Temperate forest ecosystems are most extensively found throughout the Northern Hemisphere, and less extensively in the Southern Hemisphere. The specific regions containing temperate forests include Europe, North America, Asia, South America, Australia, and New Zealand. Northern temperate forests are often composed of deciduous trees that drop their leaves each year, providing a supply of rich nutrients to animals and plants as they decompose. Southern temperate forests, on the other hand, are primarily composed of broad leaved evergreen trees that keep their leaves year round. Most temperate forest ecosystems are heavily exploited and degraded. The underlying bedrock and geology of temperate forests around the world are highly variable, as are the soils, vegetation communities, disturbances, and plant adaptations found within them.