"My life now is just trees."

So says Judi Dench in a new BBC documentary. In Judi Dench: My Passion For Trees, the veteran actress reveals that she has been planting trees in her garden for decades, naming each one after a deceased friend.

Her love for our wooden friends takes her to Kew GardensA botanical garden in southwest London, it claims to have the largest collection of plants and fungi in the world., where she spends a year working alongside arborist Tony Kirkham. We see him teach her how trees live, age and - yes - communicate.

Scientists are gradually learning how trees keep in touch through an underground communication network. Fungi attach to tree roots, forming a symbiotic relationship (known as a "mycorrhizaThis difficult word comes from the Greek for "fungus" and "root"."). Trees give fungi sugars; fungi send water and soil nutrients back. But there is more to it than that.

The fungi spread through the soil, connecting trees. Through these links, trees can transmit chemical messages to each other. If one is attacked by a bug, it can relay a "warningKirkham gives the following example. A caterpillar nibbles an oak leaf. The oak notices and shuts down its photosynthesis, making itself unattractive to the insect. The chemical change is conveyed to other trees in its network, which do the same, in case more caterpillars come." to others in its network.

There is also evidence that healthy trees can "help" younger or weaker ones by channelling nutrients toward them. "They've grown together and they nurture each other," observes Kirkham. "Trees are like people."

Experts have coined a name for this network: the Wood Wide Web. Others push the internet analogy further, describing it as a social network. The trees, they say, "talk" to each other.

Nobody has done more to anthropomorphiseAttribute human characteristics to something which is not human. trees than Peter Wohlleben, a German forester. In his bestselling book The Hidden Life of Trees, Wohlleben sets out his view of how trees interact. They "suckle" their "beloved children", keep "friends" and guard against enemies. They make decisions, store memories and develop distinct personalities.

For Dench, trees' powers of communication are a big part of their appeal. "When I planted trees in memory of my friends I always hoped they would be part of a community," she says. "And now it's so reassuring to find out it's true."

Certainly, say some. There's a lot we still don't know about how trees (and fungi) interact. That said, studies have shown time and again that they can spread messages to each other. Rather than proud individuals vying for sunlight and nutrients, trees should be seen as a community, constantly conversing and cooperating. They are more like us than we thought.

Don't get carried away, reply others. Trees do not have brains. They cannot think, let alone talk. There is nothing deliberate about the way they send out their chemicals: their "messages" probably just evolved as a survival mechanism, arming them and their neighbours against predators and diseases. In fact, viewing trees as humans says more about us than them.

Kew Gardens - A botanical garden in southwest London, it claims to have the largest collection of plants and fungi in the world.

Mycorrhiza - This difficult word comes from the Greek for "fungus" and "root".

Warning - Kirkham gives the following example. A caterpillar nibbles an oak leaf. The oak notices and shuts down its photosynthesis, making itself unattractive to the insect. The chemical change is conveyed to other trees in its network, which do the same, in case more caterpillars come.

Anthropomorphise - Attribute human characteristics to something which is not human.