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NERC-NSFGEO Community And Structural Collapse During Mass Extinctions (CASCaDE)

NERC-NSFGEO 大规模灭绝期间的群落和结构崩溃 (CASCaDE)

基本信息

批准号：
NE/X015025/1
负责人：
Alexander Dunhill
金额：
$ 94.61万
依托单位：
University of Leeds
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2023
资助国家：
英国
起止时间：
2023 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FX015025%2F1
关键词：
NERC NSFGEO Community Structural Collapse

项目摘要

A thorough understanding of extinction events has never been more important as we are entering a biodiversity crisis that is being heralded as the "Sixth Mass Extinction". But are we really heading for a mass extinction and how will this current event compare to the catastrophic biotic crises of the geological past? The geological record provides a wealth of information for studying ecosystem dynamics and collapse under rapid climate change and understanding these events may be key in helping to predict the consequences of anthropogenic warming for existing and future marine ecosystems. One great unanswered extinction question is why do rapid warming events of the Palaeozoic and Mesozoic consistently trigger mass extinction whereas similarly extreme climatic events of the Cenozoic do not? An argument put forward to explain this mismatch is that modern ecosystem structure was established in the early Cenozoic in the aftermath of the Cretaceous-Paleogene mass extinction (66 Ma) and that the reason for the lack of Cenozoic mass extinctions lies in the increased robustness of modern marine ecosystems. However, palaeobiological studies of extinction currently lack critical sources of information about how organisms interact with one another within ecosystems. We know from contemporary ecological studies that interactions between organisms play a pivotal role in the structure, function and resilience of modern ecosystems. Therefore, it makes it very difficult to interpret the dynamics of extinctions and ecosystem collapse across mass extinction events without a good understanding of the biotic interactions within communities.CASCaDE will drive a fundamental change in extinction palaeobiology via a novel and cross-disciplinary approach combining recent advances in ecological modelling with palaeontology. Specifically, we will test the role of marine ecosystem robustness and stability (which is determined by predator/prey interactions in food webs) in determining vulnerability to climate-triggered extinction cascades. We will investigate various periods of rapid global warming in the geological record - some that triggered mass extinction and others that did not. We will use a computer modelling approach to simulate several hypothetical extinction scenarios on fossil ecosystems pre-dating the climatic change events. These scenarios will be developed to represent known environmental stresses associated with rapid greenhouse warming i.e. rise in ocean temperature, ocean anoxia, and ocean acidification. We will then test which hypothetical extinction scenario best predicts post-event ecosystem structure. Specifically, we will test the hypothesis that differences in Palaeozoic/Mesozoic and Cenozoic food web structure and ecosystem resilience interacted with extreme climatic conditions differently leading to wholesale ecosystem collapse in the Palaeozoic and Mesozoic but not in the Cenozoic. We will also explore how uncertainty in the reconstruction of the food webs linked to varying fossil preservation potential might influence out predictions.CASCaDE aims to push quantitative palaeobiology and conservation biology into new territory via modelling biotic interactions within ancient ecosystems and enabling predictions of extinction risk to rapid warming in modern marine ecosystems based upon extreme climatic events and mass extinctions in the distant past. We will apply the most likely scenarios of past climate change extinction cascades to food webs from modern marine ecosystems in order to predict whether anthropogenic global warming is likely to trigger Palaeozoic/Mesozoic-level mass extinction cascades or whether increased Cenozoic ecosystem robustness will buffer the oceans from complete ecosystem collapse.

随着我们进入生物多样性危机，对灭绝事件的透彻了解从未像现在这样重要，这场危机被称为“第六次大灭绝”。但我们真的会走向大规模灭绝吗？与过去地质时代灾难性的生物危机相比，目前的事件会有什么不同呢？地质记录为研究快速气候变化下的生态系统动力学和崩溃提供了丰富的信息，了解这些事件可能是帮助预测人为变暖对现有和未来海洋生态系统的后果的关键。一个悬而未决的大灭绝问题是，为什么古生代和中生代的快速变暖事件总是会引发大规模灭绝，而类似的极端气候事件新生代却不会？解释这种不匹配的一个论点是，现代生态系统结构是在白垩纪-古近纪大规模灭绝(66 Ma)之后的早新生代建立的，而没有新生代大规模灭绝的原因在于现代海洋生态系统的健壮性增强。然而，关于物种灭绝的古生物学研究目前缺乏关于生物如何在生态系统中相互作用的关键信息来源。从当代生态学研究中我们知道，生物之间的相互作用在现代生态系统的结构、功能和弹性方面发挥着举足轻重的作用。因此，如果不能很好地了解群落内部的生物相互作用，就很难解释大规模灭绝事件中物种灭绝和生态系统崩溃的动力学。CASCaDE将通过一种新的跨学科方法将生态建模和古生物学的最新进展结合起来，推动灭绝古生物学发生根本性的变化。具体地说，我们将测试海洋生态系统的稳定性和稳定性(由食物网中的捕食者/猎物相互作用决定)在确定气候引发的物种灭绝级联的脆弱性方面所起的作用。我们将调查地质记录中全球快速变暖的不同时期--一些引发了大规模灭绝，另一些则没有。我们将使用计算机模拟方法来模拟气候变化事件之前化石生态系统上的几个假想的灭绝情景。这些情景将被制定为代表与温室气体迅速变暖相关的已知环境压力，即海洋温度上升、海洋缺氧和海洋酸化。然后，我们将测试哪种假设的灭绝情景最能预测事件后的生态系统结构。具体地说，我们将检验这样一个假设，即古生代/中生代和新生代食物网络结构和生态系统弹性的差异与极端气候条件的相互作用不同，导致古生代和中生代生态系统的大规模崩溃，而不是新生代。我们还将探索与不同化石保存潜力相关的食物网重建的不确定性如何影响预测。CASCaDE旨在通过对古代生态系统内的生物相互作用进行建模，并根据遥远过去的极端气候事件和大规模灭绝来预测现代海洋生态系统中的灭绝风险到快速变暖，从而将定量古生物学和保护生物学推向新的领域。我们将把过去气候变化灭绝级联最有可能的情景应用于现代海洋生态系统的食物链，以预测人为全球变暖是否可能触发古生代/中生代水平的大规模灭绝级联，或者增强的新生代生态系统稳定性是否将缓冲海洋免受生态系统彻底崩溃的影响。