滇东南岩溶山区树种配置的初步研究

3年来在滇东南岩溶山区开展的树种配置试验的初步研究结果表明 :影响岩溶山地林木生长的主要因素是坡度、岩石裸露率、土类、土层厚度和土壤中的石砾含量 ,而坡向、坡位、土壤的吸湿水、旱季土壤含水率、pH值及土壤养分对林木生长的影响不明显。在岩溶地区的造林应采取特殊的措施 ,尽量保护原有植被 ,对于形成复层的林分结构具有非常重要的作用 ,特别是在多石的薄层石灰土类型上 ,人工种植的阔叶树生长较差 ,通过种植针叶树 ,能形成乔灌草结构的复层林分 ,对改善岩溶山区的生态环境效果十分明显。在吸湿水、全氮、水解氮、速效磷、速效钾、pH值、有机质和旱季土壤含水率等 8个土壤性状中 ,吸湿水、速效磷、速效钾 3个性状在年度间的差异非常显著 ,其中吸湿水平均增加 3 6 6 % ,每kg干土中的速效磷和速效钾平均分别增加9 99mg和 4 2 5 9mg ,显示出林木对土壤的改良作用。在多石的石灰土类型上 ,适宜营造墨西哥柏、郭芬柏和冲天柏等针叶树 ,在其中土层较厚的地方可种植银荆 ;在厚层山地红壤类型上 ,适宜营造墨西哥柏、冲天柏、郭芬柏、川滇桤木、滇合欢、银荆、杜仲、酸枣、苦刺等针阔、阔阔混交林以提高其生态和经济效益

Study of Species Collocation of Karst Mountainous Areain Southeastern Yunnan

The species collocation experiment of afforestation at the karst mountainous areas in Southeastern Yunnan was conducted from 1997 to 2000 The experimental results implied that the main factors affecting the tree's growth at the karst mountainous areas were gradient, the ratio of rock bareness, soil group, soil layer thickness, stone and gravel contents of the soil, while the effects of exposure, slope site, hygroscopic water of soil, soil moisture content of dry season, soil pH value and soil nutrients on the growth of tree were not significant Special measures should be adopted in the afforestation of those areas Conserving the original vegetation was very critical for the formation of multi storied stand, especially at the stony mountain with thin soil layer, the growth status of broadleaved tree species was not desirable Through the combined measure of protecting original vegetation and planting coniferous trees, the multi storied stand including tree, shrub and grass could be established, which was quite helpful for improving the ecological environment of karst mountainous areas Three years after afforestation setting up, among the eight indexes considered such as hygroscopic water, total nitrogen content, hydrolysable nitrogen content, rapidly available phosphorus, rapidly available potassium, pH value, organic matter of soil and water content of soil in dry season, there were significant annual differences of hygroscopic water, rapidly available phosphorus and rapidly available potassium The hygroscopic water content, rapidly available phosphorus and rapidly available potassium increased by 3 66 %, 9 99 mg/kg dry soil , and 42 59 mg/kg dry soil respectively, which showed the improvement of afforestation on soil characteristics On the lime soil of stony sites, the suggested afforestation species were Cupressus lusitanica, Cupressus goveiana and Cupressus duclouxiana, for sites with thick soil layer, Acacia dealbata was a desirable species also On the thick red soil of mountainous areas, the mixed forests of coniferous and broadleaf, broadleaf and broadleaf, using species such as Cupressus lusitanica, Cupressus duclouxiana, Cupressus goveiana, Alnus sp , Albizia mollis, Acacia dealbata, Eucommia ulmoides, Choerospondias axillaris and Sophora davidii, could heighten both ecological and economic benefits