Abstract:
The fixing soil capability of roots of 4 local herbaceous herbs,Heteropogon contortus,Eulaliopsis binata,Cymbopogon distans,Schizachyrium delavayi,which are widely distributed in dry-hot valley of Jinsha River,was studied by in situ measurement.The results showed that:(1) Roots of the 4 local herbaceous herbs enhanced anti-shearing strength of soil and fixed soil.Among the selected 4 herbs,the one with the strongest capability of enhancing soil anti-shearing strength was Schizachyrium delavayi,which was 72.5%,while the lowest was Heteropogon contortus with 2.8%.(2) Roots can reduced soil's anti-shearing strength in some special condition,which played a role in loosening the soil.It appeared in the study that the soil anti-shearing strength in the 1st sample of Heteropogon contortus was lower than that in the bare soil sample.(3) Roots can enhance soil anti-shearing strength as they enlarge the maximal shear damage displacement.Among the 4 herbs,the largest and smallest damage displacement belonged to Eulaliopsis binate and Cymbopogon distans respectively during the process of destruction,which increased by 109.4% and 32.7% than that of the bare soil sample.The extension of maximal damage displacement of soil was larger than that of the anti-shearing strength caused by herbs.(4)Among the 4 herbs,Schizachyrium delavayi had the strongest capability in fixing soil,which could be suggested as the pioneer plant for the purpose of ecological recovering,slope protection and plant fencing in ecoengineering in dry-hot valley of Jinsha River.