MathBench > Environmental Science

The Case of the Missing Mountaintop


Biodiversity Hotspots

The Appalachian region is special because of its high biodiversity -- which simply means that it has a wide variety of animals, plants, and other organisms. Areas like this are called "biodiversity hotspots", not because they have hot weather (although they often do), but because evolution seems to have run riot in these spots, creating and maintaining many rare or unique species in a small area.

Islands are often hotspots, because species can evolve there separately from the mainland. Mountain ranges are often hotspots as well, because the mountainous terrain tends to discourage migration. In the map below, the warmer colors indicate hotspots -- primarily the Appalachian Mountains to the East and the Sierra Nevada Mountains to the west. In the middle -- well, its a big open grassland, wonderful for many things, but not so good at coming up with rare species.



But why does biodiversity even matter? So long as there are a lot of plants and animals, why should we care how many species they fall into???

You need to think in terms of species as filling different niches in an ecosystem -- sort of like different professions fill a lot of different niches in an economy. An economy with many kinds of jobs has a lot of flexibility and stability, and a lot gets done. An economy with only a few types of jobs (for example, only fast food workers and computer repair people) would not accomplish much, and would be much more vulnerable to change.

In the same way, areas with high biodiversity are thought to have higher stability and flexibility. More of the energy in ecosystem can be used. More of the waste in the ecosystem gets processed. More ecosystem services -- everything from water purification to soil stabilization -- happen.

white spotted slimy salamanderThe biodiversity found in the streams of this corner of hellbender salamanderthe world is rivaled only by the tropics.  For example, the highest percentage of endemic salamanders in the world is found in Appalachia ("endemic" means that these salamanders are only found in ONE location in the entire world). These are unique species that have evolved in the Appalachian environment. In fact, up to 50% of the salamanders in the Appalachian mountains are found nowhere else in the world -- they are so famous, they even have their own facebook page.

What are commonalities amongst the places with high biodiversity?
Why do you think the great plains have lower levels of biodiversity?
What is the reason Florida has so much biodiversity?
Why does Hawaii have such high diversity?