The evolution of vegetation and biodiversity change during the Paleogene and early Neogene

Lead Research Organisation: University of Bristol
Department Name: Geographical Sciences

Abstract

The Asian monsoon system is a major feature of the Earths climate and impacts on almost half of the population of the world. The monsoon also has a profound effect on the regions flora, fauna and ecosystems. Moreover large parts of China are also noted for their exceptionally high biodiversity. We also know that the monsoon system has changed over geological time and this is intimately linked to the growth of Tibet and the Himalayas which occurred during the Paleogene (66 to 23 million years ago) and early Neogene (23 million years ago to 3 million years ago). And finally we know that this time interval also witnessed the birth of this modern vegetation patterns. So how are all of these aspects linked together. Why is biodiversity so high in parts of China? When did these ecosystems develop? And how is this all connected to Tibetan uplift and the evolution of the monsoon?

Our project aims to bring together a unique group of world leading researchers in palaecology, geology and climate modelling to identify the nature of ecological change during the Paleogene and early Neogene and establish the underlying mechanism of changes and thresholds.

We will do this with a series of three field trips to span the latitudinal and elevation gradients within China, from Tibet, Yunnan and S. China. These field trips will enable us to collect new information on the changes in ecosystem and biodiversity. We will be able to assess the amount of change, and in a few key sites identify whether the changes have been smooth or relatively abrupt, the latter indicating possible threshold behaviours of the system. We will also use this data to reconstruct estimates of the climate and palaeoelevation of the sites. This information can then be used to help develop and test climate, ecosystem, and biodiversity models. These models will allow us to identify the key mechanisms that have driven change in this region over geological time, and the interactions between the ecosystem and climate change.

The outcomes will be a fuller understanding of the evolution of life on the planet, and will also enable a unique evaluation of the models used for future climate change projections.

Planned Impact

The research generated through this proposal will have potential impact on organisations interested in ecosystems, biodiversity and climate. The monsoon systems are important for sustaining a large population and are a significant part of the economy of the region and so there are many organisations which get impacted by potential changes. Our research also has considerable interest to the wider public. Therefore our impact plan will focus on three aspects:

(a) We will leverage links to policymakers in national government, non-governmental organisations and international agencies, through membership of institutions such as the Cabot Institute in Bristol and Policy Bristol. Both of these groups have dedicated staff focussing on policy briefings. We will also work closely with NERC in communicative activities. We will run two workshops for relevant stakeholders on the results from the project.

(b) There is a lot of interest from the general public in issues such as vegetation change, biodiversity and climate change and we plan to participate in a wide variety of strategies to engage them in our work. This is especially true for the field work components which often generates significant interest. We will cover the field trips through photographic and filming opportunities, and will make extensive use of twitter. We will also produce a website for the project, and participate in science festivals such as Festival of Nature and Times Cheltenham Science festival.

(c) The research will also have significant scientific importance and so we will also ensure that our work is clearly disseminated to the academic beneficiaries (related to ecosystems, climate and geology, see previous section). We will aid this work by ensuring that we participate in conferences in a wide variety of different areas and by publishing papers in journals linked to the various communities.

Publications

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Saupe EE (2019) Climatic shifts drove major contractions in avian latitudinal distributions throughout the Cenozoic. in Proceedings of the National Academy of Sciences of the United States of America

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Chiarenza AA (2020) Asteroid impact, not volcanism, caused the end-Cretaceous dinosaur extinction. in Proceedings of the National Academy of Sciences of the United States of America

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Evans D (2018) Eocene greenhouse climate revealed by coupled clumped isotope-Mg/Ca thermometry. in Proceedings of the National Academy of Sciences of the United States of America

 
Description The East Asian Monsoon plays an integral role in human society, yet its geological history and controlling processes are poorly understood. Using a general circulation model and synthesis of geological data we explore the drivers and dynamical mechanisms which have controlled the evolution of the monsoon system over the last 150 million years. We find that the monsoon is primarily controlled by the uplift of the Himalayan-Tibetan Plateau, resulting in a strengthening of the monsoon from dry conditions in the middle Cretaceous (~100 million years ago) through to 'super-monsoon' conditions by the Middle Miocene (~15 Myr ago). In contrast to recent previous work, we show that past CO2 variations have had little influence on monsoon evolution.

We have also shown that the paradigm of the uplift of the Tibetan Plateau is misleading. Until the late Miocene, Tibet was formed from a series of collisions and that there was no such thing as the "plateau" in earlier times, although there were a number of high mountain terranes. This has important consequences for the climate and biota in the region and helps explain our discovery of a fossil palm tree in the region.

Moreover, we have also shown that for much of the Oligocene there was a significant valley system within the plateau. This has important consequences for our geophysical evolution of Tibet.
Exploitation Route The papers from this work are already being well cited. Indeed several papers are in the "highly cited" category on web of science. We are developing further research projects to extend the research.
Sectors Environment

URL https://www.umbrella.bridge.bristol.ac.uk/
 
Title Ancient orogenic and monsoon-driven assembly of the world's richest temperate alpine flora 
Description Understanding how alpine biotas formed in response to historical environmental change may improve our ability to predict and mitigate the threats to alpine species posed by global warming. In the world's richest temperate alpine flora, that of the Tibet-Himalaya-Hengduan region, phylogenetic reconstructions of biome and geographic range evolution show that extant lineages emerged by the early Oligocene and diversified first in the Hengduan Mountains. By the early to middle Miocene, accelerated diversification and colonization of adjacent regions were likely driven jointly by mountain building and intensification of the Asian monsoon. The alpine flora of the Hengduan Mountains has continuously existed far longer than any other alpine flora on Earth and illustrates how modern biotas have been shaped by past geological and climatic events. 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
URL http://datadryad.org/stash/dataset/doi:10.5061/dryad.k6djh9w3s
 
Description Project featured in UKRI-China Impact Expo 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact This involved preparing an exhibition and contributing material for a video. Two of our team attended the expo.
Year(s) Of Engagement Activity 2018