瑞士苏黎世大学Zosso, Cyrill U.和Schmidt, Michael W. I.及其研究团队报道了在整个土壤变暖背景下，底土中复杂聚合物和热解碳的迅速流失。相关论文于2023年3月30日发表于国际顶尖学术期刊《自然—地球科学》杂志上。

研究人员表明，4.5年的全土壤变暖(+ 4 °C)，导致变暖的底土(20 - 90 厘米)中的聚合土壤有机碳(特定的聚合物对有机碳的贡献总和)减少，但没有检测到表层土壤的变化。变暖刺激了木质素酚类(-17± 0%)的底土流失，这些酚类来自于木本植物生物质、可水解脂质角质和木栓质(-28± 3%)以及不完全燃烧过程中产生的热解碳(-37± 8%)。

值得注意的是，鉴于这些化合物已经被提议用于长期碳封存，它们在变暖的土壤中迅速流失。研究人员得出这样的结论，底层的土壤中复杂的聚合碳易于分解，并提议，在未来变暖的情况下，分子结构本身可能无法保护化合物免受降解。

据介绍，底土含有超过一半的土壤有机碳(SOC)，预计在未来几十年将经历快速变暖。然而，在全球变暖的情况下，人们对这个巨大碳库的稳定性的理解是不明确的。特别是复杂分子结构(聚合物)的命运仍然存在争论。

附：英文原文

Title: Rapid loss of complex polymers and pyrogenic carbon in subsoils under whole-soil warming

Author: Zosso, Cyrill U., Ofiti, Nicholas O. E., Torn, Margaret S., Wiesenberg, Guido L. B., Schmidt, Michael W. I.

Issue&Volume: 2023-03-30

Abstract: Subsoils contain more than half of soil organic carbon (SOC) and are expected to experience rapid warming in the coming decades. Yet our understanding of the stability of this vast carbon pool under global warming is uncertain. In particular, the fate of complex molecular structures (polymers) remains debated. Here we show that 4.5 years of whole-soil warming (+4°C) resulted in less polymeric SOC (sum of specific polymers contributing to SOC) in the warmed subsoil (20–90cm) relative to control, with no detectable change in topsoil. Warming stimulated the subsoil loss of lignin phenols (-17±0%) derived from woody plant biomass, hydrolysable lipids cutin and suberin, derived from leaf and woody plant biomass (-28±3%), and pyrogenic carbon (-37±8%) produced during incomplete combustion. Given that these compounds have been proposed for long-term carbon sequestration, it is notable that they were rapidly lost in warmed soils. We conclude that complex polymeric carbon in subsoil is vulnerable to decomposition and propose that molecular structure alone may not protect compounds from degradation under future warming.

DOI: 10.1038/s41561-023-01142-1

Source: https://www.nature.com/articles/s41561-023-01142-1