Ecology of the past on film: Hayley Keen

October 6, 2015
WDG

Whilst conducting her PhD research Hayley Keen helped produced two of short films about her research project Past environmental change on the eastern Andean flank, Ecuador:

  1. on her field work, which was the winning entry into the American Geophysical Union (AGU) student video competition in 2014, and
  2. a presentation summing up her PhD project in just 3 minutes!

First prize in the AGU student video competition (2014)

Three minute thesis (The Open University, 2014)

Follow Hayley’s ongoing research on this blog and on Twitter @Hayley1keen 

Keen PhD Thesis 2015

September 30, 2015
WDG

Hayley Keen getting excited about sediments during fieldwork in Ecuador (2012). Photo: J. Malley

Hayley Keen getting excited about sediments during fieldwork in Ecuador (2012). Photo: J. Malley

Keen, H.F. (2015) Past environmental change on the eastern Andean flank, Ecuador. PhD Thesis, Department of Environment, Earth & Ecosystems, The Open University.

Abstract
The eastern Andean flank of Ecuador (EAF) contains some of the world’s most biodiverse ecosystems. Andean montane forests are threatened due to anthropogenic pressures and both current and projected climate change. This thesis examines the palaeoecological history of two stratigraphic sequences (Mera Tigre West [MTW] and Mera Tigre East [MTE]) obtained from the Ecuadorian modern lower montane forest. The sediments preserved were analysed using eight analytical techniques, allowing an insight into the ecosystem’s potential response to projected changes derived from their past responses. Palaeoecological studies on the EAF are rare, and those that do exist are debated relating to: i) the inference of robust ecological data from pollen records in floristically diverse locations, and ii) the past source area of sediments preserved in fluvially exposed sequences, potentially leading to contamination with older material.

A statistical sub-sampling tool was developed (debate i), capable of producing statistically robust count sizes for each pollen sample; MTW and MTE count sizes ranged from 196-982 showing the diversity within sequences. The depositional environment of MTE was analysed, investigating sediment provenance throughout (debate ii). Results found that large scale volcanic events were critical in the preservation of the sediments, whereas fluvial influence caused a regional sediment source area in the upper stratigraphy, impacting on the palynological interpretation of MTE. Pollen records demonstrated the presence of a diverse vegetation community with no modern analogue at MTE (abundant taxa (>15 %): Hedyosmum, Wettinia, Ilex) and upper montane forest at MTW (Alnus, Hedyosmum, Podocarpus). Fire was not the main driver for the vegetation reassortment at either site (MTW correlation coefficient: -0.37, MTE: 0.16). The two sites have demonstrated the EAF plays host to floristically dynamic ecosystems, susceptible to drivers of change (fire and landscape) and should be considered when predicting the montane forests’ future response to environmental change.

Supervisors: Dr. William D. Gosling (The Open University/University of Amsterdam), Dr. Encarni Montoya and Dr. Sarah Sherlock (both The Open University).
Examiners: Dr. Dunia Urrego (University of Exeter), and Prof. David Gowing (The Open University).
Chair: Dr. Mark Brandon (The Open University).

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

Publications (so far): Continue Reading

Palaeoecology at UvA and Twente 2015: Teaching and Learning

September 21, 2015
cmcmicha

By Crystal McMichael

The month-long palaeoecology module at UvA is coming to an end. We have had two weeks of lectures and microscope work, an introduction to quantitative palaeoecology, and we just finished a week of fieldwork in Twente, which is in the easternmost part of the Netherlands.

Students working in the field (photo: M. Groot)

Students working in the field (photo: M. Groot)

Will Gosling and I tried something new for the field excursion this year. We split the class into eight groups, and gave each group a set of pollen and phytolith samples from an ‘unknown location’. Unknown in this context means being from one of the eight primary sites that we would visit during the field excursion. The students were required to perform vegetation surveys and characterize soils at each of the primary sites that we visited. The goal of each group was to figure out which location their set of ‘unknown’ samples came from. Basically, we had them doing forensic palynology, with idea that they could then better visualize the different vegetation assemblages seen in the palaeoecological records.
Continue Reading

Pollen database of Early-Miocene Amazonian palynological diversity

June 29, 2015
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By Milan Teunissen van Manen
MSc Biological Sciences, University of Amsterdam.

As part of my MSc research project on Early-Miocene paleodiversity shifts due to marine incursions in the Amazon basin, I recorded and photographed large numbers of palynomorphs. The database consists of a set of images (Teunissen van Manen, 2015a) that I took with my smartphone (bundled in pdfs for sharing purposes) and an Excel overview file (Teunissen van Manen, 2015b) where each of the entries is described. Some of the entries are well documented taxa (C’mon, who hasn’t heard of Zonocostites ramonae and Mauritidites franciscoi before?) while others are “types” that are not formally described – mainly because in Amazonian sediments new, unseen palynomorphs pop up all the time. Indeed, this was the reason why I started the database in the first place: I was merely trying to keep up with the vast diversity that I encountered during sample counting.

