Ancient human impacts in Amazonia – the debate continues…

How well can you ever really know 5.5 million km2 of hyperdiverse forest? The Amazon region, and this question, are at the heart of several ongoing debates in the natural sciences – why are there so many species? how much carbon can the forest store? how much did ancient humans impact the forests, and can we still see their effects today?

How fully can you really know a forest as huge and diverse as the Amazon?

This last question was the subject of a paper by Caroline Levis and colleagues published in the prestigious journal Science in March this year, which caused significant ripples within and outside the scientific community. In a nutshell, the article found that tree species humans have cared for are five times more likely to be forest ‘hyperdominants’ than you’d expect. Past human impacts also help explain where these species are found now, accounting for up to 20% of the variation in their distribution (for comparison, environmental factors explained up to 30%). The paper’s conclusion, as picked up by the media, is that “modern tree communities in Amazonia are structured to an important extent by a long history of domestication by Amazonian peoples.”

Theobroma cacao – the tree cocoa beans come from – was one human-influenced species in the Levis et al study

So, debate settled? Not quite. Responding to the paper some critics pointed out that the potential influence of soil nutrients hadn’t been adequately considered; others suggested the data showed that human effects were only significant within 20km of archaeological sites; and yet another argued that most of the human-influenced trees are so short-lived that pre-colonial individuals would be dead by now. Furthermore, another study published around the same time showed these Amazon forest plots are disproportionately close to places highly affected by ancient humans, so maybe it was inevitable that the sampled areas would still be showing their influence.

This, perhaps, goes to the heart of the problem with trying to uncover the human history of all Amazonia: there isn’t much detailed region-wide environmental data, the non-random tree plots cover a vanishingly small fraction of the forest, and there are many archaeological sites we may never find. Reflecting on the paper and its findings at a recent TPRG meeting, it was sobering to consider how this can limit the conclusions of wide-ranging studies like this.

It was also striking how, when it comes to ancient human impacts on forests, people can draw very different conclusions from the same data. As I embark on my research into the effects of past humans and climate change on southern Brazil’s Araucaria forests, these will certainly be important things to bear in mind!



The original paper by Caroline Levis and colleagues can be found here: Some scientists have responded to the paper in its eLetters section (, and Christopher Dick posted his thoughts on his research group website ( The paper on the link between forest plots and areas of ancient human impact was published by Crystal McMichael et al., and can be found here:

Thoughts on PAGES OSM- with photographic evidence

I am aware that not many people had the great opportunity like me to attend PAGES OSM 2017. Therefore, I wanted to share some of the key things that got stuck with me after the conference.



There was an outstanding list of presentations and strong sessions. I am not aiming to pick a favourite, but I would like to highlight the following ones: “From the Mediterranean to the Caspian: paleoclimate variability, environmental responses and human adaptative strategies” with convener Ana Moreno et al, “Do species move or die” with convener N. Whitehouse et al, and specially “Disturbance dynamics across special and temporal scales” with convener Graciela Gil-Romera et al. Papers discussed there were largely multidisciplinary, and generated good discussions.

I felt that the plenaries weren’t as broad, strong or focused as I would have expected. I felt some of them were a little scattered in ideas, and one of them not really tackling the issue of climate change. Nevertheless, I really enjoyed Erik Wolf’s presentation on “Warm worlds”, his presentation was not full of great research and facts, but also felt genuine, and quite fun.

What was a kind of surprise for me, but not for others, was the high quality of research in poster presentations. Back in my time of undergrad and Master studies, a poster presentation was for those that didn’t have a strong enough study to make it to the presentation. Now I can see poster presentation as the new place to showcase research. Having had two posters for PAGES OSM myself (details of presentations below), I can see this as the largest opportunity to actually share and especially discuss, about my research. Added to that is the fact that your work will have a much larger exposure as posters are generally for a whole day which does not compare with the only 15 minutes of oral presentation. I really enjoyed both my posters ads well as oral presentations anyway.


At one of my posters


Fun time!


