Oxford Brooks University | Ecology of the past

Shining a light on fossil sunshine

December 15, 2016
WDG

Dr. Phil Jardine

An international team of scientists have reconstructed the longest ever record of past sunshine using pollen trapped in lake sediments collected in Ghana, Africa. The study published today in Scientific Reports enables us to understand past changes in solar input to the global system over the past 140,000 years. Previously we have had to rely upon computer models to mathematically determine past solar inputs to the Earth. “This work really is a first; being able to peer back in time to understand how the Sun has driven our global system over many of thousands of years is a very exciting prospect” said joint-lead author Dr. Phillip Jardine of The Open University.

The Sun is a key component of our natural environment, driving a multitude of processes at Earth’s surface, from photosynthesis generating energy within plants, through to global-scale circulation patterns in our oceans and atmosphere. Understanding more about how the Sun has behaved in the past, and the influence this had on Earth’s environment, will help scientists predict future climate change.

Dr. Jardine used a technique pioneered by one of his co-authors, Dr. Wesley Fraser of Oxford Brookes University, to determine past changes in solar input, specifically changes in ultraviolet (UV) radiation. Plants protect themselves from the harmful nature of ultraviolet radiation by incorporating a number of specific chemical compounds into their tissues that absorb and dissipate the energy of UV radiation. Pollen grains of flowering plants are also provided protection by these UV-absorbing chemicals, thus act as a long-term recorder of ultraviolet radiation from the Sun.

Pollen grains are readily trapped in lake sediments, where they can be preserved for millions of years. By extracting material from Lake Bosumtwi, Ghana, the pollen that was released by flowering plants thousands of years ago can be separated from the lake sediment and chemically analysed for UV-absorbing chemical compounds. It is this chemical signature within the ancient pollen grains that provides us with information about past levels of solar ultraviolet radiation.

“What we present here is a new opportunity to explore how the Earth has changed” said Dr. William Gosling (University of Amsterdam). “I am particularly excited about this because it will means that we can gain a better understanding of why vegetation changed in the past, and consequently this will allow us to anticipate better what the likely impacts of projected future climate change will be.”

This study is available now at www.nature.com/articles/srep39269

Jardine PE, Fraser WT, Lomax BH, Sephton MA, Shanahan TM, Miller CS & Gosling WD (2016) Pollen and spores as biological recorders of past ultraviolet irradiance. Scientific Reports. DOI: 10.1038/srep39269

Published open access:

Julier, A.C.M., Jardine, P.E., Coe, A.L., Gosling, W.D., Lomax, B.H. & Fraser, W.T. (2016) Chemotaxonomy as a tool for interpreting the cryptic diversity of Poaceae pollen. Review of Palaeobotany and Palynology 235, 140-147. DOI: 10.1016/j.revpalbo.2016.08.004

Organisms and environments: Frontiers in palaeoecological technique development

October 16, 2014
WDG

XIX INQUA Congress
NAGOYA, JAPAN 27 July－2 August, 2015

Grass pollen from Lake Bosumwti picked for individual chemical analysis

Abstract submission is now open for the XIX International Union for Quaternary Research (INQUA) Congress. “Ecology of the past” researchers will be there and are hosting a special session, entitled Organisms and environments: Frontiers in palaeoecological technique development, at which we hope to bring together a wide range of palaeoecologists working on novel proxy development. Members of the “Ecology of the past” group will be showcasing recent findings on the environmental significance of pollen chemistry change through time; linked to the 500,000 years of solar irradiance, climate and vegetation change in tropical West Africa project (Fraser et al., 2014). Please take a look at our session and consider submitting YOUR abstract today!

For information on abstract submission click here. Closing date for abstract submission 20 December 2014.

For further information on our session click here, or “Continue reading” below…

Predicting the future by understanding the past: Climate change

October 9, 2014
WDG

As part of the “500,000 years of solar irradiance, climate and vegetation changes” Natural Environments Research Council funded (NE/K005294/1) project we have produced a wall chart explaining the type of research we do and how it can help to place on-going, and projected, climate change in context. The wall chart is designed for use in schools and universities. To obtain a copy of this, and other wall charts, please contact the British Ecological Society (direct wall chart link here).

