Changes in Soil Carbon Fractions and Enzyme Activities Under Different
Vegetation Types of the Northern Loess Plateau
Abstract
Restoring vegetation can effectively reduce soil erosion and
significantly improve soil properties and quality. To analyze the
response of soil organic carbon components and related enzymes to
different vegetation types in the northern Loess Plateau, we collected
soil samples of four vegetation types: Xanthoceras sorbifolia (XS),
Hippophae rhamnoides (HR), Caragana korshinskii (CK), and Grassland
(GL). We used these samples to analyze the organic carbon components
(i.e., soil organic carbon (SOC), microbial biomass carbon (MBC), easily
oxidized carbon (EOC), particulate organic carbon (POC) )and enzyme
activities (i.e., amylase, catalase, urease and sucrase). We found that
the content of the soil organic carbon fractions and the enzyme
activities was greater in the upper layer than in the lower layer for
each vegetation type except for MBC and catalase activity, where we
observed no significant difference between soil layers. The EOC and
amylase of GL vegetation were significantly higher than in other
vegetation types. POC, SOC, urease and sucrase were considerably higher
in SX vegetation than in other vegetation types. The maximum soil MBC
content was found in HR vegetation, and among the four vegetation types,
MBC content varied significantly differences in the lower layer, but no
significant difference was observed in the surface soil. Correlation
analysis demonstrated that the MBC content significantly influenced
urease and sucrase activities, and that SOC significantly influenced
urease and sucrase activities. These results emphasize the importance of
the organic components of soil and the activities of soil enzymes in
different kinds of vegetation in the Loess Plateau, providing a basis
for improving the sustainable restoration of vegetative ecosystems.