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

我们生活在一个自然系统发生广泛变化的时代，这些变化使我们的星球适合居住。气候正在变暖，由于我们对自然资源和空间的广泛和不断扩大的使用，我们正处于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生态系统因快速气候变化而恢复和崩溃的手段。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时期特别容易发生大规模灭绝，而另一些时期则不然。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的相对重要性，相对于系统生产力的变化，在快速的全球变暖时期，就像我们今天所生活的那样，对生态系统的稳定性。从技术上讲，这项研究将回答为什么古生代和中生代的快速变暖事件总是引发大规模灭绝，而新生代类似的极端气候事件却没有？研究人员将验证一种假设，即在白垩纪-古近纪大灭绝之后建立的现代生态系统结构的进化，使新生代群落与过去相比，对全球变暖的影响相对有弹性。为了做到这一点，他们将i)重建全球变暖事件期间的海洋食物网，同时考虑到保存偏见；Ii)随时间估算海洋食物网底部的生产力和生物量；Iii)通过推进和应用食物网建模方法预测初级和次级灭绝；iv)检验网络结构在新生代海洋生态系统稳定性中的作用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.