The Department of Environment and Natural Resources (DENR) submitted Mount Apo on December 12, 2009 for inclusion in the UNESCO world heritage list. The mountain is considered by DENR as the center of endemism in Mindanao. It has one of the highest land-based biological diversity in terms of flora and fauna per unit area. It has three distinct forest formations, from lowland tropical rainforest, to mid-mountain forests, and finally to high mountain forests.