Study On The Characteristic Of The Root And The Soil Moisture In Caragana Belt With Different Pitch And Plant Diversity

The study was carried on Caragana shrub-grass-lam composite model with different spacing in siziwang, including 5m,10m,16m. Adopt Soil profile method and Root excavation method, Survey Soil moisture dynamics and Department of irrigation distribution of grass-roots in April to September in 2008.At the same time, Observation micro-climate and Plant diversity of plot.The results show that :⑴Caragana shelter belts can improve micro-climate environment in arid regions, at the same time,the different plant density, the extent of the impact of different climatic factors, especially the impact of changes in wind speed obviously.⑵The distribution characteristics of all roots and roots(D>0.5mm) were similar; The horizontal distribution of 5m and 10m distance was decreased with the Caragana distance;The horizontal was like wave as distance is 16m; With different spacing between the Irrigation Department of the quality of the vertical distribution of grass as follows: the overall quality of all the roots of the distribution is reduce with soil gradually deepened; From the study shows that the root of 16m distance the coefficient of variationin is smaller in the horizontal direction.⑶Soil moisture was changes in the different trends in the vertical direction, 5m is interval to reduce the type, 10m is increase with distance-based, and 16m is increased for the first, then reduced; From the soil moisture dynamic point of view of the vertical, 16m spacing is relatively small changes in soil moisture, soil moisture content in the 50cm below the lowest coefficient of variation; With different levels of pitch changes in soil moisture is anastomosis with the root level of the basic changes; the seasonal variation of soil moisture and seasonal precipitation changes are basically the same, is the highest value in August.⑷there are great differences with different spacing between the plant diversity index, evenness, number of species ;10m pitch with Peashrub spacing with the growth of better than the other, but from changes in terms of the diversity of plants, 16m distance with species richness than large, the higher the diversity of species, plants more evenly distributed.