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
Huisman, S.N.*, Bush, M.B. & McMichael, C.N.H. (2019) Four centuries of vegetation change in the mid-elevation Andean forests of Ecuador. Vegetation History and Archaeobotany. DOI: 10.1007/s00334-019-00715-8
This is the first is a series of blog posts based on papers discussed at our “Amsterdam Palaeoecology Club” meetings. The APC meetings are organized to promote palaeoecological discussion and to help the scientific development of our MSc and BSc research students. At each meeting we discuss a paper and the progress of individual projects. Short summaries of the papers and discussions are then made by the student introducing the paper. First up is MSc researcher Rianne van Duinen with her thoughts on Kaplan et al. (2016).
Rianne on field work in Twente during the 2017 edition of the BSc Palaeoecology course at University of Amsterdam
We discussed the paper “Large scale anthropogenic reduction of forest cover in Last Glacial Maximum Europe“ by Kaplan et al. (2016) which was found by the group to be super interesting and it incited a lot of discussion. The paper was mostly concerned with the anthropogenic influences and past vegetation of Europe. The main conclusion was that humans had a very big impact on forests during the last glacial period through the use of fire. The authors suggest that human actions are the explaining factor for the low amount of forests cover suggested by pollen records during the last glacial maximum (c. 21,000 years ago). The suggestion from Kaplan et al. that human modification of forest cover through fire during the glacial links with a recent study from Sevink et al. (2018) that suggests, based on pollen and charcoal data from the Netherlands, that human use of fire altered forest cover into the Holocene. In our discussion it was also noted that animals (mega-herbivores) were not really taken into account or discussed, even though animals probably had a big impact on the vegetation (e.g. see Bakker et al., 2016). Furthermore, another discussion point was the charcoal records that were used in the Kaplan et al. study, more specifically the number of cores. Kaplan et al. only used three cores to map out the effect of charcoal. It would be interesting to see what happens when more data from more cores is used. The Global Charcoal Database has a lot of data on European cores (c. 38% of the cores are from Europe) so there is a lot of potential for this. All in all, the article by Kaplan et al. raised a lot of questions and opened up a nice discussion.
The 2018 edition of the University of Amsterdam masters course “Environments Through Time” is now up and running. The course sits at the interface between ecology, physical geography and archaeology and seeks to provide students with a better understanding of how long-term (>100’s years) datasets can provide insights in to past environmental change.
In the first week of the course the students had to present their ‘favourite’ paper in just three (3) minutes! Quite a challenge and lots of fun. This years selection of papers themed around:
mega-fauna extinctions (Bakker et al., 2016; Gill et al., 2009; van der Kaars et al., 2017),
impacts of human land use practices (Bitusik et al., 2018; Carson et al., 2014; Chepstow-Lusty et al., 2009; Gauthier et al., 2010; Tisdall et al., 2018), and
climatic drivers of vegetation change (Haug et al., 2001; Tierney et al., 2017; Tudhope et al., 2001).
For full list of papers presented see below.
In the second and third weeks (now ongoing) students get to deconstruct published chronologies and conduct time series analsis of multi-proxy datasets. Data for these excercises is frequently is extracted from databases such as Neotoma, Pangea, NOAA – paleoclimatology datasets database and the Global Charcoal Database – which shows the importance of these open access databases for developing effective research led eductation, as well as pushing forward to frontiers of research.
My name is Veerle, and I am in my first year of the Master in Biological Sciences, Ecology & Evolution track, at the University of Amsterdam. I also completed my BSc Biology at the University of Amsterdam, specializing in Ecology and Global Change. One of my favorite courses during my BSc was Palaeoecology, which led to a BSc research project with William Gosling and Crystal McMichael on the farming history in the Netherlands. I really enjoyed this project and it made me even more interested in palaeoecology. This year I have gotten the amazing opportunity to do another project with Crystal McMichael…. including a field expedition together with Britte Heijink and Nina Witteveen to Panama and Colombia! This was an amazing experience with a lot of fun, mud, insect repellent and most of all really nice cores! I am super excited to tell you about my field experiences, so soon we will post another blog about that!
Collecting the soil
Now that we’re back in Amsterdam, I’m analyzing phytoliths from Gigante (Panama) to reconstruct the fire and vegetation history. I’m especially interested in past agriculture and forest management to see if there were humans present in the area and how they affected the vegetation. Hopefully I can show you some nice results about that in the future!
My name is Nina Witteveen and I’m doing a research project for my master (Biological Science) with Crystal McMichael and William Gosling. I’m analyzing phytoliths to reconstruct the vegetation changes of Campo Libre (Napo, Ecuador) of the past 30,000 years. It is so exciting to count phytoliths of such an old age!
Simon Scholz is currently doing a charcoal analysis and two years ago, Maaike Zwier performed a physical analysis in the sediment. With all these results combined, I will investigate how climate changes and human influence have changed the vegetation of Campo Libre. Hopefully this research will give more insight into the effect of a changing climate on this biodiversity hotspot!
I’ve completed my thesis for the Biology bachelor at the UvA under the supervision of Crystal and Will. Together with other students we performed phytoliths, pollen and charcoal analysis from sediment of Well-Aaijen (Limburg, the Netherlands). More specifically, I’ve looked at the vegetational changes during the transition from hunter-gatherers to farmers through pollen and phytolith analysis. I’m very happy to be working with Crystal and Will again, this time in a more tropical setting!
In January of this year, I travelled to Panama with Veerle Vink, Britte Heijink and Crystal McMichael. It was a great experience! Surrounded by Howler Monkeys, we made our way through streams and Geonoma palms to collect soil surface samples for future phytolith analysis. Definitely a highlight of my fieldwork so far! I am now back in the microscope lab, and always up for a (paleo)chat 🙂
Veerle and I trying to protect ourselves from the mosquitos.
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
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!
Our last day in the Amazon was spend with some of the local students, Louisa Fernando Gomez Correa and Mariana Gutierrez Munera.
The second and third weeks of the Environments Through Time course at the University of Amsterdam has focused on obtaining practical experience of developing chronologies, analyzing multi-variate data-sets, and conducting time series analysis. The focus of the course has been on Quaternary environmental change, however, the skills learnt can be applied to almost any time-scale so long as you have time control points you want to tie together, and multiple things you can track changing through that time.
Over the two week period the students worked on a previously published paper that they had selected that contains: (i) chronological information (at least 3 control points), and (ii) multiple variables that change through the time series (at least 9 variables). In week two they deconstructed the chronologies and generated their own revised versions. For example students have (re-)calibrated radiocarbon dates, made different decisions on dates to include/exclude, and used different approaches to constructing the age vs. depth model, e.g. contrasting linear point-to-point vs. Bayesian methodologies. In week three they have taken the data-set(s) associated with their paper and re-evaluated it in light of the revised chronologies using cluster analysis, ordination techniques, and wavelets.
The joy of wavletes
Through this exercise students have gained experience of how to critically assess scientific literature and gained an appreciation of where re-analysis of data-sets can (and cannot) make a difference. Personally I have be delighted with the high level of engagement and enthusiasm for the material and have been excited to have a chance to delve into literature that I would not otherwise be aware of.
Scales of change (ecological, geological, and human).
Humans as drivers of environmental change.
Extra-terrestrial forcing of environmental change.
Earth system feedbacks.
The week was completed with each student giving a three (3) minute presentation of their favourite paper. The papers presented ranged from the extinction of giant sharks, through forest-savannah transitions, to how climate change thwarted Ghengis Kahn. Next week we continue by disecting how chronologies are constructed.