不同造林模式桉树人工林凋落物和土壤水源涵养能力的差异

Difference in Litter and Soil Water Conservation Capacity of Eucalyptus Plantations under Different Afforestation Models

通过对尾巨桉人工林(纯林)、尾巨桉+杂交相思混交林模式A(水平分布排列1行桉树+1行相思树)、尾巨桉+杂交相思混交林模式B(纵向分布排列2列桉树+2列相思树)三种不同造林模式凋落物和土壤的水源涵养能力进行了比较分析。结果表明:(1)三种林分凋落物现存量为1.87~3.52 t⋅hm^(-2),表现为混交模式A>混交模式B>桉树纯林;(2)凋落物最大持水量为5.05~9.12 t⋅hm^(-2),有效拦蓄量为3.92~6.91 t⋅hm^(-2),均表现为混交模式A>混交模式B>桉树纯林;(3)三种林分类型土壤容重均值为1.297~1.340 g⋅cm-3,表现为桉树纯林最大,混交模式B最小;土壤非毛管孔隙度均值为5.02%~6.61%,土壤总孔隙度均值为44.86%~45.72%,均表现为混交模式B>混交模式A>桉树纯林;(4)三种林分土壤(0~60 cm)最大持水量和有效持水量为891.80~914.33 t⋅hm^(-2)和100.33~132.07 t⋅hm^(-2),均以混交模式B最大,桉树纯林最小。综合凋落物和土壤持水能力,混交模式B的水源涵养能力最强,其次是混交模式A,桉树纯林最弱。说明桉树与相思树混交林比桉树纯林具有更强的水源涵养能力,营造桉树混交林有利于改善林分生态。该研究结果为广西东南区域发展桉树混交林,促进桉树人工林可持续经营提供了参考依据。

Litter and soil water conservation capacity of plantations under three different pat-terns,Eucalyptus urophylla×E.grandis plantation(pure forest),E.urophylla×E.grandis+Acacia mangium×A.auriculiformis hybrid forest pattern A(horizontal distribution of horizontal arrange-ment 1 eucalypti row+1 acacia row)and E.urophylla×E.grandis+A.mangium×A.auriculiformis hybrid forest pattern B(longitudinal distribution of 2 eucalyptus columns+2 acacia columns)were compared,and the results showed that:(1)The standing litter of the three forest stands ranged from 1.87 to 3.52 t·hm^(-2),following the order of mixed mode A>mixed mode B>pure eucalyptus forest.(2)The maximum water capacity of litter was from 5.05 to 9.12 t·hm^(-2),and the effective storage capa city was from 3.92 to 6.91 t·hm^(-2),all of which followed the order of mixed mode A>mixed mode B>pure eucalyptus forest;(3)Average soil bulk density of the three forest stands was from 1.297 to 1.340 g·cm-3,with pure eucalyptus forest as the largest and mixed mode B the smallest;the average non-capillary porosity of the soil was 5.02%-6.61%,and the total porosity of the soil was 44.86%-45.72%,following the order of mixed mode B>mixed mode A>pure eucalyptus forest.(4)The maxi-mum and effective soil water conservation capacity of the three forest stands(0-60cm)were 891.80-914.33 t·hm^(-2) and 100.33-132.07 t·hm^(-2),respectively and mixed mode B had the highest soil capacity and pure eucalyptus forest had the lowest soil capacity.Considering litter and soil water conserva-tion capacity,mixed mode B has the strongest water conservation capacity,followed by mixed mode A,and pure eucalyptus forest has the weakest.The mixed forest of eucalyptus and acacia has stron-ger water conservation ability than pure eucalyptus forest does,and creating a mixed eucalyptus for-est is beneficial for improving ecology of forest.The research results provide a reference basis for the development of eucalyptus mixed forests and the promotion of sustainable management of euca-lyptus plantations in the southeastern region of Guangxi.