Huadong Valley is flanked by the Central Mountain Range to its east and the Coastal Mountain Range to its west. Height differences between the valley and surrounding mountains reach up to 2,000 meters. Combined with abundant water resources, the area hosts a wide variety of organisms and ecosystems, including alpine streams, forests, evergreen hardwood forests, subtropical grassland, tropical grassland, tropical rainforests, shrubbery, rivers, and estuaries.