PhD: When was the South Pacific colonised?

October 19, 2017

Title: When was the South Pacific colonised? A lake sediment approach to understanding climate:human drivers of ecosystem change on remote Pacific Islands

Location: University of Soithampton (Geography & Environment)

Supervsiory team: Dr. Sandra Nogué, Prof Mary Edwards, Prof. David Sear, Dr. William Gosling (University of Amsterdam), Prof. Inger (Tromso University), Prof. Janet Wilmshurst (Landcare research and University of Auckland)

Rationale: The Pacific islands of Polynesia were among the last places on earth to be colonised by humans. The precise dates of colonisation are debated – a situation which arises from the different sources of evidence (1, 2). New lake sediment records from the Cook Islands (Atiu, Mangaia) and Samoa (Upolu) and Tonga show very clear evidence of disturbance, but what is unclear is to what extent the signal represents the arrival of humans or a change in climate (2). A key question for the analysis of sedimentary records is the ability to distinguish natural variability in the environment of Pacific Islands from that arising from the arrival of humans in a temporal and spatial context. We aim to use a multi-proxy approach based on SedDNA, lipid biomarkers, fossil charcoal, and pollen preserved in lake sediments to identify: a) the presence of humans and/or livestock that were brought with them, and b) the related environmental change. Multiproxy approaches supported by statistical analysis, will be deployed to four sites where we already have good chronological controls and high resolution records of palaeoclimate. We are well placed to apply new methods and higher resolution analyses to address fundamental questions about the response of remote pacific islands to climate and human forcings.

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PhD: Stress in Paradise

October 19, 2017

Title: Stress in Paradise: Quantifying the frequency and impacts of ENSO driven droughts in tropical Pacific Island Nations

Location: University of Soithampton (Geography & Environment)

Supervisory team: Prof. David Sear, Prof. Justin Sheffield, Prof Ian Croudace (National Oceanographic Centre, Southampton).

Rationale: Because of their small size and isolation, islands in the Pacific have limited and fragile natural resources, making them more vulnerable to climate hazards and stresses than are continents1. Pacific Island Nations (PINS) also occupy the region of the earth’s surface most immediately impacted by ENSO events. The impacts of El Nino events are felt across 3,975 islands, 13 island nations, affecting a population of 12.9 million who rely on rainfall for freshwater and food security. To date our understanding of the mechanisms of drought, their frequency and duration, and their biophysical effects in PINs remain poorly quantified. In addition island types experience droughts differently, varying according to their location, topography, geological history and ecology. Droughts are also thought to have been important drivers of the human colonization of the Pacific2. Drought frequency is likely to increase in the tropical pacific but again its specific impacts are largely unknown. This PhD seeks to develop a step change in our understanding of droughts based on novel coupling of long term data on drought frequency with process based drought modelling.

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PhD position: When was the South Pacific colonised?

October 31, 2016

Funded PhD studentship at:
Palaeoenvironmental Laboratory
Department of Geography & Environment
University of Southampton

Title: When was the South Pacific colonised? A lake sediment approach to understanding climate:human drivers of ecosystem change on remote Pacific Islands

Supervisors: Sandra Nogue, Pete Langdon, David Sear (all University of Southampton), and William Gosling (University of Amsterdam)

Deadline: 2 January 2017

To find out more about the project, check eligibility criteria, and details of how to apply click here.

The team lake coring in the South Pacific. Photo Jon Hassall, see more:

The team lake coring in the South Pacific. Photo Jon Hassall, see more:

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Past environmental change on Samoa

February 16, 2016

Zoe and William just after the graduation ceremony (UvA)

Zoe and William just after the graduation ceremony (UvA)

Two students (Zoe van Kemenade and Tessa Driessen) have recently completed projects looking at past environmental change on Samoa working in the Research Group of Palaeoecology & Landscape Ecology at the University of Amsterdam (UvA). Zoe’s project, part of her BSc Future Planet Studies (major Earth Sciences) at UvA, was entitled “A multi‐proxy analysis on the effect of climate and human activity on the environment of Samoa during the Holocene” and investigated charcoal, macro-fossils, and algae. Tessa’s project, “Biodiversity, fire and human dynamics on Samoa over the last 9200 years”, was completed as an internship during her MSc in Environmental Biology at Utrecht University (UU) that was co-supervised by Rike Wagner-Cremer. Tessa focused on the fossil pollen record to reconstruct past vegetation change. Both projects were conducted in cooperation with Jon Hassel and David Sear (both University of Southampton) who provided access to the Samoan sediments; for more on the Southampton Pacific Islands projects check out their blog Palaeoenvironmental Laboratory at the University of Southampton.

The results from both projects, and work by the University of Southampton team, will be presented at this years GTO conference (European conference of tropical ecology) in Gottingen next week.

