charcoal | Ecology of the past

Miller PhD thesis 2014

March 26, 2014
lottiemiller

Miller, C.S. (2014) 520,000 years of environmental change in West Africa. PhD Thesis, Department of Environment, Earth & Ecosystems, The Open University.

CSM (2014)

Abstract:

Global temperatures are predicted to rise by 2–2.5°C by 2065, profoundly affecting the Earth’s environment. The response of ecosystems to past climate fluctuations can inform on how systems will respond in the future. This thesis focuses on Quaternary environmental changes in West Africa, a region important because of its high ecological value and role in the global carbon cycle.

In 2004, the International Continental Drilling Program recovered c. 291m of sediments spanning the last c. 1 Myr from Lake Bosumtwi (Ghana). Pollen, charcoal and nitrogen isotopes (d¹⁵N) were analysed from the most recent c. 150m (c. 520 kyr). The latitudinal position and long duration of this core makes it unique for understanding West African monsoon dynamics and vegetation change.

To aid characterisation of the Bosumtwi pollen succession, an atlas of present-day pollen was constructed for 364 pollen and spore taxa.

The pollen record from Bosumtwi reveals dynamic vegetation change over the last c. 520 kyr, characterized by eleven biome shifts between savannah and forest. Savannah vegetation is dominated by Poaceae (>55%) associated with Cyperaceae, Chenopodiaceae-Amaranthaceae and Caryophyllaceae. Forest vegetation is palynologically diverse, but broadly characterised by Moraceae, Celtis, Uapaca, Macaranga and Trema. Low d¹⁵N values correspond to forest expansion and these are driven by high lake levels. The timescale indicates that the six periods of forest expansion correspond to global interglacial periods. The record indicates that the wettest climate occurred during the Holocene, and the driest during Marine Isotope Stage 7.

The vegetation and d¹⁵N records show a strong response to glacial-interglacial variability between c. 520–320 kyr and 130–0 kyr. Between c. 320–130 kyr there is a weaker response to glacial-interglacial cycles probably related to high eccentricity during the peak of the 400-kyr component of eccentricity, with high eccentricity resulting in greater seasonality and ultimately drier conditions.

Supervisors: Dr. William Gosling, Dr. Angela Coe (both The Open University) and Dr. Tim Shanahan (University of Texas at Austin)

Examined by: Prof. Henry Lamb (University of Aberystwyth) and Dr. Pallavi Anand (The Open University).

To borrow a copy from The Open University Library click here.

PCRG January

February 12, 2014
WDG

January 2014 has been pretty mad for me but included presenting a poster at the Quaternary Research Association annual meeting, and taking on the role of chair of the British Ecological Society “Eduaction, Training and Careers Committee“.

Tardigrade egg found in Ghanaian pollen trap by Adele

Here is a summary of what other people have been up to:

Lottie Miller: submission and approval of thesis corrections (hooray), working on British Ecological Society grant application.
Hayley Keen: is finishing up lab work (macro charcoal – done, XRF – done, wood macrofossils – thin sectioned, awaiting identification, pollen – just 4 more samples!); and dealing with minor review revisions to first submitted paper (hooray).
Frazer Bird: finished the data collection for two Ecuadorian lakes (Banos and Pindo) and will hopefully begin to write up this data soon; attended the NERC stats course (very useful; would advise everyone to try and get on it).
Nick Loughlin: has split and logged the sediment cores recovered from Lake Huila (Ecuador) during recent fieldwork, and begun preparing the samples for pollen.
Adele Julier: has been preparing pollen trap samples from Ghana and learning tropical pollen.
Emily Sear: has mostly been on holiday and we are still waiting for the post card! She has also been working at getting results that make sense from the MS2.
Phil Jardine: has been oxidising spores to see what it does to the chemistry, generating FTIR data with the oxidised samples and starting the numerical analysis, and editing film footage from the 2013 Ghana trip.
Encarni Montoya: has been doing pollen lab and analysing pollen from Baños, and comparing the midges trends from Pindo and Baños with Frazer.
Wes Fraser: Reported back to Royal Society on finding from research grant – paper containing exciting results to follow in next couple of months.

