Valencia Castillo, B.G. (2014) From glacial to modern conditions: Vegetation and climate change under human influence in the Central Andes. PhD Thesis, Department of Environment, Earth & Ecosystems, The Open University.
Conservation, restoration and management strategies are employed to maintain Earth’s biological diversity and physical environment to a near “natural” state. However, the concept of “natural” is generally inexact and may include degraded landscapes. In absence of long-term empirical data of natural baselines, impacted assemblages (human altered baselines) could be falsely assumed to be natural and set as conservation or restoration goals. Therefore, the identification of long-term ecological baselines becomes a pressing requirement especially in threatened biodiversity hotspots such as the tropical Andes that were under human pressure for several millennial.
This thesis aims to identify ecological baselines for tropical Andean ecosystems based on multi-proxy palaeoecological reconstructions from three Andean lakes. Trends of vegetation change are used to identify when landscapes became anthropogenic in the Andes. Because vegetation assemblages at c. 10 ka experienced negligible anthropogenic impacts and had modern-like climate condition, this time was considered the most recent period likely to provide insight into natural ecological baseline conditions.
Changes in vegetation assemblages were evaluated over time departing from 10 ka around Miski and Huamanmarca, two sites that remained virtually impervious to human impacts. Baselines in Miski and Huamanmarca drifted continuously over time and showed that baselines are dynamic entities. The vegetation assemblages derived from Miski and Huamanmarca suggest that that human impact was not homogeneous throughout the Andean landscape.
Once baselines were defined it was possible to evaluate if the spatial distribution of Andean woodlands represented by Polylepis was a product of human impacts. A MaxEnt model generated based on 22 modern environmental variables and 13 palaeoecological vegetation reconstructions showed that Polylepis woodlands were naturally fragmented before humans arrived in South America (14 ka). However, the influence of humans during the mid and late Holocene enhanced the patchiness of the forest generating a hyper-fragmented landscape.
To borrow a copy from The Open University Library click here.
I’m an Environmental Biology Master student from Utrecht University (UU) doing a research internship in Amsterdam with William Gosling and Rike Wagner of the UU. Most people would describe me as a typical biologist because I like identifying plants and know some birds by their name. Personally I disagree because I lack the beard and hardly wear woollen socks. Besides looking at birds and plants I’m also interested in biodiversity and palaeoecology, and I will try to combine these interests in my research project on a sediment core from Samoa. I will be working on lake sediment cores from Samoa and hope fossil record can give me an overview of the natural history of the island (past c. 10,000 years); and an insight into what impact human colonisation had on the biodiversity. To explore the islands natural history I will be looking at pollen, charcoal and non pollen palynomorphs.
The sediment core on which I will be working has already been recovered and currently resides in beautiful Southampton (UK). So I’m spared of a 30 hour trip to tropical Samoa and the opportunity to return with some Samoan tattoo’s and a tan… So thanks to David Sear and his team at the University of Southampton with whom I will be collaborating for this project.
I have a long standing interest in tropical islands. Before commencing this research internship I did my first masters internship at WWF Indonesia. For my WWF internship I spent three months in the tropics collecting baseline ecological data on timber companies located in a new reserve in Sumatra. Furthermore, during my bachelor degree, I did a research internship at Naturalis Biodiversity Center investigating the “Correlation between higher altitudes and endemic plant species” in the Malayan archipelago. Our results turned out much better then we hoped for and fingers crossed our article will be accepted soon!
In three weeks I will be starting in the lab in Amsterdam and hopefully in a few months will be able to post an update about my results here.
Netherlands Annual Ecology Meeting
10-11 February 2015
by William Gosling
On Wednesday I attended my first Netherlands Annual Ecology Meeting (NAEM) unfortunately, due to prior commitments, I was not able to attend the whole event, but I still managed to get a nice insight into the vibrant Dutch Ecological research community. Particularly exciting for me was the “Biodiversity in Space and Time” theme. Plenary sessions by Alexandre Anotonelli (University of Gothenburg) and Hans ter Steege (Naturalis Biodiversity Center, Leiden) focused on the Amazon ecology past and present. The subsequent session on the same theme, organized by Daniel Kissling (University of Amsterdam) and Niels Raes (Naturalis Biodiversity Center), was also excellent and ranged from species richness patterns past and present in Gabon (Andre van Proosdij, Naturalis Biodiversity Center), through soil microbes (Kelly Ramirez, Netherlands Institute of Ecology) to the role of sea level change on island biodiversity (Kenneth Rijsdijk, University of Amsterdam). I am looking forward to attending more of these meetings in the future and getting involved with the NERN community.
