As a young, naïve scientist, being exposed to the world of field work for the first time, my first week in Panama was an exciting and new experience. Not only has my mind been blown (several times, might I add) but my interests have broadened and the way I view the natural world has largely changed. Having taken biology in undergrad, I theoretically knew about a lot of the things I encountered, but there is nothing like the intimate experience with the rainforest to really get you engaged and fully understand the diversity around you.
Now for a little history…The isthmus of Panama, officially formed 2.8 million years ago, brought about a lot of changes that have shaped the world as we know it. Rising to connect North and South America and separating the Atlantic and Pacific oceans, the two oceans became dramatically different and the physical changes drove evolution. This also facilitated the Great American Biotic Exchange whereas North American mammals migrated down into South America, and the South American marsupials migrated northward. The results of this are what we saw this past week.
Beginning the trip with 3 days of hiking at the pristine Barro Colorado Island set the stage for what we would encounter throughout our time in Panama. A variety of plant species, unique to the neo-tropics, so diverse that only on the island, there are more tree species than the US and Canada combined! Microbes, as it turns out, are vital for the growth and success of trees. They participate in negative feedbacks with trees which maintain biodiversity we see in the rainforest. Eliminating these microbes and fungi would decrease diversity and create many changes in the ecosystems.
To really get a better idea of the work done on these plant-microbe interactions, we designed and carried out short research projects. The project I participated in investigated the difference in damage of seedlings in the open, sunny areas of the forest and adjacent shaded areas, particularly looking at herbivore and pathogen damage on the leaves. Although not the first time I’ve looked at leaves, it was the first time looking at them from this point of view and trying to assess their damage. Most shocking, was how damaged all the trees and seedlings around us seemed, and yet they were able to still grow and survive despite this stress!
Having spent a large part of the time in the forest, we were not only surrounded by trees and plants, but by a multitude of insects. Some interested in sucking our blood or crawling up our pants, others paying no mind to us, only trying to escape as our footsteps grew near. Although I still do have a fear of spiders, especially big ones, I have developed a much greater appreciation. Those tiny little legs, spinning large, delicate webs, just waiting for their prey. What an interesting life story!
But nothing, and I mean nothing, beats the appreciation I have developed for ants. These tiny little creatures, creating colonies so large and vast, so well designed and each with such a distinct job, working smoothly like a bunch of cells in a single organism. Digging up several leaf-cutter ant colonies we got to see the networks they built, the organization of their workers and the fungus they cultivate to feed themselves. As Dr. Abouheif stated, they are the farmers of the ant world!
Panama is truly a unique place. The shift in climates leads to complete turnover of tree species from the Atlantic to the Pacific side which are only about 60km apart. This means that in just one day you can cross the isthmus and be in the wet rainforest in the morning, and the drier forest in the afternoon. To get a better view, we rose up 51 meters above ground to observe the tree canopy from above. The canopy crane near Fort Sherman has been extensively used to research respiration rates of leaves at the top of the canopy as well as all of tropical forest organisms that live in the upper canopy. The only way to reach them is to climb up in the sky! Having worked on land my whole life it’s hard to imagine working up in the tree canopy, seeing the boundary between the atmosphere and the highest leaves, and all the insects that never wander down to the ground. This experience was truly exceptional and opened my eyes to how little I actually know of what is around me.
Walking through the forest I have managed to shift my perspective and have begun to pay much closer attention to the plants and trees, trying to notice how they are similar or different, and rather than constantly waving away insects, to observe them and notice their special patterns and behaviours.
Taking a break from the field work, the last few days of the week we explored topics such as Big Data phylogenetics, gene editing, mathematical modelling and chemical ecology, all of which are very important to further our understanding of the natural world and not only answer questions about what we see today, but what was there in the past and what is to come.
Not least of all, meeting some extraordinary scientists, both fellow students and guest speakers, and being able to interact with them and learn more about their work has been a wonderful and inspiring. Looking forward to all that is to come!
Allen, W. H. (December 01, 1996). Traveling across the Treetops. Bioscience, 46, 11, 796-799.
ODea, A., Lessios, H. A., Coates, A. G., Eytan, R. I., Restrepo-Moreno, S. A., Cione, A. L., Collins, L. S., Jackson, J. B. C. (August 03, 2016). Formation of the Isthmus of Panama. Science Advances, 2, 8.)
Rajakumar, R., San, M. D., Dijkstra, M. B., Huang, M. H., Wheeler, D. E., Hiou-Tim, F., Khila, A., Abouheif, E. (January 01, 2012). Ancestral developmental potential facilitates parallel evolution in ants. Science (new York, N.y.), 335, 6064, 79-82.
Sedio, B. E., Wright, S. J., & Dick, C. W. (September 01, 2012). Trait evolution and the coexistence of a species swarm in the tropical forest understorey. Journal of Ecology, 100, 5, 1183-1193.
Spear, E. R. (January 01, 2016). Phylogenetic relationships and spatial distributions of putative fungal pathogens of seedlings across a rainfall gradient in Panama. Fungal Ecology.