摘要
泥炭地是重要的陆地碳汇, 但由于具有自然综合体的特性, 泥炭地长期碳累积过程及其对气候变化的响应具有复杂性, 会受到生态系统多要素交互作用的制约。生态系统模型通过参数化描述碳循环过程, 是解开气候响应复杂性的有效工具。本研究简要介绍了DigiBog模型的基本结构及针对我国季风区特征的改进方案, 并以长白山老里克的全新世雨养型泥炭地为代表性研究对象, 在参数校准的基础上, 基于模型模拟分析了泥炭地碳累积过程的参数敏感性及其对不同气候强迫和情景的响应机制。结果表明: 1)泥炭地的长期碳累积受多种要素共同控制, 除气候要素(温度、降水)外, 直接控制泥炭生产-分解过程和水文过程的局地非气候要素作用突出;2)泥炭地在长时间尺度上表现出气候适应性, 能在气候突变后通过调节泥炭累积和水文过程, 向无气候强迫模拟的基准水平恢复;在短期温度升高6 ℃和降水减少40 % 的极端情形下, 泥炭地能在4000年内自发恢复碳汇功能;3)在未来暖湿化背景下, 由于降水增加对碳汇功能的促进作用不足以抵消温度升高对碳汇功能的削弱作用, 泥炭地的净碳平衡不断下降, 在最高排放SSP5-8.5情景下可能于2070~2080年向碳源转变, 但21世纪末时的总碳损失相较于总碳储量低于1 %。通过对比分析发现, 我国季风区雨养型泥炭地碳累积的控制因素和气候响应特征与前人利用DigiBog模型对温带海洋性气候区雨养型泥炭地的研究结果不完全一致, 这主要反映了两个研究区在气候条件、泥炭地优势植物和水文过程方面的差异。
Peatlands are important terrestrial carbon sinks. However, due to their nature as natural integrated systems, the long-term carbon accumulation processes of peatlands and their responses to climate change are complex, being complicated by the interactions of multiple ecosystem factors. Ecosystem models, which parameterize carbon cycle processes, are effective tools for unraveling the complexity of climate responses. This study provides a brief introduction to the basic structure of the DigiBog model and its improvements considering the characteristics of the monsoon region of China. Using the rain-fed Laolike peatland (42°28'40″N, 128°39'54″E) from the Changbai Mountains as a representative study site (peat depth 5 m, initiation age 11500 a B.P.), after model calibration we conducted model simulations to analyze the parameter sensitivity of peatland carbon accumulation as well as response mechanisms of peatlands under different climate forcings and scenarios. The results indicate that: (1) Long-term carbon accumulation of peatlands is controlled by multiple factors. In addition to climate factors (temperature and precipitation), local non-climate factors that directly regulate peat production-decomposition processes and hydrological processes play a prominent role;(2) Peatlands exhibit climate resilience over long timescales, being capable of recovering to no-climate-forcing baseline conditions through self-regulation of peat accumulation and hydrological processes following abrupt climate shifts. In the extreme cases of abrupt temperature increase of 6 ℃ and precipitation decrease of 40 %, the carbon sink function autogenically restores within 4000 years. (3) Under the background of future warming and wetting scenario, as the strengthening of carbon sink function from increased precipitation is insufficient to counteract the weakening effect from rising temperatures, the net carbon balance of peatlands will continue to decrease, potentially causing peatlands to shift to a carbon source during 2070~2080 under the highest emission SSP5-8.5 scenario. However, the total carbon loss at the end of 21th century is less than 1 % of the total carbon storage. From comparisons with previous studies, this study suggests that the controlling factors and climate response characteristics of carbon accumulation from rain-fed peatlands in China's monsoon regions are not entirely consistent with previous DigiBog-based studies on rain-fed peatlands in temperate oceanic climate regions. This discrepancy primarily reflects differences in climate conditions, dominant peatland vegetation, and hydrological processes between the two regions.
作者
李萌
夏正宇
李跃峰
董彦民
于子成
LI Meng;XIA Zhengyu;LI Yuefeng;DONG Yanmin;YU Zicheng(Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains,Ministry of Education,School of Geographical Sciences,Northeast Normal University,Changchun 130024,China;State Key Laboratory of Black Soils Conservation and Utilization(Under Construction),Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Changchun 130102,China)
出处
《第四纪研究》
北大核心
2025年第3期789-805,共17页
Quaternary Sciences
基金
国家自然科学基金项目(批准号:42494822、42330509和42201167)
中央高校基本科研业务费项目(批准号:2412023YQ006)
吉林省科技厅自然科学基金项目(批准号:20230101077JC)共同资助。
关键词
泥炭地
数值模型
碳累积
全新世
未来预测
peatlands
numerical models
carbon accumulation
Holocene
future projections
