壤(0～40cm)有机质含量为1.127%～2.228%,全氮、有效磷和速效钾总量依次为2.39～4.16g/kg,0.90～1.40mg/kg和29.04～41.44mg/kg,说明该地区红椎次生林分具有较显著的生态经济效益。

This paper conducted a comparison test on the measures,the existing litter biomass and its nutrient content,the soil Physicochemistry properties,ect of the Castanopsis hystrix secondary forest(CHSF,12～15 year's old) and the similar Cunninghamia plantation (CP,15 year's old) in Donglan County,Guangxi.The results show:(1)By comparison,the mean height-breast diameter,the mean tree height and the mean volume of the CHSF in the middle and bottom gradient are 1.6～4.0 times higher than those in the upper-gradient.(2)The existing litter biomass,the maximum net absorbing water and the main nutrients content(N,P,K)in the different CHSF forest site respectively especially those in the CHSF middle-gradient forest are higher than those in the CP forest.(3)The CHSF soil(0～40 cm deep)volume density in different forest site is 0.785～(1.349 g/cm^3).However,the maximum capillary moisture capacity and the soil aeration in the CHSF forest site are slightly higher than the CP forest site.(4)The soil organic matter(0～40 cm deep) of different CHSF site is slightly higher than that in the CP site.The total nitrogen content,the dissoluble phosphate and the dissoluble kalium content respectively are 2.39～(4.16 g/kg),0.90～1.40 mg/kg and 29.04～(41.44 mg/kg).It shows that the CHSF has a significant effect on the benefits of society,economy and ecology in these regions.