Donald Zak

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Donald Zak

Burton V. Barnes Collegiate Professor

Office Location(s): 2540 Dana Building
Phone: 734.763.4991
Fax: 734.936.2195
Zak Lab
Dr. Zak's Soils Lab Website
View Curriculum Vitae

  • Affiliation(s)
    • School of Natural Resources and Environment
  • Fields of Study
    • Microbial ecology and ecosystem ecology
  • About

    Academic background

    I received my Ph.D. from Michigan State University in 1987, and I conducted postdoctoral research at the University of Minnesota (1988). I have been at the University of Michigan since 1988, and I have been an associate editor for Ecology, Ecological Monographs, and Soil Science Society of America Journal.

    Research interests

    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. 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 general ecology, soil ecology, and ecosystem ecology.


    Soil Ecology 
    NRE 430 EEB 489

    This course centers on the overlap of soil science and ecology. Our goal is to understand: (1) how the interactions of landform, topography, climate, and biota result in patterns of soil development and the distribution of soils that we observe within the landscape; (2) how physical, chemical and biological properties of soils affect water and nutrient availability to plants; and (3) how nutrients are cycled within terrestrial ecosystems and how these processes are influenced by human activities. In the field portion of the course, we will sample and describe soils of four ecosystems and observe first-hand how differences in landform, topography, climate and biota influence soil development. In the laboratory, we will analyze our soil samples for a number of physical, chemical, and biological properties. Using laboratory data in conjunction with field data, each student will select two of the four ecosystems for detailed comparison in a research paper. Although we will focus our attention on local ecosystems of Michigan, skills learned in this course may be broadly applied within a variety of terrestrial ecosystem types in other geographic regions. Students are expected to have a background in chemistry and biology. In particular, a working knowledge of chemical equilibria, ionic solution chemistry, pH, and oxidation-reduction reactions is highly recommended. Students without such background should consult with the instructor before enrolling. Also useful (although not required) are familiarity with biochemistry, plant physiology, microbiology, geology, and local flora. You will find it very helpful if you have had, or are currently enrolled in, Woody Plants (NRE 437). If you have not done so, we highly recommend that you enroll in these courses concurrently! While the lecture portion of the course provides background knowledge, the laboratory portion of the course is an opportunity for students to gain hands-on experience sampling and describing soils in the field and analyzing various soil physical, chemical, and biological properties in the lab. The importance of the laboratory is reflected in the proportion of the time each week devoted to it. In each lab section, students will be grouped into teams of two or three. Activities and assignments in the lab will be cooperative efforts among team members. Attendance is critical to permit equal participation among team members, and all laboratory assignments are due at the beginning of the next laboratory meeting. Assignments will vary with each specific activity, and specific instructions for each lab assignment will be contained in the weekly lab handout.

    Ecosystem Ecology

    Ecosystem Ecology focuses on current theories regarding the control and function of aquatic and terrestrial ecosystems, the approaches and techniques being used to test these theories, and the application of theory to the management and restoration of ecosystems. The scope includes examples from terrestrial, marine, and freshwater ecosystems. Our goal is to develop students’ understanding of the physical, chemical, and biological factors controlling the dynamics of aquatic and terrestrial ecosystems. Ecosystem Ecology is a lecture course that focuses on understanding the physical, chemical and biological processes regulating the dynamics of terrestrial and aquatic ecosystems. We discuss classic and current topics in ecology that have built our understanding of ecosystem organization and function. The course integrates across disciplines of physiological, microbial, population, and community ecology to understand how and why ecosystems differ in composition, structure, and function, and how ecosystems change over time. Students are expected to have a solid background in biology and ecology. We also expect that students will be able to use general principles of mathematics, physics, chemistry, and biology as tools to understand ecological processes occurring at the ecosystem level. The scope of the course includes examples from terrestrial, marine, and freshwater ecosystems. Selected topics for discussion include: “What are ecosystems and why are they so complex?”; “The principles of biogeochemistry - nutrient cycling, mass balance, and microbial function”; “Global ecology - are processes in ecosystems additive across a range of spatial scales?,” “The use of chemical tracers of energy flow through organisms and their environment,” and “Do species matter for ecosystem function?”. There are three lecture periods each week involving a lecture presentation by the instructor focusing on assigned readings from the required textbook and the primary scientific literature. We welcome questions in lecture, and we encourage your participation in the discussion of all topics.

