ENGAGING INTRODUCTORY GEOSCIENCE STUDENTS IN RESEARCH WITH AN ACTIVITY EXAMINING STOMATAL CELLS IN FOSSIL LEAVES

Classroom activities relating to leaf stomatal cell research are valuable curriculum components for introductory geology, climate science, or environmental science courses. Gingko leaves have stomatal cells, which are used to exchange gasses with the environment and they are common in the fossil record. The ratio of stomatal cells to other cells in fossil leaves provides important details about climate variations in Earth’s past. Researchers at the Smithsonian Institute‘s Natural History Environmental Research Center are examining the stomatal cells on living and fossil gingko trees to try and understand the relationship between stomatal cells and carbon dioxide concentration in the atmosphere so that climate during the Cenozoic can be better understood. Fossil Atmospheres is an online community engagement component of their research, and it is an excellent resource for educators who are incorporating leaf stomatal cell research into the classroom.

Using best practices for community based learning curriculum design I developed an activity suitable for online and face-to-face courses in earth science using the Fossil Atmospheres online platform. The activity consists of three parts: a preparatory discussion, observation and data collection, and a reflection. The preparatory discussion requires students to familiarize themselves with stomatal cells and their value in studying paleoclimates, and to participate in an in-class discussion. The observation and data collection component involves first learning how to identify stomatal cells in scanning electron microscope images of modern and fossil gingko leaves on the Fossil Atmospheres online platform and then continuing to look at samples and record observations. The final component of the activity allows students to reflect on their contribution to the earth science community through their participation in the fossil stomatal cell research project.