January 14, 2014
Lake Huila
So we’re back from a hot and humid Ecuador to the joys of a British winter. Ecuador is an amazing country and the diversity of the flora and fauna surpasses anything that I have experienced before. Continue Reading
December 13, 2013
Nick and Will with Carman (director of the Pindo Mirador biological station)
Three members of the PCRG (William Gosling, Encarni Montoya and Nick Loughlin) visited Ecuador (November-December 2013) to develop collaborations with Ecuadorian institutions, recover more lake sediments, and find new potential sites for projects. Below are some photos from:
Full reports on specific aspects of the fieldwork to follow.
October 31, 2013
Photo taken close by the study site. The road that pass through Eastern Andes, and the magnificent Montane forest of western Amazonia behind. (Photo by M. L. Cárdenas)
Who would have thought that building a road in Andes would have allowed us to gain new and unique insight of pristine western- Amazonian forests? (I would have thought completely the opposite). Initially Patricia Mothes, chief of the volcanologist section of the Intituto de Geofisica in Ecuador, was called to look at sediments exposed by road works on the eastern flank of the Ecuadorian Andes. Arriving at the site she found thick (>20 vertical meters) deposits of grayish and dark brown interbedded layers of sediments which looked like they have been recently deposited. At closer inspection Patricia discovered that there were even wood pieces and leaves within the dark sediments (now known to be highly organic) that had the appearance of have been deposited within modern time. She wanted to know more. So a PhD student was recruited (a.k.a. Macarena Cárdenas) to work with the sediments at the Palaeoenvironmental Change Research Group at the Open University under the supervision of Dr William Gosling… And so the study began.
After several years spent dating the sediments, analyzing their composition (physical and elemental) and the fossils (pollen and wood) contained within them preliminary insights into vegetation change on the eastern Andean flank during the middle Pleistocene (c. 200,000-300,000 years ago) were revealed and published (Cárdenas et al., 2011a; Cárdenas et al., 2011b). Further work covering stratigraphically lower sediments (older than those previously published; c. 500,000 year) and more detailed sedimentary and fossil analysis of the entire sequence completed a PhD thesis (Cárdenas, 2011).
I am now pleased to announce that the extended work included in my PhD thesis has now been published in a new article in Palaeogeography, Palaeoclimatology, Palaeoecology (Cárdenas et al., online). The new paper is an extended version from previous publications from the same research and provides further evidence of the unique insights that can be gained from palaeoenvironmental studies in this region. These are some of the oldest Quaternary sediments ever discovered and studied from the mid-elevation eastern Andean flank / western Amazon and upon their analyses we were able to get for the first time an insight of how human-untouched Amazonian forests were back in time (up to 500,000 years ago!), how was their diversity and how they responded to intense volcanic activity and climatic change.
By Dr Macarena L. Cárdenas
REFERENCES
Cárdenas, M.L. (2011) The response of western Amazonian vegetation to fire and climate change: A palaeoecological study. In: Department of Earth & Environmental Sciences, p. 242. The Open University, Milton Keynes
Cárdenas, M.L., Gosling, W.D., Pennington, R.T., Poole, I., Sherlock, S.C. & Mothes, P. (online) Forests of the tropical eastern andean flank during the middle pleistocene. Palaeogeography, Palaeoclimatology, Palaeoecology. DOI: 10.1016/j.palaeo.2013.10.009
Cárdenas, M.L., Gosling, W.D., Sherlock, S.C., Poole, I., Pennington, R.T. & Mothes, P. (2011a) The response of vegetation on the Andean flank in western Amazonia to Pleistocene climate change. Science, 331, 1055-1058. DOI: 10.1126/science.1197947
Cárdenas, M.L., Gosling, W.D., Sherlock, S.C., Poole, I., Pennington, R.T. & Mothes, P. (2011b) Response to comment on “the response of vegetation on the Andean flank in western Amazonia to Pleistocene climate change”. Science, 333, 1825. DOI: 10.1126/science.1207888
October 1, 2013
Human modification of the landscape in the Andes (Peru)
Whilst working on intergrating palaeoecological and archaeological data for a recent publication (Gosling & Williams, 2013) I was struck by the range of sources I had to go to to obtain data from the two different disciplines. The paper focuses on the how societies in the high Andes have developed over the last 5000 years and the role, if any, that changes in natural resource (ecosystem service) avaliability might have played in pacing any societal changes. However, when I got the first set of review comments back I was left considering my (academic) resource base, how I accessed this, and how that influenced my ability to conduct research; especially when moving slightly outside the area of my specialism.