    General Ecology

    Ecology is an integrative scientific discipline concerned with understanding the interaction of organisms with one another and how organisms interact with their physical environment. In this course, we will build your understanding of the fundamental processes controlling the abundance, distribution, and diversity of organisms that inhabit the Earth. To accomplish this task, we will develop principles and theory that span levels of biological organization, beginning with the physiological attributes of organisms enabling them to inhabit particular environments. We will use these principles to understand the population dynamics of organisms and how the interactions among organisms control the composition (i.e., who’s there) of biotic communities. Then, we will explore how and why the interaction of organisms with the physical environment causes energy to flow and elements to cycle within terrestrial and aquatic environments. Humans are a part of nature; they are not apart from it. In the final section of this course, we will explore how human activity has altered the abundance, distribution and diversity of organisms on Earth as well as how our activities have modified the flow of energy and elements in ecological systems. The primary goal of our course is to develop your understanding of the underlying processes controlling the abundance of organisms, the communities in which they reside, and the ecosystems they compose in combination with the physical environment. It is our expectation that everyone successfully completing this course will master the scientific principles necessary to understand a wide range of ecological dynamics, enabling them to use this knowledge as an ecologically literate member of society. We will accomplish this goal with the use of lectures, selected reading to enhance lecture material, and directed discussion and exercises. As discussed above, ecology is an integrative science drawing off principles in biology and evolution as well as from the physical sciences of climatology, geology, chemistry and physics. It is mandatory that each student has completed BIO 162, and it is beneficial (but not expected) if other course work in the aforementioned areas has been taken in the past or concurrently. Students are expected to attend all scheduled course meetings. Lecture time will be used to build important concepts that are integral to our understanding of ecology, and we strongly encourage questions during lecture and active engagement in all parts of this course. Your ability to master and apply knowledge in this course will be evaluated with the use of in-class exams and exercises during your weekly discussion. Exams are not cumulative, but they are integrative. As such, it is necessary to master principles early in the course, because they are a foundation for further learning later in the course.

    Ecosystem Science in the Rockies

    The Rocky Mountains are an ideal setting to study the relationships between climate, geology and ecology; all are intertwined to create landscape-level patterns of terrestrial and aquatic ecosystems that are readily observable across this climatically and geologically diverse region. In this course, we will use the Rocky Mountains as a field laboratory to explore, illustrate and explain principles of climatology, geology and ecology. These areas of study do not stand alone; rather, they interact in understandable and predictable ways to create the Rocky Mountain environment. Our goal for the course is to build your understanding of environmental science and develop a conceptual framework to understand how the physical environment (i.e., climate and geology) controls on the distribution of organisms in mountainous regions. We will employ an active, field-based approach in which you will learn basic principles and apply them to understand interactions among climate, geology and ecology. Most days will begin with a brief lecture on fundamental concepts and an explanation of an exercise designed to illustrate these principles in the field. Thus, we will spend the majority of our time in the field making observations, collecting data, and discussing the information we have obtained. The course is organized in a hierarchical manner: climate and geology set the broad stage for terrestrial and aquatic ecological processes. Thus, we will begin our course by developing your understanding of climatology and geology. We will integrate the influence of climate on geological and ecological processes, and in turn, how geology, through its effect on relief, can alter climate and create a range of conditions to which terrestrial and aquatic organisms have adapted in the Rocky Mountains. You will leave this course with an understanding of how climate and geology create the physical conditions that give rise to the range of terrestrial and aquatic ecosystems that typify the Rocky Mountain region. Given the field orientation of the course and its location, there are several ways in which you should prepare yourself to gain the most from this experience. Students with general course work in geology and ecology will be well prepared to take on the intellectual challenges of this course. In addition, those in good physical condition will be well prepared to take on the physical challenges of this course. Realize that we will travel by foot when doing field work, and on several occasions we will hike from relatively low elevations (ca. 6000 ft) to the alpine ecosystems which lie over 10,000 ft.

  • Education
    • PhD Forest Ecology, 1987, Michigan State University
    • MS Forest Soils, 1983, University of Idaho
    • BS Forest Science, 1981, Ohio State University
  • Research Areas of Interest
    • Microbial ecology and ecosystem ecology
  • Graduate students
    • Huijie Gan