杉木林采伐迹地再造林后土壤调蓄水分功能恢复研究

摘要

[目的]探讨杉木人工林采伐前、后及其采伐迹地造林后林地土壤调蓄水分功能的变化，揭示采伐地造林后，幼林对土壤蓄水功能的调节恢复作用。[方法]采用定位连续观测方法，在24年生杉木人工林伐前、伐后以及造林后1年、3年、5年、8年的样地内采集土壤样品，进行室內测试分析。[结果]表明：与伐前相比，杉木人工林采伐后1 m 深土壤层毛管孔隙度提高了1．70％，非毛管孔隙度下降了4．95％；伐后1 m 深土壤层最大持水力、最小持水力和毛管持水力比伐前分别提高了4．02％、2．67％和5．31％，但土壤贮水力下降14．30％；020，2040 cm 土层的初渗速率分别下降19．81％和16．95％，稳渗速率分别下降12．97％和14．49％；造林后林分对土壤调蓄水分功能的调节作用，随着林龄增加而增大，8年生幼林020，2040 cm 土层对土壤水分的初渗调控能力恢复到采伐前的62．50％和58．83％，稳渗的调控恢复到采伐前的62．22％和48．79％；若以伐后与伐前土壤的最大持水力、最小持水力和毛管持水力的差值为100％，8年生幼林其与伐前的差异只有16．90％，17．84％和23．20％。土壤贮水力恢复到采伐前33．34％的水平。[结论]杉木人工林的采伐导致土壤调蓄水分功能减弱，采伐迹地再造林能逐步改善林地土壤调蓄水分功能，而且随着幼林林龄增加调节功能逐步增强。%[Objective]In order to understand the changes of regulation function of soil moisture for the pre-harvest, post-harvest and reforestated Chinese fir (Cunninghamia lanceolata)plantation.[Method]By continuous observa-tion in fixed locations of 24-year-old Chinese fir plantation,the soil samples before harvest,1 year after harvest and 1 year,3 years,5 years,and 8 years after reforestation were collected,and the function of soil water regulation and storage capacity were investigated by laboratory data analysis.[Result]The results showed that compared with pre-harvest period,the capillary porosity of soil 1 m in depth increased by 1 .70% at post-harvest period,and the non-capillary porosity decreased by 4.95%;the water holding capacity,the minimum holding capacity and capillary power of the soil increased by 4.02%,2.67% and 5.31 % respectively,but the water storage capacity declined by 1 4.30%;the initial infiltration capacity of the soil 0 20cm and 20 40 cm in depth decreased by 1 9.81 % and 1 6.95% respectively,the stable infiltration capacity also fell by 1 2.97% and 1 4.49% respectively;during the re-forestation stage,the water regulation and storage function gradually improved along with the ages of the Chinese fir plantation,for example,the initial infiltration capacity of the soil with 0 20 cm and 20 40 cm in depth at Chi-nese fir plantation 8 years after reforestation recovered to 62.50% and 58.83% respectively,the stable infiltration capacity also recovered to 62.22% and 48.79% compared with pre-harvest stage;If the soil before cutting with the maximum water holding capacity after cutting,minimum water holding capacity and capillary water holding capacity of 1 00% of the difference.with the 8-year-old stand differences before cutting only 1 6.90%,1 7.84% and 23.20%;the soil water storage capacity returned to 33.34% of pre-harvest level.[Conclusion]The regulating function of soil moisture was weakened by harvest;however,with the reforestation activities,all the capacity of soil moisture will gradually recovered.