The “Ecology of the past” blog is run by William Gosling and contains content from people associated with his scientific research. The research presented in the blog is centered on trying to place modern environments in to context.
I’m rattling down an unpaved road in the Ecuadorian Amazon. The brakes screech at every turn, and the chain is close to falling off. Unsurprisingly, the rain is pouring, turning the road into a maze of puddles and mud. The road follows the Anzu River, and I can hear its roar off to my right.
I’m forcing a perfectly innocent bike to brave the Amazon because this road leads to the Herbario Amazónico of the Universidad Estatal Amazónica (ECUAMZ). ECUAMZ (an acronym for “Ecuador Amazon”) is the only herbarium in the Amazon, and contains a repository of plant specimens for preservation and help with field identifications. It was established by Dr. David Neill, a specialist in the Fabaceae (legume) family and world-renowned expert in tropical botany, and Dr. Mercedes Asanza, the coordinator of the herbarium. They have agreed to mentor me over the summer and teach me about tropical plants. The Herbario Amazónico, which contains over 17,000 vascular plant species, is the perfect place to learn.
The view from the top of the tower at Jatun Sacha.
I’m a palynologist — the only people in the world who will excitedly point to your yellow-dusted car and shout “that’s probably Pinus pollen!”— but I have much to learn about identifying which plant produces which pollen. There are around 18,000 known species of flowering plants in Ecuador, and about 4,000 of these species are endemic to the country. I’m here to learn how to identify some of them, and to learn more of their ecology.
Most days, this involves poring over books and staring intently at preserved leaves, flowers, and seeds. Many of the names sound like elaborate spells (Castilla elastica! Topobea setosa!), and at first all of the leaves look the same. But now it sometimes feels like the trees leave clues behind, waiting for a botanist to put them all together.
Me using binoculars to see the leaves in the canopy, at Jatun Sacha.
For example, the leaves of some plant families have distinctive patterns of veins—the lines on their leaves. The arrangement of the leaves also helps narrow down the possibilities. Perhaps the most fun way to identify plants is to crush up a leaf and smell it. Some plant families, such as Piperaceae (the peppers), have characteristic odors. The description of a particular odor may vary from botanist to botanist, but to me, plants from the Piperaceae family smell like black pepper. Other families, such as the Lauraceae (the laurels) and Myrtaceae (the myrtles), have essential oils in their leaves.
Outside the herbarium, I visit an established tree plot in Jatun Sacha, a 2,200 hectare protected reserve close by, which is also run by Drs. Neill and Asanza. In this plot, every tree over 10 cm in diameter has already been identified, so I can use these known identifications to learn the plants.
When out in the forest, finding all the clues is hard work. First of all, everything grows on everything in the Amazon. It is hard to even determine where the leaves of the tree are, and what is simply something growing on the tree or on the tree next door, or an ambitious treelet on the ground! If it is raining, my eyes are pelleted by water drops as I stare up at the leaves. To make an accurate identification, I also need to find any flowers or seeds that might be hiding in the tops of the trees. Many of the trees form the canopy, typically 30 m (98 ft) from the ground. The trees, of course, are stubbornly standing there, uncaring that I can’t see anything through the haze of rain, vines, lianas, and bromeliads.
On a rare sunny afternoon, I climb a 30-m (98-ft) metal tower at Jatun Sacha. Climbing up the tower, I come closer and closer to the leaves, seeds, and fruits I had been staring at down below. The palm fronds brush my shoulders, and the shadows that cover the ground below slowly disappear. At the top, the forest stretches out almost from horizon to horizon, creating a green blanket that covers the world. The Napo River, which eventually joins the main Amazon River downstream near Iquitos, Peru, sparkles in the distance. Breezes are almost nonexistent on the forest floor, but up here, a gentle wind tugs at my hair. Identifying trees is often frustrating, but there is nothing like a view of the Amazon from the canopy.
The Anzu River, which I ride my bike over every day on the way to ECUAMZ
Despite the challenges, learning to identify plants is important, as is understanding their ecology. As climate change continues, scientists use information from plants to predict what will happen to our ecosystems, including the Amazon. These models and predictions, however, are only as good as their data. Collecting data on what trees are currently in which locations is crucial to understanding how the most biodiverse ecosystem in the world will change.
