The Benefits of Termites

Explanation: What good are termites? They chew the wooden foundation and walls of your house and create economic ruin. But ... in the forest, look again.

This week we are highlighting the amazing ecological functions of Cubitermes, a genus of termite found throughout the tropics and consisting of dozens of species. Cubitermes build mounds that house colonies of thousands to a million or more individuals.

This week's photos come from a long trek I took with colleagues into Salonga National Park, the largest tropical park in Africa, in the heart of the Congo River Basin. There, the mounds take on the shape of some impossible gigantic mushroom.

A typical mushroom shape of a Cubitermes mound.

Salonga National Park, Democratic Republic of the Congo.

But the mounds do so much more than provide amazement to travelers.

The termites add to the nutrients and productivity of the thin tropical soils. In one study (Donovan et al. 2001), after 13 days of working tropical soil, Cubitermes termites improved soil quality by raising the soil pH, and increasing organic carbon, as well as balancing other minerals and nutrients.

In the Central African Republic, another study showed that combining Cubitermes mounds into the soil produced a significantly greater yield of maize (Mokossesse et al. 2012).

Cubitermes mounds provide shelter for a variety of other invertebrate and vertebrate species, especially ants and other termite species. In a study conducted in Cameroon, Dejean et al. (1997) dissected 90 mounds and found 354 colonies of ants of 75 species in 31 genera, and that more ant colonies were found within active termite mounds than in abandoned ones. In a similar study, Dejean and Durand (1996) discovered 799 ant colonies of 151 species among 37 genera within Cubitermes mounds, and concluded that the termites provide critical nesting sites for other species.

Look closely at this Cubitermes mound ... it is wrapped around the stem of a tree growing from its core.

It may be that the tree is now benefiting from the increased soil nutrients provided by the termites' activities.

Many termite mounds provide such "nurse" functions to plants of the rainforest.

One study mapped the complex 3-D architecture of Cubitermes mounds by using X-ray tomography. They found that the termites rearrange the tunnels over time, probably as an anti-predator strategy but also to balance the tunnel network with efficiency of traversing the system for themselves (Perna et al. 2008).

There is so much more to these termites than first meet the eye!

This Cubitermes mound has been built along the trunk of a large tropical tree, which may serve to strengthen its architecture.
Note the mound of leaves and other forest "litter" at the base of the mound, which likely resulted from actions of secondary species inhabiting the mound or otherwise using its structure.



Information:
     Dejean, A., B. Bolton, and J.L. Durand. 1997. Cubitermes subarquatus termitaries as shelters for soil fauna in African rainforests. Journal of Natural History 31:1289-1302.
     Dejean, A., and J.L. Durand. 1996. Ants inhabiting Cubitermes termitaries in African rain forests. Biotropica 28(4b):701-713.
     Donovan, S.E., P. Eggleton, W.E. Dubbin, M. Batchelder, and L. Dibog. 2001. The effect of a soil-feeding termite, Cubitermes fungifaber (Isoptera: Termitidae) on soil properties: termites may be an important source of soil microhabitat heterogeneity in tropical forests. Pedobiologia 45(1):1-11.
     Mokossesse, J.A., G. Josens, J. Mboukoulida, and J.F. Ledent. 2012. Effect and field application of Cubitermes (Isoptera, Termitidae) mound soil on growth and yield of maize in Central African Republic. Agronomie Africaine 24(3):241-252.
     Perna, A., C. Jost, E. Couturier, S. Valverde, S. Douady, and G. Theraulaz. 2008. The structure of gallery networks in the nests of termite Cubitermes spp. revealed by X-ray tomography. Naturwissenschaften 95(9):877-884.

EPOW - Ecology Picture of the Week