不同植被对桂西北石漠化地区土壤生化作用强度的影响

Effects on Biochemical Activities Intensity of Soil Microorganisms under Different Vegetation Restoration in Karst Areas of Northwest Guangxi

为了深入了解不同植被对石漠化地区土壤品质变化的影响,对桂西北石漠化地区13种不同植被典型样地的土壤理化性质、纤维素分解作用、氨化作用、硝化作用及无机磷转化作用进行了比较研究。结果发现,不同植被土壤的生化作用强度有明显的差异,以乡土树种为优势种的样地,其土壤生化作用强度通常高于外来树种为优势种的样地,青檀、鞍叶羊蹄甲、圆果化香、侧柏、青冈、任豆、阴香、吊丝竹等乡土树种可作为石漠化地区植被恢复的先锋树种;除植被覆盖度低的类芦样地外,以湿地松、小叶桉为优势种的样地土壤生化作用强度较低。从生态恢复效果及经济社会效益角度考虑,在石漠化地区植被恢复过程中,应重视不同树种的优化配置及生态恢复技术的合理运用。

In order to understand the effects of different vegetation on changes of soil quality, soil physical and chemical properties, cellulose decomposition, ammonification, nitrification and inorganic phosphorus transformation action of 13 typical plots under different vegetation in the Karst rocky de sertification area of northwest Guangxi were studied comparatively. The results indicated that, soil biochemical activity intensity had significant differences among plots under different vegetation. The soil biochemical activity intensity of the native-tree-dominanted plots was usually higher than that of the exotic-species-dominanted plots. The native species, such as Pteroceltis tatarinowii, Bauhinia brachycarpa , Platycarya longipes, Thuja ccidentalis, Cyclobalanopsis glauca , Zenia insignis, Cinnamomum burnanii, Dendrocalamus minor, et al. can be used as the pioneer species in vegetation restoration of Karst rocky desertification areas. Except the low vegetation coverage plot which domi nant species was Neyraudi reynaudiana, the soil biochemical activity intensity of the plots where dominant species was Pinus elliottii or Eucalyptus eccserta were lower than that of the other ones. Thinking of the ecological restoration effects and the economic and social benefits, the optimal alloca tion of different tree species and the rational use of ecological restoration techniques must be treasuredduring the process of vegetation rehabilitation in Karst rocky desertification areas.