Ecology of the past

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.

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.

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.

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/.

 

To learn more about Jatun Sacha Biological Reserve, please visit https://www.jatunsacha.org/jatun-sacha-biological-reserve/.

 

About Florida Institute of Technology

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.