Presentation by Laurel Hartley, associate professor, Department of Integrative Biology, University of Colorado (Denver).

Understanding ecological systems and being able to reason about ecological disturbance is important for informed citizenship. This presentation will discuss several related research projects that explore student recognition of biodiversity and student reasoning about ecological systems and disturbance. Our work shows that, as students develop increasingly sophisticated understandings of ecological systems they 1) develop a recognition of the hierarchical structure of ecological systems, 2) reduce their reliance on inappropriate analogies, 3) move from describing biodiversity through the lens of essentialism to describing both central tendency and variability and 4) move from describing ecological communities as static to describing them as dynamic. An anlysis of ecological literacy of grades 6-12 students in five states indicates that only a small fraction of students are able to reason to the highest standards in our three level learning progression. Finally, our work shows that reasoning about ecological systems is correlated with familiarity with biodiversity. This research has implications for the teaching of ecology at the K-16 levels.