A Technical Look At Termite Mounts Foretells Changes in Africa's Ecosystems
Photo by sheilaellen via Flickr Creative Commons
Despite their reputation as pests, termites are actually fascinating creatures particularly for their complex social structures. But that isn't the only thing that hast attracted the attention of scientists lately. It seems that by watching where termites decide to build mounds, secrets to the ecological changes of Africa's savanna are revealed. Researchers at the Carnegie Instution's Department of Global Ecology mapped over 40,000 termite mounds across 192 square miles of savanna, and through their imaging and analysis of the mounds, they've found that not only do the mounds reveal how the area has evolved, but they might be able to use them to predict how the ecology will shift in the future. How climate change will impact an ecosystem is difficult, but perhaps a little less so thanks to termites. In Kruger National Park in South Africa, mound-building termites are picky, choosing locations that are the right balance of moisture, drainage and on sloaps above seeplines, areas where, according to PhysOrg, "water has flowed below ground through sandy, porous soil and backs up at areas rich in clay. Typically woody trees prefer the well-drained upslope side where the mounds tend to locate, while grasses dominate the wetter areas down slope."
The termites are great geologists, and watching these insects, in addition to the usual indicators like changes in tree lines and vegetation, gives researchers a new perspective on how climate change is impacting the environment on the savannas.
"By understanding the patterns of the vegetation and termite mounds over different moisture zones, we can project how the landscape might change with climate change," explained co-author Greg Asner at Carnegie. "Warming is expected to increase the variability of future precipitation in African savannas, so some areas will get more, while others get less rain. The predictions are that many regions of the savanna will become drier, which suggests more woody species will encroach on today's grasslands. These changes will depend on complex but predictable hydrological processes along hill slopes, which will correspond to pattern changes in the telltale termite mounds we see today from the air."
And it's from the air that they're studied, specifically with the Carnegie Airborne Observatory (CAO), an airborne mapping system that can scan 40,000 acres per day to create 3D images of structures including vegetation and termite mounds.
Usually mound-building termites get respect for their architectural skills, lending inspiration to architects who incorporate biomimicry into their building plans. But now the choices these little insects make about their homes is getting attention for a much bigger issue.