Heather certainly made a difference with her poster



PAGES OSM really worked as a hub for researchers of common interest in past climate and the environment coming from different disciplines and geographical areas. I met not just colleagues from various institutions from the UK, but also from Chile and Brazil. I also meet new people, especially from Spain, that are doing similar studies in the Mediterranean that I would have not known otherwise. There were great networking opportunities, which is always welcome you can end them up having some quality tapas in a fantastic old town centre.



I think this has been one of the best organisations I have seen in a conference. I did not notice major issues besides the change of the timetable for the plenaries in the very first day, and some queuing for the lunch time (we really needed those 2 hours lunch break to do this and rest the great lunch afterwards).  I saw everything very well thought and programmed, from the rooms and the system for the presentations to be loaded, up to the timing of the food for breaks and lunch. There was always plenty of bottled water available for us to drink, and of course, a good Wi-Fi (which wasn’t available for free at the Palynology meeting in Bahia last year!)

One thing worth mentioning: the food was fan-tas-tic.  We were almost a 1000 delegates, and the food was always ready, and delicious. The best for me, there was catering for vegetarians and people that have a gluten free diet… and it wasn’t boring! The one not minor issue was that the amount of food for people with special dietary was limited. I saw several colleagues struggling to get enough to eat in most days. Nevertheless, there was something that was never missing: red wine always available at the tables for lunchtime.


Gluten free and vegetarian options at the opening ceremony


Coffee breaks with fruits!


Tasty salad and creamy butternut squash soup for lunch!



The Auditorio de Zaragoza is a spacious place, modern and of a very professional feeling. We could all fit well -yet cosy- for the poster sessions, and at the main room for the plenaries (having in mind that not all people attend the very early talks). Just one thing I found disappointing, which was that two rooms for oral sessions were located in a hotel that was nearby the Auditorio. These rooms were not near to the quality of rooms inside the Auditorio and they felt a little isolated. Still, the organisation on those and the rest of rooms worked out very well, at least in the sessions I was attending.

Zaragoza is a fabulous city to visit, plenty of places of cultural and historic importance, the Goya Museum and archaeological sites amongst them, as well as rich architecture. Places to go for dinner or tapas were plenty, and all at reasonable prices.

Nuestra Senora del Pilar Cathedral and the Ebro River


Gorgeous Aljaferia! Vestiges of the time of the caliphs



I am quite pleased to have attended in PAGES OSM, I’ve got a lot from it. Looking forward to the next one!


by Macarena



H. Plumpton; F. Mayle; B. Whitney. Impact of mid-Holocene drought upon Bolivian seasonally-dry tropical forests

J, Iriarte; M. Robinson; J. de Souza; M. L. Cárdenas; F. Mayle; R. Corteletti; P. DeBlasis. The Making of the Forest: Human-induced spread of Araucaria forest out of their natural range in the southern Brazilian highlands

Iriarte; R. Smith; J. Gregorio de Souza; F. Mayle; B. Whitney; M. L. Cárdenas; J. Singarayer; J. F. Carson; S. Roy; P. Valdes. Out of Amazonia: Late-Holocene climate change and the Tupi-Guarani trans-continental expansion

M. L. Cárdenas; F. E. Mayle; J. Iriarte; J. Gregorio de Souza; P. Ulguim; M. Robinson; R. Corteletti; P. DeBlasis. Past vegetation changes in the context of land use and late Holocene expansion of the Jê pre-Columbian culture in Southern Brazil

Freeman, M. L. Cárdenas; V. Iglesias; J. M. Capriles; C. Latorre; J. Freeman; D. Byers; J. Finley; M. Cannon; A. Gil; G. Neme; E. Robinson; J. DeRose. PEOPLE 2K (PalEOclimate and the PeopLing of the Earth): Investigating tipping points generated by the Climate-Human Demography-Institutional nexus


Palaeo-science in the Pyrenees at PAGES YSM 2017

Morillo de Tou – the beautiful location of the YSM

I recently attend the PAGES (Past Global Changes) YSM (Young Scientists Meeting) as well as the OSM (Open Science Meeting) 2017 in sunny Spain. The YSM was particularly exciting – a group of 80 early career researchers met in the Pyrenees, at the restored village of Morillo de Tou.

