Spatio-temporal Simulation and Statistical Analysis of Soil Total Nitrogen in Alpine Meadow of Gannan

Abstract

To determine the temporal and spatial characteristics of soil nitrogen in the alpine meadow of Gannan, China, the contents of soil organic nitrogen, mineral nitrogen and soil total nitrogen in Gannan alpine meadow from 1971 to 2020 were simulated based on the localized CENTURY model, on this basis, the spatial and temporal distribution of soil nitrogen of the study area was visualized. The influence of various environmental factors on soil nitrogen in the alpine meadow of Gannan was analyzed. The results show that from 1971 to 2020, the soil organic nitrogen in the study area has moderate spatial variability. Active soil organic nitrogen pool and chronic soil organic nitrogen pool accounted for 11.2% and 39.8% of total soil organic nitrogen, respectively. The inert soil organic nitrogen pool accounts for 49.0% of the total organic nitrogen in the soil. In spatial distribution, the total organic nitrogen and total mineral nitrogen in the alpine meadow of Gannan showed a decreasing trend from west to east, and the total mineral nitrogen content in the soil decreased significantly with the increase of soil depth. Correlation analysis of soil nitrogen and environmental factors and structural equation model showed that precipitation, elevation, soil organic matter content and silt content had positive correlation with soil organic nitrogen and mineral nitrogen contents. The effects of sand content and temperature on soil organic nitrogen and mineral nitrogen contents were negatively correlated.