Identifying new plants is also critical. Each year, approximately 2000 new plant species are discovered worldwide, and about 150 of them are from Ecuador. Unfortunately, during 2018 the Amazon was also deforested at the highest rate in the past 10 years; in the Brazilian Amazon 7,900 square kilometers of forest were cleared. We are caught in a race against time. If we don’t work to identify new plant species, we risk losing all of their clues.
Rachel Sales is a Ph.D. student studying the history of the Amazon–Andes region at Florida Tech. Additional information about her and her lab is available online at https://research.fit.edu/paleolab/.
Founded at the dawn of the Space Race in 1958, Florida Tech is the only independent, technological university in the Southeast. Featured among the top 200 universities in the world according to Times Higher Education World University Rankings, the university has been named a Barron’s Guide “Best Buy” in College Education, designated a Tier One Best National University in U.S. News & World Report, and is one of just nine schools in Florida lauded by the Fiske Guide to Colleges. Fields of study include science, engineering, aeronautics, business, humanities, mathematics, psychology, communication and education. Additional information is available online at http://www.fit.edu.
IBED is looking for an Earth scientist/ecologist with expertise and interest in soil carbon cycling, in relation to the role of soil microbial communities therein to support ongoing work within the Department of Ecosystem & Landscape Dynamics (ELD). We are particularly looking for a researcher with an international track record with expertise in one, or more, of the following areas:
Interactions between organic carbon and the mineral soil.
Microbe-organic C interactions.
Molecular and computational approaches for analysing soil microbial communities and their functionality.
Scaling of soil carbon cycling processes from microbe to globe.
Linking global carbon cycle models and laboratory experiments.
This is one of two positions currently open in Earth Systems Science within ELD. The other position is related to Environmental Chemistry and we will be looking at complimentary between the two appointments.
For further details and information on how to apply click here.
IBED is looking for an environmental chemist/environmental scientist experienced in studying sources, transport, transformation and degradation and fate of chemicals in ecosystems to support ongoing work within the Department of Ecosystem & Landscape Dynamics (ELD), and create links with the Department of Freshwater & Marine Ecology. We are particularly looking for a researcher with an international track record with expertise in one, or more, of the following areas:
The fate and effects of organic contaminants of emerging concern in the environment.
The mitigation of environmental pollution.
Environmental policy and circular economy.
Regional and larger-scale systems analysis of human impacts on the environment.
This is one of two positions currently open in Earth Systems Science within ELD. The other position is related to Soil Carbon Cycling and we will be looking at complimentary between the two appointments.
For further details and information on how to apply click here.
Zhang, Y., van Geel, B., Gosling, W.D., Sun, G., Qin, L. & Wu, X. (2019) Typha as a wetland food resource: evidence from the Tianluoshan site, Lower Yangtze Region, China. Vegetation History and Archaeobotany. DOI: 10.1007/s00334-019-00735-4
Vegetation responses to late Holocene climate changes in an Andean forest By Klaas Land (currently studying MSc Biological Sciences (Ecology & Evolution) at the University of Amsterdam.
The discussion during the APC meeting on the 19th of March was on the paper by Schiferl et al. (2018), a very recent study on the climatic shifts in the late Holocene and their effects on the South American tropics. The study had analysed a core going back about 3800 years from Lake Palotoa, which was in the Andean foothills (1370m elevation). They found that subtle changes to the fossil pollen record could be identified around the estimated periods for the Little Ice Age (LIA) and Medieval Climate Anomaly (MCA). The focus in the paper was set on the results concerning the Hedyosmum and Sloanea species, which increased in abundance during the MCA. Both species were also abundant during the LIA, but Hedyosmum dipped in abundance between the two periods, while Sloanea stayed abundant up to modern times. Both these species are characteristic of wet soils, and thus it was theorised that there must have been an increase in moisture in the atmosfeer. Another interesting trend in these periods, was the decrease in abundance of the Dictyocaryum palm, a species that prefers to have its head in the clouds but is otherwise out-competed by a closely related palm species, Iriartea (Henderson, 1990). The discussion that followed was mostly about how Dictyocaryum could be used to directly identify the spatial movement of the cloud layer, based on the appearance and abundance of the palm. Since pollen are known to show a regional signal, it might be interesting to look at the vegetation on a more local scale, using phytoliths. It just so happens that Dictyocaryum produces a particular kind of phytolith (Huisman et al., 2018) that can be identified and counted fairly easily. A core from a mid-elevation Andean lake could give valuable insight into the abundance of Dictyocaryum and other cloud immersion dependant species, and in turn show the effects of climatic shifts on the cloud forests of the Andes.