Morillo de Tou

Morillo de Tou


The spectacular surroundings were matched by spectacular science, with a combination of great talks and posters as well as breakout group discussions and workshops. The schedule was pretty packed, but we made time for some star gazing with local astronomers and a night of traditional Aragon music and “dancing” in the moonlight. Overall, I thought the YSM was an excellent opportunity to meet other young scientists, and discuss issues of particular import to our community.

A highlight for me was the breakout discussion on communication with the public and communicating the relevance of palaeo-science to funders and policy makers. We had some great discussions in our group, centering on the need to engage children in science from a young age. We also talked about the importance of telling a story when you present your work, and how talking to politicians and journalists in a positive, optimistic way can enhance engagement.

We also discussed the idea of setting up a PAGES working group for young scientists, with regular meetings to discuss funding, careers and to network. Watch this space!


The conference venue at Morillo de Tou


I enjoyed presenting my PhD work in the Monday morning session, and received some helpful feedback from fellow YSM participants through a peer review scheme. I think the scheme was a great way to encourage everyone to consider their own presentation style, by reviewing their peers’.

A further benefit of attending the YSM was that we already knew 80 people attending the OSM in Zaragoza, so there were plenty of friendly faces amid the ~900 OSM participants. This made the OSM much less intimidating and more enjoyable. Overall, the organisation of the YSM was incredible and I would certainly encourage early careers researchers to attend the next one in 2021. The only complaint was the cold coffee at breakfast – conference mornings without coffee are a tough sell for sleepy PhD students… but the beautiful Spanish sunshine more than made up for it.

Morning views across the lake at Morillo de Tou


If you’re interested in what went on at PAGES 17 (YSM and OSM) check out the #PAGES17 on twitter for some great insights.

By Heather Plumpton 





At FAPESP’s highlights: The Jê Project

The Jê group: Farmers and sedentary 

This time, written by scientific journalist Marcos Pivetta, this article covers what has been discovered so far by the archaeological research within the project and gives a first glance of what has bee found from the palaeoecological research performed by Macarena L.  Cárdenas and Frank Mayle.



To read the whole article click here, available in Portuguese. Right hand click in the page to automatically translate in google.



About FAPESPSão Paulo Research Foundation (FAPESP, Portuguese: Fundação de Amparo à Pesquisa do Estado de São Paulo) is a public foundation located in São Paulo, Brazil, with the aim of providing grants, funds and programs to support research, education and innovation of private and public institutions and companies in the state of São Paulo.

The Big Reveal – Our Tropical Phytolith Reference Collection goes live!


I just thought I’d have a little brag, and celebrate the fact that I have produced a tropical phytolith reference collection here at the University of Reading in the TPR lab. The full collection (as it stands until the next PhD student comes to help build it!) contains 152 taxa, sampled from various Herbaria around the world. My thanks go to Prof Jose Iriarté at the University of Exeter for lending me some of his material, as well as Dave Harris at the Royal Botanic Gardens in Edinburgh who let Dr John Carson sample their herbarium and live specimens. The spread of taxa includes all those denoted as diagnostically useful by Piperno’s 2006 book ‘Phytoliths’ (the bible of tropical phytolith studies) plus some extras which may turn out to be useful.


The online database of our phytolith reference collection is now available on our Palaeobank website: Feel free to take a browse!


Unfortunately, I haven’t had a chance to photograph any of the slides under the microscope yet, but here are some photos of the collection in its lovely new cabinet:

Phytolith ref coll cabinet

Phytolith reference collection cabinet, organised alphabetically by family name


Poaceae draw in phytolith ref coll cabinet

An array of Poaceae reference slides in the collection


All of this means of course that I can now begin working on my fossil phytolith samples, once I’ve finished pollen counting…


by Heather Plumpton 


Exhausting but exhilarating – BES Annual Meeting 2016

BES conference photo

The ACC conference centre in Liverpool lit up at night – a great venue with excellent vegan food choices


Last week I attended my first British Ecological Society Annual Meeting and I still don’t think I’m fully recovered. With around 1200 delegates, 12 sessions running in parallel at any one time, lunchtime workshops and socials every night, it was a pretty intense experience. But of course it was worth all of the exhaustion; I met a lot of new people (as well as catching up with a few old friends), listened to some really great presentations, participated in several workshops, and got to present some early results of my own PhD work.

