As gardeners and landscapers, we deal extensively with plants. Yet for many, our real understanding of the life of plants only scratches the surface. Would you, for example, believe that trees “talk” to each other, help each other out when a tree is ill or hurt, warn other trees of impending danger, and support their young?
Part of why we are not aware of the communications and connections between trees is that trees live in a very long time frame and even their electrical and chemical communications are slow compared to smaller, shorter-lived organisms. If trees are living within a supportive forest environment, they can live hundreds of years. There is a spruce in Sweden, for example, that is over 9,500 years old.
The key element is that trees survive well in an intact, healthy forest. They create a microclimate that provides protection from wind and weather (such as drying heat). They warn each other of danger, such as predators like porcupines or insects. They share food with ailing member trees. There is a structure to the forest that helps all the individuals within. Trees that ordinarily live this way do not do well when planted alone. Lone trees live much shorter lives.
The Hidden Life of Trees explains in detail accessible even to lay persons how trees communicate. They use tree equivalents of our senses. They send and receive chemicals through the air and through their roots, they use electrical impulses and vibrations in their roots, and they use visual signals such as flowers to attract pollinators and leaves turning color to signal the cessation of photosynthesis which insects appear to understand. They use a complex system of underground fungi to share nutrients and communicate between trees. Trees can even distinguish the roots of their own species from other tree species. It also seems possible that all beings in the forest are communicating as a community.
Planted tree farms do not exhibit these amazing abilities to communicate and support member trees. It is thought that their roots are too damaged from planting to be able to share information, selective breeding may damage their ability to communicate, and they often have no fungal network so these forests are silent compared to intact forests. Tree farm members live like loners—they do not live long lives and they do not support each other.
There are some species of trees such as birch and aspen that have evolved to live as loners. They live shorter lives than forest species and they use different methods of defense and growth because they do not have the forest community to feed and warn them.
There is much more fascinating information about the lives of trees in this little book. There is so much there that I plan to carefully read the book again to catch what I missed the first time through. Also, there is so much new research being done to expand our knowledge of tree communication that I look forward to a follow-up book at some point to increase our understanding even further in this area. We can only become better gardeners as we gain greater understanding of all plants and their “hidden” lives.
Book Review by: Ann Guthals