Hello everyone, my name is Samuel Perez and I am working on microbial communities at Harvard Forest with Professor Anne Pringle from Harvard University. I am a rising senior majoring in Organismic and Evolutionary Biology.This summer, I am working with decomposer fungi in the Chronic Nitrogen Plots and the Soil Warming Plots in Barre Woods. My project at the Harvard Forest is to study the effects of nitrogen deposition and soil warming on the species diversity of decomposer fungi.
The process of decomposition is important because it allows nutrients sequestered in living organisms to return to the soil to be used by other organisms in building their physical structures and powering up chemical processes. If everything living continued building matter without breaking things down, the Earth would run out of basic nutrients required for building new things. Part of the microbial community provides the essential ecological benefit of breaking down dead organic matter to feed themselves, and in doing this, they release nutrients back into the soil to be used in other terrestrial processes. Microbial communities that are involved in the process of decomposition include bacteria, protists and fungi, and my particular interests lie with the last of these.
Harvard Forest provides many great opportunities for studying global change, and in the umbrella of global change, factors like global warming, nitrogen deposition, soil warming and other large-scale changes will be important in predicting the future of Earth's ecosystems. These large scale changes have been implicated in potential decreases in species diversity across many different types of organisms, and the Pringle lab want to see if species diversity in the decomposer community could decrease as a result of global change.
We predict that we will see fewer species of decomposer fungi in plots with excess nitrogen in the soil and with warmer soils, but the negative effects will be disproportionate, with some groups able to adapt to their environments while others will be unable to grow in the manipulated conditions or be at a disadvantage.
The project will form part of my senior thesis and will be used by the Pringle Lab and the Frey Lab at the University of New Hampshire in their long-term studies of microbial communities in the soil.



















The Warm Ants project consists of many mini projects taking place within the chambers. One of these projects is a 24-hour baiting, which means that we must observe which ants are attracted to tuna baits set out in the different temperature chambers for all hours of the day, on the hour. Two of us – Margaurete and Adam – took the night shift from 10pm to 6am, and encountered an unexpected visitor. While waiting near the shed to continue the data collecting, a large insect flew right into us, startling the stillness of the night. As it landed, we were so surprised to see a large Luna moth flying towards the light of the shed. Disoriented, the Luna moth stayed in our hands until the rare beauty joined the other insects attracted to the light by the shed. Later on, a second Luna moth joined it, and we were able to enjoy the moths through most of the night. It was a great experience to be able to see and interact with the two beautiful moths in the forests, and a first experience for both of us!