July 31, 2013
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.
January 16, 2013
Join us… PCRG members on fieldwork in Ecuador
The AXA Research Fund Postdoctoral Fellowship scheme is opening shortly!
All applications must be pre-approved by the host institution so if you are interested in applying for a project through The Open University expressions of interest are required by 25th January 2013.
January 9, 2013
Two NERC algorithm funded PhD studentships are currently available with the PCRG. The projects are focused on understanding past environmental change in west tropical Africa and Amazonian-Andean Ecuador. Both projects will involve field work and build on on-going research within the lab.
Closing date 31/01/2013
One project will work on samples collected during fieldwork in 2012 near Papallacta (Ecuador).
Further project details and how to apply below…
Continue Reading
October 10, 2012
One of the key goals of the fieldtrip to Ecuador (August-September) was to sample organic and volcanic (tephra) layers from sedimentary exposures with the aim of obtaining new information about past envrionmental change in the region. Our Ecuadorian collaborator, Dr Patricia Mothes (Instituto Geofisico), had identified four of sites she thought might be useful too us: El Fatima Dique, Mera “2” Dique, El Rosol and Vinillos.
At the Fatima site, near Puyo, a thin organic bed was sampled sandwiched between volcanic ash deposits. Wood macrofossils from this deposit have been dated to the last glacial period.
For further descriptions of what we found and field photos read on…
September 15, 2012
The second part of our Ecuadorian expedition took in lakes and sections close to the towns of Papallacta and Cosanga. The variation in climatic conditions was marked as we experienced first hand the transition from freezing fog and driving rain to burning sun and heat within a few tens of kilometers as we travelled from >4000 m down to around 1000 m elevation.
Sampling the sedimentary section at Vinillos was hampered by a tropical downpour. Sediments recovered from here include volcanic ash, mud slide deposits including large wood macrofossils and fine grained organic sediments probably deposited in still water environments.
Preparing to recover a short core from a pond near the antenas at Cujuca. Short cores will be used for Chironomid analysis.
Tomorrow we will attempt to recover short cores from two more lakes. Then our final few days here in Ecuador will be spent visiting partners and packing up.
June 8, 2012
Particpants on the Numerical Analysis course 2012: Lottie Miller, Guiomar Sanchez, Maria Rubio, John Douglass and Sonia Jaehnig (left-right). Photo courtesy of Manuela Milan.
Last month I attended the Numerical Analysis of Biological and Environmental Data course at University College London (UCL) in order to decipher which techniques of multivariate data analysis would be useful to apply to my data from Lake Bosumtwi (Ghana). The course was led by Dr Gavin Simpson (UCL) and Prof. John Birks (University of Bergen), both of whom are well experienced in quantitative palaeoecology.
The course provided an introduction to the methods, guidance as to when to use the techniques and then outlined the assumptions, limitations and strengths of the various methods. The need to fully understand the techniques applied before attempting to critically evaluate the results was also strongly emphasised.
The course consisted of lectures covering measures of dispersion, cluster analysis, dendrograms, regression analysis, tree models, gradient analysis, transfer functions, time series and hypothesis testing. Afternoon practical computer classes involved using R, C2 and CANOCO to implement the various techniques covered in the lectures.
Overall the course was a great introduction to statistical analysis which I would certainly recommend for anybody working with complex and noisy datasets. In the next few days I will be using my newly learnt R skills to run indirect gradient analysis such as PCA, CA, DCA and NMDSCAL to search for environmental gradients within my data.
Numerical Analysis of Biological and Environmental Data training couse is an annual event and was held at UCL, on 14-25th May 2012. For more information about the course see Gavin’s website or read his blog From the bottom of the heap.
Ecology of the past 