Although various theories have been proposed to explain their formation, none had conclusively addressed their origin until recently. In breakthrough study published in the journal Nature in 2022, a team of international scientists led by researchers from Germany's Max Planck Institute for Chemical Ecology may have found the missing link.
According to their findings, fairy circles are the result of interactions between grasses, sand termites (Psammotermes allocerus), and water availability in the desert. They propose a two-step mechanism known as the self-organizing Turing pattern.
1.Termite Behavior:
Sand termites, abundant in the Namib Desert, use their saliva and fecal material to build underground nests and connect them with foraging tunnels. These nest and tunnel structures promote water uptake and redistribution in the soil, creating patches with higher moisture content.
2. Grass Response:
The increased water availability in these termite-modified patches allows grasses to thrive, forming circular patches of vegetation. The grasses outcompete other plants for resources( sunlight and water), creating the characteristic "fairy circles."
Key Factors:
Competition for Water and nutrients: The high density of grasses within fairy circles indicates intense competition for the moisture provided by the termite activity and the limited nutrients in the desert soils.
Feedback Loop: The dense grass cover promotes further termite activity due to increased moisture and food availability.
Overall, the study proposes that the combination of localized water sources, termite activity, and grass response results in the formation of self-organizing patterns, leading to the emergence of fairy circles. This breakthrough is significant in enhancing our understanding of these mysterious desert phenomenon and highlights the intricate connections between different organism in the ecosystem.
