-
A keystone species is a species
that has a disproportionately
-
strong effect on the health and
functioning of its ecosystem.
-
Identifying and studying keystone species
-
can be useful in studying and
preserving the health of an ecosystem
-
Here's two examples of keystone species.
-
Reintroducing wolves
in the greater Yellowstone ecosystem
-
had cascading positive effects
-
on plant populations, on soil health,
-
in all the processes
that depend on both.
-
And restoring sea otters
along the Pacific Coast of North America
-
depressed populations of marine
herbivores and predators,
-
which allowed other species to recover.
-
Keystone species are
not just limited to charismatic mammals.
-
Effectively any organism
in an ecosystem could be keystone.
-
The critical characteristic
of a keystone species
-
is that a large portion of the flow of
energy and sources through an ecosystem
-
depends on that species.
-
This can occur when the species
consumes resources itself,
-
or promotes or inhibits the
consumption of resources by others.
-
Consider the north american
coastal redwood
-
Not only does this tree
provide raw sources of carbon
-
for other organisms to consume
-
it also alters the local climate.
-
Increasing moisture,
building organic rich soils
-
and providing a complex substrate
-
for other organisms to live in
-
from bryophytes to birds to insects to
microorganisms.
-
In effect, redwoods create
ecosystems within ecosystems
-
That's how highly connected they are
within the network of
-
all biological interactions
along the Pacific Coast
-
These species and many others
were discovered by accident
-
by misguided human actions
leading to their removal.
-
Resulting in negative downstream
consequences due to their absence.
-
But it doesn't have to be that way.
-
Tools from Network Science now allow us to
identify keystone species
-
using information about the interactions
that connect members of an ecosystem.
-
Such as when on spices feeds on another
or relies on another for its survival.
-
Using this network approach we don't have
to wait for the accidents to realize
-
what drives the ecosystem health.
-
Understanding keystone species
can help us explore ways
-
to restore biodiversity that sustains us.
-
And here, at the Santa Fe Institute
we'd like to apply concepts
-
across disciplinary boundaries so we can
use the idea of keystone species to
-
understand how innovations revolutionized
economy or how life itself began on earth.