Enhanced terrestrial nutrient release during the Devonian emergence and expansion of forests: Evidence from lacustrine phosphorus and geochemical records
Enhanced terrestrial nutrient release during the Devonian emergence and expansion of forests: Evidence from lacustrine phosphorus and geochemical records
复制标题
泥盆纪森林出现和扩张期间陆地养分释放增强：来自湖相磷和地球化学记录的证据
DOI：
10.1130/b36384.1
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Whiteside, Jessica H.
中科院分区：
文献类型：
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作者：
Smart, Matthew S.;Filippelli, Gabriel;Gilhooly III, William P.;Marshall, John E.A.;Whiteside, Jessica H.
陆地植物根系的进化在整个泥盆纪逐步发生，复杂根系的第一个证据出现在吉维特中期。这一生物创新为陆地磷 (P) 通过风化和侵蚀转移到海洋系统提供了增强的途径。这种增强与古土壤记录一致，并引发了关于泥盆纪海洋富营养化和大规模灭绝原因的假设。为了深入了解磷在陆地和海洋领域之间的迁移，我们报告了对中泥盆世和晚泥盆世湖泊和近湖泊序列的调查的地球化学记录，这些序列跨越了一些关键的海洋灭绝区间。根部创新被假设增强了磷的输送，来自欧美的多个泥盆纪序列的结果表明，陆地来源的磷净损失与早期裸子植物的出现同时发生。来自格陵兰岛和苏格兰北部/奥克尼群岛多个中晚泥盆世地点的证据显示，P的净损失几乎相同。此外，所有地点在时间上都接近一次或多次泥盆纪灭绝事件，包括与卡恰克灭绝事件以及与弗拉斯尼/法门尼大规模灭绝相关的两个脉冲的精确相关性。对于所有地点，风化、气候和氧化还原代理数据，加上养分输入的变化，揭示了与现存湖泊系统相似的地球化学反应。轨道强迫气候周期性似乎是所有重要陆地营养脉冲的催化剂，这表明陆地植物的扩张可能与区域和全球气候的变化有关。
The evolution of land plant root systems occurred stepwise throughout the Devonian, with the first evidence of complex root systems appearing in the mid-Givetian. This biological innovation provided an enhanced pathway for the transfer of terrestrial phosphorus (P) to the marine system via weathering and erosion. This enhancement is consistent with paleosol records and has led to hypotheses about the causes of marine eutrophication and mass extinctions during the Devonian. To gain insight into the transport of P between terrestrial and marine domains, we report geochemical records from a survey of Middle and Late Devonian lacustrine and near-lacustrine sequences that span some of these key marine extinction intervals. Root innovation is hypothesized to have enhanced P delivery, and results from multiple Devonian sequences from Euramerica show evidence of a net loss of P from terrestrial sources coincident with the appearance of early progymnosperms. Evidence from multiple Middle to Late Devonian sites in Greenland and northern Scotland/Orkney reveal a near-identical net loss of P. Additionally, all sites are temporally proximal to one or more Devonian extinction events, including precise correlation with the Kačák extinction event and the two pulses associated with the Frasnian/Famennian mass extinction. For all sites, weathering, climate, and redox proxy data, coupled with nutrient input variability, reveal similar geochemical responses as seen in extant lacustrine systems. Orbitally forced climatic cyclicity appears to be the catalyst for all significant terrestrial nutrient pulses, which suggests that expansion of terrestrial plants may be tied to variations in regional and global climate.