The Southern Carpathians of Romania are at the tip of Europe’s third-longest mountain chain. Here, ancient woodland cascades over the hillsides and the full suite of apex predators still roam amongst the trees.    For many years, there has been a missing element of these wild landscapes. The woodlands have been devoid of their biggest sculptor, until now.   Since 2013, European bison have come back into the equation. They disturb and disrupt as they feed, trample and push their way through the trees, leaving a dynamic wake of ecological processes no other species can achieve. Tune in to hear all about it.