Wednesday, 24 February 2016

garden switchboard

For more than a century, botanists have known about the symbiotic partnership between fungi and plants—the networks of fungal mycelium bundled with the roots of shrubs and trees described as a “mycorrhiza” association that is mutually beneficial in helping the other extract certain nutrients from the soil. What researchers are just discovering, however, is the breadth and depth of those connections and the nature of that relationship that’s akin to a subterranean vegetable information superhighway: the long tendrils of the fungal mycelia link individual plants in myriad ways and are the lines of transmission for chemical signals through garden plots and whole forests.
In a fascinating overview from BBC Earth magazine’s archive, featured recently on Dave Log 3.0, ecologists examine how this fungal internet allows plants over great distances to not only warm one other of intruders, it facilitates the sharing of nutrients and even allows the older generations to aid new spouts with sustenance, sabotage of unwanted neighbours and even parasitic behaviours. I feel a little guilty for my potted companions now, who might feel essential restricted to solitary confinement. I suspect, however, there are other modes of plant communication. After seeing more devastating wildfires for Australia in the headlines, I learnt that not only are the eucalyptus trees evolved to be explosively flammable—not unlike the strange venomousness given to everything there—and many of the seeds of other trees will not germinate without a periodic scorched-earth policy (or alternatively, arson by self-immolation), further prior to the settlement of Europeans, the stretches of eucalyptus forest that are a familiar sight today did not exist. The Aborigines, who had been landscape artists for tens of thousands of years, were careful cultivators and kept the forests pruned back, favouring grasslands that acted as fire-breaks and foraging grounds for game. It seems the Aborigines knew the risk of letting Nature run its favoured course, and that begs the question: what is Australia’s (or any land’s) natural state—wild or tamed, either by exception or by tradition?