The colors in the image above represent the amount of plant life on the ground in April 2013 and April 1984 in the church forest region of Northern Ethiopia. Church forest locations are highlighted with circles on the images above. The green-colored areas had more abundant green trees, shrubs, grasses, and crops at the time the image was taken than areas that are shown as yellow or orange. These images were created with NASA Landsat satellite imagery acquired in 2013 and 1984. These images were used to create an index called a Normalized Difference Vegetation Index (NDVI). An index value of 1.0 represents the highest concentration of green vegetation and an index value of 0.0 is an area with no living vegetation. By the 1980's the forests of Norther Ethiopia had already been reduced to less than 10% of the trees that once covered the region. Today, approximately 2% remain. The church forests are important protectors of these remnants of biodiversity.