It's the start of autumn in Dalby and Cropton Forests. Change is in the air as the sun's power is fading. After months of warm weather, and even a false autumn, more leaves are beginning to turn a golden yellow and many of the birds are preparing for their migration south. Life among the trees might seem to be slowing down, but underneath the canopy there is a transformation taking place. It's showtime for one of the delights of autumn: fungi.There's a final visit to the beaver family in Cropton. Having spent summer hard at work, building dams, increasing flood plains and having two young kits to look after, we follow the beavers in the run up to autumn. They work at an astonishing speed, late at night and in the early mornings, so every visit is full of surprises.Throughout the summer, apprentice Holly has become embedded in forest life. She's now a master of the chainsaw and is becoming an expert on all the trees that grow in the forest. With her exams approaching, she learns about threats to the trees and how important it is to identify vulnerable trees, which might be prone to breaking or falling down.Alongside the animals and plants that call Dalby home, we meet some four-legged friends who are visiting to take part in a very special event; the Canicross. The canine competitors of the race come in all shapes and sizes and, having never previously had a Chihuahua take part, the organisers are in for a surprise.