“The clearest way into the Universe,” writes the naturalist and philosopher John Muir, “is through a forest wilderness.” The installation “For Forest,” a seven-week epic designed by the Basel-based curator Klaus Littmann, sees 300 trees transplanted into the Wörthersee soccer stadium. During that time visitors are invited to observe the new forest in its new habitat and to consider—the hope is—what the absence of wilderness would mean for the planet. —J.V.