Despite their minute body size, termites provide a vital role in maintaining ecosystem health in Australia’s tropical north.
Termite mounds are a prominent feature of north Australian landscapes - the building of which relevant to their size, is equivalent to humans erecting a skyscraper twice the size of the Empire State building in the USA.
Their tiny size however, belies not only their construction skills but their enormously vital role in maintaining ecosystem health.
Through their feeding and burrowing they maintain soil health and ecosystem services.
Helping soils store water
The tropical savannas of northern Australia are subject to highly seasonal rainfall, and often suffer dry periods of up to eight months.
When termites are removed from an area, the soil’s ability to store water is decreased by up to 30 per cent.
The survival of plants during the dry season depends on soils retaining the maximum amount of what little rainfall there is.
Termites help this process by creating macropores in the soil, which allow rainwater to infiltrate deep under the surface.
Research by CSIRO scientists, in collaboration with the Tropical Savannas Cooperative Research Centre (CRC), shows that when termites are removed from an area, the soil’s ability to store water is decreased by up to 30 per cent.
Redistributing nutrients in the landscape
Research has shown that the presence of termites doubles the rate of decomposition of plant material in an area.
Nutrients from these materials are re-distributed into the ecosystem when:
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termites are consumed by predators (other insects, spiders, frogs, reptiles, birds and small mammals)
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termite mounds erode due to wind and rain, leaving patches of highly fertile soil.
Promoting biodiversity
Termites, capable of feeding on dead plant material and protected by their cool moist mounds, are active all year round.
Most other insects, only feeding on fresh plant growth following rains, are dormant during the long dry season. Thus termites, by providing a constantly available food source during the lean dry periods, support a diversity of predatory species.
Hollow termite mounds provide good habitat and protection for insects, birds, reptiles and small mammals from the frequent grass fires that are an integral element of northern savanna landscapes.
Restoring landscapes
By improving the nutrient content of the soils - which boosts plant growth - termites may be providing the first step in restoring an ecosystem.
During recent trials, it was found that termites are particularly resilient, as they were often the only macroinvertebrates left in a damaged ecosystem following cattle grazing.
CSIRO scientists are now further investigating the relationship between termites, and other invertebrates, and soil health. They are particularly looking at the potential of termites to restore degraded cattle country.
Find out more about our work in Biodiversity & Ecology.