June 8, 2023
Open access:
Strandberg, N.A., Edwards, M., Ellison, J.C., Steinbauer, M.J., Walentowitz, A., Fall, P.L., Sear, D., Langdon, P., Cronin, S., Castilla-Beltrán, A., Croudace, I.W., Prebble, M., Gosling, W.D. & Nogué, S. (2023) Influences of sea level changes and volcanic eruptions on Holocene vegetation in Tonga. Biotropica. DOI: 10.1111/btp.13231
December 6, 2022
Open access:
Heijink, B.M., Mattijs, Q.A., Valencia, R., Philip, A.L., Piperno, D.R. & McMichael, C.N.H. (2022) Long-term fire and vegetation change in northwestern Amazonia. Biotropica DOI: 10.1111/btp.13175
March 8, 2019
The second of our discussion papers for the “Amsterdam Palaeoecology Club”:
Mick ready to catch bumble bees!
Detecting the European arrival in the Caribbean
By Mick Bönnen (currently studying for MSc Biological Sciences, Ecology & Evolution track at the University of Amsterdam)
The paper we discussed was “Columbus’ footprint in Hispaniola: A paleoenvironmental record of indigenous and colonial impacts on the landscape of the central Cibao Valley, northern Dominican Republic” by Castilla-Beltrán et al (2018). The paper provides a multi-proxy paleoecological reconstruction of the Caribbean island nation of the Dominican Republic, spanning the last 1100 years. Personally I found this to be a very interesting paper, packed with information and interpretations on the impact of anthropogenic factors on past Caribbean environments. What this paper nicely demonstrates is the difference in impact between pre-colonial and post-colonial societies on the vegetation of the Dominican republic. Pre-colonial Hispaniola was inhabited by indigenous societies, the Taíno people, and while this paper clearly shows them having had an environmental impact in the form of fire management (e.g. for slash and burn agriculture), small scale deforestation and the introduction of cultivars such as maize and squash, their environmental impact remains modest compared to post-colonial disturbances. Columbus arriving in AD 1492 signified a moment of change in the landscape. The paleorecord suggests that, after an initial collapse of the Taíno population, the colonization of the Dominican Republic by the Spanish brought with it deforestation, crop monoculture and the introduction of European livestock, all of which still characterizes the landscape to this day.
The discussion mainly focused on the chronology used. One of the radiocarbon samples was excluded from the age-depth model for no apparent reason, which led us to discuss the importance of critically evaluating your calibrated radiocarbon dates and which ones to incorporate in your age-depth model. The age-depth model currently used implied a shift in pollen composition c. 30 years before the arrival of the Spanish. We were unsure how to interpret these findings because you would expect the shift to happen afterwards, so my initial thought was that it had to be a fault in the chronology. This chronology however does imply a large charcoal peak followed by a rapid decline that coincides precisely with the arrival of the Spanish, and it turned out that this was the reason the authors settled on this chronology.
Even though this paper by Castilla-Beltrán et al. didn’t spark any heated discussions, its incorporation of ecology, botany, history, archeology and geology still showcases the interdisciplinary nature of paleoecology, something I very much enjoy about this field of research.
References
July 20, 2018
AFQUA: The African Quaternary environments, ecology and humans
2ndInternational Conference and Workshops
14-22 July 2018-07-15 National Museum, Nairobi, Kenya
Day 6
The final day of talks at AFQUA 2018 took a more applied approach in the first session “Applying the Quaternary: The role of the past in supporting the future”. This session focused on how we can focus Quaternary science to produce outputs that directly meet concerns and needs of society. Examples included the quantification of the fossil charcoal record to provide insights into the nature and impact of fires in the past (C. Adolf), how we can use information on past vegetation change and disturbance factors to anticipate how ecosystems on Madagascar might respond to future changes (E. Razanatsoa), and how climate histories can be extended through tree ring data (D. Colombaroli).
February 2, 2018
By Seringe Huisman (MSc Biological Sciences, Institute for Biodiversity & Ecosystem Dynamics, University of Amsterdam)
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.
November 19, 2017
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
December 20, 2013
The latter half of 2013 seems to have been incredibly busy and I have not managed to get my monthly update posts completed since October. Rather than a rapid series of backdates here is a quick summary of what I think the main activities through this period have been!
Thesis defence: Congratulations to both Lottie and Natalie for sucessfully defending their PhD theses! Exeptional effort and hard work from both of you. Well done.
Publications: Four articles have gone through the final stages and been published in top journals. Well done to Lottie, Maca, Wes for leading three of those publications covering Lake Bosumtwi, Erazo and pollen/spore chemistry respectively. Personally I am delighted that the revised tropical pollen atlas is now online and open access. The final stages of publication of the atlas with Review of Palaeobotany and Palynology were hard work but great to see it online and avaliable. Thanks to Lottie and Dan Livingstone for their invaluable contributions.
Grant: We have been awarded further 14C dates from NERC radiocarbon facility to improve the chronology on Laguna Khomer Kotcha Upper so that the timing of temperature osscilations revealed by new chironomid analysis (by Frazer Bird) can be related to the last global degalciation (c. 18,000 years ago) and the Younger Dryas cooling event (c. 12,800 – 11,500 years ago). This research builds on that of former PCRG PhD student and current research collaborator Joe Williams (Williams et al., 2011; Williams et al., 2012).
Teaching: I have been working primarily on the Geological record of environmental change (S369) presentation, and writing the landforms section for the new level 2 environmental science module.
Fieldwork: Trips to Ghana (Adele and Phil) and Ecuador (Nick, Encarni and Will) have been super successful; AND all the samples have made it back! See posts elsewhere on the blog for details of field work fun.
I am sure other stuff has happened… more in the New Year… and maybe some more pictures when I can get back on my newly “optimized” (killed) office computer 🙂
Ecology of the past 