22 Sep 2008
05:27 pm IST

Every ecosystem has a guardian, an angel, precisely speaking a Keystone Species protecting it, perhaps unbeknonwst to you.

If the sea starfish is removed from the ecosystem, the mussel population explodes uncontrollably, driving out most other species, while the urchin population annihilates coral reefs. Sea otters in kelp forests keep sea urchins in check. Kelp roots are merely anchors, and not the vast nutrient gathering networks of land plants. Thus the urchins only need to eat the roots of the kelp, a tiny fraction of the plant's biomass, to remove it from the ecosystem.

In North America, the grizzly bear is a keystone species, as ecosystem engineers. They transfer nutrients from the oceanic ecosystem to the forest ecosystem. Another ecosystem engineering keystone species is the beaver, which transforms its territory from a stream to a pond or swamp.

In the African savanna, the larger herbivores, especially the elephants, shape their environment. The elephants destroy trees, making room for the grass species. Without these animals, much of the savanna would turn into woodland.

An entire population of giant Kangaroo Rats is a Keystone species in Central Californian Ecosystem. These rats, names as 'nature's lawsmower' due to its eating habits, are endangered.

“The giant kangaroo rat is the ecosystem engineer of the Carrizo Plain, clipping the grass, creating the burrows and enriching the soil that provides the conditions necessary to support a full suite of endangered species,” says Scott Butterfield, a Nature Conservancy ecologist.

Recently scientists have started monitoring these giant rats closely using remote sensing satellite. The study could additionally yield important information on the impact of climate change on the environment in general.

Giant Kangaroo Rats as Ecosystem's Engineers - Can you imagine that?!

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Be the change,
Krish Murali Eswar
"A small body of determined spirits fired by an unquenchable faith in their mission can alter the course of history. Gandhiji."