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多年冻土区森林土壤可溶解性有机碳研究进展及影响因素
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Abstract:
多年冻土区是典型的生态环境脆弱区和全球重要的土壤碳库。气候变暖引发的多年冻土融化加剧了土壤中可溶解性有机碳(DOC)的释放与迁移，对全球碳循环产生了显著影响，进而可能加剧全球气候变化。近年来，相关研究集中探讨了多年冻土泥炭地可溶性有机碳的季节变化特征，包括浓度变化、化学组成以及迁移特性，揭示了温度、土壤水分状况、植被变化、泥炭地排水及微生物活动等多种因素对可溶性有机碳的显著影响。随着全球气候变暖加剧，多年冻土的退化进一步加速了土壤活动层内微生物群落组成的改变，推动了碳的矿化过程，增加了向大气释放的潜在风险。当前广泛应用的紫外可见光谱与高分辨率质谱技术虽可揭示DOC的芳香性及腐殖质等特征，但仍然缺乏分子层面的深入解析。此外，针对中高纬度多年冻土泥炭地的研究仍然较为匮乏。因此，未来需进一步深入研究多年冻土泥炭地DOC特征的季节变化机制及其环境影响因素。
Permafrost regions are ecologically fragile zones and important global soil carbon reservoirs. The thawing of permafrost induced by climate warming accelerates the release and migration of dissolved organic carbon (DOC), significantly impacting global carbon cycling and exacerbating climate change. Recent research has extensively examined the seasonal variations of DOC concentration, composition, and sources within forest soils in permafrost regions. Studies indicate substantial DOC variability influenced by factors such as temperature fluctuations, soil moisture, vegetation dynamics, microbial activities, and hydrological conditions. DOC in these regions demonstrates notable seasonal variation, influenced by factors including thaw depth, vegetation type, drainage patterns, and microbial activities. Techniques such as ultraviolet-visible spectroscopy and high-resolution mass spectrometry have been applied to evaluate DOC’s chemical characteristics, particularly its aromaticity and humic components. However, these approaches have limitations in revealing molecular-level information, especially within mid-to-high latitude permafrost peatlands, where related studies remain scarce. Future investigations should focus on elucidating the underlying mechanisms of DOC seasonal variability and exploring environmental factors influencing DOC dynamics in diverse permafrost ecosystems.
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