A cura di NedCuttle21(Ulm)

Un articolo pubblicato sulla rivista canadese Hakai Magazine parla del carsismo e della vulnerabilità degli ecosistemi carsici. L’autore, Bruce Grierson, ha incontrato una coppia di esperti del settore il cui lavoro scientifico e di sensibilizzazione si svolge prevalentemente nella Columbia Britannica, in particolare nell’isola di Vancouver, dove il diboscamento operato dalle compagnie del legname a spese della foresta pluviale costituirebbe una seria minaccia per la preservazione del paesaggio carsico sottostante e della sua biodiversità.

In the twilight hush of the fanciest restaurant in town, Paul Griffiths pulls out a tiny device that looks like a primitive cellphone and sinks it in his water glass. He’s trying to figure out where the water came from—here, Campbell River, a small coastal community in British Columbia, or somewhere else?

The instrument, an electrical conductivity meter, reveals the path the water took from its source to Griffiths’s glass by measuring the charged minerals picked up along the way.

“Twenty-two, 23, 24 …,” says Carol Ramsey, reading the display.

A server orbiting past the table stops midstride and stares.

“We’re just testing the conductivity of your water,” Ramsey says cheerfully.

“Do you know where this ice came from?” Griffiths asks.

“Uh … the ice machine? I’m not sure,” the server says shyly.

“Is it possible to get a glass of just tap water?” Griffiths suspects the ice is bringing down the numbers.

Maybe the ice was shipped in from the nearest big cities to the south, Victoria or Vancouver, where drinking water comes from reservoirs. The server returns with a glass of ice-free water. Immediately, the reading climbs past 40. The higher number is a geological tell. It’s proof that the water ran underground through karst, an underground ecosystem of dissolved rock.

Immagine: Patjosse