闽北不同类型毛竹林土壤水分时空变化规律

目的]揭示不同林分土壤空间和不同位点上的水分时空变化规律,旨在为毛竹林合理经营提供科学依据。方法]采用野外定点观测法,以闽北地区竹杉混交林(Ⅱ)、毛竹纯林(Ⅲ)、竹阔混交林(Ⅳ)3种不同类型毛竹林为研究对象,杉木纯林(Ⅰ)和常绿阔叶林(Ⅴ)为对照开展试验。结果]各林分的土壤含水量的季节变化基本与研究区域的降雨和蒸发季节变化一致,每月平均土壤含水量在22.98%~37.88%之间,年均土壤含水量排序为:常绿阔叶林(31.95%)竹杉混交林(30.46%)竹阔混交林(30.10%)杉木纯林(29.78%)毛竹纯林(29.31%)。空间垂直变化上,常绿阔叶林地各层土壤含水量之间差异显著(p0.01),随着土壤层深度的增加土壤含水量逐渐降低,但是其他林分不同土层土壤含水量之间的差异不显著。结论]林分类型和土层深度对土壤含水量的共同作用有差异,但未达到显著水平,林内降雨量是影响土壤含水量的直接因子。

Spatiotemporal Changes of Soil Water Content Under Different Types of Phyllostachys Edulis Forests in Northern Fujian Province

Objective] The temporal and spatial variation of soil moisture was revealed under different bamboo forest stands in order to provide the scientific basis for the sustainable management of Phyllostachys edulis forests. Methods] Based on the field test, three typical P. edulis forests(P. edulis and Cunninghamia lanceolata mixed forest, P. edulis pure forest and P. edulis and broad-leaved tree mixed forest) in northern Fujian Province were investigated in comparison with C. lanceolata pure forest and evergreen broadleaved forest. Results] The seasonal changes of soil moisture content were consistent with the rainfall and evaporation. Monthly average soil moisture content ranged from 22.98% to 37.88%, and broad-leaved tree mixed forest had the largest mean annual soil moisture content of 31.95%, and followed by P. edulis and C. lanceolata mixed forest, P. edulis and broad-leaved tree mixed forest, C. lanceolata pure forest and P. edulis pure forest(30.46%, 30.10%, 29.78, and 29.31%, respectively). The moisture contents of different soil layers of evergreen broadleaved forest had significant differences(p<0.01) in the soil profiles, and the soil moisture contents decreased with soil depth, however, the moisture contents of other forest types had no significant differences in the soil profile. Conclusion] The impacts of forest types and soil depth on soil moisture contents were different, but did not reach significant levels, and the precipitation in the forest canopy was the direct factor influencing soil moisture contents.