A Study On Covariance Between Plants And Environment In Natural Restoration Process Of Degraded Karst Forests

On covariance relations between recovery procedure of degenerated vegetation and the environment are difficult to research of succession. This article takes the vegetation of different recovery stage in southern karst rocky desertification (Huajiang) area as the research object. We choice typical places by means of "the spatial series replaces the time series ", carry on the coenology investigation and the microclimate observation. Through researching of the characteristic changes of microclimate and dominant specie group of community in recovery procedure of the degenerated karst vegetation, we proposed the concept that appraisal the microclimate c of community, expounded the relations of covariance between dominant specie group and the environment stability, as well as the relations of covariance between specie group and the stability of dominant environmental factors. The main results as follows:There are six kinds of microhabitat types,such as the soil surface, the stone surface, the stone drain, the stone cistern, stone slot and the stone hole and there are the different habitat type's combinations of soil surface-stone surface, the stone surface--soil surface, the stone surface in the degeneration karst areas of Huajiang. The different habitat type's combinations have the different ecology characteristic and the validity of plants using.The stability of community environment is low in primary period; the change of light, soil temperature, relative humidity, temperature is bigger. Since the characteristic of microhabitats are different, the various microclimates factor is different among microhabitats. The environmental stability is enhanced with restoration of the vegetation.The dominant environment factors that affect vegetation restore is the light intensity, the soil moisture and the soil temperature. From the stage of bare land (rocky desertification) to the arboreal community stage, substitution of dominant specie group is change process which the stability of dominant environment is from low to the high. The pioneer species adapt unstable light environment in the primary period. On the contrary, to stable light environment of the later period, at the same time, comparatively, the pioneer species can endure fierce change temperate and high temperature in the primary period, the climax species occupy the superiority easily with the stable environment of soil temperature; In addition, the pioneer species adapt unstable soil moisture environment of the primary period, the climax species adapt soil environment of sufficient moisture content of later period.The dominant specie group replaces in turn from pioneer species, to transition species to climax species, the pioneer species occupy superiority in bare land (the rocky desertification) stage and herbaceous community stage, the transition species occupy superiority in the shrubby, and the climax species in arboreal stage. The change between replacement of specie group and environmental factors is covariant. The restoration of vegetation can be improved distinctly; on the contrary, the form of microclimate promotes the restoration of vegetation and the substitution of dominant specie group.The covariance relations between stability of the soil moisture, the light intensity, the soil temperature and specie group show the process of the stability enhance that substitute process of the community from the pioneer species, to the transition species to the climax species. That is to say, the pioneer species adapt unstable soil moisture environment of the primary period, the climax species adapt soil environment of sufficient moisture content of later period.