岩溶石漠化山地自然恢复12年后入侵植物的生态学分析

Ecology analysis of invasive plants after 12 year’s natural restoration in karst desertification area

采用野外调查和统计分析相结合的方法,对桂北地区自然恢复12年后的岩溶石漠化山地的入侵植被进行调查分析。结果表明,石漠化山地入侵植被由21种植物组成,隶属于7科13属,其中52%为草本植物,且92%是阳生植物,大部分植物的种子具有易传播和快速生长的特征。圆叶乌桕生长较好,枝叶繁茂,林下入侵植被主要为一些耐阴植物;在朴树样地上,由于朴树长势良好,充分地利用了石漠化山地的水分和养分,并且朴树的冠幅较大、枝叶较多,其林下入侵植物相对较少,总盖度只有12%;石山榕、榔榆和盐肤木样地上,受其冠幅较小、枝叶较少的影响,林下入侵植物较多,且多为阳性植物,总盖度分别为50%、60%和40%;火棘属于灌木,枝叶细小,林下植物可以充分利用光能,长势迅速,总盖度达65%;对于入侵植被覆盖度大的地方,必须进行适当的抚育管理,从而达到更好的生长效果。不同林分中,入侵植物总盖度的变化大小是:朴树<圆叶乌桕<盐肤木<石山榕<榔榆<火棘;高度变化大小是:朴树<圆叶乌桕<石山榕<榔榆<盐肤木<火棘;密度变化大小是:朴树<圆叶乌桕<石山榕<盐肤木<火棘<榔榆;总生物量变化大小是:朴树<圆叶乌桕<石山榕<火棘<盐肤木<榔榆。通过植被的生态学分析,在石漠化山地生态重建过程中,不同坡度的地方采用不同的混交模式,还可以起到防止水土流失、病虫害、森林火灾的作用。

After 12 years natural restoration, research of invasive plants in karst desertification area of north Guilin was done by field investigation and statistical analysis. The results showed that, vegetation coverage of karst desertification area had been greatly changed, in addition to the artificial plants, a large number of natural plants had invaded, which including 21 types of plants and belong to 7 family and 13 category, most of them were herbaceous plants, it accounted for 52%, 4 arbors, it accounted for 20%, 3 lianes, it accounted for 14%. Most of them were heliophobes, it accounted for 92%, and heliophytes accounted for 8%. There were only some shade plants under stands, because Sapium rotundifolium grew well and had large branch; Under Celtis tetrandrassp stands, total coverage of invasive plants was only 12%, it also because Celtis tetrandrassp fully utilized the moisture and nutrition and had large branch; However, under Ficus sublanceolata, Ulmus parvifolia and Rhus chinens stands, there were much more heliophobes invasive plants because of small crown width, the total coverage were 50%, 60% and 40%; Pyracanthafortuneana was shrub with small and thin branch, so the invasive plants had enough sunny to grow, the total coverage was 65%; In order to have a better growth result, some tending management must be done in the stands with high coverage. In the 6 different stands, total coverage changes of invasive plants as followings： Celtis tetrandrassp〈Sapium rotundifolium〈Rhus chinens〈Ficus sublanceolata〈Ulmus parvifolia〈Pyracanthafortuneana; Height changes were： Sapium rotundifolium〈 Celtis tetrandrassp 〈Ficus sublanceolata 〈Ulmus parvifolia 〈Rhus chinens 〈Pyracantha fortuneana; Density changes were： Celtis tetrandrassp 〈Sapium rotundifolium〈Ficus sublanceolata〈Rhus chinens 〈Pyracantha fortuneana〈Ulmus parvifolia; Total biomass changes were： Cehis tetrandrassp〈Sapium rotundifolium〈Ficus sublanceolata〈Pyracantha fortuneana〈Rhus chinens〈Ulmus parvifolia. According to ecology analysis, different mixed trees model could be adopted in different slopes for ecological reclamation of coal waste pile, which also had the prevention function of soil and water loss, disease and insect pest, forest fire.