New Forest and Biodiversity Experiment at Harvard Farm

Led by Jeannine Cavender-Bares – a new faculty member at the department of Organismic and Evolutionary Biology and incoming director of the Harvard University Herbaria – the new “Forest and Biodiversity at the Harvard Forest” ("FAB") experiment will examine how forest diversity and introduced pests and pathogens affect forest function.

The research will incorporate phylogenetic diversity, or the evolutionary relationships among biological entities, in this case trees and their associated pathogens. Using fourteen native tree species with varying susceptibility to environmental stressors, Cavender-Bares and her research team will address these questions:

• How do multiple dimensions of biodiversity in forests, including species richness, phylogenetic diversity, and variation in ecological niches of tree species affect forest function, stability, and resilience?
• How are interactions among tree species influenced by their ecological and phylogenetic similarities?
• How do pests and pathogens differ in their impacts on forests depending on forest diversity?

The experiment will occur at Harvard Farm, located roughly ¾ miles southeast of Harvard Forest’s main campus in Petersham. Preparation of the experiment is underway and will include over 200 forest plots varying in species richness, phylogenetic diversity, climatic niche, and successional status, with some plots being monocultures of individual species and others having as many as 12 different species. Plots will include different species mixes from maple, birch, beech, walnut, pine, and magnolia families. The tree species within each family occupy relatively different ecological niches, including those that are early and late successional.

Two of the species, Eastern Hemlock (Tsuga canadensis) and American Beech (Fagus grandifolia), are under significant stress due to the increasing presence of introduced host-specific pathogens in the region. To better understand how the tree communities interact in the absence of these pathogens, each plot will be replicated to include Beech or Hemlock individuals that have been treated to remove pathogens.

Cavender-Bares hopes that the experiment will provide a collaborative platform for research that will lead to a better understanding of how changes in the environment affect forests locally and how to better prepare for climate change. Shown are researchers from the Advancing Spectral Biology in Changing Environments to Understand Diversity (ASCEND) team including Jeannine Cavender-Bares, Allison Scott, Mariana Susana Hernandez-Leal, José Antonio Guzmán Quesada, Steven Augustine, and Juan Ramírez-Lerma, who are planting trees. If you would like to get involved, please contact Cavender-Bares.