My research focuses on quantitative ecology. This means using advanced mathematical and statistical tools to investigate relationships between living organisms and their environment. Most of the research in the Green Quantitative Ecology lab (QuantEco) is focused on fish and wildlife conservation. The two main themes are:

  • Population risk assessment: what biological traits influence the vulnerability of populations to threats like pollution, climate change, and habitat loss? How does uncertainty about basic life history parameters (e.g., survival rates or reproductive rates) "scale up" to population-level effects?
  • Measuring human impacts: how do human activities such as agriculture, urbanization, and pollution affect fish and wildlife populations? Can the effects of multiple influences be separated, statistically, using data from large-scale monitoring programs?

Current projects

Spatial ecology of small mammals in urbanizing environments

deer mouseSmall mammals such as mice, rats, and voles are an important component of terrestrial ecosystems. As consumers of seeds and vegetation they exert enormous influence over plant communities; they are also an important prey item for numerous predators.  Some species are also vectors of important human and animal diseases. At the same time, the environments where small mammals live are rapidly being altered by climate change and land use change as human populations increase.

Understanding how small mammals are affected by changes in their environment is critical to understanding changes in natural communities and emerging risks to human health. This project uses field sampling, physiological measurements, and sophisticated statistical modeling approaches to investigate how small mammals are impacted by their changing environment.

Human impacts on stream communities

Stream samples in GeorgiaStream organisms respond to natural and human influences at multiple spatial and temporal scales. The abundance and diversity of stream biota are important indicators of overall watershed and stream health. Understanding how different factors influence these organisms across spatial and temporal scales is crucial for conservation of aquatic communities and ecosystems, as well as promoting water quality. Using data from state-wide stream biomonitoring programs, in combination with broad-scale spatial datasets, we are using sophisticated statistical approaches and machine-learning techniques to investigate how natural and human drivers within watersheds affect the communities that live in the state’s streams.


Population consequences of individual toxic exposure

Many animal species are at risk from toxic pollutants released by human activities. Accurate assessment of these risks is necessary to make scientifically sound decisions about the production, regulation, and safe use of chemicals. This project builds on modeling frameworks developed at two biological levels of organization: toxic effects to individuals using the General Unified Threshold of Survival (GUTS) framework, and population modeling using population projection matrices. Integrating these frameworks will allow us to investigate how individual-level effects "scale up" to populations. 

The long-term goal of this project is to develop generalized life history-based population dynamics models that can be parameterized for many species, integrate them with toxicokinetic-toxicodynamic models such as GUTS, and use these integrated models to estimate population responses to realistic toxic exposures. By modeling multiple species, and relating the population responses to species-specific life history traits, we hope to identify biological characteristics that predict vulnerability to toxic exposure. The results of this investigation will allow us to predict vulnerability in species for which detailed life history data are not available, and to identify species that might be at risk.

Drivers of coral decline

coral collageCorals are relatives of the jellyfish (Cnidaria) that build a hard exoskeleton from compounds in seawater. Their exoskeletons form large-scale structures called coral reefs that serve as habitat for some of the most diverse communities on Earth. Reef-building corals are currently under threat from numerous natural and human-caused factors. Together with external collaborators and undergraduate students, we are using publicly-available spatial data on coral status, ocean conditions, and inputs from shore to explore how specific human activities may or may not be responsible for the decline of these ecosystem engineers...and what management actions are likely to have an impact.

Click here to see a poster recently produced by Matt Freiler, 2022 graduate, for his Honors Capstone thesis. This work is currently being developed into a journal manuscript.

Student involvement in research

My success as a researcher and educator depends on the contributions of students of all levels—including undergraduates—in my research program. This means not only guiding students through the research process in the lab and field, but also keeping them involved through reporting and publication. Training undergraduates in field methods and data analysis has been vital to my research productivity. The quantitative and analytical skills students gain in my lab are essential in the modern job market; the quantitative and programming skills help prepare students for graduate work and for careers in academia, government, non-governmental organizations (NGOs), and industry. If you are interested in joining the QuantEco lab please contact Dr. Green by e-mail to discuss current opportunities.

Interested in joining the lab?

KSU undergraduates: if you are interested in doing research in the lab, please send me an e-mail ( so we can have a conversation about your interests and how they might fit in to current projects. There are many ways you can get involved so please reach out!

Potential graduate students: If you are interested in joining the lab as a master's student, please reach out by e-mail so we can discuss potential projects. Students in the lab will enter the KSU Master of Science in Integrative Biology (MSIB) program. The next available openings will be for Fall 2023.