Mauritidites franciscoi
TP 100

Seeing the added value of having a digital record of the palynological diversity from the Amazon basin samples, my project supervisor, Carina Hoorn (UvA), encouraged me to publish the database online so others could also access it. I’d like to invite you to take a look. I hope it can maybe help you with identifying taxa or, who knows, linking taxa across the Amazon basin… if you do, please let me know!

…or maybe it will have you rejoice in the huge diversity and alien beauty of pollen morphology, just as it rejoiced me as I was working through my (seemingly endless) samples.

REFERENCES

Teunissen van Manen, Milan (2015a): Miocene Amazonian Palynological Diversity – Image files. figshare. http://dx.doi.org/10.6084/m9.figshare.1396453

Teunissen van Manen, Milan (2015b): Miocene Amazonian palynological diversity database – Entries record. figshare. http://dx.doi.org/10.6084/m9.figshare.1396562

This project was conducted with Research Group of Palaeoecology & Landscape Ecology, part of the Institute for Biodiversity & Ecosystem Dynamics.

There And Back Again: Returning To The South Pacific

Ecology of the past blogger Tessa (https://ecologyofthepast.info/2015/02/16/introducing-tessa-driessen/) will be working on the pollen from these Samoa cores. Exciting times…

Jon Hassall's avatarPalaeoenvironmental Laboratory

Last year I was told that my fieldwork in Samoa and New Caledonia was the best I’d ever experience; turns out that was a lie. This year I was fortunate enough to return to Samoa, and even more fortunate to go to the small island of Atiu in the Cook Islands. There was one very simple reason for me, along with Prof. David Sear and Dr Pete Langdon, to return to the South Pacific: we needed more sediment from the lakes on these islands. This sediment is crucial to determine how a massive band of rain – called the South Pacific Convergence Zone (SPCZ) – has moved in the past. Millions of people are dependent on the SPCZ for drinking water. Data from satellites has shown that various climatic phenomena that operate in the Pacific Ocean cause the South Pacific Convergence Zone to move. With future climate change likely…

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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.

Introducing Tessa Driessen

February 16, 2015
TessaDriessen

Tessa DriessenHi I’m Tessa and really excited to introduce myself here!

I’m an Environmental Biology Master student from Utrecht University (UU) doing a research internship in Amsterdam with William Gosling and Rike Wagner of the UU. Most people would describe me as a typical biologist because I like identifying plants and know some birds by their name. Personally I disagree because I lack the beard and hardly wear woollen socks. Besides looking at birds and plants I’m also interested in biodiversity and palaeoecology, and I will try to combine these interests in my research project on a sediment core from Samoa. I will be working on lake sediment cores from Samoa and hope fossil record can give me an overview of the natural history of the island (past c. 10,000 years); and an insight into what impact human colonisation had on the biodiversity. To explore the islands natural history I will be looking at pollen, charcoal and non pollen palynomorphs.

The sediment core on which I will be working has already been recovered and currently resides in beautiful Southampton (UK). So I’m spared of a 30 hour trip to tropical Samoa and the opportunity to return with some Samoan tattoo’s and a tan… So thanks to David Sear and his team at the University of Southampton with whom I will be collaborating for this project.

I have a long standing interest in tropical islands. Before commencing this research internship I did my first masters internship at WWF Indonesia. For my WWF internship I spent three months in the tropics collecting baseline ecological data on timber companies located in a new reserve in Sumatra. Furthermore, during my bachelor degree, I did a research internship at Naturalis Biodiversity Center investigating the “Correlation between higher altitudes and endemic plant species” in the Malayan archipelago. Our results turned out much better then we hoped for and fingers crossed our article will be accepted soon!

In three weeks I will be starting in the lab in Amsterdam and hopefully in a few months will be able to post an update about my results here.

Tessa

Ecology of the past 2014

January 4, 2015
WDG

William shortly after a haircut

William shortly after first Dutch haircut

2014 has seen more people visit this blog and more “clicks” through to articles than in any previous year (see Annual Report 2014). So thanks for reading! I hope that the information provided is useful. For me 2014 has been a big year of change; with the largest work related change being taking up my new post at the University of Amsterdam in September.

2015 promises to be an exciting year with a number of key projects generating exciting findings (including chironomid climate for the Neotropics, Andean flank evolution, and ‘deep time’ palynomorphs) , the start of the XPERT network, and new proposals and collaborations being developed here in the Netherlands (including new proposal to work in Europe!).

Any comments, thoughts or contributions on the blog welcome.

William

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