LB 18-164 - Using geospatial data in a woody encroachment case-study for undergraduate ecology students

Case studies have been historically underutilized in teaching undergraduate science despite their known effectiveness in promoting student engagement and developing critical thinking skills. Here, we designed a case study aimed at improving rangeland literacy and teaching mechanisms of land cover change in herbaceous systems. We specifically developed a multi-lecture activity based on data from an actual example of woody encroachment occurring within a private ranch in Central Texas, USA. Our student learning objectives were to (1) assess changes in rangeland vegetation associated with different management approaches using geospatial data, (2) graphically present changes in biomass and land cover data over time, and (3) discuss impacts of woody encroachment on rangeland structure, functioning, and ecosystem services. The case study was implemented in one section of an undergraduate plant ecology course during the Spring 2023 semester at St. Edward’s University in Austin, TX. Students used the Rangeland Analysis Platform (RAP), an open-source web application used to analyze rangeland vegetation data from satellite imagery, to evaluate differences in biomass and woody / herbaceous cover within a Central Texas ranch with areas of varying fire history. Students then created graphs to interpret their spatial data and develop hypotheses regarding the effects of fire frequency on woody encroachment in rangelands. Additional learning activities were implemented before and after the geospatial investigation to introduce students to rangelands and to discuss the ecological impacts of woody encroachment in herbaceous systems. Finally, students completed a survey before and after participating in the case study that evaluated their understanding of rangelands, woody encroachment, and rangeland management techniques (e.g., fire, grazing). For each survey question, student understanding was measured on a scale from 1 to 5, where 1 was “strongly disagree” and 5 was “strongly agree.” We found that student understanding of woody encroachment in rangelands increased after engagement in this activity. Students particularly scored higher on questions regarding rangeland characteristics and the role of fire in maintaining rangelands. For example, in response to the statement, “I have a clear understanding what a rangeland is,” students scored an average of 2.5 pre-activity and 4.7 post-activity. In response to another question about how fire impacts the abundance of woody plants in rangelands, students scored an average of 4.6 pre-activity and 5.0 post-activity. These results show that case studies in which students analyze real data are an effective evidence-based approach to achieve student learning about ecological processes.