Effect of changing from natural forest to economic forest on soil water
infiltration and its underlying mechanisms
Abstract
Soil infiltration is a hydrological process dramatically affected by
land use/cover changes. Taking the miscellaneous woody forest (MWF), a
natural vegetation cover in the Dabie mountainous area, China, as the
reference (control), this study aimed to evaluate the effect of litter,
root traits, and soil properties on soil infiltrability and quantify the
characteristics of soil infiltration processes of four
intensively-managed sloping economic forests, including Castanea
Mollissima forest (CMF), Castanea Mollissima-tea inter-planting forest
(CMTF), Camellia Oleifera forest (COF), and Camellia Oleifera-tea
inter-planting forest (COTF). The results showed that significant
differences in soil water infiltration under different land use and
management types (p < 0.05). Soil initial infiltration rate
(IIR), average infiltration (AIR) and steady infiltration rate (SIR)
decreased 39.63%-60.88%, 46.11%-67.39% and 49.88%-72.8%,
respectively after the native forests were developed to economic
forests, following the order: MWF > CMTF >
COTF > CMF > COTF, but no significant
difference was found between CMTF and COTF (p > 0.05). Soil
water infiltration characteristics measured by IIR, AIR, and SIR were
positively correlated to litter coverage, litter thickness, the maximum
water-holding capacity of the litter, effective water-retention
capacity, maximum water-retention capacity, root traits, capillary
porosity, non-capillary porosity, total porosity, soil organic matter,
and clay and silt content (p < 0.05), but negatively
correlated with the bulk density, and sand and gravel content (p
< 0.05). Variation partitioning analysis showed that soil
water infiltration was more susceptible to soil properties than litter
characteristics or root traits. The redundancy analysis explained 99.97
% of the variation to explore the relationship between litter
characteristics, root traits, soil properties, and soil water
infiltration characteristics, and the clay content is the main factor
affecting soil water infiltration. The structural equation model
suggested that land use and management indirectly affect soil
infiltrability by modulating soil properties through affecting litter
and root traits, with clay content having a higher contribution.