Key Laboratory of Groundwater Resources and Environment (Jilin University), Ministry of Education, Changchun 130026, China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130026, China.
Key Laboratory of Groundwater Resources and Environment (Jilin University), Ministry of Education, Changchun 130026, China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130026, China.
Sci Total Environ. 2024 Apr 20;922:171361. doi: 10.1016/j.scitotenv.2024.171361. Epub 2024 Feb 29.
Wetland degradation can induce alterations in plant biomass, soil properties, and soil ecoenzyme activities, consequently influencing soil organic carbon components. Despite extensive investigations into the relationships among plant characteristics, soil properties, and soil organic carbon components, the enzymatic mechanisms underlying changes in soil organic carbon components, particularly the impact and contribution of ecoenzyme activities, remain poorly understood. This study compared the soil organic carbon components at a depth of 0-20 cm in wetlands in the semi-arid western Songnen Plain under different degradation levels and explored plant biomass, soil properties, and soil ecoenzyme activities. The results showed that the soil total organic carbon, labile organic carbon, and recalcitrant organic carbon contents in the degraded wetlands were generally lower than those in the non-degraded wetlands. Furthermore, the soil nutrient contents and soil β-1,4-glucosidase, L-leucine aminopeptidase, and acid phosphatase activities were also lower in the degraded wetlands than in the non-degraded wetlands. Vector analysis of enzymatic stoichiometry revealed that wetland degradation did not increase microbial carbon limitation. The soil organic carbon components showed significant positive correlations with plant biomass, soil water content, soil total nitrogen, soil total phosphorus, as well as soil ecoenzyme activities. Variation partitioning analysis revealed that plant biomass, soil properties, soil ecoenzyme activities collectively accounted for 78.5 % variation in soil organic carbon components, among which plant biomass, soil properties, soil ecoenzyme activities, and their interactions explaining 4.2 %, 8.0 %, 7.9 %, and 24.5 % of the variation, respectively. Therefore, the impact of soil ecoenzyme activities and soil properties on soil organic carbon component changes was greater than that of plant biomass, with the interaction of these three factors playing a crucial role in soil organic carbon formation. This study provides a theoretical basis for scientifically evaluating the carbon sink function of degraded wetland soil and preserving the wetland soil carbon pool.
湿地退化会导致植物生物量、土壤性质和土壤生态酶活性发生变化，从而影响土壤有机碳组分。尽管人们广泛研究了植物特征、土壤性质和土壤有机碳组分之间的关系，但对于土壤有机碳组分变化的酶学机制，特别是生态酶活性的影响和贡献，仍知之甚少。本研究比较了不同退化水平下半干旱西部松嫩平原湿地 0-20 cm 深度处的土壤有机碳组分，并探讨了植物生物量、土壤性质和土壤生态酶活性。结果表明，退化湿地的土壤总有机碳、活性有机碳和惰性有机碳含量普遍低于非退化湿地。此外，退化湿地的土壤养分含量和土壤β-1,4-葡萄糖苷酶、L-亮氨酸氨肽酶和酸性磷酸酶活性也低于非退化湿地。酶化学计量向量分析表明，湿地退化并没有增加微生物碳限制。土壤有机碳组分与植物生物量、土壤含水量、土壤全氮、土壤全磷以及土壤生态酶活性呈显著正相关。方差分解分析表明，植物生物量、土壤性质、土壤生态酶活性共同解释了土壤有机碳组分 78.5%的变异，其中植物生物量、土壤性质、土壤生态酶活性及其相互作用分别解释了 4.2%、8.0%、7.9%和 24.5%的变异。因此，土壤生态酶活性和土壤性质对土壤有机碳组分变化的影响大于植物生物量，这三个因素的相互作用对土壤有机碳的形成起着关键作用。本研究为科学评价退化湿地土壤碳汇功能和保护湿地土壤碳库提供了理论依据。
