Abstract
Vegetation restoration can stimulate changes in soil properties and root
traits, which then cause change in rill erosion process (indicated by
rill erodibility ( Kr) as well as critical shear stress (
τc)). The present work chose eight typical
herbaceous plants, commonly appeared at diverse vegetation succession
period on the Chinese Loess Plateau, for discovering how soil properties
and root traits affected rill erosion. In total, we collected 240
undisturbed soil samples for flow scouring within the hydraulic flume in
the presence of six shear stresses (range, 5.94-18.58 Pa). According to
our findings, Kr and τc were 0.015-0.411 s
m -1 and 0.050-6.059 pa among eight typical species.
Cultivated species have high Kr and low
τc, the Kr was 4.70 to 24.28 times greater
than other species, and τc was 89.23% to 98.30%
less than other species. In addition, plants that had the tap root
system had a 4.80-fold increased Kr value compared with those
that had the fibrous root system, and τc was
49.78% less than those with fibrous root system. The Kr and
τc were affected by root-soil complex, with
interaction effects of root and soil being 54.2% and 50.4%,
respectively. The Kr decreased with bulk density, soil cohesion,
soil organic matter and soil aggregate as power functions, and decreased
with root surface area density and root length density being exponential
functions. The τc increased with specific root
length and bulk density as power functions. Of those above-mentioned
soil properties and root traits, Kr was dominantly affected by
cohesion and root surface area density, and τc
was affected by bulk density and specific root length. Kr was
simulated through soil cohesion ( Coh) and root surface area
density ( RSAD), and τc were simulated by
soil bulk density ( BD) and specific root length ( SRL) as
power functions. Our constructed model achieved satisfactory
performance.