Level Terrace Enhances the Distribution of Soil Organic Carbon Along the Depth Gradient in Mixed Forests: Microbial Mechanisms and Carbon Fraction Dynamics on the Loess Plateau
Description
1. Soil organic carbon and its fractions mineral-associated organic carbon (MAOC), particulate organic carbon (POC), soil organic carbon (SOC) 2. Soil nutrient availability regulatory factors Soil bulk density (BD) , Soil water content (SWC) , Soil pH, Total nitrogen (TN) , Total phosphorus (TP) , dissolved organic carbon (DOC) , dissolved organic nitrogen (DON), Nitrate nitrogen (NO3⁻-N) , ammonium nitrogen (NH4⁺-N) , Available potassium (AK) , available phosphorus (AP) 3. Microbial biomass and extracellular enzymes Microbial biomass carbon (MBC) , microbial biomass nitrogen (MBN) , Microbial biomass phosphorus (MBP) . The activities of soil β-glucosidase (BG), β-N-acetyl-glucosaminidase (NAG), leucine aminopeptidase (LAP), alkaline phosphatase (AlkP), and cellobiohydrolase (CBH) .