近日，美国加州大学Bowen, Jennifer C.课题组在研究运河网络调节退化热带泥炭地的水生碳损失中取得新进展。相关论文于2024年3月8日发表于国际顶尖学术期刊《自然—地球科学》杂志上。

课题组成员研究了人为干扰对覆盖在泥炭地排水管道网络中，泥炭溶解有机碳(DOC)水生生物命运的影响。实验测定了印度尼西亚西加里曼丹收集的，运河水域的微生物呼吸速率和DOC的光化学矿化，结果表明，这两种途径都会导致水柱中的DOC快速氧化为二氧化碳。通过对泥炭DOC处理控制的系统评估，研究确定了预测每日速率所需的关键变量，并表明在东南亚各地的排水渠道中，DOC氧化量可能在15至310mgC m^-2d^-1之间。具体取决于特定日期的水化学、水文和气象。

典型条件下，DOC氧化平均为70mgC m^-2d^-1，表明这一过程可能会使运河输出的泥炭DOC减少约35%。研究结果强调，排水渠道网络是土地扰动后陆地碳损失的热点，并强烈调节整个景观中泥炭碳的水生损失。

据了解，东南亚泥炭地覆盖了地球陆地表面积的0.2%，储存了全球泥炭土壤碳总量的十分之一。近年来的森林砍伐和排水系统破坏了这些碳储存的稳定，增加了对水生生物和大气储存库的碳输入。

附：英文原文

Title: Canal networks regulate aquatic losses of carbon from degraded tropical peatlands

Author: Bowen, Jennifer C., Wahyudio, Putri J., Anshari, Gusti Z., Aluwihare, Lihini I., Hoyt, Alison M.

Issue&Volume: 2024-03-08

Abstract: Southeast Asian peatlands cover 0.2% of Earth’s land surface, but store one-tenth of all peat soil carbon globally. Recent deforestation and drainage have destabilized these carbon stores, increasing carbon inputs to aquatic and atmospheric reservoirs. Here we investigate the impact of anthropogenic disturbance on the aquatic fate of peat dissolved organic carbon (DOC) within networks of drainage canals overlying disturbed peatlands. We measured microbial respiration rates alongside photochemical mineralization of DOC for canal waters collected across West Kalimantan, Indonesia, and found that both pathways lead to rapid DOC oxidation to carbon dioxide in the water column. Carrying out a systematic assessment of the controls on peat DOC processing, we identify key variables needed to predict daily rates and show that DOC oxidation may range from 15 to 310mgC m^-2d^-1 in drainage canals across Southeast Asia, depending on the water chemistry, hydrology and meteorology on any given day. DOC oxidation averaged 70mgC m^-2d^-1 under typical conditions, indicating that this process may reduce canal export of peat DOC by ~35%. Findings from this study demonstrate that drainage canal networks are a hotspot for terrestrial carbon loss following land disturbance and strongly regulate aquatic loss of peat carbon across the landscape.

DOI: 10.1038/s41561-024-01383-8

Source: https://www.nature.com/articles/s41561-024-01383-8