MSc Earth Sciences | Ecology of the past

Amazonia – natural wilderness or abandoned parkland?

April 5, 2019
WDG

Judith being enthusiastic on fieldwork in the Austrian Alps during her Bachelors degree

Amazonia – natural wilderness or abandoned parkland?

By Judith Kirschner (currently studying for MSc Earth Sciences: Geo-ecological Dynamics track at the University of Amsterdam)

In the 4^th edition of our “Amsterdam Paleoecology Club” (APC), we discussed ‘A 6900-year history of landscape modification by humans in lowland Amazonia’ by Bush et al. (2006)¹. The high-resolution record presented in this paper shows impressively that what we might perceive as native rainforest today could rather be a since a long time actively modified landscape.

The chronology from Lake Sauce (Peruvian Andes) suggests a continuously forested landscape under significant anthropogenic impact over the last 6900 years. Indicators of human activity are taken to be the varying presence of crop pollen (Zea mays) throughout the record, combined with the continuous occurrence of charcoal. Two extra-large fire events are dated at c. 6700 and between 4500-4230 cal BP, probably enhanced by the relatively drier climate of the mid-Holocene. However, it is not clear yet if human actions formed a response to climate change or were part of social and cultural changes.

Environments Through Time paper presentations

November 6, 2018
WDG

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.

Environments Through Time is taught in English, delivered by myself (William Gosling), Crystal McMichael and Milan Tunissen van Manen and currently has 31 registered students from MSc Biological Sciences and MSc Earth Sciences degrees.

Full list of papers presented by students on the Environments Through Time course in 2018 Continue Reading

Environments Through Time – weeks 2 & 3

November 19, 2017
WDG

Britte reconfiguring the chronology for Lake Pata

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.

For more information on this course see: Environments Through Time – week 1

Environments Through Time – week 1

November 3, 2017
WDG

Me teaching human impacts on environmental change…

The first, ever, week of the Environments Through Time course at the University of Amsterdam has just finished. The course sits within the MSc Biological Sciences (Ecology & Evolution) and MSc Earth Sciences (Geo-ecosystem Dynamics) but is also avaliable to other masters students. In the first week we have thought about four main topics:

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.

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The Enviornments Through Time course is taught by: William Gosling, Crystal McMichael, and Milan Teunissen van Manen.