Abstract: he study on the root distribution characters of Robinia pseudoacacia and soil moisture status in the Loess Plateau showed that on shady slope,there was no obvious difference in the horizontal distribution of R.pseudoacacia fine roots within 2.0 m from the stem,and the maximal distribution depth of the roots could reach 2.0 m.In sunny slope,the vertical distribution of the roots within 0.5 m from the stem could also reach that depth.The root amount in shady slope was larger than that in sunny slope,and the affected depth of R.pseudoacacia roots on soil moisture status reached 3.3 m in shady slope,while 2.7 m in sunny slope.

Key words: Photosynthesis, Transpiration, Stomatal resistance, Environmental factors, Correlation