Regional Differentiation and It’s Influencing Factors of Soil Easily-oxidized Organic Carbon in Subtropical Phyllostachys edulis Forests

【 Objective】 The vertical and latitudinal distribution of soil easily-oxidized organic carbon (EOC) in the north subtropical, middle subtropical ， and south subtropical regions of Phyllostachys edulis forests were studied to reveal the main influencing factors of its regional differentiation, which provided scientific basis for carbon sequestration, management ， and stability of soil organic carbon pool in P. edulis forests.【 Method】 Through field investigation and experimental analysis, the variation rules of soil easily-oxidized organic carbon content along soil layer and latitude was revealed. Factor detection, interaction detection and risk detection of geodetector were used to analyze the factors affecting the regional differentiation of soil easily-oxidized organic carbon.【 Result】 1) Soil easily-oxidized organic carbon content of P. edulis forests decreases with deepening of soil layers in each region, but its proportion to total soil organic carbon increased with the deepening of soil layer. Easily-oxidized organic carbon contents of 0−60 cm soil layer of northern subtropical P. edulis forests (5.16 g·kg−1) was higher than that in the middle (4.56 g·kg−1) and southern (4.86 g·kg−1) subtropics. The stability of soil carbon pool decreased with decreasing latitude. 2) Mean annual temperature (MAT) was the most important factor in explaining soil easily-oxidized organic carbon of P. edulis forests, with q values ranging from 0.376 to 0.452, followed by elevation (q=0.392, P−1) and lowest at 15−17 ℃ (2.69−6.20 g·kg−1). Soil easily-oxidized organic carbon contents was highest in each soil layer at elevation of 700−900 m. The highest easily-oxidized organic carbon contents was reached at a layer of 0−10 cm when stand biomass was 75−90 t·hm−2. 【Conclusion】The content of easily-oxidized organic carbon in the soil of the P. edulis forests decreased with the deepening of the soil layer, and its proportion in the total soil organic carbon content showed the latitudinal distribution of north subtropics © 2024 Chinese Society of Forestry. All rights reserved.