不同密度飞播马尾松林凋落物及土壤持水性能比较分析

Comparing water-holding capacity in forest litter and soils for an aerially seeded Pinus massoniana plantation with different stand densities

根据飞播马尾松Pinus massoniana林的林木密度,将林分分为Ⅰ组(900~1 500株·hm^(-2)),Ⅱ组(1 500~2 100株·hm^(-2)),Ⅲ组(2 100~2 700株·hm^(-2)),Ⅳ组(2 700~3 300株·hm^(-2))等4个密度组,并分别各密度组设立标准地调查和样品测定,分析比较其凋落物和土壤的持水性能。结果表明:(1)各密度组凋落物储存量都表现为半分解层大于未分解层,凋落物总储存量、最大持水量和有效拦蓄量均为密度组Ⅱ>密度组Ⅲ>密度组Ⅰ>密度组Ⅳ,最大值分别为4.26,11.55和9.79 t·hm^(-2),且密度组Ⅱ的最大持水量和有效拦蓄量均显著高于其余密度组(P<0.05),凋落物总储存量各密度组间无显著差异(P>0.05)。(2)土壤非毛管持水量、毛管持水量和最大持水量的范围分别是332.62~628.93,2 210.17~2 859.98和3 792.45~3 984.91 t·hm^(-2),均表现为密度组Ⅱ>密度组Ⅲ>密度组Ⅰ>密度组Ⅳ,但各密度组间无显著差异(P>0.05)。综合分析表明:飞播马尾松林密度为1 500~2 100株·hm^(-2)时,凋落物和土壤的持水性能最好。

In order to provide guidelines for making effective measures to improve water-holding capacity for an aerially seeded Pinus massoniana plantation,this research was conducted to compare water-holding capacity of forest litter and soils with method of one-way ANOVA test in different stand densities.Four groups [Group Ⅰ（900-1 500 culm·hm^-2）,Group Ⅱ（1 500-2 100 culm·hm^-2）,Group Ⅲ（2 100-2 700 culm·hm^-2）,and GroupⅣ（2 700-3 300 culm·hm^-2）],were set up according to aerially-seeded Pinus massoniana forest density.Sample-plot surveys and sample determination were carried out for a fixed 20 m×20 m standard plot which selected with three replications in each group.Results showed that,（1） the litter storage capacity for each density group in the half-decomposed litter layer was higher than the undecomposed layer.Total storage capacity for litter,maximum water-holding capacity,and effective water-holding capacity of the Group Ⅱ were the largest,respectively up to 4.26 t·hm^-2,11.55 t·hm^-2,9.79 t·hm^-2,and were in the order of density Group ⅡGroupⅢ Group ⅠGroup Ⅳ compared with other groups.The maximum water-holding capacity and effective water-holding capacity of density Group Ⅱ were significantly higher than those of the other density groups（P〈0.05）;however,the total storage capacity of litter in each density group was not significantly different（P〈0.05）.（2） The non-capillary water-holding capacity,capillary water-holding capacity,and maximum waterholding capacity of soil in the four groups showed no significant differences between density groups（P〈0.05）.In conclusion,by controlling stand density of an aerially seeded Pinus massoniana plantation at 1 500-2 100culm·hm^-2,the water-holding capacity of the litter and soil would be maximized.