Vegetation responses to late Holocene climate changes in an Andean forest

May 31, 2019
klaasland

Vegetation responses to late Holocene climate changes in an Andean forest
By Klaas Land (currently studying MSc Biological Sciences (Ecology & Evolution) at the University of Amsterdam.

The discussion during the APC meeting on the 19th of March was on the paper by Schiferl et al. (2018), a very recent study on the climatic shifts in the late Holocene and their effects on the South American tropics. The study had analysed a core going back about 3800 years from Lake Palotoa, which was in the Andean foothills (1370m elevation). They found that subtle changes to the fossil pollen record could be identified around the estimated periods for the Little Ice Age (LIA) and Medieval Climate Anomaly (MCA). The focus in the paper Continue Reading

Reconstructing past fire temperatures from ancient charcoal material

February 10, 2019
WDG

Gosling, W.D., Cornelissen, H. & McMichael, C.N.H. (2019) Reconstructing past fire temperatures from ancient charcoal material. Palaeogeography, Palaeoclimatology, Palaeoecology 520, 128-137. DOI: 10.1016/j.palaeo.2019.01.029

Click here for open access until 01/04/2019

Note: This article is developed directly from work conducted by Henk Cornelissen during his BSc Future Planet Studies thesis project at the Institute for Biodiversity & Ecosystem Dynamics, University of Amsterdam.

Loughlin PhD Thesis 2018

July 25, 2018
nicholasloughlin

Nick recovers a sediment core for his PhD project.

Nick Loughlin

Loughlin, N.J.D. (2017) Changing human impact on the montane forests of the eastern Andean flank, Ecuador. PhD Thesis. School of Environment, Earth and Ecosystem Sciences, The Open University.

Abstract:

The montane cloud forests of South America are some of the most biodiverse habitats in the world, whilst also being especially vulnerable to climate change and human disturbance.

Today much of this landscape has been transformed into a mosaic of secondary forest and agricultural fields. This thesis uses palaeoecological proxies (pollen, non-pollen palynomorphs, charcoal, organic content) to interpret ecosystem dynamics during the late Quaternary, unravelling the vegetation history of the landscape and the relationship between people and the montane cloud forest of the eastern Andean flank of Ecuador. Two new sedimentary records are examined from the montane forest adjacent to the Río Cosanga (Vinillos) and in the Quijos Valley (Huila). These sites characterise the natural dynamics of a pre-human arrival montane forest and reveal how vegetation responded during historical changes in local human populations.

Non-pollen palynomorphs (NPPs) are employed in a novel approach to analyse a forest cover gradient across these sites. The analysis identifies a distinctive NPP assemblage connected to low forest cover and increased regional burning. Investigation into the late Pleistocene Vinillos sediments show volcanic activity to be the primary landscape-scale driver of ecosystem dynamics prior to human arrival, influencing montane forest populations but having little effect on vegetation composition.

Lake sediments at Huila from the last 700 years indicate the presence of pre-Hispanic peoples, managing and cultivating an open landscape. The subsequent colonization of the region by Europeans in the late 1500’s decimated the indigenous population, leading to the abandonment of the region in conjunction with an expansion in forest cover ca. 1588 CE. After approximately 130 years of vegetation recovery, montane cloud forest reached a stage of structural maturity comparable to that seen in the pre-human arrival forest. The following 100 years (1718-1822 CE) of low human population and minimal human impact in the region is proposed as a shifted ecological baseline for future restoration and conservation goals. This ‘cultural ecological baseline’ features a landscape that retains many of the ecosystem service provided by a pristine montane forest, while retaining the cultural history of its indigenous people within the vegetation. Continue Reading

Introducing Britte Heijink

March 2, 2018
WDG

Veerle and I trying to protect ourselves from the mosquitos.

Veerle and I trying to protect ourselves from the mosquitos.

Hi all!

My name is Britte Heijink and I’m doing my MSc Biological Science thesis research project with Crystal McMichael and William Gosling. I travelled with Veerle Vink and Crystal to the Colombian part of Amazonia to collect samples for my project. At Amacayacu National Park, we collected soil cores from different locations in the plot. Now that we’re back in Amsterdam, I’m analysing the soils to reconstruct the fire and vegetation history from the plot using charcoal and phytoliths. I am specifically looking to see if humans have been present in the system and how they potentially affected the vegetation at Amacayacu.

 Here I’m Sampling pieces of soil cored by Louisa and checking for large pieces of charcoal

Here I’m Sampling pieces of soil cored by Louisa and checking for large pieces of charcoal

I’ve completed my bachelor thesis for Bèta-Gamma (Liberal Arts and Sciences) under the supervision of Crystal and Will here at the UvA. I’m really excited to work with them again, and already looking forward to our meetings at the Oerknal 😉  I will be finished by the end of September, and then possibly return for a literature study.

