Witteveen PhD thesis

November 8, 2024
WDG

Witteveen, N.H. (2024) Long-term forest recovery in Amazonia: Insights from phytolith analysis. PhD Thesis, University of Amsterdam, Amsterdam. ISBN: 9789493260290

Abstract

The aim of this thesis was to provide insight into past human activities in Amazonia, and the long-term forest recovery that followed, using phytolith analysis. The first part of this thesis focused on improving phytolith analysis as a proxy for vegetation changes in Amazonia. The morphological variation of 24 Amazonian palm phytoliths were assessed (Chapter 2) to improve the taxonomic resolution of palm phytolith identification, and results indicate the potential to differentiate Euterpe, Bactris, Oenocarpus, Attalea, Iriartea deltoidea, and Socratea exorrhizaChapter 3 demonstrated that phytolith assemblages (from terrestrial soil cores) varied across a gradient of (modern) human disturbance in Surinamese rainforests. In Chapters 4-6, we developed beta regression and GLM models to predict forest cover and biomass changes within 200 m and 1 km of Amazonian lakes, respectively, using grass phytoliths. Applying these innovations in Chapters 5-6 demonstrated that past human activities were on localized scales in Suriname and temporally heterogenous in Ecuador. Palm enrichment of Attalea, Oenocarpus and Astrocaryum occurred within 0 km, 1 km, and 8 km of an archaeological site in Suriname (Chapter 5). In Ecuador, forest cover and biomass ranged between 48-84% and 77-247 Mg/ha, respectively, and the largest decreases (between 1000-1255 CE) were paired with fires (Chapter 6). Overall, the type, intensity, timing, and frequency of disturbances are important factors influencing long-term forest recovery and ecological legacies in Amazonia.

Handel: https://hdl.handle.net/11245.1/7e7ef2f7-7341-4978-9d89-d23fe46f24ae

The long history of people in the rainforest of Suriname 

July 25, 2024
ninahylkjewitteveen

In this article I summarize and describe the scientific research that was performed near Botopasi in Suriname, which was published in Ecology as ‘Pre-contact and post-colonial ecological legacies shape Surinamese rainforests’ (https://doi.org/10.1002/ecy.4272). 

Figure 1: Our research team in the field

Background

In October 2021, between COVID-19 restrictions, I joined archaeologist dr. Cheryl White and her team to excavate the remnants of a ‘lost village’ of Saamaka Maroons in the Surinamese rainforest. Maroons are the descendants of enslaved Africans, who, in the late 1600s, fled plantations to live in freedom in the Surinamese rainforests. Dr. White has been investigating the first villages and the movements of Suriname’s Maroon communities for decades and is an expert in this topic. 

Our wonderful research team consisted of Farisha Kartosemito B.Sc., Sushmeeta Ganesh B.Sc., Jõvan Samson B.Sc., Agir Axwijk B.Sc., Santosh Singh M.A., Thanya Fonkel MPA, Harrold Sijlbing, Dombi Lö, Gerno Eduards & Farik Eduards. We were welcomed in the village Botopasi, and after a day of hard work in the field, we enjoyed delicious Surinamese food and played troefcall!

As an ecologist, I was interested in the ecological effects of past human activities on the forest ecosystem. In these rainforests, Maroon and Indigenous communities often burn and remove trees near their homes to grow a variety of crops like cassava, tayer, maize and banana. After some years, the cultivation site is abandoned and forests can grow back. But do those forests recover back to their original state? 

What did the forest look like before people arrived and settled in the landscape of Boven Suriname?

To study how Maroon communities have shaped Surinamese forests over time, I made a reconstruction of the landscape of the past (going back thousands of years). The landscape was near an archaeological sites called ‘Beng Tau’, where Maroons lived in the 17th century. We used plant fossils and charcoal remains to reconstruct the forest from the past, to research if people were using fire and growing crops, and how the forests recovered from that.

Results and implications

Figure 2: Phytoliths from the banana plant

The charcoal remains and plant fossils, particularly from maize and banana, confirmed Saamaka Maroons settled in the area since ca. 1700 and practiced slash-and-burn agriculture was near the archaeological site called ‘Beng Tapu’ (Figure 2). The site may have been a cooking area, because remnants of pottery with maize, rice and banana were found. Within 1 km of Beng Tapu, we found large fragments of charcoal, and plant fossils from maize and banana. Smaller charcoal fragments and banana were found within 5 km of the archaeological site. Nowadays, agriculture is practiced within 8 km of the archaeological site and Suriname river. The area used for agriculture likely expanded over time. 

How did the forest recover from these activities? 

Within 1 km of the archaeological site, forests were burnt and used multiple times. Here, forests have a lower biomass than further away from Beng Tapu, meaning fewer or smaller trees have grown back. Also, Attalea and Oenocarpus palm trees increased. Still today, the Saamaka Maroon community uses the maripa palm to make oil. Therefore, the number of maripa palms may have increased due to human activities like cooking and oil production! Attalea and Oenocarpus palms are also adapted to open conditions and fire, showing the influence people had on the environment and how the forest responded to fires.

