PCRG February

Laboratory activity has continued through February with progress on pollen counts (Lottie and Hayley) and chironomid (non-biting midges)¬†picking (Frazer). Hayley also managed to escape the microscope lab for a short period: 1) to commence work on selecting samples from tephras for Ar-Ar dating, and 2) to counduct loss-on-ignition analysis of organic samples to identify the constituents of her sediment. I did not make it on to the microscope ūüė¶

I was however very pleased to welcome Macarena Cardenas back into the lab as a visiting Research Fellow. Maca will be working on the pollen reference collection, assisting with PhD student analysis and continuing to write papers during her renewed association.

Frazer, Hayley and I have also begun planning for field work in Ecuador for April-May. We will be working in collaboration with the Instituto Geophisico in Quito and the plan is to visit the Mera site which Hayley is working on, and to collect lake surface samples for Frazer to examine the midges. In preparation for the collection of midges samples expert, and project co-supervisor, Steve Brooks (Natural History Museum) visited for a day to brief us on how best to do this.

Away from research I have been working on writing exam questions and tutor marked assignments for the level 3 module The geological record of environmental change (S369, to those familliar with OU codes!). Hopefully, I have managed to set some interesting and challenging tasks for our students. . .

Relay team palaeo

The Open University Les Irvine Memorial Relay 2012 "Team Palaeo"The 21st The Open University Les Irvine Memorial Relay was held yesterday (29/02/2012) and four teams from the Environment, Earth & Ecosystems department were entered amoung the 40 which took part. Run over four legs and covering a 1.1 mile course at Walton Hall it was another fun event.

For the third year running a team of palaeoecologists took part. This year “Team Palaeo” comprised Hayley Keen, myself, Frazer Bird and Lottie Miller (left to right on photo) and we were the fastest finishing team from the department!

Nitrogen isotopes in lake sediments

As a component of my doctoral research, I am examining nitrogen (N) isotopes within sediments obtained from Lake Bosumtwi (West Africa). Below I review and comment on the key uses and limitations of using N isotopes to interpret past environmental change with particular reference to lake sediments. Discussion is based on the key text by Talbot (2001).

Talbot, M.R. 2001. Nitrogen isotopes in palaeolimnology. Tracking environmental change using lake sediments. Volume 2. Physical and geochemical methods (ed. by W.M. Last and J.P. Smol), pp. 401-439. Kluwer Academic Press, Dordrecht.

NOTE: This text is avaliable to Open University students as an ebook via the library

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British Ecological meetings

BES careers 2012

I am currently a member of the British Ecological Society (BES) council. The BES is a ‘learned society’ based at Charles Darwin House in London which publishes four academic journals, has thousands of members and is open to anyone with an interest in ecology. As part of my role on council I serve on two committees which run different aspects of the societies activity: 1) meetings, and 2) education, training and careers. This month we have had meetings of both these committees. Two highlights of the societies activity related to these committees were:

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Thinking about proxies

All areas of research have strengths and limitations which are readily acknowledged by the scientists involved. The reconstruction of past climates (palaeoclimates) from biological indicators contained within the fossil record (proxies) presents some specific challenges; for example key limitations might be gaps in a sedimentary sequence or post-depositional degradation of samples. Understanding and interpreting data sets in the face of these challenges require the researcher to develop a wide range of skills. Huntley (2012)¬†focuses upon the uncertainties within palaeoclimate reconstruction which he considers to be ‚Äúfrequently overlooked‚ÄĚ (p. 2) by scientists making climate¬†reconstructions from proxy records. Specifically Huntley urges researchers to consider carefully:

  • What a given proxy is actually capable of reconstructing, i.e. what climate variables controls its distribution?
  • What other variables might be influencing the proxy, i.e. could there be multiple influences, might these vary through time?
  • What is the spatial relevance of the proxy, i.e. macro versus micro scale?
  • Can multiple proxies be compared, either within or between sites?

In other words: which and how many climatic variables can be reconstructed form any one aspect of the fossil record?

Below I review and comment on some key arguments made by Huntley (2012) related to the use of proxies in reconstructing palaeoclimates.

Huntley, B. (2012) Reconstructing palaeoclimates from biological proxies: Some often overlooked sources of uncertainty. Quaternary Science Reviews 31: 1-16.

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PCRG January

January 2012 has been a busy one for the Palaeoenvironmental Change Research Group members we have been getting out and about (attending three research meetings), there has been activity in the labs (pollen, chironomids and geochemical analysis all being undertaken) and developments with the publication of our research (book chapter published and two papers moved along in the publication process).

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Environmental change in the humid tropics and monsoonal regions

Bush, M.B. & Gosling, W.D. (2012) Environmental change in the humid tropics and monsoonal regions. The SAGE handbook of environmental change: Volume 2. Human Impacts and Response (ed. by J.A. Matthews, P.J. Bartlein, K.R. Briffa, A.G. Dawson, A. De Vernal, T. Denham, S.C. Fritz and F. Oldfield), pp. 113-140. SAGE, London. ISBN: 978-0-857-02360-5

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