One of the most wonderful experiences in my academic career so far has been the fieldwork to Panama and Colombia with Crystal, Veerle, and Nina. It was a lot of hard work, and 90% of our time was spent covered in mud, sweat, and insect repellant, but the experience of working in a tropical rainforest was completely worth it! Veerle and I will write another blog about our fieldwork soon. Come see us in the microscope lab if you want to hear our dangerous and amazing stories before that!

Cheers,

Britte

Our last day in the Amazon was spend with some of the local students, Louisa Fernando Gomez Correa and Mariana Gutierrez Munera.

Our last day in the Amazon was spend with some of the local students, Louisa Fernando Gomez Correa and Mariana Gutierrez Munera.

Success for BSc project students

July 18, 2017
WDG

BSc students on the Palaeoecology course prior to undertaking a research project with us.

Many BSc students undertook our “Palaeoecology” course prior to choosing to do a research project with us.

This year 15 (fifteen!) bachelors students completed their research projects in palaeoecology based within the Department of Ecosystem & Landscape Dynamics at the University of Amsterdam. The students had a variety of backgrounds with the majority coming from the BSc Biology and the BSc Future Planet Studies programs.

Each project was set up to test a particular ecological or biogeographic hypothesis. Investigations included the exploration of the role of humans in modifying ecosystems in Amazon, the nature of the pre-farming landscape in the the Netherlands, and how to chemically identify fossil charcoal. In undertaking their projects individual students had the opportunity to variously develop skills in microscopy, spatial modelling, or analytical chemistry. The high quality of the data produced means that hopefully many of these data sets can be used in future scientific publications. Well done to all!

If you are interested in conducting a similar project (at any academic level) with us please do not hesitate to get in contact. For further details of ongoing research within the Department of Ecosystems & Landscape Dynamics visit our web pages by clicking here.

Biodiversity and the functioning of tropical forests

July 12, 2016
WDG

Biodiversity and the functioning of tropical forests
PhD defense University of Wageningen
Candidate: Masha T. van der Sande
Date: 06/07/2016

Watch Masha’s thesis defense on WUR TV (featuring W.D. Gosling as an opponent…)

WRUTVClick here to watch the video

Past environmental change on Mauritius: Unknown macro-fossils

December 18, 2015
WDG

Unknown macro-fossil JdK-type2

Unknown macro-fossil JdK-type2

Past environmental change on Mauritius has been the focus of research with the Palaeoecology & Landscape Ecology group at the University of Amsterdam (UvA) for a number of years. This research has been lead by Erik de Boer and Henry Hooghiemstra and has already resulted in a number of key publications on the environmental history of the island (de Boer et al., 2013, 2014, 2015). One current past environmental change research project working on Mauritius is being undertaken by Jona de Krui; a student within the UvA BSc Biology program supervised by myself and Erik. Jona’s is working on a study site (modern day swamp) on the north-east of the island and is focused on improving our understanding changes in the:

  • depositional environment (loss-on-ignition analysis),
  • fire activity (macro-charcoal analysis), and
  • vegetation (macro-fossils) over the last c. 1000 years.

Jona has now completed the analysis of all his samples and we are currently collating the data sets; however, a number of the macro-fossils which he has discovered remain unidentified. Below are images of the unknown macro-fossils if you have any suggestions on identifications please comment, or get in touch directly.

Continue Reading

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

Theses rush at The Open University

May 17, 2015
encarnimontoya

Hi palaeo-people!!

Alice Kennedy (far right) celebrating post-viva examination.

Alice Kennedy (far right) celebrating post-viva examination.

It is been a while since the Milton Keynes’s part of the group have manifested in the blog. The main reason is that we have been a bit busy basically…submitting theses!!!!

So this very short post is to congratulate Hayley Keen, Frazer Bird and Alice Kennedy for their recent handing in during the last two months and to celebrate that we have a new doctor in the group!!! Alice defended her thesis on 14th May, having as tribunal Prof. John Marshall (Southampton), Dr Phil Sexton (Open University) and Dr Sarah Sherlock (Open University). Next viva will be Hayley’s on 28th May (exam panel: Dr Dunia Urrego [Exeter], Prof. David Gowing [Open University], and Dr Mark Brandon [Open University]). Frazer will be defending his research next 25th June in front of Dr Pete Langdon (Southampton), Dr Neil Edwards (Open University), and Dr Sarah Sherlock (Open University).

Well done guys, this has been hard work and we are sure that your projects will have amazing contributions to high quality research!

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