近日，云南大学冯卓团队揭示了在二叠纪末危机期间，区域森林砍伐后的风化反馈驱动了历时的C-S循环扰动。2025年10月27日出版的《美国科学院院刊》杂志发表了这项成果。

二叠纪-三叠纪（P-Tr）过渡（~252 Ma）见证了地球上最严重的生物危机，这一危机长期以来被认为与西伯利亚圈闭火山活动和相关的环境剧变有关。全球碳(C)和硫(S)循环的主要扰动主要来自海洋δ¹³C和δ³⁴S记录，而现有的陆地记录很少将δ³⁴S波动与火山成因硫酸盐气溶胶的广泛扩散和沉降联系起来。然而，越来越多的证据表明，P-Tr陆地生态系统的崩溃是历时性的，这对假设的全球同步共同强迫提出了质疑。

研究组报道了中国西南地区古热带泥炭地钻孔岩心HK-1的黄铁矿多S同位素（δ³⁴S_py和Δ³³S）和整体有机δ¹³C的记录。δ³⁴S_py的变化定义了三个不同的阶段，δ³⁴S_py在P-Tr转变过程中显著下降，表明陆地硫酸盐流入的显著增加与主要的碳循环扰动相一致。值得注意的是，总体上较小的正Δ³³S值（+0.01 ~ +0.12‰）排除了平流层硫酸盐的主导作用。

总体而言，δ¹³C_org、δ³⁴S_py和Δ³³S观测到的变化支持华夏植物区系的灾难性崩塌，导致风化和硫酸盐释放加剧。这一推断事件发生在P-Tr海洋灭绝之后，在高纬度悉尼盆地记录的几次100天的陆生植物崩溃和C-S循环的扰动之后。陆地生态系统崩溃和随之而来的C-S扰动的跨纬度历时性挑战了单一全球火山驱动因素的假设。相反，区域性森林砍伐及其叠加在全球生物地球化学循环扰动上的连锁效应，在这里成为形成地球上有记录以来最大危机的关键因素。

附：英文原文

Title: Regional postdeforestation weathering feedback drove diachronous C–S cycle perturbations during the end-Permian crisis

Author: Chen, Jianbo, Lu, Binjian, Du, Longye, Lin, Mang, Shen, Shu-zhong, Montaez, Isabel P., Feng, Zhuo

Issue&Volume: 2025-10-27

Abstract: The Permian–Triassic (P-Tr) transition (~252 Ma) witnessed Earth’s most severe biocrisis, which has long been linked to Siberian Traps volcanism and associated environmental upheaval. Major perturbation of the global carbon (C) and sulfur (S) cycles is mainly inferred from marine δ13C and δ34S records, whereas few existing terrestrial records link δ34S fluctuations to widespread dispersal and fallout of volcanogenic sulfate aerosols. Mounting evidence, however, reveals that the collapse of P-Tr terrestrial ecosystems was diachronous, questioning a hypothesized globally synchronous common forcing. Here, we present records of pyritic multiple-S isotopes (δ34Spy and Δ33S) and bulk organic δ13C for a paleotropical peatland drill core (HK-1) from Southwest China. The δ34Spy variations define three distinct phases with a notable decline in δ34Spy across the P-Tr transition, suggesting substantially elevated terrestrial sulfate influx coincident with major carbon cycle perturbation. Notably, overall small positive Δ33S values (+0.01 to +0.12‰) rule out a dominant role for stratospheric sulfates. Collectively, the observed changes in δ13Corg, δ34Spy, and Δ33S support catastrophic collapse of the Cathaysian Flora leading to intensified weathering and sulfate release. This inferred event, slightly after the P-Tr marine extinction, postdates by several 100-ky terrestrial floral collapse and perturbation of the C–S cycles documented in the high-latitude Sydney Basin. Cross-latitudinal diachroneity of terrestrial ecosystem collapse and consequent C–S perturbation challenges the hypothesis of a single, global volcanic driver. Rather, regional deforestation and its cascading effects overprinted on the global perturbations of biogeochemical cycles emerge here as critical factors shaping Earth’s largest recorded crisis.

DOI: 10.1073/pnas.2504841122

Source: https://www.pnas.org/doi/abs/10.1073/pnas.2504841122