From Local to Global: A Birds-Eye View of Changing Landscapes

Abstract

[ILLUSTRATION OMITTED] Biodiversity lessons in middle and high school science classes commonly focus either on sampling and analyzing an aspect of local ecological communities or on learning about an international issue such as rainforest destruction or coral reef degradation. Drawing connections between these geographical extremes is challenging, especially for students who have never traveled far from home. A common thread underlying local and international changes in biodiversity is landscape alteration, both human-induced and those triggered by natural events such as landslides and volcanic eruptions. As part of a curriculum development project entitled Crossing Boundaries (http://crossingboundariesproject.org), we designed an inquiry-based activity that introduces students to landscape change and potential impacts on associated biological communities. Using pairs of current and historical satellite images (Figure 1), students explore landscape change in a variety of U.S. and international settings. Rather than engaging in a quantitative study of biodiversity, this exercise frames student thinking about a variety of landscape change agents and their potential effects on associated plant and animal communities. Students use Google Earth, a free software program, to from one location to the next on a virtual globe, exploring change over the past couple of decades at a variety of sites (Table i). [FIGURE 1 OMITTED] Google Earth is becoming popular for classroom presentations and independent student explorations. The ability to fly in Google Earth's simulated three-dimensional environment to any location on Earth can open the door to global investigations. The activity described here uses 20 pairs of high-resolution historical and current satellite images that depict landscape changes in a variety of locations and biomes around the world These images were selected from a larger collection compiled by the United Nations Environmental Program and published in print (UNEP, 2003), on the Web (http://na.unep.net/digital_atlas2/google.php), and within Google Earth's Global Awareness layer (click on the UNEP link in Google Earth). Each of these sources provides and pairs of images, accompanied with an explanation of the causes and impacts of the various examples of landscape change. Rather than providing these explanations, we created an inquiry-based activity in which students build their own interpretations through analysis of the paired imagery. Using Google Earth, students navigate from site to site. At each site, they use Google Earth's transparency function to switch back and forth between the and satellite images. Through analysis of these images, students observe both human and natural causes of environmental change and infer how such changes might affect the plant and animal communities at each site. Although Google Earth provides historical imagery at an almost endless number of sites around the world, the United Nations' paired imagery is particularly for this exercise because it was selected to represent a variety of causes of landscape change. After pilot-testing this activity during a weeklong professional development institute focusing on biodiversity, 21 New York State middle and high school biology and environmental science teachers completed an anonymous Web-based evaluation. Sixteen teachers (76%) rated the activity very useful and the remaining five (24%) rated it useful. Discussion among these teachers indicated excitement about using the activity in a variety of ways--as an introduction before conducting local field-based biodiversity studies, as a wrap-up after conducting such studies, and especially as a way to build conceptual links between local studies and biodiversity issues on a global scale (Appendix: Teacher Perspective 1). This activity addresses both content and process standards. …