William giving his personal view on the work of Tessa at her gradation ceremony (Utrecht University)

William giving his personal view on the work of Tessa at her gradation ceremony (UU)


Introducing Tessa Driessen

February 16, 2015

Tessa DriessenHi I’m Tessa and really excited to introduce myself here!

I’m an Environmental Biology Master student from Utrecht University (UU) doing a research internship in Amsterdam with William Gosling and Rike Wagner of the UU. Most people would describe me as a typical biologist because I like identifying plants and know some birds by their name. Personally I disagree because I lack the beard and hardly wear woollen socks. Besides looking at birds and plants I’m also interested in biodiversity and palaeoecology, and I will try to combine these interests in my research project on a sediment core from Samoa. I will be working on lake sediment cores from Samoa and hope fossil record can give me an overview of the natural history of the island (past c. 10,000 years); and an insight into what impact human colonisation had on the biodiversity. To explore the islands natural history I will be looking at pollen, charcoal and non pollen palynomorphs.

The sediment core on which I will be working has already been recovered and currently resides in beautiful Southampton (UK). So I’m spared of a 30 hour trip to tropical Samoa and the opportunity to return with some Samoan tattoo’s and a tan… So thanks to David Sear and his team at the University of Southampton with whom I will be collaborating for this project.

I have a long standing interest in tropical islands. Before commencing this research internship I did my first masters internship at WWF Indonesia. For my WWF internship I spent three months in the tropics collecting baseline ecological data on timber companies located in a new reserve in Sumatra. Furthermore, during my bachelor degree, I did a research internship at Naturalis Biodiversity Center investigating the “Correlation between higher altitudes and endemic plant species” in the Malayan archipelago. Our results turned out much better then we hoped for and fingers crossed our article will be accepted soon!

In three weeks I will be starting in the lab in Amsterdam and hopefully in a few months will be able to post an update about my results here.


INQUA 2015: Climate change in the tropical South Pacific during the Late Quaternary

October 27, 2014


inqua-JPPosted on behalf of Prof. David Sear (University of Southampton)

The next INQUA Congress will be held in Nagoya (Japan) on July 27 – August 2, 2015

This is a call for contributions to session P05 on ‘Climate change in the tropical South Pacific during the Late Quaternary’.

The session abstract is as follows:
Establishing well dated, quantitative, highly resolved palaeoclimate data for the major climate systems of the tropical south Pacific has become a research priority owing to the paucity of instrumental data from this critical region of the Earth. Whilst the quantity of proxy climate data for this region is increasing rapidly, compared to records from the Northern Hemisphere there is a surprising paucity especially when considering the importance of this region to global climate. Such information is vital for fully understanding inter-hemispheric climate linkages, global energy fluxes and the long-term evolution of natural climate variability such as the El Nino-Southern Oscillation. The dearth of pre-industrial climate records from this region contributes to large uncertainties associated with future climate change impacts far beyond the south Pacific. This session aims to bring together researchers working on Late Quaternary ocean/climate proxies with those whose research lies in modelling ocean-climate processes and dynamics in the tropical south pacific region, and their implications for global climate.

We hope this session will be of interest to you. If you plan to contribute to this session, please submit your abstract before December 20, 2014 click here.

We hope to see you at INQUA 2015.

Best Wishes,

David Sear, Julian Sachs, Kim Cobb, John Chiang, Peter Langdon – session conveners.

Professor David Sear
Geography & Environment
University of Southampton

Dead heads

July 30, 2013

DeadHeads12th International Workshop on Subfossils Chironomids
10-13th June, New Forest, UK

Last month Frazer and Encarni attended the 3-days “dead heads” workshop that was held at the Beaulieu Hotel , in the New Forest National Park (UK). It was perfectly organised by Pete Langdon and Steve Brooks,  and was a great opportunity for both of us who are relatively new to the midges’ community. With around 40 participants from Europe, America and Asia, we greatly enjoyed the discussions that came up about the state-of-the-art for this interesting proxy and the implications for palaeoclimatology, palaeolimnology, and different aspects of ecology like conservation, restoration or community assemblages. In addition, useful topics such as current methodological problems with age-depth model uncertainties, the usefulness and limitations of transfer functions, and taxonomy were also debated.

Besides oral and poster presentations, the workshop offered several tutorials during the afternoons, key amoung these were an introduction to R carried out by Richard Telford and Steve Juggins, and taxonomic support for head capsules ID leaded by Steve Brooks and Oliver Heiri.

In our specific case, Frazer contributed with an oral presentation titled Understanding the modern distributions and ecological tolerances of the Neotropical Chironomidae fauna: The potential as a palaeoecological proxy” base on his PhD research. We were both so glad to make contact with other people working in South America, in particular Julieta Massaferro and Alberto Araneda presented very interesting data from Argentina and Chile.

Although these meetings are normally biannual, next conference location and date is yet to be decided, but we hope to have the chance to join this very friendly and supporting community again. We encourage people with all kind of experience (or lack of) to attend any further events.

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