Hello all! You might have been wondering if I died in the middle of Amazonian nowhere, since I haven’t come back to writing a blog after we left for fieldwork in July. Given we were in an Amazonian region full of venomous snakes that could have been the case, but the good news is I just didn’t get around writing it because I got carried away by the findings of my project! We actually had a very successful field trip – apart from some minor issues like the lake swallowing equipment, sinking waist-high into the mud each step of our 7 hour long ‘trail’ to the lakes, and almost not getting my precious samples through airport security.
Focus on Global Ecology, including: global biodiversity patterns and ecosystem functioning, human impacts on biodiversity, biogeography of species interactions, and/or global changes in ecosystems, biodiversity and ecosystem services.
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.
Researchers in the Institute for Biodiversity and Ecosystem Dynamics (IBED) at the University of Amsterdam have been studying the páramos and Andean ecosystems for over 50 years. These highly diverse ecosystems are currently restricted to mountain-tops (resembling an archipelago of islands in the sky), but in the past dominated large surface areas throughout the Northern Andes. Climate change determined the degree of páramo fragmentation and connectivity in the past, and site-specific results have been integrated into a GIS-environment (visualization) for southern Colombia and the entire Northern Andes by IBED researchers Suzette Flantua and Henry Hooghiemstra.
Watch the ‘Time machine: Ice ages in the Andes’ video and see its presentation at the recent IBED Open Day:
IBEDs Crystal McMichael hard at work sampling sediments in the Andes
Insights into recent field work in Ecuador by a team lead by Crystal McMichael can be found in a recent blog from our collaborators at the Instituto Geofisico, Escuela Politecnica Nacional, Quito (Ecuador).