Building a Lasting Foundation in Ecological Literacy in Undergraduate, Non-majors Courses

Ecological issues permeate our lives, whether or not we are aware of them. The same is true, of course, for other sciences such as physics or chemistry. However, in an age of rapid and global environmental changes, it seems particularly important to cultivate a society of citizens (including both voters and politicians) who are well educated with respect to ecological processes and concepts. Some universities are revising their core curricula to require students to take at least one course within the theme of ecology, the environment, or sustainability, and are developing non-majors courses to meet this need (Rowe 2002). While sometimes viewed as a burden to teach (Klemow 1991a), or not as prestigious as teaching “majors” subjects, undergraduate, non-majors courses in ecology present a special opportunity to arm students who may never otherwise take another science course with ecological concepts to serve them for the rest of their lives. I discuss here key concepts for a foundation in ecological literacy in undergraduate non-majors courses, which of these concepts students deem as important, and strategies for elucidating the linkages between an understanding of ecology and the lives of students.

Many frameworks for ecological literacy have been proposed in the academic literature (Jordan et al. 2009), as well as lists of core ecological concepts that comprise ecological literacy (Klemow 1991b). My own goals as an educator are to equip students with tools and concepts they will take with them in their lives beyond college, whether they are thinking about local issues, such as where to locate a proposed park, or global issues, such as biodiversity loss. Because the field of ecology is broad and interdisciplinary, it is not feasible to cover the whole field in one semester. I advocate focusing on a few divergent topics, and making explicit linkages between these ecological concepts and how they can serve as a framework for interpreting the world from an ecological perspective. These concepts include trade-offs, succession, population dynamics, element cycles, and global ecology.

The notion of trade-offs (i.e., two traits that cannot simultaneously be maximized), underlies the evolutionary and physiological bases of life history strategies, and makes intuitive sense to students: for example, students easily grasp why a single female elephant cannot have 100 baby elephants given their long gestation time. Trade-offs are also inherently obvious in the land-use decisions societies make (Foley et al. 2005). Land uses that provide ecosystem services, such as biodiversity preservation and carbon sequestration, tend to have lower amounts of crop production, and vice versa.

Succession is directional change over time in ecological communities as resources change, and includes both stochastic and deterministic components. This concept challenges the students’ view of ecological communities as basically static, and underscores the role of life history variation and disturbance in community assembly. I discuss this topic by speculating on what would happen to your yard if you stopped mowing it. What would it look like in 5 or 50 years? What types of species would replace others, and why?

The populations of organisms can shrink over time, remain the same, or increase. Exponential and logistic growth, processes that regulate population size and carrying capacity, are essential concepts for discussing both the conservation of threatened species and human population trajectories over time.

Ideas about how energy and matter flow among different compartments in ecosystems, and global biogeochemical cycles, are fundamental to an understanding of how ecological communities function, and also provide a platform for discussing many current environmental issues, including climate change and the effects of nitrogen pollution from agricultural runoff.

Many students are simply unaware of the magnitude and diversity of human modifications to the planet. The list of topics is extensive: biodiversity loss, land-cover change and habitat fragmentation, biotic invasions, ocean acidification, and the effects of increasing green house gas concentrations in the atmosphere.

Although not an exhaustive list, these five concepts are important building blocks in the foundation of ecological literacy.

