A growing body of research supports the idea that plants provide a helping hand (so to speak) to other plants. The research is summarized in an article in the January online issue of Science magazine.
I was introduced to the idea that plants cooperate with each other by the excellent book The Hidden Life of Trees by Peter Wohlleben. Wohlleben describes a sort of arboreal social security system utilizing underground fungal networks, through which trees redistribute resources and provide for mutual defense.
Where Wohlleben portrays trees of the same species as having a communal life, the research described in the Science article focuses on how closely related herbaceous plants provide mutual assistance. But both portray plants as more aware and active than previously thought in terms of how they relate to each other and their environment.
For example, annual sunflowers (Helianthus annuus) space their leaves so as not to shade nearby relatives. Drawing from this insight, researchers found that they could plant sunflowers that are close kin much more densely than is normal in commercial agriculture. These dense plantings produced 47% more oil from the resulting seeds.
Other research has found that plants will restrain their root growth in order to make space for their close relatives, and that they may stimulate their kin to launch a stronger chemical defense against herbivores.
One question not answered in the article is what constitutes “close kin” within the context of a plant species.
In any case, I like this line of research because it makes plants appear to be more engaged with the world, more mysterious, and more interesting. It also provides a portrait of the natural world in which cooperation and mutual aid provide a counterweight to the struggle of all against all. Anyhow, read the article and see what you think.