热带次生林利用与土壤物理性质变化

利用海南岛吊罗山林区内的生态定位观测站近３ａ的定位观测数据，和定期采样进行的土壤物理性质测定，分析了不同的次生林砍伐程度和利用方式（包括次生林对照、择伐５０％、择伐７０％、皆伐迹地、垦植橡胶和刀耕火种垦植甘蔗、蕃茨等样方）对土壤温度、土壤含水量、土壤团聚结构、土壤机械组成、土壤容重、孔隙度和土壤持水特性等土壤主要物理性质的影响，结果显示，热带次生林的过度砍伐和不合理的刀耕火种，严重地影响了土壤重要

THE UTILIZATION OF TROPICAL SECONDARY FOREST AND THE CHANGE OF SOIL PHYSICAL PROPERTIES

By Using the data from the long term ecological observational station in forest region of Diaoluo Mountains, Hainan island,and by testing physical properties of soil sampled periodically,the effects of different secondary forest felling intensity and utilization ways,including quadrats of secondary forest control,selective felling 50% selective felling70%.clear felling slash, cultivating rubber,slash-and-burn and cultivating sugarcane and sweet potato,etc., on main soil physical properties,such as soil temperature,soil water content,soil aggregate structure,soil mechanical composition,soil volume weight, porosity and water retention property,were analysed Results show that,over-felling of tropical secondary forest and the unreasonable slash-and-burn cultivation seriously influences,the main soil surface temperature and temperature differences,decrease soil water content and water retention ability,destroy soil structure,and lead to soil clay loss,soil sandification and so on,resulting in deterioration of soil ecological environment,directly influencing forest regeneration,forest land exploitation and utilization.Among them,the influences of slash-and-burn cultivation and clear felling slash are most serious.It is suggested that selective felling 50% and strip cropping of rubber would be the reasonable management and utilization ways if soil physical properties are only considered.