The Cedar Creek Long Term Ecological Research Program (CDR) uses observed and experimentally created gradients in biodiversity and multiple global change factors to investigate long-term consequences of human-driven ecosystem changes. 

The grasslands, savannas, and forests of our site allow us to concurrently generate deep site-level knowledge, while also seeking generalizable insights across life history strategies and evolutionary lineages via models, synthesis, and multi-site experiments. Over the >40 years of CDR research, we have developed a suite of experimental and observational platforms to uncover key biodiversity-related processes and feedbacks that arise from combinations of biotic and abiotic changes.

Four decades of research at CDR (LTER I – VII) have revealed that when community or ecosystem responses (e.g., biomass, species composition) are strongly coupled to varying conditions (e.g., interannual weather), lags and feedbacks can be obscured for decades, underscoring the need for long-term data to generate a general understanding of temporal dynamics. Our long-term work has positioned our work to reveal when and why multi-decadal lags and long-term feedbacks occur as well as the role of biodiversity change on lags and feedbacks to ecosystem functioning. Building from this history of discovery, in LTER VIII we are currently testing whether the effects of plant biodiversity, altered environmental conditions, and their interactions will change in magnitude or direction across time because of lags and organism-environment feedbacks.

At Cedar Creek, we concurrently examine the long-term responses of ecosystems under ambient and altered environmental conditions in which naturally occurring plant biodiversity responds to altered conditions (i.e., biodiversity is a response to change) as well as in experiments in which plant biodiversity is experimentally controlled (i.e., biodiversity is a driver of change). Seen through this lens, the many experimental and observational platforms in CDR’s grassland, savanna, and forest habitats, represent four types of studies in which we track long-term dynamics and feedbacks between biodiversity and ecosystem functions. These are the focal themes for LTER VIII:

1. Successional Trajectory Studies: in which biodiversity and ecosystem processes respond to changes in land use or management (i.e., fire or tilling cessation) and unmanipulated variation in the environment (e.g., site-level weather or climate);
2. Plant Biodiversity Experiments: in which ecosystems respond to experimentally maintained plant diversity (e.g., planted and maintained species richness and composition);
3. Global Change Experiments: in which biodiversity and ecosystem processes respond to manipulated global change drivers (e.g., nutrient and C supply, soil disturbance, water availability, or temperature); and
4. Global Change & Plant Biodiversity Experiments: in which ecosystems with experimentally maintained plant biodiversity levels

Through new data collection and synthesis of data from CDR and elsewhere, our long-term work is positioned to reveal when and why multi-decadal lags and long-term feedbacks occur as well as the role of biodiversity change on lags and feedbacks to ecosystem functioning.