AFQUA 2018 – day 4

July 17, 2018
WDG

AFQUA: The African Quaternary environments, ecology and humans
2ndInternational Conference and Workshops
14-22 July 2018-07-15 National Museum, Nairobi, Kenya

Day 4

Yesterday (day 3) was excursion day of the AFQUA conference (photos to follow). Day 4 of the meeting was back in the National Museum Nairobi and kicked off with a session on “African archaeological landscapes”. The opening talk reviewed the career of Karl Butzer who coined the term ‘geoarchaeology’ back in the 1970’s when writing about his work integrating geological, archaeological and anthropological information (C.A. Cordova). Two talks then followed highlighting work on Lake Makagadikgadi from the perspective of archaeology and landscapes (D.S.G Thomas) and geochemical fingerprinting of stone tools to determine their source (D.J. Nash).

To take us up to lunch Boris Vanniere and Daniele Colombaroli gave a ‘double header’ plenary talk highlighting the exciting advances in the development of the Global Charcoal Database and how understanding past fire histories in Africa is key to interpreting environmental change. The after lunch session continued the palaeo-fire theme with records from Lake Botswana (C.E. Cordova), Lake Bosumtwi (W.D. Gosling – me), and Madagascar presented (A. Razafimanantsoa); as well as work on the usefulness of the morphometric’s of charcoal in determining the plant of origin (L.Bremond).

In the final session of the day we were back to “Southern Africa” as a theme. Under which banner we were “boggled” by sea-surface and sub-surface temperature reconstructions (M.A. Berke), shown how to extract climate records from Hyrax middens (B.M. Chase) and given insights into the past flora of the Cape Floristic region from fossil pollen records spanning 130,000 years (L.J. Quick).

OPEN ACCESS ONLINE:

Miller, C.S., Gosling, W.D., Kemp, D.B., Coe, A.L. & Gilmour, I. (2016) Drivers of ecosystem and climate change in tropical West Africa over the past ∼540 000 years. Journal of Quaternary Science online. DOI: 10.1002/jqs.2893

Shanahan, T.M., Hughen, K.A., McKay, N.P., Overpeck, J.T., Scholz, C.A., Gosling, W.D., Miller, C.S., Peck, J.A., King, J.W. & Heil, C.W. (2016) CO2 and fire influence tropical ecosystem stability in response to climate change. Scientific Reports 6, 29587. DOI: 10.1038/srep29587

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).

Understanding Climate Changes

An interview with Adele Julier

May 26, 2014
philjardine

Following on from Wes Fraser’s insightful and revealing interview, cactus-hugger Adele Julier tells us about her academic background and her role on the Lake Bosumtwi pollen chemistry project.

 

For more videos check out the “Ecology of the past” YouTube channel.

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.

Lottie 2014

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.

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