Wild caribou are the single most important land-based species for both human communities and ecosystems in the Arctic. Abundant across the polar region, these animals play an essential role both as herbivores that impact tundra vegetation and as an important source of food to Indigenous hunters. In many cultures, caribou also have incalculable spiritual value.
Caribou herds of North America, which collectively include more than one million animals in Canada and another 750,000 in Alaska, represent the largest terrestrial mammal migrations on Earth, traveling thousands of kilometers from the northern edges of the boreal forests to the Arctic barrens of the coastal tundra. However, most herds have been in decline in recent years because of the consequences of climate change and increased human development. Scientists believe that caribou have declined by about 56 percent in North America in the last 20 years, largely due to habitat loss and degradation.
Despite the importance of caribou in the region and the intense research efforts devoted to them, measuring the effects of accelerating oil and gas exploration, pipelines, mining operations, Arctic seaports and associated road construction across the region's vast population of animals is challenging because most studies are specific to one or two caribou populations, and results are difficult to generalize.
Assistant research professor Logan Berner of Northern Arizona University's School of Informatics, Computing, and Cyber Systems (SICCS) was recently awarded $718,000 by the National Science Foundation for "Fate of the Caribou: from local knowledge to range‐wide dynamics in the changing Arctic," a three-year study of how increased human development affects caribou herds against the backdrop of a dynamic and changing physical environment. The project was funded through the NSF's Navigating the New Arctic program, one of 10 "Big Ideas" unveiled in 2016 and presented as bold, long-term research and process ideas that identify areas for future investment at the frontiers of science and engineering. The Big Ideas represent unique opportunities to position the U.S. at the cutting edge of global science and engineering leadership by bringing together diverse disciplinary perspectives to support convergence research.
By partnering with Indigenous conservation managers and agencies in Alaska and northern Canada that monitor caribou populations, Berner hopes to contribute in several important ways to the science of the changing Arctic through the lens of caribou ecology, land-use change and impacts on local communities.
"Our interdisciplinary research team will collaborate with members of local Indigenous and rural communities to conduct large-scale ecological analyses across multiple caribou herds in North America using novel ecological modeling, decades of satellite observations, and extensive field data," he said.
Along with Regents' professor Scott Goetz, a co-principal investigator, the research team consists of ecological modelers, Earth scientists, remote sensing and computing experts and caribou biologists with strong links to the Indigenous agencies that manage and conserve the caribou herds. In addition to NAU researchers, the team includes Elie Gurarie of the State University of New York, William Fagan and Anne Gunn of the University of Maryland and Mark Hebblewhite of Montana State University, supported by NSF grants totaling nearly $2.2 million. There are also several unfunded collaborators from groups including the Wek'èezhìı Renewable Resources Board, the U.S. National Park Service and Environment Yukon.
"This is an exciting project because it brings together people I've been working with for some time, but it's the first time we're unifying the various components that each of our groups contribute to the broader effort," Goetz said. "NSF's Navigating the New Arctic program was big enough to allow each of the groups to have the resources necessary to bring us all together on one big, coordinated project."
In its research description, the team wrote: "Our research will help advance understanding and management of caribou as we partner with the Indigenous-led caribou and natural resource management boards that are central to Arctic governance. We will work with them to produce actionable science that can inform the policies and co-management of caribou herds stretching from Hudson's Bay to western Alaska. By studying multiple populations across a near-continental level under a unified analytical framework, and by developing field, remote sensing and community-derived environmental datasets, we will be able to identify both general principles and herd-specific processes that influence the dynamics and distribution of caribou populations."
Training the next generation of Arctic scientists
The project is designed to help train the next generation of Arctic scientists by supporting three postdoctoral researchers, two Ph.D. students and undergraduate technicians in fields including wildlife ecology, environmental informatics, natural resource management and social science.
Ph.D. student Katie Orndahl, who studies with Berner and Goetz in NAU's Global Earth Observation and Dynamics of Ecosystems (GEODE) lab, is part of the research team. During the summers of 2018 and 2019, Orndahl led a small team that conducted research at 60 sites along the Alaskan Canadian border, across interior Alaska, central Yukon and the Yukon North Slope, linking field data with unmanned aerial vehicles (UAVs) to scale up to satellite imagery. She is familiar with the Alaska tundra environment from her work prior to joining the GEODE lab.
The research team will build on data she collected by collecting new field data from a much broader geographic area, including the Western Arctic Herd range and the Porcupine, Cape Bathurst and Bathurst caribou herd ranges in the Northwest Territories. The team will engage local communities and agency collaborators in the field campaigns, which will target 20-25 sites each summer, and expects to assemble field data from approximately 100 additional sites across northern North America.
"During our work, we followed the migratory route of the Porcupine herd across ever-changing landscapes and met many smart and enthusiastic folks along the way," Orndahl said. "Above all, it was clear just how important caribou are to the Arctic, both ecologically and culturally. The field work we've conducted so far would not have been possible without a fantastic group of collaborators, and I'm excited this project will build on what we've done so we can better understand and protect the caribou."
Berner, who specializes in ecological and environmental informatics research, is part of Goetz’s GEODE lab, which uses a wide array of remote sensing methods—from UAVs to satellite imagery—to study ecosystem structure and function. The lab team’s work focuses on understanding ecosystem responses to environmental change, and modeling interactions between forests, tundra, climate, land use change, disturbance and biodiversity, exploring how vulnerable or resilient ecosystems are in a time of global environmental change.
Berner was also recently awarded a $372,581 grant by NASA for a three-year project, "Mapping plant biomass distribution and change across the rapidly warming Arctic tundra biome." The project's goal is to advance understanding of the amount, distribution, composition and recent changes in plant aboveground biomass across the rapidly warming Arctic tundra biome using field, satellite and geospatial data. This project, along with Goetz's NASA's Arctic Boreal Vulnerability Experiment (ABoVE) projects, will help ensure the success of the ambitious multi-disciplinary effort to understand the fate of caribou within the context of the New Arctic.