水保所知识产出(1956---)知识库

Plant root systems can greatly reduce soil loss, and their effects on soil erosion differ across species due to their
varied root traits. The purpose of this study was to determine the effects of root morphology traits of herbaceous
plants on the soil detachment process. Ten herbaceous plants (dominant species) in the Loess Plateau were se-
lected, and 300 undisturbed soil samples (including living roots from the selected herbages) were scoured
with flowing water to measure their soil detachment capacities under six levels of shear stress (4.98 to
16.37 Pa). Then, the root traits of each soil sample were measured, and the rill erodibility and critical shear stress
wereestimatedbasedontheWaterErosion PredictionProject(WEPP)model.Theresults showedthatrootmor-
phology traits varied greatly among the ten selected herbages. Accordingly, resulting variations in soil detach-
ment capacity (0.030 to 3.297 kg m −2 s −1 ), rill erodibility (0.004 to 0.447 s m −1 ), and critical shear stress
(4.73 to 1.13 Pa) were also observed. Plants with fibrous roots were more effective than those with tap roots
in reducing soil detachment. Their mean soil detachment capacity and rill erodibility were 93.2% and 93.4%
lower,respectively,andtheir meancriticalshear stress was1.15times greaterthan that oftheherbaceous plants
with tap root systems. Of all the root traits, root surface area density (RSAD) was the primary root trait affecting
the soil detachment, and it estimated the soil detachment capacity well (R 2 = 0.91, normalized squared error
(NSE) = 0.82). Additionally, an equation with few factors (soil aggregate and RSAD) was suggested to simulate
the soil detachment capacity when the plant root parameters and soil properties were limited.