Little Things Have Tremendous Influence in the Functioning Of Ecosystem – A Lesson from the African Savannah

The latest issue of the journal PLoS Biology has a paper titled “Spatial Pattern Enhances Ecosystem Functioning in an African Savanna” authored by Robert M. Pringle, Daniel F. Doak, Alison K. Brody,  Rudy Jocqué and Todd M. Palmer. I read it with great fascination. It showed in clear cut terms how small things play a great role in ecology.

When we think of the savannah ecosystem lions, elephants, and giraffes pop up in our mind. But it seems the lowly termite has a mega role in the ecosystem. They contribute mightily to grassland productivity in central Kenya via a network of uniformly distributed colonies. Termite mounds enhance plant and animal productivity at the local level, while their even distribution over a larger area maximizes this productivity.The termites have tremendous influence and are central to the functioning of this ecosystem.

Dr Pringle and his associates began to quantify ecological productivity relative to mound density. They found that each mound supported dense aggregations of flora and fauna. Plants grew more rapidly near the mounds, and animal populations and reproductive rates fell sharply with greater distance.

Satellite imagery of the mound was even more spectacular. The mounds stood at the center of a burst of floral productivity. The highly regular spatial pattern of fertile mounds generated by termites actually increases overall levels of ecosystem production.

Dr Pringle believes that the termites import coarse particles into the otherwise fine soil in near their mounds. These coarser particles promote water infiltration of the soil. They also discourage disruptive shrinking and swelling of topsoil in response to precipitation or drought. Nutrients such as phosphorus and nitrogen were high in the mounds.

The new findings have important implications for conservation