Particular highlights for me were:

  1. The tropical ecology (climate and land-use change) session, including a fascinating presentation by Steven Sylvester who climbed into the high Andes to find pristine forest ecosystems, potentially untouched by humans. This was followed by another excellent presentation on patterns of fire in the Serengeti, and how James Probert is using remote sensing to track fire changes and identify drivers – the interaction between climate and humans look to be interesting here.
  2. Monday lunchtime workshop on ‘Making Brexit work for ecology and the environment’ run by the BES policy team. Some interesting perspectives on the risks and opportunities for conservation and ecology were highlighted; Brexit might allow for a weakening of current standards of habitat and species protections, but it could also be an opportunity to strengthen the protection of taxa that are particularly threatened in Britain, but not elsewhere in Europe. We have to try to see the positives!
  3. An interesting mix of talks in the theoretical, interdisciplinary & computational ecology session, including one by a fellow palaeoecologist – Jane Bunting. I particularly enjoyed her presentation on how palaeoecologists and neo-ecologists need to work more closely together. Perhaps a BES palaeo Special Interest Group should be started??

The whole conference was rounded off in style with the Gala Dinner and after-party, which included a live band performing with video from Planet Earth playing on a large screen in the background – a proper ecology party!

BES gala dinner twitter photo %40pierre_griet

Our table at the BES Gala Dinner, before the David Attenborough party started! Courtesy of @pierre_griet

For anyone who didn’t make it but is interested in what went on, check out #BES2016 on twitter – there was an incredible amount of tweeting going on! Overall, it was a great conference – exhausting but exhilarating – and I’d thoroughly recommend it to anyone considering going next year.

by Heather Plumpton 


PhD Opportunity


Millennial-Scale History of Amazon Forest Dynamics


Lead Supervisor: Francis E. Mayle, University of Reading, Department of Geography & Environmental Science, SAGES


Co-supervisors: Stuart Black, Department of Archaeology, SAGES; Shovonal Roy, Department of Geography & Environmental Science, SAGES


Studies of a network of 1-hectare forest plots across Amazonia have revealed significant ecological changes (e.g. increasing biomass) over recent decades, but whether they reflect atmospheric change (e.g. fertilization from rising CO2 concentrations), or instead secondary succession following pre-Columbian (pre-AD1492) human disturbance, is controversial.  Furthermore, the likely impact of increasing drought over the 21st century, predicted by climate models, is also uncertain.  A palaeoecological approach can potentially reveal the impact of mid-Holocene drought (a potential analogue for future drought) as well as Pre-Columbian land use.  However, a major disadvantage with lake-based pollen analysis (the traditional palaeovegetation proxy) is that suitably old lakes are rare in Amazonia, and the spatial resolution of pollen records is generally far too coarse to enable meaningful comparison with ecological data from 1 ha plots.  The aim of this project is to circumvent this problem by using a novel suite of palaeoecological proxies from soil profiles to reconstruct the millennial-scale vegetation histories of individual 1 ha plots of different types of forest across ecotonal southern Amazonia.       

Nerc_PhDopportunity_Frank Mayle_2017

Forest-Savannah transition, Bolivia

Approach and Methods

Phytoliths (microscopic silica bodies) are diagnostic of different plant taxa and, crucially, unlike pollen, are well preserved in soils and reflect plants growing in situ, thus facilitating direct comparison between ecological and palaeoecological data from the same forest stand.  Stable carbon isotope analyses differentiate C4-dominated savanna/open ground vs C3 forest, while charcoal and geochemistry reveal fire history and soil properties, respectively.  Previous research shows that these soil pits likely span at least 6,000 yrs BP, and will thus enable the respective impacts of mid-Holocene drought and pre-Columbian land use to be explored.  Floristic and ecological data will be downloaded from the RAINFOR database.  Appropriate numerical and statistical analyses will be undertaken to reveal intra- and inter-site relationships between different ecological, geochemical and palaeoecological data.