Tropical Botany in Belize
by Nick Loughlin
Getting back to the UK after fieldwork is always jarring and this time is certainly no different, the change from 32°C days walking through the savanna and lowland forests of Belize to the -2°C early mornings walking through snow in Milton Keynes is an abrupt transition. I have recently returned from a 2 week field course in tropical botany run by the Royal Botanic Garden Edinburgh (RBGE) in conjunction with their MSc course on the ‘Biodiversity and Taxonomy of Plants’. The field course allowed for 10 NERC funded PhD students in relevant fields to accompany the MSc students out to Belize to learn a host of valuable skills in tropical botany and ecology. During our time in Belize we visited 2 main locations, Las Cuevas Research Station within the Chiquibul forest reserve and the Rio Bravo Conservation and Management Area (RBCMA), in my next two posts I will briefly cover the places we visited and the botany we learned.
Before I get going I would just like to thank all of the staff from the RBGE who led the field course, (David, Louis, Tiina, Becky, Chris and Helen) their ability to teach the major characteristics of 70+ tropical families to many of us who are not botanists or taxonomists in an engaging way was astounding, although I don’t believe I will ever be able to identify a Euphorbiaceae from its vegetative characteristics. Also thanks to the students from the MSc course who were great fun, if any of you move away from botany and taxonomy and want more of an idea about the world of tropical palaeoecology, give me a shout.
Two weeks ago I attended the biannual International Biogeography Society (IBS) conference in Bayreuth, together with 600+ other people from more than 50 different countries. This IBS conference, my first IBS meeting, proved to be an exciting event during which I met scientists from many different disciplines and heard talks on cutting-edge biogeographical research.
The IBS conference was held in the Bavarian city of Bayreuth, in the middle of the biodiverse landscape of Upper Franconia. This landscape provided the training ground for Alexander von Humboldt, the founder of the field of biogeography. The 4-day conference included a wide variety of symposia and many, many posters. The conference dinner in the German Steam Train Museum was highly memorable. The conference was closed by a lecture from Daniel Simberloff, once a doctorate student of Edward O. Wilson, who received the Wallace Award for his outstanding contributions to invasion ecology.
I had a talk in the plenary symposium of ‘Ecosystem response to past climate change’, organized by David Nogués-Bravo and Francisco Rodríguez-Sánchez. The symposium covered the dangers of climate change to biodiversity and tried to assess if the range and rate of adaptation, migration, persistence, or extirpation, that are registered in deep-time records, palaeorecords, and the recent past, are adequate responses for predicted climate change in the future. I addressed this issue from the point of view of a small remote island, where migration is obviously a limiting factor. I showed how I reconstructed climate and its effect on island biota during the last 40,000 years using long-term palaeoecological records from Mauritius (de Boer et al, 2013 & 2014). These records show that different climate regimes result in different ecosystem response to climate change in the past. Local extirpation or population collapse of larger vertebrates was a natural phenomenon in the lowlands of Mauritius due to frequent climate extremes (I will discuss this in more detail in my next blog; de Boer, 2015). Despite these population collapses, island biota have always (in the timeframe of my records) survived natural climate change. Therefore, my take home message was not to focus on the effects of (future) climate change alone. Other key components of global change, such as invasive species and habitat destruction, are more imminent threats to the biodiversity of many islands. For more information on my research, including publications, click here.
More information on the IBS read on (below) or visit the IBS website or blog. All abstracts and other details of the IBS conference in Bayreuth can be found here. The next IBS meeting will take place in Salvador, Bahia (Brazil) in March 2017.
The Cross-disciplinary Palaeo-Environmental Research Training (XPERT) network commences in 2015. This international network will bring together early career researchers from five countries to learn new skills and develop collaborative projects. Training will be provided during a field school in Ecuador, and a summer school at the University of Amsterdam. For further details please visit the respective field school, summer school and staff pages hosted on this blog.