Symbiotic relationship between trees and ants

We still know there is a rule for unintended consequences - if we leave our bodyguards when the danger has passed, then there will be another threat that will bother us. . A new study has demonstrated that this rule is also true for acacia trees in Africa.

Over thousands of years, this thorny shrub has become a source of food and shelter for aggressive ants to protect trees from animals that want to eat acacia leaves. This is a symbiotic relationship that benefits both acacia and ants.

Scientists while conducting research on the decline in the number of large animals in Africa wondered what would happen if these animals did not eat acacia leaves. That's why they fenced some acacia trees to prevent elephants, giraffes and other animals from approaching.

Ants are taking care of acacia trees.(Photo: AP)

Surprisingly, after a few years the fenced trees looked sick and grew slower than their unconnected relatives. It turns out that when there are no animals eating leaves disturbed, acacia does not bother to pay attention to ants. They secrete less nectar and grow less protruding spines for ants to shelter. As a result, the bodyguards will destroy the trees replaced by other insects that perforate the bark.

Todd Palmer, assistant professor of zoology at the University of Florida, said: 'Although symbiotic relationships between trees and ants seem to evolve over a very long period of time. But they are also very far apart. '

Palmer is currently in Kenya explaining in an email interview: 'In 10 years' time, we found that when mammals are no longer able to eat leaves, ants are also less used. Since then the tree began to 'pay' in the form of nectar for less.

He said: 'If you asked me 10 years ago what would happen if I separated large mammals out of the system, I would answer,' I'm sure the tree won't be happy. ''.

In fact it is the leaf-eating animal that is the driving force behind the tree that benefits ants . When this ' payback ' was reduced, the ants' guards began to starve, causing its nest to shrink.

Some ant colonies reduce their defenses and start taking care of the nests that live on trees and bile. Or they will be replaced by another ant colony that feeds somewhere that can live with perforated beetles that can be used as a nest.

Palmer said: 'For me it's a lesson learned from research. The decrease in the number of large herbivores under human impact can cause unforeseen consequences for their habitats. '

Ted R. Schulz, an entomologist at the Smithsonian Institution's National History Museum, said that lack of herbivores, plants encounter a worse situation.'This is amazing, beyond all we can predict.' Although not a member of Palmer's research team, Schultz also gave an opinion about the symbiotic relationship which is quite complex but well balanced.

He said: 'This system balances the number of participants: trees, herbivores, key ant colonies and three other ant colonies that are always in dispute to gain space on the tree. When separating a component from the system - for example, herbivores - other components change their position in a way that we are almost unpredictable. '

So can the tree recover its bodyguard ants if the animals eat grass again? Palmer seeks answers by re-exposing plants to herbivores ' to see how they will re-establish relationships with symbiotic ants; vice versa whether this reunion is just enough, and right or too early or too late. '

The research was funded by the US National Science Foundation, the Smithsonian Institution, the National Geographic Society and the African Elephant Species Program.