滇东南岩溶地区石质山封山育林效果初探

滇东南岩溶地区石质山地封山育林效果观测试验在砚山县铳卡农场试验示范基地的封山育林地进行,面积20.8hm2.依据不同立地环境所设的固定样地的观测材料,自1997年起封护3年后,石质山地的木本植物的平均高、地径、冠幅,每公顷生物量、截留量、种类,草本植物的生物量、总生物量和总盖度分别增加30.3%、17.2%、11.8%、42.2%、20.1%、5.94%、27.9%、40.7%和21.2%.土壤的养分、含水率、pH值以及紧密度也产生了变化.土壤中的吸湿水、水解氮、速效磷、速效钾、有机质和土壤含水率分别增加105.0%、-8.3%、6.3%、95.3%、10.9%、12.9%和8.0%,土壤的pH值从7.25降低到6.60.植被和土壤状况的变化说明封山育林对促进石质山地植被的恢复,防止面蚀,保持水土,减小地表径流,减少水土流失,提高林地土壤肥力都具有明显的作用.不同坡位及坡向的封山育林以山体中部和阴坡效果最明显.

Effect of Closing Hillsides to Facilitate Afforestation at Stony Hillsides of Karst Area in Southeastern Yunnan

The effect of closing hillsides to facilitate afforestation at karst mountain area of southeastern Yunnan was studied through the observation and investigation on the 20 hm 2 demonstration base of Chongka farm, Yanshan county In accordance with the observation data from each sample, three years after closed, the average height, diameter at ground, crown mean width, biomass per hectare, interception, species of wood plants; biomass of herbaceous plants; total biomass and total coverage respectively increased by 30 3%, 17 2%, 11 8%, 42 2%, 20 1%, 5 94%, 27 9%, 40 7% and 21 2% The hygroscopic water, hydrolysable nitrogen, rapidly available phosphorus, rapidly available potassium, organic matter and moisture content of soil increased by 105 0%, -8 3%, 6 3%, 95 3%, 10 9%, 12 9% and 8 0% respectively The pH of soil decreased from 7 25 to 6 60 The changes of vegetation and soil indicated that closing hillsides produces significant effect on vegetation recovery of stony hillsides, prevention of surface erosion, soil and water conservation, alleviation of surface run off and soil and water losses, and increase of forest soil fertility The observationdata of samples at different slopes site and exposures showed that closing hillsides at the middle part, and shade slope could obtain the desirable effect