Ecosystem resilience and recovery from the Permo-Triassic crisis

人们很难不对二叠纪-三叠纪大灭绝(PTME)产生兴趣。世界历史上没有一场灾难像现在这样影响深远、影响广泛。与PTME相比，即使是恐龙的死亡看起来也没有那么糟糕，因为尽管这些陆地巨人被灭绝了，但许多其他东西幸存了下来，特别是在海底。相比之下，在二叠纪末期，没有环境、没有栖息地、没有地点是安全的。死亡发生在最深的海洋，最浅的水域，从赤道到极地。了解约250年前的PTME期间发生了什么，以及生命是如何恢复的，是NERC资助的一项新研究计划的主题。它被称为Eco-PT，是英国和中国科学家之间的一项重要合作。指责PTME的矛头指向西伯利亚的一个巨大火山区。它们在物种灭绝时喷发，并喷出大量破坏性气体。这包括二氧化碳，它被认为导致了戏剧性的温室效应，并导致危险的炎热、缺氧和酸化的海洋--所有这些都对海洋生物造成了不良后果。目前尚不清楚的是，为什么情况变得如此糟糕--还有其他大型火山喷发没有造成如此大的伤害。该项目将研究陆地和海洋的灭绝情况，以研究这两个截然不同的生态系统何时以及如何崩溃。是万物同时灭绝，还是陆地的灭绝先于海洋的灭绝，还是海洋的灭绝先于陆地的灭绝？中国拥有世界上最好的岩石进行这样的研究，密集的化石收集将有助于回答这些问题。将使用新的超高精度测年技术实现对年龄的精确控制，该测年涉及火山矿物中的铀衰变。也有可能在陆地和海洋灭绝之间存在反馈，例如陆地上的植物死亡可能改变了对海洋的营养输入，从而改变了浮游生物种群，使正常的食物网不再可持续。将使用最新的技术调查潜在的原因。因此，一种新的技术，包括分析化石花粉中的分子，将被用来评估臭氧损失的作用。除了其他火山气体，这种二氧化硫也可能参与了陆地的灭绝，现在可以通过研究保存在中国这个时候形成的陆地岩石中的微量硫化合物及其同位素来研究这种作用。还将使用最先进的建模方法来更好地了解大灭绝期间和之后的区域和全球气候变化，并重建生态系统恢复的风格。不同情景的气候模拟将使我们能够更好地理解这些条件，并将帮助我们更清楚地理解超级温室世界的本质。从PTME中恢复的漫长时期也是世界历史上最令人着迷的时期之一。一些群体迅速反弹，而另一些群体则保持了数百万年的低迷。复苏风格差异很大；一些群体表现出多样性的增加，但他们的差异没有增加，而另一些群体则两者都增加了。这对生态系统的稳定性及其恢复力(应对进一步压力的能力)意味着什么，将使用生态系统建模方法进行调查，这些方法着眼于物种之间的相互作用以及陆地动物的形式和功能之间的相互作用。

It is hard not to have a fascination for the Permo-Triassic mass extinction (PTME). No other catastrophe in history of the world was so far-reaching and all encompassing. Even the death of the dinosaurs does not look quite as bad when compared with the PTME because, even though these terrestrial giants were wiped out, lots of other things survived, especially at the bottom of the ocean. In contrast, no environment, no habitat and no location was safe at the end of the Permian. Death struck in the deepest oceans, in the shallowest waters, and from the equator to the pole. Understanding what happened during the PTME, ~250 myrs ago, and how life recovered is the subject of a new NERC-funded research programme. Called Eco-PT, it is a major collaboration between British and Chinese scientists. The finger of blame for the PTME points to a giant volcanic region in Siberia. These erupted at the time of the extinction and belched out huge volumes of damaging gases. This included carbon dioxide which is thought to have caused dramatic greenhouse warming and lead to dangerously hot, oxygen-poor and acidified oceans - all bad consequences for marine life. What isn't understood is why conditions got so bad - there have been other giant volcanic eruptions that have not done anywhere near so much harm. The project will look at the extinctions on land and in the sea to examine when and how these two very different ecosystems collapsed. Did everything die at once or did the extinction on land precede that in the oceans or vice versa? China has the best rocks in the world for such a study and intense collecting of fossils will help answer these questions. Precise controls on the age will be achieved using new, ultra-high precision age dating involving uranium decay in volcanic minerals. It is also possible that there was feedback between the terrestrial and marine extinctions, for example plant dieback on land may have changed nutrient input into the oceans and so altered plankton populations that normal food webs were no longer sustainable. The potential causes will be investigated using the latest techniques. Thus, a new technique, involving analysis of molecules in fossil pollen will be used to asses the role of ozone loss. Other volcanic gases, such a sulphur dioxide may also have been involved in the terrestrial extinction and this role can now be investigated by examining trace concentration of sulphur compounds and their isotopes preserved in terrestrial rocks that formed at this time in China. State-of-the-art modelling approaches will also be used to better understand regional and global climate changes during and after the mass extinction and to reconstruct the style of ecosystem recovery. Climate modelling of different scenarios will enable these conditions to be better understand and will help us understand the nature of super-greenhouse worlds with greater clarity. The prolonged recovery from the PTME is also one of the most fascinating intervals of the world's history. Some groups bounce back quickly whereas others remained in the doldrums for millions of years. The recovery style varied greatly; some groups show an increase in diversity but not their disparity whereas others show an increase of both. What this meant for ecosystem stability and its resilience (ability to cope with further stresses) will be investigated using ecosystem modelling approaches that look at interaction between species and the interplay between form and function in terrestrial animals.