Guardian: On an early summer’s morning in northern Tasmania, the Tamar valley looks like an Australian slice of Tuscany. There are groves of walnut trees beside white-barked eucalyptus, a lavender farm, apricot orchards and small fields of olives. Vineyards run down to the river and fat black cattle graze the pasture. Yachts are anchored in the winding reaches of the tidal river. The Tamar seems a model of sustainable development – green and welcoming. Except that the Australian government has …