广西马山岩溶山地植被恢复过程的种类更替与小气候动态

Species Replacement and the Dynamics of Microclimate of Karst Upland Vegetation in Guangxi Mashan in the Process of Restoration

于2002年8月29～30日,采用“空间代替时间”的方法,研究广西马山县岩溶山地封山育林过程中植被种类更替与小气候变化之间的关系。结果表明,封山育林初期生境条件是干燥、高温、低湿,小气候因子日变幅度大,植物群落是一些耐干旱、耐瘠薄的草本和灌木;封山育林中期,植物群落结构包括灌-草2个层次,夏季气温开始下降,湿度增大,光照度开始降低,土壤温度波动略为平缓,耐阴的灌木和草本种类增多,原生性森林群落的乔木幼树开始出现;封山育林中后期,群落的平均高度达7～15m,出现乔-灌-草3个层次的结构,逐渐形成森林小气候,群落内光照强度降低、夏季气温低、湿度增大,基本上由原生性森林群落的组成种类占主导地位,演替初期的阳性先锋草本和灌木种类基本上消失。

To study the microclimate variation on the karst upland forest in Mashan,Guangxi Zhuang Autonomous Region reservation process by methodology of 'Temporal for Spatial',during 29th to 30th,August,2002.It reveals that in the initial phase of restoration,the habitat tends to be drought and high temperature, with intense daily changes microclimate.In this stage, the communities are mainly made up of sclerophyll grasses and drought-tolerant shrubs. While in the middle phase,the vertical profile of the community can be divided into two distinct layers,shrub and grass.In summer both temperature and intensity of illumination slightly decrease,and the air is more humid in the surveyed site.At the same time,soil temperature is getting less fluctuation. The community is composed with shade-tolerant shrub and grass,inhabiting new woody seedlings belonging to primary forest. Then in the later phase, the community physiognomy presents as high as 7~15m.The vertical profile of the community can be divided into three layers, arborous,shrub,and grass,chiefly dominated by primary forest species.The microclimate of this stage tends to be similar to that of forest,as inside the communities,it is both low illumination intensity and low temperature in summer,yet it is getting much more humid comparatively. Pioneer sun species of grass and shrub, used to dominate in the initial phase, disappear completely.