This classroom activity is aimed at an understanding of different ecosystems by understanding the influence of temperature and precipitation. Students correlate graphs of vegetation vigor with those of temperature and precipitation data for four diverse ecosystems, ranging from near-equatorial to polar, and spanning both hemispheres to determine which climatic factor is limiting growth.

This visualization, from the US Geological Survey, provides a simple schematic of the various pathways that water can take as it cycles through ocean, lakes, atmosphere, surface and ground.