Open access online:

Flantua, S.G.A., Hooghiemstra, H., Grimm, E.C., Behling, H., Bush, M.B., González-Arango, C., Gosling, W.D., Ledru, M., Lozano-García, S., Maldonado, A., Prieto, A.R., Rull, V. & Van Boxel, J.H. Updated site compilation of the Latin American Pollen Database. Review of Palaeobotany and Palynology 223, 104-115. DOI: 10.1016/j.revpalbo.2015.09.008

Valencia PhD thesis 2014

March 5, 2015
WDG

Bryan-Kuelap-gate-2010-smallValencia Castillo, B.G. (2014) From glacial to modern conditions: Vegetation and climate change under human influence in the Central Andes. PhD Thesis, Department of Environment, Earth & Ecosystems, The Open University.

Abstract
Conservation, restoration and management strategies are employed to maintain Earth’s biological diversity and physical environment to a near “natural” state. However, the concept of “natural” is generally inexact and may include degraded landscapes. In absence of long-term empirical data of natural baselines, impacted assemblages (human altered baselines) could be falsely assumed to be natural and set as conservation or restoration goals. Therefore, the identification of long-term ecological baselines becomes a pressing requirement especially in threatened biodiversity hotspots such as the tropical Andes that were under human pressure for several millennial.

This thesis aims to identify ecological baselines for tropical Andean ecosystems based on multi-proxy palaeoecological reconstructions from three Andean lakes. Trends of vegetation change are used to identify when landscapes became anthropogenic in the Andes. Because vegetation assemblages at c. 10 ka experienced negligible anthropogenic impacts and had modern-like climate condition, this time was considered the most recent period likely to provide insight into natural ecological baseline conditions.

Changes in vegetation assemblages were evaluated over time departing from 10 ka around Miski and Huamanmarca, two sites that remained virtually impervious to human impacts. Baselines in Miski and Huamanmarca drifted continuously over time and showed that baselines are dynamic entities. The vegetation assemblages derived from Miski and Huamanmarca suggest that that human impact was not homogeneous throughout the Andean landscape.

Once baselines were defined it was possible to evaluate if the spatial distribution of Andean woodlands represented by Polylepis was a product of human impacts. A MaxEnt model generated based on 22 modern environmental variables and 13 palaeoecological vegetation reconstructions showed that Polylepis woodlands were naturally fragmented before humans arrived in South America (14 ka). However, the influence of humans during the mid and late Holocene enhanced the patchiness of the forest generating a hyper-fragmented landscape.

Supervisors: Dr. William D. Gosling , Dr. Angela L. Coe (both The Open University) and Prof. Mark B. Bush (Florida Institute of Technology).

Examined by: Dr. Robert Marchant (University of York), and Prof. David Gowing (The Open University).

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

Media articles

Relics discovered in Mexico’s Teotihuacan, BBC News

Tree of the year finalists announced, BBC News

Journal articles

Kessler, M., Toivonen, J.M., Sylvester, S.P., Kluge, J. & Hertel, D. (2014) Elevational patterns of Polylepis tree height (Rosaceae) in the high Andes of Peru: role of human impact and climatic conditions. Frontiers in Plant Science: Functional Plant Ecology 5, Article 194.

Sylvester, S.P., Sylvester, M.D.P.V. & Kessler, M. (2014) Inaccessible ledges as refuges for the natural vegetation of the high Andes. Journal of Vegetation Science 25, 1225-1234.

Keller, A., Danner, N., Grimmer, G., Ankenbrand, M., von der Ohe, K., von der Ohe, W., Rost, S., Härtel, S. & Steffan-Dewenter, I. (2014) Evaluating multiplexed next-generation sequencing as a method in palynology for mixed pollen samples. Plant Biology online.

Frazer on climate change & insects – AGU video

September 8, 2014
WDG

Frazer Matthews-Bird’s video on his PhD research examining long-term (>50 year) climate change from fossil insects (chironomids) has been shortlisted for the American Geophysical Union (AGU) student competition prize. Please watch Frazer’s video and “Like”; the most liked video will win free entry into the AGU Fall meeting 2014.

View all the videos on the AGU YouTube channel.

PCRG September

October 2, 2013
WDG

Section of fossil wood from Ecuador

Section of fossil wood from Ecuador

Having been away for half of the month I asked people to provide a summary of what they have been up to. Here is what they admitted to…

Natalie Ludgate and Lottie Miller have submitted their theses! Well done.

Hayley Keen: “Continual pollen counting, second lot of Argon dating done, and first set of wood macrofossils back and ready for identification!”

Frazer Bird: “At the start of September I began working as a technician as part of Encarni’s project. I am looking at the midges from the core we collected together on our last field trip. Things are going well, although the midges are hard to find in the older sections the preservation in early sequences is great. The resolution of this core looks to be fantastic also so and hopefully we will get some interesting results when we compare all the proxies.   Away fromthe lab I presented at INTECOL 2013 in London, The talk seemed to go down well and was noted as highly commended by the judging panel. Great publicity all round for the midges!!!”