Some pollen from Adele’s pollen traps in Ghana

We have also had 4 papers published with 2014 dates on them:

Cárdenas, M.L., Gosling, W.D., Pennington, R.T., Poole, I., Sherlock, S.C. & Mothes, P. (2014) Forests of the tropical eastern Andean flank during the middle Pleistocene. Palaeogeography, Palaeoclimatology, Palaeoecology, 393: 76-89. doi: 10.1016/j.palaeo.2013.10.009
Fraser, W.T., Watson, J.S., Sephton, M.A., Lomax, B.H., Harrington, G., Gosling, W.D. & Self, S. (2014) Changes in spore chemistry and appearance with increasing maturity. Review of Palaeobotany and Palynology, 201, 41-46. doi:10.1016/j.revpalbo.2013.11.001
Miller, C.S. & Gosling, W.D. (2014) Quaternary forest associations in lowland tropical West Africa. Quaternary Science Reviews, 84, 7-25. doi: 10.1016/j.quascirev.2013.10.027
Sayer, E.J., Featherstone, H.C. & Gosling, W.D. (2014) Sex & Bugs & Rock n Roll: getting creative about public engagement. Trends in Ecology & Evolution, 29, 65-67. doi: 10.1016/j.tree.2013.12.008

Ecosystem service provision sets the pace for pre-Hispanic societal development in the central Andes

July 31, 2013
WDG

Water resources in the Vacas region (near Cochabamba, Bolivia) deminished around the time of the founding of the urban centre at Tiawanaku

Gosling, W.D. & Williams, J.J. (2013) Ecosystem service provision sets the pace for pre-Hispanic societal development in the central Andes. The Holocene, 23(11): 1617-1622. doi: 10.1177/0959683613496296

Click here to download an open access version of this manuscript via The Open University Open Reseach Online repository.

Encarni Montoya

January 9, 2013
WDG

Hi all,

I am Encarni Montoya and I have recently joined the Palaeoenvironmental Change Research Group.

Field work in Ecuador 2012

I am a NERC Research Fellow with a project entitled “Evaluation of forests sensitivity to past climatic changes” (FORSENS), which will be running until September 2015. The project is based on a multi-site, multi-proxy and multi-disciplinary approach to aid the understanding of Neotropical forests’ dynamics since the Last Glacial Maximum (LGM; c. 21,500 years ago).

I presented details in a poster at the recent INTIMATE/CELL-50k Join Workshop this 12-15^th November at Budapest, Hungary. Click here to view my poster and find out more details about the project.

Prior my arrival to PCRG, I was working at The Botanical Institute of Barcelona (CSIC-ICUB, Paly nology and Paleoecology Lab) and the Autonomous University of Barcelona (Tropical and High Mountain Paleoecology). I am a palaeoecologist mainly focused on Late Glacial environmental change in Neotropics, being interested in the climate-vegetation-human relationships. For this purpose, I mainly use pollen, microscopic charcoal and non-pollen palynomorphs. I am also involved in several editor tasks, as regular referee os several Q1 journals, and the editor of the “Humans and Biosphere Commission” Newsletter.

If you are interested in my project please do not hesitate to get in contact.

NERC Fellowship success

July 4, 2012
WDG

I am delighted to report that Dr Encarnacion Montoya Romo (currently of the Botanical Institute of Barcelona) has been awarded a NERC Fellowship to join the PCRG. The project is entitled “Evaluation of tropical forests sensitivity to past climate change” (FORSENS) and will examine environmental change at four study sites from different regions of the Neotropics: 1) Khomer Kotcha (Bolivia; 17oS, 4100 m above sea level [asl]) [1-3], 2) Consuelo (Peru, 13oS; 1400 m asl) [4-5], 3) Banos (Ecuador; 0oS, 4000 m asl), and 4) a new lowland site from Columbia/Ecuador to be collected during field work during the project.

The aim of the project is to explore the spatial and temporal consitance of tropical vegetation response to aridity (mid-Holocene dry period) and warming (last deglaciation). The project will use fossil pollen, chironomids, charcoal, non pollen palynomorphs and organic biomarkersto build up a comprehnsive picture of environmental change. The diversity of the project means we have a number of exciting partners, including: Steve Brooks (Natural History Museum), Prof. Mark Bush (Florida Tech), Prof. Valenti Rull (Botanical Institute of Barcelona) and the Dr. Pauline Gulliver (NERC radicarbon facility).

The fellowship will commence in October 2012. Further information will appear on is blog and group website soon.

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