红树林恢复对湿地土壤有机碳库的影响及其调控因素
- Effects of mangrove restoration on wetland soil organic carbon pools and its regulatory factors
- 基金项目：中央财政林业科技推广示范项目（闽【2024】TG28号）；福建省林业科技项目（No.2025FKJ16）；国家自然科学基金（No.42171102）
- 摘要：人工红树林恢复对湿地土壤有机碳变化具有重要影响。本研究以福建沙埕港不同恢复年限(2年、6年、16年、25年)的人工红树林为研究对象，以天然红树林与养殖滩涂(恢复前)为对照，研究红树林恢复对湿地土壤有机碳库变化的影响及其调控因素。结果表明：(1)随着红树林恢复年限的增加，土壤盐度、有机质、总碳和总氮含量显著增加(p<0.05)，pH值降低，β-葡萄糖苷酶活性先降后升，而纤维二糖水解酶活性虽呈上升趋势但未达到显著性水平(p>0.05)；(2)红树林恢复16年后，土壤有机碳、颗粒态有机碳、矿物结合态有机碳含量和碳储量均显著高于天然红树林和养殖滩涂(p<0.001)，而在恢复25年后，尽管这些指标仍在增长，但增速已趋缓，且与恢复2年红树林相比分别增加了61.0%、225.8%、51.9%和50.9%，但土壤碳库稳定性指数随红树林恢复年限的增加呈下降趋势；(3)结构方程模型和相关性分析结果表明，红树林恢复过程中，土壤盐度、有机质、总碳和总氮含量及土壤酶活性是碳储量积累的正向驱动因素，而pH值与碳库稳定性指数呈正相关。研究结果可为揭示人工红树林长期恢复过程中土壤碳库的变化规律提供理论依据。
- Abstract：Artificial mangrove restoration plays a critical role in shaping the dynamics of wetland soil organic carbon (SOC). This study investigated the effects of mangrove restoration on changes in wetland soil organic C pools and their regulating factors, using artificially restored mangroves in Shacheng Port, Fujian Province, with restoration durations of 2, 6, 16, and 25 years. Natural mangroves and pre-restoration aquaculture tidal flats were used as control treatments. The results showed: The results showed: (1) With increasing restoration years, soil salinity, organic matter, total C (TC), and total nitrogen (TN) contents significantly increased (p<0.05), while pH decreased. β-glucosidase activity first decreased then increased, whereas cellulose-binding enzyme activity showed an upward trend but did not reach statistical significance (p>0.05). (2) After 16 years of restoration, soil organic carbon (SOC), particulate organic carbon (POC), mineral-associated organic carbon (MAOC), and C stocks were all significantly higher than those in natural mangroves and aquaculture tidal flats (p<0.001). However, after 25 years of restoration, while these indicators continued to increase, the growth rate had slowed. Compared to 2-year-old restored mangroves, the 25-year-old restored mangroves exhibited increases of 61.0%, 225.8%, 51.9%, and 50.9% in SOC, POC, MAOC, and C stocks, respectively. However, the soil C stability index decreased with increasing restoration years. (3) Structural equation modeling and correlation analysis revealed that soil salinity, organic matter, TC, TN content, and soil enzyme activity were positive drivers of C stock accumulation during mangrove restoration. Meanwhile, pH values and the C stability index were positively correlated. These findings provide theoretical insights into the long-term dynamics of soil C pools during artificial mangrove restoration.
