TRI Field Notes: Underground Fungi Networks in Ecuador

By Camille Delavaux, 2015 TRI Fellow in Ecuador

My original plan was to go to Yasuní National Park, Ecuador and compare mycorrhizal fungal abundance with plant diversity. Mycorrhizal fungi, if you haven’t heard of them, are symbiotic fungi that form relationships with plants. The plant gives the fungi carbon (since fungi can’t photosynthesize), and the fungi scavenges for nutrients and water to trade for the carbon (mostly phosphorous). It fascinates me that these fungi may form shared, underground networks between plants in a forest. The idea that this network maintains diversity by trading resources is shared by other researchers, but it hasn’t been well-studied in wet, muddy, difficult-to-access tropical forests. Ninety percent of tropical plants form the kind of mycorrhizal fungi I study: arbuscular mycorrhizal fungi. The general idea is that these plants can tap into the fungi network to obtain nutrients or water they need, partially offsetting competition, promoting survival of weaker plants, and leading to a more diverse plant ecosystem.

On the way to a field site near Loja.

On the way to a field site near Loja.

Then the roadblocks of doing research — especially in the tropics — arrived. First, we had problems amending the permit, so I switched field sites. It was last-minute for me, but it was alright: I was still going to test my original hypothesis! When I arrived in Loja, Ecuador, my new field site, my assistant and I hiked five hours to our research plots after taking a 12-hour night bus from Quito. That day we found out that what’s “on paper” isn’t always reality. My plots were almost impossible to find, even as we were guided by someone who had worked on them for four years. After my frustration died down, I decided I was still going to do research here. I was forced to be adaptable, creative, and negotiate while in an environment I only knew for a few hours. I sought information from others around me to learn more about the multiple research sites here, and eventually deduced that we needed to focus on the nutrient enrichment plots. We used the slow internet connection to write long messages to our collaborators in Germany, but the connection failed completely. So we traveled an hour to the nearest city and even used my assistant’s cell phone to connect with our German colleagues.  After a week of wondering if I’d have a thesis project at all, we agreed on how to adapt to the realities of the field site.

Now my project is looking at mycorrhizal abundance in plots with different levels of nitrogen and nhosphorous additions. It’s a pretty neat project, especially with anthropogenic N deposition and lower availability of P fertilizer in the future. The change was bit scary, but I’m still excited. I’m also extremely exited to be presenting on this research at the International Conference on Mycorrhiza in August! Now that the storm has calmed, I’m enjoying this beautiful cloud forest in the mountains. I’m also enjoying the research center, filled with interesting people from around the world, a sweet cat, and wonderfully hot showers. We’ve begun to visit the neighboring towns (which, here, means three hours away), and have gone to do lab work at the local university. In about a month we’ll be transporting the samples back to the United States to begin the long process of laboratory work.

“TRI Field Notes” share the stories of TRI Fellows as they conduct independent summer research throughout the tropics.  The Tropical Resources Institute (TRI) is a center at the Yale School of Forestry and Environmental Studies.  For more information on research and fellowships visit