To facilitate the our ability to identify pollen in the fossil record we have been building a searchable digital tropical pollen database. Our work builds upon the architecture provided by Bush & Weng (2007) for their Neotropical pollen database (Palaeoecology lab, Florida Institute of Technology). We have used Bush & Weng’s freeware tool and expanded it to include an additional 364 pollen and spore types from tropical Africa. The images are of pollen reference material collected over the career of Prof. Dan Livingstone and curated in the Department of Biology, Duke University; full collection details of each specimen are indicated on each individual electronic record. In conjunction with the open access publication “Atlas of the tropical West African pollen flora” (Gosling et al., 2013) we have made the entire updated pollen database available. We hope that this will prove to be a useful tool for palynologists working in Africa and the wider tropics and that it will encourage others to develop the database further.
With the redesign and refocusing of the blog underway, I’m delighted to announce the launch of our very own “Ecology of the past”YouTube channel. Initially this will host videos produced as part of the Lake Bosumtwi pollen chemistry project, which includes a strong emphasis on impact and outreach activities. The videos are being targeted to a secondary school/sixth form audience, and will demonstrate both how we are doing the research and who we are as academics, highlighting the different roles and career pathways within the team. As time goes on this channel will be a platform for videos from other members of the research group, again showing who we are, what we do and how we do it.
For now, here are the first two videos: a diary of the field trip to Ghana that Adele and I went on last Autumn, and an accompanying piece showing how you too can make your own pollen trap. Enjoy!
My first fieldwork from the OU, in 2005, was pollen trapping on the Galapagos. Here I am looking beardy on Bainbridge.
February was an exciting month for me principally because of the finalization of my move to the University of Amsterdam (UvA) where I will become head of Paleo and Landscape Ecology in September. The decision to leave The Open University (OU) has been a difficult one. When I joined the OU as a RCUK Research Fellow in Ecosystem Science in 2005 I would not have believed that I would be in a position to take on a job such as the one in Amsterdam only nine years later. Building the group here during the last nine years has been a lot of fun and I have got to work with some great people. Stand out moments include:
Obtaining my first grant as Principle Investigator (c. US$20,000 from the National Geographic for field work in Bolivia),
Recruiting, and graduating, my first PhD research students (Joe Williams and Macarena Cardenas),
Being invited to participate in large international research efforts (notably the Lake Bosumtwi project),
Co-editing my first book (Bush et al., 2011), having my first student to publish a paper getting it in Science (Cardenas et al., 2011), and helping to write a popular science text co-published by the Natural History Museum (Silvertown et al., 2011)
There have been many more amazing things here but I don’t want to swamp this post with a retrospective of my OU career…
Ongoing excitement within the PCRG is happening on a number of fronts:
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
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
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.
Face-to-face teaching of practical skills in field geology is one of the most interesting and rewarding aspects of being a lecturer at The Open University. Over the last few days I have been lucky enough to participate in the running of the Sedimentary Rocks & Fossils in the Field topic within our second level Practical Science module (SXG288). This is one of two opportunities that students taking this module get to head into field, examine rocks, develop observational skills and test scientifc hypotheses; the other field based topic is Igneous & Metamorphic Rocks in theField.
Sedimentary Rocks & Fossils is based from Longridge Towers School in Northumberland (whilst the regular students are away). Longridge provides the ideal base for this topic because of its close proximity to some world class sedimentary rock and fossil exposures. Over an intensive three day field experience students examine sedimentary deposits from the Silurian and Carboniferous exposed mainly along the Northumberland coast; however, this is not a simple guide to the geology of the region. The topic is founded on the principle of problem based learning and at each field location students are expected to make observations, record them accurately and interpret the past environment. Findings are consolidated and dicussed during evening lab sessions.
On the rocks at Scremerston
This year we were delighted to welcome >40 students, some of who flew in from abroad, to study this topic over two sessions. Given the positive feeback recieved so far I think all enjoyed the topic and gained important geological field skills (for evidence of this also see photos below). I wish them all luck in their future studies and hope that they continue to be interested in Earth Science and progress towards our Natural Science degree qualification.
For further photos see below, follow #SXG288 on twitter, or visit the SXG288 Facebook page.
Earlier this month Rachel Gwynn (Geography, UCL) visited the PCRG to use our core splitter to reveal what was contained within two cores collected from the Carribean. She has also been kind enough to provide photos of the sediments and an insight into the story so far:
Sediments from Fresh Water Pond Barbuda (Photograph Rachel Gwynn)
Lake sediment cores covering the past few hundred to thousand years have been taken from two lakes, Wallywash Great Pond in Jamaica and Freshwater Pond in Barbuda. The sediments form part of the NERC-funded project Neotropics1k (PI Prof. Jonathan Holmes), which is concerned with climate variability in the northern Neotropics over the past millennium. The sediment cores show marked changes in composition and colour, from pale marl to dark organic mud. These colour changes, which are clearly visible in the photographs, represent changes in sediment composition that are in turn related to lake-level variations caused by long-term climate shifts. Deeper, open-water conditions under wetter climate are represented by the marls, whereas lowered lake levels, caused by direr climate, are associated with organic-rich sediments.
Wallywash Great Pond– core section W2
Thirteen separate units have been identified through the 1 m core length, varying between light coloured marl, dark organic and shelly sediments.
The abundance of preserved Ostracod valves increases throughout the marl and shell rich layers but drops significantly in the organic rich material.
Barbuda Freshwater Pond- core section FWP
This core has four distinct units. 0-23 cm is a calcareous mud with a diffused lower boundary into a shelly calcareous mud at 25-35.5 cm. 35.5-38 cm and 38-52 cm is two variations of calcareous mud.
These units, as with the W2 core, have been defined using a Munsel Soil Chart.
The Ostracod valves are thought to be abundant throughout the core due to the high marl content.
Wallywash Great Pond Jamaica (photograph Rachel Gwynn)