Watching a forest grow: Long-term experiments as catalysts for collaborative science

The BiodiversiTREE experiment at the Smithsonian Environmental Research Center was launched in 2013 with the planting of ~18,000 trees across 72 plots, each with one of three tree species diversity treatments (1, 4, or 12). The goal of the project is to determine whether the choice of tree planting diversity affects how forests develop, potentially influencing the construction of biological communities, environmental conditions, and ecosystem processes. In this talk, we will highlight some of the scientific discoveries made over the first decade and a half of the experiment with a focus on tree-insect interactions. We will pair these discoveries with insights that are equally important regarding the value of investing in long-term site-based experimental work for long-lived organisms. We illustrate how this type of project requires long-term, sustained input from institutions and scientists across multiple disciplines and career stages, while also enabling the creation of a place-based scientific community and storytelling training for multiple cohorts of scientists, each measuring a community at a specific moment in time during the experiment. Trees, as organisms that will likely outlive the researchers who planted them, require collaborative, long-term, and global perspectives. Specifically, we draw on common forestry principles, such as the concept of mixed-age stands, to highlight the lessons learned over the past decade as the canopy has closed in this young forest experiment, and to indicate where we see future opportunities.