Just as fossilized footprints, burrows, and coprolites represent trace fossils or organisms, paleosols can be considered trace fossils of an ancient ecosystem. Much like the small percentage of species that are fossilized, very few species within an ecosystem leave any discernible trace in paleosols. However, their more general effects within a paleosol may be preserved. A good example of this is root traces. Analyzing the pattern of root traces, the sequence of soil horizons, and other features can help identify the type of vegetation that was present during the formation of the soil. General features such as stature and spacing determine what botanists call a 'plant formation.' Distinct from a community or association, plant formation is not defined by any particular species. Examples of plant formation include forests, woodlands, and grasslands. Because it may not be possible to determine whether a particular plant was an oak, eucalyptus, or other species, plant formations in paleosols make it possible to identify an ancient woodland ecosystem from an ancient grassland ecosystem. (Retallack 2001)