单 位：
中国林业科学研究院热带林业研究所海南岛尖峰岭热带林生态系统定位研究站
关键词：
热带山地雨林;土壤物理性质;土壤恢复;更新方式
摘 要：
通过样地调查和取样测定,运用方差分析、差异显著检验和聚类分析方法,以海南热带山地雨林原始林(0501,植被类型代码)为对照,对热带山地雨林皆伐后的天然更新林(0502)、皆伐炼山后人工促进天然更新林(0503)和皆伐炼山后种植人工林(0504)等3种次生林的土壤物理差异和恢复程度进行了研究,结果表明:(1)热带山地雨林采伐更新造成土壤密度的增加和表层毛管孔隙度的差异,进而引起总孔隙度的变化,影响0~40 cm土层的最小持水量及20~40 cm土层的毛管持水量;皆伐天然更新措施(0502样地)的土壤质地较好,表层土粒淋洗下移较少,整个剖面土壤毛管孔隙度较高,土体发育良好,具有很强的持水保水能力;皆伐炼山措施(0503和0504样地)使表层土壤易于向下淋溶和淀积,底层毛管孔隙度降低,增加了中层土壤密度并形成明显的淀积层,影响土壤的通气透水性能,容易造成雨季地表径流和旱季底层水分难向上传输;人工造林更新措施(0504样地)造成土壤表层土粒淋洗严重,各层毛管孔隙度降低和中、底土层非毛管孔隙度的减少,中、底土层明显的板结,影响林地的通气透水性能,各种持水保水能力大大降低,容易产生地表径流和存在土壤表层砂化危险。(2)皆伐天然更新林具有与原始林相似的土壤物理性质。人工促进天然更新林土壤属黏壤土至黏土质地,表层毛管孔隙度较大,底层毛管孔隙度最小及持水量递减率明显。人工更新林土壤为砂质黏壤土至黏土,表层土粒淋溶下移和砂化现象明显,中、底土层具有明显淀积层,持水保水能力最低。(3)皆伐迹地天然更新林(0502)和人工促进天然更新林(0503)土壤物理恢复程度较接近原始林,人工更新林(0504)土壤恢复程度明显不及天然更新林,次生林的土壤总孔隙度和持水量恢复较好,土壤颗粒比例较难恢复,表层土壤密度和中层土壤粉黏比的恢复度较差,中层土壤的毛管与非毛管孔隙度之比的恢复度较表层和底层高,皆伐炼山对深层土壤的恢复影响较大。
译 名：
Study on Differences and Restoration Degrees of the Soil Physical Properties of Tropical Montane Secondary Forest in Hainan Island
作 者：
LUO Tu-shou,LI Yi-de,CHEN De-xiang,XU Han,LIN Ming-xian(Research Institute of Tropical Forestry,CAF;Jianfengling Long-term Research Station for Tropical Forest Ecosystems,Guangzhou510520,Guangdong,China)
关键词：
tropical montane rainforest;soil physical property;soil restoration;regeneration method
摘 要：
The differences and restoration degree of soil physical properties of the three secondary tropical montane rainforests including natural regeneration forest after clear-cutting(0502),artificial promoting natural regeneration forest with some native plants cultivated(0503),and manmade forest with native plants cultivated after clear-cutting and burning(0504) were compared with virgin tropical montane rainfores(0501) by ANOVA and clustering analysis.The results are as follows:(1) Cutting of tropical rainforests and the following regeneration caused the increasing of bulk density and the differences of surface layer capillary porosity,which resulted in the total porosity changed.Both of them influenced the minimum water-holding capacity of 0—40 cm soil layer and the capillary water-holding capacity of 20—40 cm soil layer.Measures with natural regeneration after clear-cutting had a better soil texture,few topsoil particles washed and illuviated by drip,higher capillary porosity,well developed soil and strong water-holding capacity.Measures with clear-cutting and burning made the topsoil being washed and illuviated easily,the capillary porosity of substrate soil decreased,the bulk density of middle stratum soil increased and illuviate lamination being shaped,the capabilities of surface flow in the rainy season and air exchange and water penetration being weaken.All of these changes caused the difficulty to transfer water from under soil in the dry season.Artificial plantation measure(0504) made the topsoil particles being washed and illuviated severely,the capillary porosity of all soil strata and anti-capillary porosity of subsoil decreased,subsoil harden obviously,air exchange and water penetration capacity being influenced,and water-holding decreased remarkably.All of them resulted in surface flow and sand-conversion possibilities.(2) 0502 had similar physical characteristics with 0501.However,the soil of 0503 belonged to clay loam to clay texture categories,with bigger capillary porosities of topsoil and least of under stratum soil,and obvious decreasing of water-holding rate.The soil of 0504 belonged to sandy clay loam to clay texture categories,with topsoil particles washed and illuviated obviously,which formed accumulation horizon in substratum and low water-holding capacity.(3) The restoration degree of 0502 and 0503 were closed to 0501.However,0504 was distinctly less than 0502 and 0503.The technical step of clear-cutting and controlled burning badly affected rehabilitation degree of substrata soil properties.The easy restoration physical indices of the secondary forests were total porosity,and water-holding capacity,contrary to the difficult restoration index-soil particle proportion.Restoration degree of bulk density of topsoil and slit/clay ratio of middle soil layer were poor.Ratio of capillary and anti-capillary of middle soil layer was higher than that in topsoil and under layer soil.Therefore,clear-cutting and burning influenced the deep soil significantly.
