近期《自然—通讯》期刊发表文章，指蚯蚓吸收土壤中的二氧化碳比排放的多。这一发现反驳了最近“蚯蚓会导致二氧化碳排放量大幅上升”的说法。
科学家知道，土壤中的二氧化碳是大气中的两倍，而蚯蚓对土壤的碳产量、碳储存量、以及碳排放量都有影响。中国科学院华南植物院傅声雷与其研究团队发现蚯蚓很有可能是碳汇（carbon sink），因为蚯蚓吸收的二氧化碳比矿化作用转化的二氧化碳多。他们的实验表明，养殖了亚洲蚯蚓和欧洲蚯蚓的土壤，最初会释放大量二氧化碳，但碳排放量会随着时间被蚯蚓的碳吸收量抵消，因此有蚯蚓与没蚯蚓的土壤在碳总排放量上相差不大。作者还提出了一种数学公式，不但能量化蚯蚓对土壤碳储存量的影响，更能准确预测土壤碳通量。
该研究团队得出的结论是，蚯蚓对土壤碳排放量的影响可能被严重高估了，至少它们不会令碳排放量增加33％。然而，地球上有超过3000种蚯蚓和各种不同的土壤，研究团队还需要更多的才能确定蚯蚓是“敌”还是“友”。（生物谷Bioon.com）
生物谷推荐的英文摘要
Nature Commmunications doi:10.1038/ncomms3576
Earthworms facilitate carbon sequestration through unequal amplification of carbon stabilization compared with mineralization
Weixin Zhang，Paul F. Hendrix，Lauren E. Dame，Roger A. Burke，Jianping Wu，Deborah A. Neher，Jianxiong Li，Yuanhu Shao& Shenglei Fu
A recent review concluded that earthworm presence increases CO2 emissions by 33% but does not affect soil organic carbon stocks. However， the findings are controversial and raise new questions. Here we hypothesize that neither an increase in CO2 emission nor in stabilized carbon would entirely reflect the earthworms’ contribution to net carbon sequestration. We show how two widespread earthworm invaders affect net carbon sequestration through impacts on the balance of carbon mineralization and carbon stabilization. Earthworms accelerate carbon activation and induce unequal amplification of carbon stabilization compared with carbon mineralization， which generates an earthworm-mediated ‘carbon trap’. We introduce the new concept of sequestration quotient to quantify the unequal processes. The patterns of CO2 emission and net carbon sequestration are predictable by comparing sequestration quotient values between treatments with and without earthworms. This study clarifies an ecological mechanism by which earthworms may regulate the terrestrial carbon sink.