Further (2-7 km) away from the archaeological site, where disturbances were fewer, the forests recovered much better but Astrocaryum palms grew back in higher numbers in the understory of the forests. What makes these palms so resilient? We are still uncertain. The forests furthest away (>8km) from Beng Tapu showed little signs of disturbances. 

Figure 3: View from the Suriname River

A long human history, and an Indigenous archaeological site?

The Saamaka Maroons were not the first people to have inhabited the forests near Botopasi. Charcoal fragments show that people were in region (the ca. 20 km radius we studied) already 2000 years ago, and fire events occurred ca. 2000, 1700,1500, 1300, 1200 and 800 years ago. We don’t know which Indigenous Cultures may have inhabited this region, because of limited archaeological and historical research here. Large charcoal fragments were found ca. 7 km away from Beng Tapu, across the Suriname River. Could this be an Indigenous archaeological site?  

Conclusion

Our results show the timing, intensity and frequency of past disturbances are very important for good forest recovery and some disturbances from the past can still impact the modern vegetation. 

Unravelling the past not only tells us about the ancestors of Maroons and the lives of Indigenous communities before the 1500s. The past also helps us to understand how forests respond to human impacts. To better guide conservation strategies, we need to do more archaeological and ecological research in Surinamese rainforests. 

Next to the Suriname River, past human activities shaped the forest and increased local palm abundances. The broader forested region showed a healthy recovery. These results indicate that the Saamaka Maroon community preserved most of the forests they inhabited since the 1700s. We can learn from traditional knowledge about which management practices are sustainable to keep forests healthy. 

If you want to know more about the “hows” of this research… dive with me into the methodology! 

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Phytoliths, starch grains and diatoms

May 29, 2024
WDG

Caroline Goossens receives the Florschütz Award.

On Friday 24 May 2024 the Palynologische Kring (Dutch palynological society) held a seminar series and laboratory workshop at the Institute for Biodiversity & Ecosystem Dynamics (University of Amsterdam). During the afternoon we had the annual meeting of the society, the presentation of our MSc Thesis prize, four seminars and two laboratory demonstrations. The MSc thesis prize “Florschütz Award” was won by Caroline Goossens (VU Amsterdam) for her thesis entitle: “An Eemian-Early Weichselian sequence in the Amersfoort Basin, the Netherlands”; the project was supervised by Natalie Van der Putten, Cees Kasse and Jeroen Schokker. We hope that Caroline will present her thesis at a future Palynologishe Kring meeting.

Teye Aukes presenting on the diatoms of ancient Rome

The talk series was kicked off by Nina Witteveen (University of Amsterdam) who presented part of her PhD thesis (currently awaiting defense), entitled: “Long-term forest recovery in Amazonia insights from phytolith analysis”. Nina discussed the impact of past peoples on the vegetation of Suriname based on her work identifying phytoliths in soil samples collected at varying distances from an archaeological site. The second talk was given my Amanda Henry (Leiden University) who demonstrated how the analysis of starch grains extracted from archaeological context can provide insights in to past diets. She used these evidences to suggest that early humans and Neanderthals had a similar diversity of plants in their diets. The third talk was given by University of Amsterdam MSc researcher Teye Aukes and focused upon his identification of diatoms from an swampy lagoon environment near Ostia (Italy). He drew conclusions from these data about the antiquity of salt production in ancient Rome. The final talk was given online by Welmoed Out (Moesgaard Museum) who presented a detailed analysis of inter- and intra-analyst variability in phytolith morphometric analysis.

After the seminars we moved upstairs to the microscope laboratory where Nina Witteveen and Ana Smuk (University of Groningen) showed off phytoliths from their study site in South America and the Netherlands.

Some of the Palynologische Kring members enjoying some refreshment after the event.

Pre-contact and post-colonial ecological legacies shape Surinamese rainforests

April 10, 2024
WDG

Open access:

Witteveen, N.H., White, C., Sánchez-Martínez, B.A., Philip, A., Boyd, F., Booij, R., Christ, R., Singh, S., Gosling, W.D., Piperno, D.R. & McMichael, C.N.H. (2024) Pre-contact and post-colonial ecological legacies shape Surinamese rainforests. Ecology, e4272. DOI: 10.1002/ecy.4272

Phytolith assemblages reflect variability in human land use and the modern environment

June 29, 2023
WDG

Vegetation History & Archaeobotany

Open access:

Witteveen NH, White C, Sanchez Martinez BA, Booij R, Philip A, Gosling WD, Bush MB, McMichael CNH. 2023. Phytolith assemblages reflect variability in human land use and the modern environment. Vegetation History and Archaeobotany. DOI: 10.1007/s00334-023-00932-2

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