Prospective Students

Dear Prospective Student:

Thank you for contacting me about joining my lab as a graduate student. My field research program focuses on how the land-water boundary in riparian zones mediates energy or water fluxes between rivers and riparian habitats. I then examine how these fluxes alter species interactions in riparian food webs. More broadly, I am interested in advancing theory in community ecology by integrating insights from this field with tools and concepts from population biology and ecosystem ecology.

My empirical research is carried out largely on the San Pedro River in SE Arizona. This study site is noted nation- and world-wide as an area of high regional species diversity hosting some 80 spp. of mammals, 40+ spp of herps and over half of the bird species found in North America. My current field pursuits address two main questions: 1) Do riparian trees link subsurface aquifers to consumers in surface-dwelling food webs in riparian forests? And, 2) How do ecosystem size, resource availability and flow-related disturbance affect the length of food chains in stream ecosystems? Additionally I am interested in 3) Quantifying patterns of relative abundance and diversity of vertebrates along the riparian-upland transition, and 4) Testing food web and climate-based hypotheses about the causes of changes in these patterns along this gradient.

I encourage students to develop thesis and dissertation topics related to these general themes on one or several taxonomic groups of choice. My taxonomic areas of expertise are in stream fish and lizard ecology; however I encourage my students to work with a variety of other taxonomic groups (microbes, insects, spiders, birds, small mammals, larger omnivorous mammals, amphibians, etc.). It is most important to me that students learn how to ask important questions that have broader application than to a single taxonomic group. The advantage of this approach is that the lab as a whole can answer much broader and more comparative questions than would be possible if our focus was more narrowly focused on one taxonomic group.

My approach to answering questions in the field is experimental and observational. I encourage students to develop dissertations that test mechanistic questions with field experiments executed at sufficiently realistic spatial and temporal scales. In addition to experiments, I encourage students to design and carry out more long term (3-4 yr) observational studies that can be used to corroborate results from experiments over longer temporal or larger spatial scales than those feasible for experimentation.

An additional aspect of my research is mathematical and quantitative ecology. I apply theoretical models of population dynamics and species interactions to answer questions about the efficacy of simple population viability models, the effects of introduced species on declining populations of native species and the effects of spatial structure on food web dynamics. I also teach an upper division and graduate level biometry course. Thus, I encourage (not require) my students to incorporate some of these tools into their dissertation such that a model or a novel statistical technique enhances the impact of results obtained in the field.

Finally, on the whole graduate mentors can be hands on or hands off. Both approaches have advantages and disadvantages depending on the student’s experience. My model for mentorship falls somewhere in the middle of this continuum. Ideally I would like to develop a collaborative relationship with my students but still allow the student to develop and publish a number of ideas independently. In practice I try to coauthor one or more papers with each student during the student’s first 2-3 years of graduate tenure at ASU. Some of these papers will be based on my own or my lab’s on-going research. These initial collaborations assure a reasonable publication record for students upon graduation and launch them into several additional chapters/papers pursued and published independently.

John Sabo

Leave a Reply