Bryan Valencia: Has been on field work in Peru during this time he presented a talk on climate change to the Asociación para la Conservación de la Cuenca Amazónica, and gave interviews to local journalists and two TV stations. He also collected sediments from two locations, and manged to obtain a new US visa. He is now working on the final stages of submitting his thesis.

Phil Jardine: Phil has been busy ordering in microscopes and other equipment for the Lake Bosumtwi project (the first of which arrived today), and setting up the trip to Ghana that he’ll be going on with new PhD student Adele Julier in late October. He’s also been attempting to learn more about geochemistry, which has proved challenging.

Encarni Montoya:

  • Lake Pindo: We have finally the results of 6 samples radiocarbon dated from NRCF through our collaborator Dr Pauline Gulliver, and we have sent 4 more to “range find” the key interval of interests for the FORSENS project. We have started the midges’ analysis although it seems this going to be focused to the upper 4 meters of sediment. We would like to discern possible preservation issues in tropical records for this proxy. Some samples for a preliminary screening looking for diatoms ahve been collected and sent to the new FORSENS collaborator Teresa Vegas-Vilarrúbia. MS samples have been also collected for the first three drives and we hope to run this analysis next month.
  • Lake Banos: We have started the pollen prep. for the upper section of the record.
  • Management tasks: We are now ready for the tropical record Lake Marcacocha pollen prep., collaborating with an ongoing project lead by Alex Chepstow-Lusty. On a different topic, I have started the organisation of department seminars, so I would like to highlight if you have any potential speaker, please contact me.
  • Publications: a co-authorship in a paper published in Perspectives in Plant Ecology, Evolution and Systematics authored by Valentí Rull and his research group in the Botanical Institute of Barcelona is now available on line (click here)

William Gosling: “I have been promoted to Senior Lecturer (hooray), started work on the new level 2 environmental science module, been working on a new paper from the Erazo study site, and had a holiday!”

PCRG August

September 4, 2013
WDG

Will's BES T-shirt logo swabbed at Greenman

Will’s BES T-shirt logo swabbed at Greenman; for more microbes on festival kit visit the “Hall of shame” on http://www.besfest.org

August was a month for travel with PCRG members heading for Peru (Bryan, and he is still there), Greenman festival (William), INTECOL conference (William and Frazer), and the Royal Geographic Society annual meeting (William, Encarni, Frazer and Hayley). Detailed reports of the UK based travels are already on the blog, and hopefully we will get a post from Bryan on his Peruvian adventure once he is back.

Back in Milton Keynes work progressed with:

  • Hayley producing a revised full draft of her pollen counting methodology manuscript,
  • Frazer starting with the first tentative attempts to apply his chironomid training data set to fossil chironomid records,
  • Phil trialing inverted microscopes and training on the FTIR,
  • Encarni plotting field work in Ecuador (more travel for November-December),
  • William seeming to spend alot of time working on research strategy for the faculty, and thinking about writing teaching material for the ongoing revison of our level 2 environmental science module, and
  • most excitingly of all, Lottie submitting her PhD thesis! WELL DONE LOTTIE.

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

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.

Lake coring equipment

July 17, 2013
WDG

Trecking with sediment corer in the high Andes of Peru

Trecking with sediment corer in the high Andes of Peru

When it comes to collecting sediments from lakes its all about having the right tools for the job. Working in remote areas of the tropics we tend to favour the Colinvaux-Vohnout corer; supplied by Vince Vohnout at Geo-core). The advantages of this system are:

  1. its light-weight nature (can be backpacked or donkeyed into field sites), and 
  2. the cam system (which allows hammering to penetrate tough sediments).

    Eric Martinez carrying an Avon Redstart back out from Laguna Khomer Kotcha (Williams et al., 2011)

    Eric Martinez carrying an Avon Redstart back out from Laguna Khomer Kotcha (Williams et al., 2011a)

With the right platform (two banana boats and an A-frame) we have manged to retrive c. 20 m of sediment from  20 m of water (c. 40 m of drill rod extended); Lake Pacucha, Peru (Hillyer et al., 2009). More typically we use two Avon Redstart inflatables and a platform following the design of Colinvaux et al. (1999).

Recent debate on the International Paleolimnology Association list server saw recommendations for a number of other systems.

Including: UWITECH gravity corer, Pylonex gravity corer, Aquatic Research Instrument products, and modified systems by Jason Curtis at University of Florida.

I would be interested if anyone has any thoughts on the relative merits of these systems (or others) and there capabilities.

Photos and references below:

Continue Reading

PCRG publications 2012

February 15, 2013
WDG

Bush, M.B. & Gosling, W.D. (2012) Environmental change in the humid tropics and monsoonal regions. The SAGE Handbook of Environmental Change (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.

Mosblech, N.A.S., Bush, M.B., Gosling, W.D., Hodell, D., Thomas, L., Van Calsteren, P., Correa-Metrio, A., Valencia, B.G., Curtis, J. & Van Woesik, R. (2012) North Atlantic forcing of Amazonian precipitation during the last ice age. Nature Geoscience, 5, 817-820

Williams, J.J., Brooks, S.J. & Gosling, W.D. (2012) Response of chironomids to late Pleistocene and Holocene environmental change in the eastern Bolivian Andes. Journal of Paleolimnology, 48, 485-501

Blog at WordPress.com.