In addition to grazing livestock, termites, elephants, and poultry are capable of reducing the chances of a forest fire through their feeding, their tracks, or by building their nests.
One strategy used to reduce the risk of forest fires is the use of animals, such as rhinos or cattle from cows or goats, which, when grazing, reduce the litter that functions as fuel in fires.
Now, a research team from the Australian National University has gone further, analyzing how birds, elephants, termites and other insects can also act as 'ecosystem engineers' through their footprints or nests. The results are published in the journalTrends in Ecology & Evolution.
For Claire Foster, a researcher at the Australian university and lead author of the study, one of the most surprising cases is that of savanna ecosystems with termites.
“In savanna grasslands, termite mounds can be like islands of nutrients - termites concentrate nutrients around their mounds. This makes the grass near these more nutritious and attracts grazing animals, making them less likely to burn and creating a buffer zone during moderately severe wildfires.", Explain.
Other species studied change the arrangement of plants or plant materials within their habitat, such as poultry that collect dead leaves to incubate their eggs and thus help to avoid flammable dry material.
In the case of elephants, they are able to form wide corridors between the foliage with their footsteps. "Gaps in fuel can be really important for the spread of fire and animal tracks can act as small firebreaks", Add.
In addition, Foster highlights the role of insects. "Some of the animals that we do not necessarily think about are insects that, by feeding on leaves, stimulate the production of defensive chemicals in plants and reduce the flammability of their leaves.", He says.
How ecosystems vary
However, the researcher points out that depending on the type of ecosystem, the behavior of animals can also increase the chances of a fire. This is the case of grazing animals, which are more effective in herbaceous habitats such as the savannah while in others, such as alpine areas, they can promote the growth of more flammable plants.
“When used strategically, and in the right ecosystems, mammals like goats and cattle can have strong fire suppressing effects, but there have also been many examples where they actually do the opposite and increase the risk of serious fires.”, He clarifies.
In this sense, Foster notes that it is also important to consider the long-term effects. "We have found examples where long-term livestock activity increased the risk of tree canopy fires in some forests”, Says the expert.
These animals eat young deciduous trees but not conifers, "which causes the forest to have a higher density of these species and increase the chances that a fire in the ground will spread towards the crowns”.
Regarding the fires in Australia, the biologist warns that the consequences of the decreases in populations of mammals such as bettongs and bandicoots and birds such as the Australian pheasant should not be ignored, since they reduce the amount of bush fuel in forests.
In Australia, litter fuel contributes to fire spread and flame height, especially when the fire is small and burns in mild to moderate weather conditions. "Thus, the conservation and restoration of populations of these animals could have two benefits: the conservation of the species themselves and the maintenance of the forests and forest lands in which they live”, He clarifies.
For Foster there is “huge unexplored potential”In this type of fire prevention strategy, although its consequences should always be studied. "In some cases, there are very clear synergies between animal conservation and fuel management. Where they exist, why not use them?”.
Claire N. Foster, Sam C. Bankset al. "Animals as Agents in Fire Regimes".Trends in Ecology & Evolution (March 5, 2020). https://doi.org/10.1016/j.tree.2020.01.002