Fire, yellowstone, cataastrophe, rebirth

This summer will be recorder as dramatic for the Mediterranean environment. The number of fire, following meny months of drought, is dramatically high. This catastrophe is probably related to global change, as dry springs ad numerous fires already occur consistently in both Australia and California since many yeras. And yet I would like to spend a word against eccessive alarmism, recalling the case of yellowstone park-

A few years ago, Yellowstone park suffered a terrible fire which destroyed almost the entire park. Many years of fire suppresion had led to eccessive amount of dead matter in the forests, increasing dramatically the risk of crown fires, which eventually happened. The catsatrophe was immense, the titles of newspaers read like "the death of Yellowtone": And yet, in the following years, the forest grew with unprecedented rapidity, due to rhe availability of nutrients released by the fire and scarce competition in the burnt grounds. In few yeras yellowton forestes qwere there again, and their functionality and biodiversity was higher than before the fire. What happened,. as immediatly appeared evident, was that the "pristine" forests of Yellowston were in fact far from the natural state, due to years of forestry practices such as fire suppression, and to the local extinction of wolf with consequent disruption of the food chain. Fire, instead of killing Yellowsont, brought Yellowston back to a more natural state.

Of course this is not alwasys the case. there are many cases in which severe fires cause the collapse of the cosystem, which falls in a metastabel state from where it can hardly recover. And yer often fire means the opposite, a regenerative force. Anyway, the fact that the catastrophe was in fact a regeneration was realized only because Yellowstone is monitored by dozens of ecologists. Had this not been true probably the rebirth of Yellowstone would have passed unobserved.