[img_inline align=”right” src=”http://padnws01.mcmaster.ca/images/dudleyplants.jpg” caption=”A growing body of work suggests plants recognize and respond to the presence and identity of their neighbours. A team from McMaster suggests plants can benefit from both altruism and biodiversity but when these processes occur at the same time, it is difficult to predict the outcome. “]Plants are capable of complex social behaviours and may exhibit altruism towards
family members – but also aggressively compete with strangers.

A growing body of work suggests plants recognize and respond to the presence and
identity of their neighbours. But can plants cooperate with their relatives?

While some studies have shown that siblings perform best-suggesting altruism towards
relatives-other studies have shown that when less related plants grow together the
group can actually outperform siblings. This implies the group benefits from its
diversity by dividing precious resources effectively and competing less.

A team from McMaster suggests plants can benefit from both altruism and biodiversity
but when these processes occur at the same time, it is difficult to predict the outcome.

“The greatest challenge for understanding plant social interactions is we can't interpret
plant behaviours as easily as we do those of animals,” said Susan Dudley, an associate
professor in the Department of Biology. “Though we have shown plants change traits in
the presence of relatives, we need to determine if this is cooperation. Linking the plant
behaviours with their benefits is challenging when multiple processes co-occur.”

Dudley and a team of researchers disentangle the sometimes contradictory research in
the latest edition of the Proceedings of the Royal Society B, describing how the identity
and presence of neighbours affect many processes acting on plant populations.

The problem, she said, is that plant social interactions are treated as a black box, with
researchers only looking at the output, or the fitness of the plant, in sibling
competition. But they need to investigate the mechanisms inside the box-by describing
how traits of individuals affect fitness-to understand how the output is reached and
which mechanisms are occurring to get there.

“Simply put, social environment matters to plants. If we first acknowledge that kin
cooperation and resource partitioning are co-occurring, we can begin to address some
very important questions,” says Amanda File, a graduate student in the Department of
Biology.

“Among these questions is whether there is a link between kin recognition and plant
performance, whether plant kin recognition can improve crop yield and how kin
recognition shapes communities and ecosystems,” said Guillermo Murphy, a graduate
student in the Department of Biology.