pollen | Ecology of the past

“Can you go back?” by Mark Bush – Part 2

September 21, 2019
WDG

Mark Bush

The second of three guest blog posts by Prof. Mark Bush (Florida Institute of Technology). Click here to read Part 1.

The next two days were spent in motorized dugouts sitting on our gear bags, with tarps pulled over us. Every now and then the driving rain would relent and we would see macaws and toucans flying across the Aguarico River. We stayed one night in a village that had been abandoned due to recent floods, another with Siona hunters who were preparing their blow darts (for monkeys). There were very few houses along the river and we hardly saw another boat in three days. Then we arrived, well almost. We had turned off the main channel onto the tiny Zancudo river. Little used, this stream was a jumble of fallen trees that the Siona chopped their way through. A large tree just beneath the surface posed a problem that was solved by stripping the bark from Cecropiatrees and laying it inside surface facing up, backing up, revving the engine, and aiming straight for the bark. The slick insides of the Cecropiaallowed the canoes to shoot the trunk and on we went. Then we reached the marsh. When I say ‘marsh’ it was a forest of Montricardia arborescens. This is an aquatic Aroid that grows about 3 m high. The trunks are about 3-5 cm in diameter and is THE favored hangout for caiman and anaconda (I have since learned). No Siona in their right mind gets out of a boat in such a marsh and so we were stuck……so close but yet so far. Our only chance of getting through the marsh was to hop out of the boats and pull them through.

The author pulling a canoe through the marsh at Zancudococha in 1988.
Photo: Miriam Steinitz-Kannan.

We had two boats and so the most dispensable members of the team, Paulo de Oliveira and I, were given the job of hauling the boats. A couple of happy hours later we were through the marsh and onto the lake.

Our first jobs were to find somewhere dry enough to camp, unload, set up camp, and survey the lake. Paul Colinvaux the team leader always launched an inflatable and surveyed the lake on first arrival. Meanwhile the rest of us set up camp. About 20 minutes into all this activity there was the unmistakable crack of a shotgun. In a few more minutes the Chief’s sons emerged from the forest with the news that they had shot a large tapir. The tapir fed the group for the next few days, but I ate tuna and a sausage that had turned blue and slimy, unable to reconcile my role in, what to me, was an unfortunate outcome of our petitioning the Siona to bring us to their sacred lake. The coring was more successful than at Cuyabeno in that we recovered 5m of sediment, but it was clearly a young system and wouldn’t answer our research question. This expedition was a disappointment scientifically, but an incredible snapshot along the gradient of Amazonian development.

: View from our campsite of an island in Lake Zancudococha (1988). Photo: M. Bush.

: The 1988 camp at Zanucudococha was a place of field biology. Chemist Mike Miller worked late into the night on limnology, while field microscopes were used to get an early glimpse of plankton and diatoms. From left to right: Melanie Riedinger-Whitmore, Eduardo Asanza, Haki, Paulo de Oliveira and Paul Colinvaux. Photo: M. Bush.

To be continued…

“Can you go back?” by Mark Bush – Part 1

September 17, 2019
WDG

Mark Bush

This is the first in a special series of three guest blog posts by my friend, mentor and collaborator the tropical palaeoecologist and biogeographer Prof. Mark Bush (Florida Institute of Technology).

We are often told that you “cannot go back”, meaning that a place that provided wonderful memories will disappoint when revisited. Putting this into current conservation-speak we don’t like to be reminded that our baselines are shifting. Recently I had a chance to revisit a part of Ecuadorean Amazonia I had not been to for 30 years. I was a bit hesitant to go. Would I be disappointed or could the experience live up to my recollection?

In 1988, I went on a lengthy field season in Ecuador. We were searching for a glacial-age record that could test the refugial hypothesis of Amazonian speciation. Some lakes that lay in Ecuadorian Amazonia showed promise as they appeared to be a long way from major river channels, and only connected by their outlets into the Cuyabeno River. Would these lakes hold glacial-aged records? Would they show a history of rainforest or savanna during the last ice age?

