Abstract:
The vegetation restoration and ecological management of Jingshajiang dry-hot valley has become a difficult problem due to the harsh nature environment such as high temperatures and drought.To study roots growth characteristics of introduced Pennisetum sinese in different slope positions in core area of dry-hot valley,ecological adaptability and feasibility was analyzed.The results showed that:① two years after introduction,most P. sinese in all slope positions survived and kept on growing;② the average diameter,biomass,content of C,m(C)/m(N) and m(C)/m(P) of the P. sinese roots increased by the increase of root orders,but root length (SRL),root length density (RLD),root volume density (RVD),root surface area density (RSAD),the contents of N,P and N/P decreased by the increase of the root orders;③ root biomass,average diameter,RLD,RVD and RSAD under different root orders in all slope positions was ranked as follow: middle slope>lower slope>upper slope,and the SRL was upper slope>middle slope>lower slope;④ for all root orders,the C content and m(C)/m(P) in roots of all slopes was ranked as lower slope>upper slope>middle slope,the content of N,P and m(N)/m(P) was lower slope>middle slope>upper slope,m(C)/m(N) was upper slope>middle slope>lower slope.In general,P. sinese in all studied slope positions grows normally,the growth condition is best in the middle slope.