A keystone species is a species which maintains the balance and
diversity of its community. Often keystone species are predators
which check the population of other species that might otherwise
become dominant. Sometimes they are mutualists which perform a
necessary function for a community. Other keystone species are
engineers, changing the habitat in a way that creates food or
shelter for other species. In conservation ecology which is the
idea of studying how an ecosystem works and helping to preserve
that ecosystem as best we can in amongst all the needs and
pressures that we humans put on it. In conservation ecology
there's this big concept called a keystone species and what that
refers to is in an arch at the very top of the arch you'll have
what's called the keystone. That's the one stone that if you
remove it may cause the entire arch to fall. So the idea here is
that there might be in some ecosystems a one species or a couple
of species that plays a major role despite being in very small
numbers beca