We started from the frontier town of Lago Agrio, which was rough in every way, dirty, and somewhere we couldn’t wait to leave. Driving to the end of the road and then picking up motorized canoes we were, by nightfall, able to get to the first tourist/research lodge to be established in what is now the Cuyabeno Faunistic Reserve. The trip there was basically uneventful, but a quick tour of the lake in our motorized dugout revealed a substantial inflowing river that had been hidden by cloud on the aerial imagery. We had been hoping for a headwater system, not an essentially riverine lake. Nevertheless, we cored the middle of the lake. The coring was tough as the river was washing clays into the system and these settled to form stiff, sticky, gray sediments. After one or two meters of coring, hammering was essential to get any penetration, but getting the core back out was the real challenge. The inflatable boats were sinking as we strained upward on the coring rig, but still we couldn’t break the device free from the clay. We tried everything: we clamped the boats to the coring rig when they were fully flooded, then bailed the boats out, hoping the added buoyancy would break the corer free. It didn’t. So we refilled the boats, re-clamped, bailed, and then all jumped out. Still nothing. In the end we resorted to the nuclear option, which is to hammer upward on the drill rig. The modified Livingstone coring rig we were using was designed to be hammered downward, but hammering upward can seriously damage the drill string. Nevertheless, it worked. Darkness was closing over us by the time we managed to free the rig, but already we knew that the core wasn’t the glacial-age record we had been hoping for. Faces in camp that evening were pretty glum. As the old axiom goes, we defined insanity by repeating the procedure in the next lake in the chain and, unsurprisingly, got the same outcome – another young core.

Victoriano, Haki, shaman and head of the Siona Nation in Cuyabeno. Photo: M. Bush.

We resolved to move on and try another target system, Laguna Zancudococha. Our hosts and guides were members of the Siona nation, and their Hako (Chief) was a vibrant 82-year old called Victoriano. There was a long discussion deciding whether we could go to Zancudococha as it was their ‘origin’ lake and therefore sacred. Eventually, it was decided that we could go. The journey would take at least two days and although Victoriano knew the way, none of the others had been there before.

To be continued…

A Study in Green

July 5, 2019
WDG

By Rachel Sales (Florida Institute of Technology, USA)

My bike is angry at me.

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.

Typha as a wetland food resource: evidence from the Tianluoshan site, Lower Yangtze Region, China

June 3, 2019
WDG

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

Looking at a time capsule from Twente

May 29, 2019
WDG

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.

Cloudy with a chance of adventure

April 8, 2019
WDG

Rachel Sales, Bryan Valencia, and Majoi de Novaes Nascimento coring a different lake. In this picture, we have just pulled a core of mud up from the bottom of the lake. Photo credit: Seringe Huisman

Cloudy with a chance of adventure
By Rachel Sales (PhD researcher at the Institute for Global Ecology, Florida Institute of Technology)

I am sitting on the shore of Lago Condorcillo in Southern Ecuador, after a long day of travel, trying to control my shivering. At roughly 10,500 ft. above sea level, the lake is very cold, with wind that howls over the barren hills dotted with giant boulders. The lake is also almost always blanketed by thick fog and pelted by driving rain. When you’re surrounded by the thick fog punctuated by lightning bolts, it’s easy to believe that some lost civilization lurks just out of sight. Tonight we are experiencing lightning storms, which is adding to the feeling that some angry, ancient life form must live at Lago Condorcillo.

Tomorrow, I will be out in the cold and rain, balancing on an inflatable boat and fighting frostbite. Mark Bush, who is my Ph.D. advisor, Courtney Shadik, who is my lab partner and tent buddy, and I will be collecting cores of mud from the bottom of Condorcillo. We will create our rig for coring by tying two inflatable boats together, and placing a wooden platform between them. Mark, Courtney, and I will then collect our mud cores from this platform.

As I’m contemplating the hazards of camping in a lightning storm, Mark says, “Tell me everything that went wrong today.” Courtney pulls a sleeping bag closer to her. I begin to describe how Google Maps can’t seem to understand distance in the Andes, and so traveling to Lago Condorcillo took much longer than we anticipated. Courtney laughs beside me and adds, “We don’t have any matches to start a fire.” Despite our troubles, I am grinning from ear to ear, no doubt spoiling the grim mood Mark is attempting to cultivate and Lago Condorcillo is doing its best to enforce.

Amazonia – natural wilderness or abandoned parkland?

April 5, 2019
WDG

Judith being enthusiastic on fieldwork in the Austrian Alps during her Bachelors degree

Amazonia – natural wilderness or abandoned parkland?

By Judith Kirschner (currently studying for MSc Earth Sciences: Geo-ecological Dynamics track at the University of Amsterdam)

In the 4^th edition of our “Amsterdam Paleoecology Club” (APC), we discussed ‘A 6900-year history of landscape modification by humans in lowland Amazonia’ by Bush et al. (2006)¹. The high-resolution record presented in this paper shows impressively that what we might perceive as native rainforest today could rather be a since a long time actively modified landscape.

The chronology from Lake Sauce (Peruvian Andes) suggests a continuously forested landscape under significant anthropogenic impact over the last 6900 years. Indicators of human activity are taken to be the varying presence of crop pollen (Zea mays) throughout the record, combined with the continuous occurrence of charcoal. Two extra-large fire events are dated at c. 6700 and between 4500-4230 cal BP, probably enhanced by the relatively drier climate of the mid-Holocene. However, it is not clear yet if human actions formed a response to climate change or were part of social and cultural changes.