Analysis On Relation Of Dicranopteris Dichotoma Growth And Micro-environmental Factors In Serious Degraded Area Of Southern Red Soil Region

Ecological restoration and reconstruction of damaged ecosystem becomes more and more concerned issue of the society. Ecological restoration in the eroded red soil region is one of representative areas in china. Dicranopteris dichotoma as pioneer vegetation in soil and water conservation and ecological restoration of eroded red soil region, plays important roles in ecological restoration and reconstruction. From the perspective of micro-landform, this study took typical section of southern red serious degraded areas as the subject, expored the distribution of soil nutrient and dicranopteris dichotoma over different parts, the relationships between growth characteristics of dicranopteris dichotoma and soil nutrient, simulated solar radiation and sunshine hourss based on high-resolution DEM, and than formulated land surface temperature on the basis of solar radiation. The methods and technologies of this study included surveying, pedology, spatial analytics mathematical statistics, and geographic information system. Micro-topography data, soil nutrient data, growth characteristics data of dicranopteris dichotoma, along with other meteorological data were used in this study.The main results were as follows:1) With the help of Real-time kinematic (RTK), micro terrains and plaques of Dicranopteris dichotoma data was acquired. Supporting by ARCGIS9.3and TGO software, achieving the0.1m×0.1m high-resolution DEM. And then, based on DEM, slope, aspect, slope position and topographic wetness index and so on, was extracted.2) The general situation of the soil nutrient was very poor, at the low level. The cover of dicranopteris dichotoma has a greater impact on soil nutrient, especially Total nitrogen (TN) and Organic carbon (TC). Moreover, dicranopteris dichotoma tends to valleys and gentle slopes.3) By calculating necessary topographic factors such as slope, aspect and terrain shading, assisted by geographic information systems, sunshinee hours and solar radiation was calculated, whilst, analyses the spa-temporal distribution law of theirs. The main rule shows that the distribution of sunshinee hours and solar radiation in the region of ridge is obvious higher that in low-lying areas. At last statisticing analysis the light and heat resource of the dicranopteris dichotoma coverage area and no dicranopteris dichotoma coverage area, displaying the light and heat resource of the dicranopteris dichotoma coverage area is much more than that no dicranopteris dichotoma coverage area.4) Firstly, the relationship of soil moisture at5cm depth, topographic wetness index was anlaysised. The soil moisture at5cm depth was positively correlated to topographic wetness index, the solar radiation was also significantly positively correlated to the land surface temperature. Secondly, the model of land surface temperature was formulated by adding solar radiation factors, topographic wetness index factors, and soil temperature at5cm depth factors to the multiple regression equation. Thirdly, by comparing the difference of land surface temperature, found that the cover of the dicranopteris dichotoma having a profound effect on land surface temperature.