Paleontologists have looked at the environmental changes that occurred in North and South America after large megafauna went extinct over the past 15,000 years, and found long-lasting impacts...............Recent studies point to the loss of mammoths, native horses and other large animals in Alaska and the Yukon as the reason a productive mix of forest and grassland turned into unproductive tundra that dominates the region today............."If we lose some of these big-bodied animals that are threatened with extinction today, we lose a lot more than those animals, we lose the entire ecosystems of which they are part"........... "We are moving into new territory in terms of what the planet will look like".

http://feedproxy.google.com/~r/sciencedaily/plants_animals/~3/Hwl--vKoNIE/151026171759.htm?utm_source=feedburner&utm_medium=email

Loss of large land mammals could change landscapes forever

Extinction of megafauna in Americas upset plants and animals for thousands of years