Henderson, A. (1990). Arecaceae. Part I. Introduction and the Iriarteinae. Flora Neotropica, 1-100. Jstor link
Huisman, S.N., Bush, M.B. & McMichael, C.N.H. (2019) Four centuries of vegetation change in the mid-elevation Andean forests of Ecuador. Vegetation History and Archaeobotany. DOI: 10.1007/s00334-019-00715-8
Schiferl, J. D., Bush, M. B., Silman, M. R., & Urrego, D. H. (2018). Vegetation responses to late Holocene climate changes in an Andean forest. Quaternary Research, 89(1), 60-74. DOI: 10.1017/qua.2017.64
Dobrochna wondering what kind of pollen and phytoliths are hidden it that piece of dirt (Krakenven, 2018)
Looking at a time capsule from Twente
By Dobrochna Delsen (currently studying for BSc Biology at the University of Amsterdam)
An unusual early morning.
It is 8:15. My train arrives at Science Park. After a ten-minute walk accompanied by other students I arrive at the university. After a short contemplation about whether I should take the elevator, I decide to take the stairs. The stairs are a bit exhausting, especially since the microscope room is at the top floor, but it gives me the necessary ‘exercise’ for the day. As I walk to the room at the end of the corridor I can see that the coat rack is still empty, except of the one lab coat that hangs there since the day my bachelors project started. I take out my student card and hold it against the door handle. The sound of the unlocking door gives me feeling of satisfaction and power. I step into the empty room with a feeling of superiority and go to my microscope where I will sit for the rest of the day.
At the time of writing this blog post I have now walked the stairs on numerous mornings, unlocked the door a few more times, finished counting (and recounting) all my pollen and phytolith slides, and started with analysing the data.
The ‘time capsule’ I am looking at is the top metre of a sediment core obtained from a pingo in Twente and the results of my identification of the micro-fossils contained within the sediments are looking starting to provide new insights into past vegetation change. The pollen and phytoliths contained within the top slide correspond with the modern vegetation I saw at Krakenven last year; the onset of agriculture in that area is possibly visible; and the phytoliths show some interesting trends as well. However, there are lots of things to think about when analysing and thinking about the at pollen and phytolith data.
For example, you have to think about which taxa to include in the pollen sum. This was also one of the discussion points related to the paper of Verbruggen et al. (2019) during the Amsterdam Palaeoecology Club (APC) meeting on April 16th. Verbruggen et al. present a multi-proxy analysis on a Holocene peat sequence in a palaeochannel in a natural depression North Belgium. The researchers excluded trees (Salix and Alnus) from the regional pollen sum, which surprised me at first, but there was a logical reason for this. The samples came from a depression, making the local region the only place that was wet enough for Alnus and Salix to thrive. If these water-loving tree taxa were included in the regional pollen sum, the other taxa would have been underrepresented in the pollen diagram. For my data it is important to exclude the aquatic pollen and spores from the pollen sum. Betula was also a possible local resident that I would exclude, but since Betula can also thrive outside the local region of Krakenven and did not represent slides over 50% I chose to leave it in the pollen sum.
The data analysis scared me off in the beginning, but I’m starting to get more confident with it. So hopefully I’ll finish this project with a nice paper.
Verbruggen, F., Bourgeois, I., Cruz, F., Boudin, M. & Crombé, P., 2019. Holocene vegetation dynamics in the Campine coversand area (Liereman, N Belgium) in relation to its human occupation. Review of Palaeobotany and Palynology, 260, pp.27-37. DOI: 10.1016/j.revpalbo.2018.05.004
Huisman, S.N.*, Bush, M.B. & McMichael, C.N.H. (2019) Four centuries of vegetation change in the mid-elevation Andean forests of Ecuador. Vegetation History and Archaeobotany. DOI: 10.1007/s00334-019-00715-8