In the afternoon heat, Minenhle Ngcobo stares into the ventilation shaft of 2-meter-tall termite mound.
Termites, sometimes called ‘white ants,’ aren’t actually ants at all, but rather an insect group consisting of just under 3,000 species of eusocial cockroaches. Found around the world, only a small number of their species actually cause damage to human dwellings.
They are so numerous that they may make up almost 10% of animal biomass and over 1,000 species are found on the African continent alone, some of which construct massive mounds through intricate teamwork.
“Like most social insects, they obviously divide the work amongst themselves, which makes for pretty efficient functioning of the mound. So, there's workers, there's the Queen, and then there's the soldiers, which are important for defense,” said Minenhle Ngcobo, a master’s student at Wits University in South Africa. Her research explores how termites influence soil health and greenhouse gas dynamics in savannas.
“So, termites often go unnoticed, but once you've seen a picture of one, you start to see them everywhere,” she said.
Though individuals are quite small, in great numbers they are unmistakable and their mounds can stretch to over 12 meters (almost 40 feet) in height.
In fact, some super colonies occupy areas of land larger than most cities, consisting of potentially millions of mounds that can remain intact for thousands of years. So, their ecological role is nearly impossible to understate, especially when it comes to soil health.
“The process of building the mound is what actually benefits the soil the most, because they bring up rich nutrients from deep below ground in the soil and raise it to the top. That process is the turning over of the soil is known as bioturbation, which is important for the soil,” said Ngcobo.
This process results in nutrient hotspots and localized increases in soil moisture which greatly benefit plant growth. Plants growing in or around termite mounds are generally greener than those further away and this also attracts herbivorous mammals. But in a warming world some species of termites may be more susceptible to change than others.
“If the soil were to shift to some degree, we would think that the Macrotermes natalensis mounds would be more resistant to disturbance versus the other species, the black mound termites,” Ngcobo said.
This matters because shifts in climate may impact shifts in termite species, which could have much wider impacts than predicted. Especially because termite mounds influence greenhouse gases and soil microbiomes. But how exactly they do so and what global impacts they may have is an area of ongoing study.
