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

我们生活在一个使我们的星球宜居的自然系统发生大范围变化的时代。气候正在变暖，我们正处于由于我们广泛和扩大使用自然资源和空间而产生的生物多样性危机之中。这些变化对地球的未来意味着什么？化石记录为我们提供了了解快速气候变化导致的生态系统弹性和崩溃的手段。在这里，研究人员将利用化石记录来探索为什么地球历史的某些区间特别容易发生大规模灭绝，而另一些则不是。为了做到这一点，他们将使用食物网建模的尖端方法来研究全球变暖期间化石群落的变化。他们的结果将使他们能够评估网络结构和组成相对于系统生产力的变化在全球迅速变暖时期对生态系统稳定性的相对重要性，就像我们今天生活的那样。更严格地说，这项研究将回答这样一个问题：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物种灭绝，而同样极端的气候事件新生代却不会？研究人员将检验这一假设，即与过去相比，白垩纪-古近纪大规模灭绝后建立的现代生态系统结构的演变，使新生代社区对全球变暖的影响相对更具弹性。为此，他们将：i)在全球变暖事件中重建海洋食物网，同时考虑保存偏差；ii)估计海洋食物网随时间推移的生产力和生物量；iii)通过改进和应用食物网建模方法来预测初级和次生物种灭绝；以及iv)测试网络结构在新生代海洋生态系统稳定性中的作用。

We live in a time of widespread change to the natural systems that make our planet habitable. The climate is warming and we are in the midst of a biodiversity crises arising from our extensive and expanding use of natural resources and spaces. What do these changes mean for the future of planet? The fossil record provides us with the means to understand the resilience and collapse of ecosystems due to rapid climate change. Here the researchers will use the fossil record to explore why some intervals of earth history are particularly prone to mass extinction, while others are not. To do this, they will examine changes in fossil communities across intervals of global warming using cutting-edge approaches from food web modeling. Their results will allow them to assess the relative importance of network structure and composition, versus changes in the productivity of systems, to the stability of ecosystems during times of rapid global warming, like those we are living in today. More technically, the research will answer the question of why rapid warming events of the Paleozoic and Mesozoic consistently trigger mass extinction, whereas similarly extreme climatic events of the Cenozoic do not? The researchers will test the hypothesis that it is the evolution of modern ecosystem structures established in the aftermath of the Cretaceous-Paleogene mass extinction that has made Cenozoic communities relatively resilient to the effects of global warming as compared to those in the past. To do this they will i) reconstruct marine food webs across global warming events while accounting for preservation bias; ii) estimate productivity and biomass at the base of the marine food web through time; iii) predict primary and secondary extinctions using by advancing and applying food web modeling approaches; and iv) test the role of network structure in the stability of Cenozoic marine ecosystems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.