We live in an era of unprecedented environmental change. Nature is changing faster than our ability to understand and document it, with profound consequences for the functioning of ecosystems and the people and economies that depend on them. At the same time, humans have relatively short memories of how the natural world used to look in the recent past, challenging our ability to comprehend the rapid changes underway. My research seeks to understand how ecosystems work, what sustains biodiversity, and how populations of plants and animals are changing in response to natural and human drivers. My motivation to teach through the College Fellows Program is to help students understand the form, extent, and pace of ecological change, and how scientists use empirical tools like experiments and long-term observations to resolve the causes and consequences of such changes.