who we are

Rebecca J. Best

Assistant Professor
Office: Physical Sciences 120/119
Google Scholar Profile

I am an aquatic community and evolutionary ecologist interested in the processes that determine the number and type of species we find coexisting in a particular community, and control the way those communities function. At Northern Arizona University, I am working on the effects of changing temperature and precipitation on aquatic connectivity, species distributions, and genetic diversity across arid landscapes.


Hillary Cooper

Postdoctoral Researcher
Office: Peterson 303
Google Scholar Profile

I am an evolutionary ecologist interested in how organisms can respond to environmental stress via genetic or plastic mechanisms. As a post-doc in THE BEST lab and the Cottonwood Ecology Group, I will be studying the evolution and ecological consequences of phenotypic plasticity to climate change and insect herbivory in cottonwood trees, and how it may then affect communities of dependent organisms. I earned a PhD in Biology at NAU in 2018 researching genetic and trait variation in cottonwoods.

Graduate students

Kaitlin Haase

Master’s Student Environmental Sciences and Policy

I am studying the biodiversity and connectivity of natural and anthropogenic perennial pools across northern Arizona in relation to aquatic habitat loss due to climate change. I graduated from Oklahoma State University with a B.S. in Natural Resource Ecology and Management and have spent four years as a seasonal field technician working on diverse monitoring projects from large mammal predator-prey interactions to rare amphibian breeding in vernal pools to plant species composition in restored wetlands. These experiences which developed my interests in community and conservation ecology along with my affinity for aquatic and southwest ecosystems led me to this position in the Best lab at NAU.

Sarah Sterner

Master’s Student Environmental Sciences and Policy

Beginning in the Fall 2018 semester I will be studying with Rebecca Best and Clare Aslan alongside the Landscape Conservation Initiative looking at the impacts land management policies have on ecosystems across boundary lines between federal, regional, and state owned lands. I graduated from Marist College in Poughkeepsie, NY in 2010 with a B.S. in Environmental Science and a Minor in Biology. Since then, I have spent the past 8 years working as a field technician and crew lead for land management agencies across the country focusing primarily on vegetation management and research. I am invested in land conservation, interested in understanding more about ecosystems responses to human influence and am excited to be studying that at NAU!

Lindsay Hansen

Master’s Student Environmental Sciences and Policy

Lindsay is interested in landscape-level impacts of global change on rivers and fish, and exploring a wide range of potential thesis topics!

Undergraduate students

Lauren Mason-Sarantopulos

Hooper Undergraduate Research Award recipient x2!

Growing up in Wyoming, I was always fascinated by the ecology of streams and rivers. Now as an undergraduate in Environmental Science, I’m particularly interested in aquatic invertebrates, and how their interactions are influenced by both the biotic and abiotic factors found in Arizona’s freshwater ecosystems. I am also passionate about wildlife conservation and environmental activism.

Joshua Rihs

Hooper Undergraduate Research Award recipient

I am an undergraduate student studying environmental sciences as well as GIS as a minor. I am currently exploring all that NAU has to offer and have really enjoyed working for and learning from Dr. Best and everyone in her lab. I will be working alongside Lauren Mason-Sarantopulos within Dr. Best’s lab throughout the 2019-2020 school year on a HURA project. The project will explore the impact transgenerational plasticity has on the mortality and growth rates, brood frequency, and clutch sizes of two native and introduced amphipod species within Northern Arizona when exposed to elevated water temperatures throughout multiple generations.

Madelyn Norstrem

NAU team leader, Cottonwood herbivory project

I am an undergraduate student in Environmental Sciences with an emphasis in Management. I am really interested in studying the interactions between biotic and abiotic factors of an ecosystem. I am currently working as an NSF REU student to help in the study of herbivory and climate change impacts on cottonwood trees. In the Fall, I will be working with Interns to Scholars studying aquatic invertebrate communities. I am hoping to take my experience from my undergrad into exploring new sets of communities and working to sustain ecosystems before continuing on with graduate work.

Lab alumni

Joann Jeplawy

Master’s in Environmental Sciences and Policy

Now at: Tetra Tech, Denver, CO

In collaboration with the Cottonwood Ecology Group, Joann studied the impacts of leaf plasticity on aquatic community composition in cottonwood leaf litter from three common gardens in Arizona and Utah.

Morgan Andrews

BS in Environmental Science, Hooper Undergraduate Research Award recipient

Now at: USGS, Washington State

Morgan worked on the effects of water temperature on the distribution of aquatic biodiversity across ponds in Arizona, using both field surveys and lab experiments. She was awarded the Best Poster in Applied Research at the 2019 Society for Freshwater Sciences meeting in Salt Lake City, Utah!

Kaitlen Bieber

Kaitlen is an Environmental & Sustainability Studies student who spent her third year studying abroad at UNAM (Universidad National Autonomous de Mexico) in Mexico City. She is interested in pursuing ecology (possibly freshwater) for my Master’s degree because understanding ecosystems at all levels is key to conservation and restoration.

Joe Sweet

BS Environmental Sciences

NASA Space Grant Intern

As a Space Grant intern, Joe worked on using remote sensing to detect the presence of water in ponds across the northern Arizona landscape, giving us much greater spatial and temporal information on habitat availability.