Even with the best syllabus, there is likely to be a difference between what educators wish students to learn and what students take away from a class. For example, all I recall from the physics course I took in college is something about a feather and a bowling ball being dropped from a great height. To help me identify which ecological concepts students found valuable in the undergraduate non-majors course “Ecology and Society” that I teach, on the final exam in Fall 2009, I asked the students to “Name the two most important concepts you learned in this class.” To determine whether the concepts students valued change over time, five months later I recontacted these same students via email and asked them to answer this question again. The results of this exercise were illuminating (Figure 1). During the final exam, twelve concepts were identified as important, and almost 20% of the students identified “global ecology” as being the most important concept. Five months later, three topics stood out, “elemental cycles,” “evolution,” and (particularly) the “interconnectedness of ecological systems” (the students’ language, not mine) (Figure 1). Interestingly, the “interconnectedness of ecological systems” was not explicitly emphasized as a separate topic in the course. Rather, over time a number of students internalized what they had learned about various topics such as food webs, human impacts, etc., and used these concepts to build a conceptual network of linkages among ecosystems, communities and human societies. Also interesting, I presented only one lecture devoted to evolution. Given that few non-majors will take a course devoted to evolution, the importance students place on this topic, as well as the close relationship between evolution and ecology, it seems important to cover at least basic evolutionary concepts in non-majors ecology courses (Berkowitz et al. 2005).

Given that students face multiple, competing demands for their time, including large course loads, part- or full-time jobs, extracurricular activities, and a variety of media options, what are ways to engage students and ensure that foundational ecological concepts are retained beyond the classroom? Educators have a number of strategies, including case studies and active learning exercises. I have developed several activities that complement lectures, with the goal of making abstract ideas more concrete, reinforcing content, and developing critical thinking skills. Below are three examples.

Population and species densities, and carbon stocks, are important for quantifying and comparing community and ecosystem processes and human impacts, but the range of values given for these are abstract to most students. To make these numbers less abstract, students go outside, break into teams, and then have to estimate how big a hectare is. These guesses are then compared to an actual hectare. Students are then assigned a country and asked to place a number of fellow students into the hectare, in proportion to the average population density of that country. This activity is coupled with a spreadsheet exercise in which students compare FAO (Food and Agriculture Organization of the United Nations) statistics on human population densities, forest cover estimates, and deforestation rates for a number of countries to test hypotheses about these interrelationships.

A classic plot in many B-movies involves animal populations (typically bees, ants, snakes or spiders) that were once regulated by density-dependent or independent processes escaping regulation and growing exponentially, with ensuing havoc. Following a unit on population dynamics, students watch a portion of a B-movie and then break into groups to propose ecological explanations for how this population escaped regulation. A “blue ribbon panel” of graduate students votes on the best explanation.

Ecology can be taught as a series of equations, without a focus on individual organisms and species. However, I believe students — particularly non-majors — benefit from getting to know a particular species and considering its unique life history traits within the context of conservation. I have students pick an animal at random from a bag (Figure 2), and design a conservation plan for that species. The species are taxonomically diverse (Aves, Mammalia, Reptilia, and Amphibia are all represented), represent different biomes (e.g., temperate grasslands, tropical rainforests, savannas, and aquatic habitats), and face different conservation threats (e.g., habitat loss, overhunting, pollution). In the “Speed Dating” part of this activity, students bring their two-page conservation plan, their animal, and then have brief, pair-wise discussions about their findings. After eight rounds, the students are asked to provide written answers to these three questions: 1. what were the similarities in conservation strategies for the different animals you learned about; 2. if conservation plans differ dramatically among different species, what are the most important features of the animals’ ecology and biology that account for these differences; and 3. are there general recommendations you would make for conservation managers trying to protect the greatest biodiversity?

In conclusion, teaching ecology to non-majors presents a unique opportunity to make ecology interesting and relevant, and to connect with students who will have little other science education. Several ecologists have called for a dialog among ecology educators to identify and refine a minimum list of core ecological concepts that underlay a foundation in ecological literacy (Klemow 1991b; Jordan et al. 2009). I echo this call for such a dialog, and also suggest that we open a dialog between educators and students to identify the concepts that students find most interesting and useful in the long-term. In addition, I encourage ecology educators to develop and share creative ideas for exploring ecological concepts in ways that make obvious and lasting connections to the lives of students.

I thank Peter Tiffin and Mark Decker for comments on previous drafts and the students of EEB 3001 for many helpful discussions about the teaching of ecology.