Training opportunities:

Training will be provided in phytolith and charcoal analysis (Mayle), stable isotope and geochemical analyses (Black) and numerical/statistical techniques (Roy).  Although most soil samples have already been collected, there will be an opportunity for the student to undertake fieldwork in Amazonia and collect more material.

Student profile:

At least a 2.1 BSc degree in biology/geography/environmental science is required.  A strong background in numerical/statistical techniques is essential.  Knowledge of ecology, biogeography, Quaternary science, and microscopy would be advantageous.

 Apply by going to the following link:




My views on the International Palynology and Palaeobotany Congress XIV IPC X IOPC


Hosted at Salvador Bahia, Brazil, between the 23rd and 28th of October


This is the first time I go to this joined conference and I have to say I am glad I made it. It is definitely an important event to know what is happening in the palynology world, as well as to let other know what you are doing. There were far too many names that did not make it, but there were abundant number of presentations.

It all started on Sunday 23rd evening with the opening ceremony, where each member of the committee gave the welcome. The speeches were followed by the signing of the Brazilian and the Bahia anthems by a talented Brazilian lady accompanied by a local guitarist. This was then followed by a traditional capoeira musical group that played a large round of songs that felt far too long for the taste of most.  Capirinhas, local beer and typical Bahian food was waiting for us to wake us up again and start the networking.


Othon Palace Hotel, Venue of the Conference



View from the Conference Venue


The week was followed by a series of presentations from 8.30am until 6pm, with four parallel sessions. There were many interesting talks, but for me the sessions ’Long-term vegetation, climate, fire dynamics and human impact in tropical and subtropical ecosystems’, ‘Quaternary palynology and botany’ and ‘Pollen-based Holocene land-cover reconstructions for climate modelling’ were highlights as they gathered the new and novel work from Europe and Latin researchers. There was also a non-pollen palynomorphs (NPP) session lead by Dr Encarni Montolla which was interesting to attend as I realised how strong and close is the NPP community. Posters presentations were abundant and with great quality of research. I saw many presentations from renowned researchers in the palaeo field such as Simon Haberle, Thomas Giesecke, Hermann Behling, Marie-Pierre Ledru, Marie-Jose Gaillard and many others! It was interesting to look at the fossil record in very deep time with the presentations on palaeobotany. Presentations on “From Gondwana to the Tropics” with Felipe Hinojosa and “Asyncronic oldest record of Nothofagus leaves in Antarctica and Patagonia” with Marcelo Leppe were eye opening.


My two presentations, ‘Pre-Columbian human land use versus climate change: understanding Araucaria forest expansion during the Late Holocene in southern Brazil’ and ‘Characterisation of the modern pollen rain-vegetation relationship of Araucaria forest of southern Brazil by analysis of moss polsters’ received many positive comments. The second received special interest of many. This was more methodological research and therefore I was in expectation to see what the community thought as it was the first time I talked about it. People were very pleased to see such analysis of modern data, and many came to me with supportive comments and also with great information on the ecology of modern taxa, such Cyathea sp. I am pleased to have showed it.


I attended the conference most of the time but I also managed to have great conversations with my Chilean colleagues (of which there were many I didn’t see for the last 10 years!), as well as European researchers.


The closure ceremony was much more active than the opening, a short speech, followed by abundant food again, beer, and the best: live Brazilian music including samba and axe which many danced… including the European community!




Local soups at the closing ceremony cocktail



Closing ceremony live music and dancing


About the Bahia experience: the city has a long and rich history and culture, buildings in the historic centre are restored colonial architecture, painted in bright colours, many of them being Catholic churches. Everywhere I went I found live music including samba, capoeira, axe and pop. There were many events happening in the streets, it was difficult to stay still. The Bahian food is interesting; a lot of it is fried, and includes of course beans and sea food. What I love about eating in Brazil are the restaurants with food by kilo, these are buffet with abundant salads and all sorts of prepared hot dishes. In these Buffet al Kilo places you pay what you eat in weight! Although poverty is quite obvious everywhere, people are in high/positive spirits and in general very friendly. I could talk to anyone and they would be quite open for a chat and help (I got tons of help in the streets, including a lady that stayed with me until I took a bus back to my hotel!). By the way, temperature was high, around 34C, and it was during spring…


La Barra beach, 15 mins walk from the Conference venue



Buffet al kilo!


