Donald R. Zak, Ph.D.

Associate Dean for Academic Affairs; Burton V. Barnes Collegiate Professor of Ecology

Ph.D. 1987, Michigan State University

M.S. 1983, University of Idaho

B.S. Cum Laude 1981, Ohio State University

Don Zak holds a joint appointment in the department of Ecology and Evolutionary Biology, College of Literature, Science, and Arts. His research investigates links between the composition and function of soil microbial communities and the influence of microbial activity on ecosystem-level processes. This work draws on ecology, microbiology, and biochemistry and is focused at several scales of understanding, ranging from the molecular to the ecosystem scale. Current research centers on understanding the link between plant and microbial activity within terrestrial ecosystems, and the influence climate change may have on these dynamics. Teaching includes courses in soil ecology and ecosystem ecology.

Awards and Grants:
Atmospheric nitrogen deposition and molecular mechanisms enhancing soil carbon storage. Sponsor: DoE Biological and Environmental Research

Long-term ecosystem response to chronic atmospheric nitrogen deposition. Sponsor: NSF Long-Term Research in Environmental Biology Program (LTREB)

Research Interests:
My research investigates connections between microbial community composition and function and the importance of microbial activity in regulating ecosystem-level processes. This work draws on microbial ecology and plant physiology, and it is focused at several scales of understanding. Plants respond to environmental factors by altering growth and longevity of fine roots, which, in part, control the amount and types of organic substrates available for microbial metabolism in soil. I have worked to understand how changes in belowground plant growth influence the composition and function of soil microbial communities. Stable isotopes and molecular techniques are the primary tools I have used to accomplish this task. My work has elucidated mechanisms of plant-microbe competition for inorganic nitrogen and the interdependence of plant and microbial productivity in a wide range of terrestrial ecosystems. Much of my current work centers on understanding the link between plant and microbial activity within terrestrial ecosystems, and the influence climate change may have on these dynamics.

Teaching Interests:
My teaching builds an understanding of the processes controlling the flow of energy and nutrients within terrestrial ecosystems and how these dynamics are altered by human activity. I accomplish this through a series of undergraduate and graduate courses that focus on microbial ecology and ecosystem ecology. In Soil Ecology (NRE 430/BIO 498), I provide students with the fundamental principles of soil science, stressing the integration of concepts into an understanding of ecosystem-level processes. I complement formal lectures with informal teaching in field and laboratory settings, an approach that has been useful for putting concepts and theory into action. Ecosystem Ecology (NRE 476/BIO 476) is a lecture course that focuses on understanding the physical, chemical and biochemical processes regulating the dynamics of terrestrial and aquatic ecosystems; it is team taught by myself and Dr. George Kling. We discuss classic and current topics in ecology that have built our understanding of ecosystem organization and function. Some aspects of population and community ecology are presented to gain an in-depth understanding of how and why ecosystems change in time and space. The course integrates across disciplines of physiological, population, and community ecology to understand how and why ecosystems differ in composition, structure, and function. Students are expected to have a solid background in biology and ecology. We also expect that students will be able to use principles of mathematics, physics, chemistry and biology as tools to understand ecological processes occurring at the ecosystem level.

Current/Recent Teaching:
General Ecology – BIO/ENVIRON 281
Soil Ecology – EEB 489/ENVIRON 430
Ecosystem Ecology – EEB/ENVIRON 476
Ecosystem Science in the Rocky Mountains - GEOLOGY/ENVIRON 341

Recent Publications

Dunbar, J., L. Gallegos-Graves, B. Steven, R. Mueller, C. Hesse, D.R. Zak and C.R. Kuske. 2014. Surface soil fungal and bacterial communities in aspen stands are resilient to eleven years of elevated CO2 and O3. Soil Biology and Biochemistry 76: 227-234.

Zak, D.R. 2014. Ecosystem succession and nutrient retention: Vitousek and Reiners’ hypothesis.  Bulletin of the Ecological Society of America 95:234-237.

Talhelm, A.F., K.S. Pregitzer, M.E. Kubiske, D.R. Zak et al.  2014. Anthropogenic carbon dioxide and ozone offset ecosystem C storage in forests. Global Change Biology 20: 2492-2504.

Freedman, Z., and D.R. Zak. 2014. A bacterial role in lignin decomposition under future rates of atmospheric N deposition. Applied and Environmental Microbiology 16: 1538-1548. .

Freedman, Z. and D.R. Zak. 2014. Soil bacterial communities are shaped by temporal and environmental filtering: Evidence from a long-term chronosequence. Environmental Microbiology in press.

Hesse, C.N., M. Vuyisich, L.V. Gallegos-Graves, J.F. Challacombe, C.D. Gleasner, L.O. Ticknor, D.R. Zak, and C.R. Kuske. 2015. Forest floor community metatranscriptomes identify fungal and bacterial responses to N deposition in two maple forests. Frontiers in Microbiology in press.

Peschel, A.R., D.R. Zak, L.C. Cline, and Z. Freedman. 2015. Elk, sagebrush, and saprotrophs: indirect top-down control on microbial community composition and function. Ecology in press.

Freedman, Z. and D.R. Zak 2015. Atmospheric N deposition alters co-occurrence in saprotrophic bacterial communities. Molecular Ecology in press.