Wang Xinwen, Liu Ziqi, Xiong Kangning, Li Yuan, Cheng Kun
School of Karst Science, Guizhou Normal University, Guiyang 550001, China.
State Engineering Technology Institute for Karst Desertification Control, Guiyang 550001, China.
Int J Environ Res Public Health. 2022 Mar 9;19(6):3210. doi: 10.3390/ijerph19063210.
Ecological restoration plays an important role in enhancing carbon sequestration ability in karst areas, and soil organic matter is one of the main carbon reservoirs in karst key zones. The serious soil erosion in karst areas leads to the loss of soil organic matter (SOM). However, the distribution characteristics of SOM and its response mechanism to soil erosion in the process of rocky desertification control have rarely been reported. In this study, soil samples of five restoration types (abandoned land, AL; grassland, GL; peanut cultivated land, PCL; land, ZBL; forest, FS) were collected in typical karst rocky desertification drainage, south China. By measuring soil organic carbon (SOC), dissolved organic carbon (DOC), and δC values and combining with spectral tools, the distribution and isotopic composition of soil shallow organic carbon in definitized karst drainage was definitized and the response of DOM spectral characteristics to soil erosion was explored. The results showed that three kinds of fluorescence components were detected by fluorescence excitation emission matrix (EEM)-parallel factor analysis (PARAFAC), C1 and C2 were humus-like, and C2 was protein-like. Abandoned could be a more suitable control measure for enhancing SOC quality in the karst regions of south China. The variation trend of SOC content, δC values, spectral indexes, and the distribution of fluorescence components from the midstream to downstream of the drainage indicated the soil redistribution. This study provides basic scientific data for karst rocky desertification control and for enhancing the soil carbon sequestration ability of karst.
生态修复在增强喀斯特地区碳固存能力方面发挥着重要作用，而土壤有机质是喀斯特关键区域的主要碳库之一。喀斯特地区严重的土壤侵蚀导致土壤有机质（SOM）流失。然而，在石漠化治理过程中，SOM的分布特征及其对土壤侵蚀的响应机制鲜有报道。本研究在中国南方典型喀斯特石漠化流域采集了五种恢复类型（弃荒地、草地、花生耕地、竹林、森林）的土壤样本。通过测定土壤有机碳（SOC）、溶解有机碳（DOC）和δC值，并结合光谱工具，明确了喀斯特流域土壤浅层有机碳的分布和同位素组成，探讨了DOM光谱特征对土壤侵蚀的响应。结果表明，通过荧光激发发射矩阵（EEM）-平行因子分析（PARAFAC）检测到三种荧光成分，C1和C2为腐殖质类，C2为蛋白质类。弃荒地可能是提高中国南方喀斯特地区SOC质量的更合适治理措施。从流域中游到下游，SOC含量、δC值、光谱指数的变化趋势以及荧光成分的分布表明了土壤的再分配。本研究为喀斯特石漠化治理和提高喀斯特地区土壤碳固存能力提供了基础科学数据。