Colonial architecture at the Historic Centre, Bahia


Coconut water post-conference… So much talking makes you thirsty!!


Overall it was a great experience. I am glad I made it.

We will see if now what the Czech Republic has to offer in four years!


By Macarena

PS. All photos are unprocessed, all in original colours


Thanks to the Je Landscapes Project that funded my flights and to the University of Reading who gave me a grant to pay for accommodation and food.



Thoughts on the ECR QRA conference 2016

As many know, Mariah is visiting us for 6 months here at TPRG. She is currently doing her PhD in Brazil, and is co-supervised by Frank Mayle.

Mariah has done great contribution to our group and has participated of the discussions and conferences. Her last participation was on this year’s QRA Postgraduate Symposium, hold in September.

We asked her to give us her impression of the QRA conference and share the poster she presented. Here is what she said:

“It was an excellent opportunity to participate in the 21st QRA Postgraduate Symposium at University of Nottingham. I meet many Quaternary students, learned different tools and views from the past. It was a great way to learn and improve my own ideas.

The program included a tour at the British Geological Survey, great speakers such as Professor Colin Waters and Professor Melanie Leng, and also a training course with Steve Hutchinson. This was all followed by a great dinner and social events at night.

Looking forward to the next year event, in Royal Holloway, University of London!”

Click here the pdf to Mariah’s poster

2016-09-16 09.22.48

Mariah with her poster at the QRA conference


Delegates at the conference. Can you spot Mariah?

Mariah Francisquini

PhD Student
Centre for Nuclear Energy in Agriculture -CENA/USP

University of São Paulo

PhD opportunity

 Assessing the resilience of Brazil’s iconic Araucaria forest

to past and future climate change


Lead Supervisor: Francis E. Mayle, Dept. Geography & Environ. Science, Univ. Reading.


Staff profile 

Broader context of the project 

Co-supervisors: Richard Walters, School of Biological Sciences, Univ. Reading; Joy Singarayer, Dept. Meteorology, Univ. Reading; Macarena Cárdenas, Dept. Geography & Environ. Science, Univ. Reading.


Applications are invited for the post of Graduate Teaching Assistant. The appointed person will be registered for a Part-Time PhD, while holding a contract of employment from the University of Reading which encompasses both doctoral studies and teaching responsibilities with an associated salary. The post will commence on 19th September 2016, for a period of 4 years. Although six potential topics are being advertised, only one post will be appointed to the strongest candidate.

Teaching duties: The appointed person will be expected to deliver seminars and tutorials to groups of 10-20 students on a regular basis, to undertake assessment marking and to undertake undergraduate dissertation supervision. They will be expected to complete the required training and development activities as specified by the Department, achieving AFHEA status within the first two years of appointment. Teaching duties will not exceed nine hours of teaching and learning work (of which no more than six will be contact hours) during term time.

The Parana pine (Araucaria angustifolia) of southern Brazil is an iconic ‘living fossil’, dating back to the Mesozoic. This evergreen conifer once dominated highland areas of Brazil’s southern Atlantic Forest (a global biodiversity hotspot), but is now critically endangered due to extensive deforestation and is, therefore, a conservation priority for Brazil. To understand its response to future climate change, a better understanding of the reasons for its current biogeographic distribution is needed, which can only be gained via knowledge of the long-term history of this species over several millennia. Was the documented expansion of Araucaria forest over the last several millennia a response to increasing rainfall, or a function of pre-Columbian indigenous peoples enabling its expansion due to its economic importance? To tackle this question, a novel multi-disciplinary approach is needed, which integrates palaeoenvironmental and archaeological data with ecological-climate modelling studies.


Watch the following video where Prof Mayle explains more about this project:

Funding Notes

Remuneration: Tuition fees will be waived up to the level set for Home/EU postgraduate researchers, and the appointed person will receive a maintenance stipend and a monthly salary commensurate with their teaching duties.

Application: Please apply using the online application form at:


How to apply:

Full details of how to apply, as well as a podcast of this advert, can be found here