海南岛热带山地鸡毛松人工林的土壤性质研究

对海南岛尖峰岭热带雨林区采伐迹地鸡毛松(Dacrycarpus imbricatusBl.)人工林与原始林以及皆伐迹地的天然更新林的土壤理化性质进行了研究,结果表明:鸡毛松人工林的土壤经过长期的恢复发育,其毛管孔隙、土壤含水率、容积湿度和容重等较原始林高;与皆伐迹地天然更新林比,其土壤容重减少,毛管孔隙、含水率和持水量有较大增加,土壤物理性能得到改善,保持了涵养水源等系统服务能力;与原始林比较,土壤有机质、P这两个关键肥力因子未得到完全恢复,N、K和交换性盐基总量得到保持,Ca和Mg有较大幅度增加,pH值和离子交换量有较大的提高,酸缓冲能力增强;鸡毛松林土壤恢复发育存在空间差异,阴坡土壤的物理性质相对较接近原始林,阳坡土壤的养分元素含量和离子交换量存在较大优势;不同层次土壤的容重、含水率、持水量、总孔隙度、大部分土壤养分元素和交换性离子含量的变化趋势与原始林的相同,但阴坡表层含水率高,通气性差,土壤P素向深层淋溶.由此认为,在热带雨林区采伐迹地适地种植鸡毛松人工林,只要经营得当,对林地土壤理化环境不会造成大的影响,群落生态系统功能会逐渐恢复.

A Study on the Soil Properties of Dacrycarpus imbricatus Bl. Plantation in Tropical Mountainous Region in Hainan Island

The soil physical chemistry characteristics of Dacrycarpus imbricatus BI.plantation are studied and analyzed in tropical mountainous rainforest region in Hainan Island,China.After the development of soils over a long period of time in clear felling areas,the capillary porosity,water content rate,moisture and bulk density of the soils in this plantation are higher than which of virgin forests.The Comparing natural regeneration woods with clear felling area,the soil bulk density shows decreases,whereas the porosity capillary,water content rate and holding water capacity are increase relatively.It implies that the soil physical characteristics have been improved and soil system service capabilities such as water conservation are been maintained.The organic matter and phosphor contents which are key factors for soil fertility(don't) obtain to recover completely,however,the content level of nitrogen,kalium and total exchangeable salt foundation are got on maintaining,calcium and magnesium are raised on a large scale,and the pH's value and ion exchange capacity are increased.Therefore,the sour buffering capacity gets on improving.There is a striking spatial dissimilarity in soil development between the sun-forward slope and sun-backward slope.In sun-backward slope area,the physical characteristics of soil approximated to which of virgin,while the content of nutrient elements and exchangeable ion in soil are higher relatively in the sun-forward slope.The change trend in soil characteristics,such as bulk density,water content,holding water,total porosity,content of a majority of nutrient elements and exchangeable ion,exhibits similarity to which of virgin with soil depth. But the sun-forward slope area,water content elevated and ventilation property decreased,phosphorus within soil layer underwent eluviations to deeper layer.This research results indicate that planting Dacrycarpus imbricatus BI.in tropical mountainous rainforest region don't affect soil properties fiercely and the function of forest community ecosystem will be resumed gradually if matching the species with the site and technique management is properly.