In un angolo di terra tra le case, in un quartiere della periferia di Londra, vivono una miriade di organismi. A dimostrazione che la biodiversità esiste anche in città. E basta pochissimo per permetterle di sopravvivere.
da un articolo del guardian:
http://www.guardian.co.uk/environment/2010/may/18/secret-life-suburban-garden
There are four bodies lying and crouching in our tiny back garden. The ecologists from theNatural History Museum (NHM) got here only minutes ago, but, while the kettle boils, they are already grubbing about behind our bins, under our windowsills, in the lawn, flowerbed and log pile.
They are doing a "bioblitz" – trying to find as many species of animal and plant as possible in this small, suburban south-west London garden. Our back garden is only 12 paces long and seven wide, with, now I look at it through the eyes of ecologists, pitifully few flowers. Happily, they appear undaunted. "The great thing is, even with gardens like this that look fairly sterile, there’s always something there," says the museum’s insect specialist, Stuart Hine. "We’ll move plant pots, and we’ll have a look through your log pile . . . Lots of spiders, centipedes, woodlice, slugs – they’ll all be there."
Bioblitzing is the latest buzz-word in conservation, and this one marks the opening of the NHM’s new Angela Marmont Centre for UK Biodiversity, which encourages the public to learn to identify more of the 55,000 species of flora and fauna that exist in England alone. (A questionnaire carried out for the opening suggests that less than a third of the population know what a sycamore tree looks like, while two-thirds do not recognise a peacock butterfly.)
A proper bioblitz would last 24 hours in a public place, bringing together members of the public and experts. "The idea is it’s a snapshot, a moment in time," explains Hine. "It’s finding everything of biological origin in one place in one time."
While we have been talking, John Tweedle, who runs bioblitzes under the museum’s Open Air Laboratories scheme, has already filled nine test tubes with bugs and slugs from around the birdbath. Hine is grubbing for spiders under the windowsill, and finds the intriguingly named missing sector orb weaver (pictured above), a lace web and a Tegenaria species of house spider – plus the egg sac of a false widow spider. Gill Stevens, the director of the new centre, is studying lichens on the log pile – a useful indicator of air pollution, she says. There are not many varieties, which may be connected to the fact that I live under the Heathrow flight path.
The centre runs three drop-in sessions for the public each week. Stevens says people can describe their find, send in pictures, or even post samples of things such as rocks, fossils or birds’ eggshells found on the ground. "It’s about encouraging people to learn more about the environment where they live; that they don’t have to go somewhere exotic to see natural history. We have to take a bit more responsibility for the quality of the environment we live in, and to do that we have to understand it a bit more."
I won’t pretend that the creatures in this particular suburbia are exotic (except for the parakeets). But still, some of the creatures they find have relatively exotic names: the vestal cuckoo bee, buff-tailed bumblebee, hairy-footed flower bee, spittlebug, wolf spider, and the lesser broad-bordered yellow underwing – the latter a moth with (confusingly) red upper-wings.
A week later, I am sent the final results: 87 species of flowering plant plus 27 mosses and a single fern on the plant list; 11 birds plus plenty of worms, slugs, algae, ladybirds, woodlice, flies, an ant, hoverflies, a weevil, bees and spiders – including a handful of things that had still not been identified. In all, nearly 200 different species – in just two hours, in this rather scruffy, badly planted patch of suburbia.