PDRA: Past environmental and climate change in West Africa

March 29, 2013
WDG

Full time Post-Doctoral Research Associate, Temporary contract for 36 months, £27,854 – £36,298
Department of Environment, Earth & Ecosystems, Faculty of Science, The Open University

Closing date : 25/04/2013

The PDRA project will descover more about past vegetation and climate change in Lake Bosumtwi (Ghana)

We are seeking a PDRA to study past climate and vegetation change in tropical West Africa as part of the NERC-funded “500,000 years of solar irradiance, climate and vegetation changes” project. You will join a multidisciplinary collaborative research team and will work with an international network of project partners. The project will utilise cutting-edge organic geochemical techniques to generate the longest continuous record of fossil pollen chemistry change. The study will build upon previous research into the sediments recovered from Lake Bosumtwi (Ghana). The data generated will shed new light on the role of climate in driving vegetation change in the tropics.

You will already hold a PhD, or be near to completing your PhD, in a relevant scientific discipline with a background in the Earth or Environmental sciences. You must have substantial experience of organic geochemistry or tropical palynology, with well-developed self-management skills and the ability to prioritise effectively.

The PDRA will work with an associated PhD student looking at modern pollen-vegetation relationships in the same region.

Co-Investigators:
Dr Barry Lomax (University of Nottingham)
Dr Wesley Fraser (Oxford Brookes University)

Project partners:
Prof . Yadvinder Malhi (University of Oxford)
Prof. Mark Sephton (Imperial College London)
Dr Tim Shanahan (University of Texas, Austin)
Dr Stephen Abu-Bredu (Forestry Research Institute of Ghana)

For further particulars click here.
For information on how to apply click here visit The Open University jobs web site.

Associated PhD project.

The PDRA will be part of an international team; partners based at University of Nottingham, Oxford Brooks University, Imperial College London, Oxford University, University of Texas at Austin and the Forestry Research Institute of Ghana

Funded PhD studentship: Tropical vegetation, environment and climate

March 21, 2013
WDG

William Gosling pollen trapping in west Africa. A studentship on the new grant will investigate modern pollen-vegeation relationships

Fully funded NERC PhD studentship tied to 500,000 years of solar irradiance, climate and vegetation changes project.
To start October 2013 now avaliable with the Palaeoenvironmental Change Research Group.

Title: Tropical vegetation, environment and climate: The present is the key to the past

Supervisors:
William D. Gosling (The Open University),
Wesley Fraser (Oxford Brookes University),
Barry Lomax (University of Nottingham),
Mark Sephton (Imperial College London) &
Yadvinder Malhi (University of Oxford)

Investigate the dynamics of modern tropical forest and savannah ecosystems
Training in micro fossil and organic geochemical analysis
Develop a comprehensive understanding of modern pollen-vegetation relationships
Field work in Ghana, in conjunction with Forestry Research Institute of Ghana

Making pollen traps on field work in Ghana

Understanding how vegetation responded to past climate change requires the development of well constrained relationships between living floras, environment and climate. This project will help constrain the great uncertainty which exists as to how tropical ecosystems are represented in the fossil record by examining the relationship between modern vegetation and the pollen it produces. The project will analyse modern pollen rain using a combination of traditional microscopic analysis [1] and cutting edge geochemical techniques [2]. We anticipate that the findings will provide new insight into past vegetation and climatic change.

For further information on the project and how to apply see the full advert: NERC PhD advert. Prior to applying please check eligibility for NERC funding by clicking here.

Closing date: 25th April, interviews will be held at The Open University during May.

To find out more about the department, research environment and student life at The Open Univerity visit the Department of Environment, Earth & Ecosystems, the Centre for Earth, Planetry, Space & Astronomical Research (CEPSAR) and OU RocSoc web pages.

Work as part of a larger research team in the UK and abroad.

References:

[1] Gosling, W.D., et al., Differentiation between Neotropical rainforest, dry forest, and savannah ecosystems by their modern pollen spectra and implications for the fossil pollen record. Review of Palaeobotany and Palynology, 2009. 153(1-2): p. 70-85.
[2] Lomax, B.H., et al., Plant spore walls as a record of long-term changes in Ultraviolet-B radiation. Nature Geoscience, 2008. 1(9): p. 592-596.