The Atlantic woodlands in west Wales are a rare reminder of the forests which used to stretch along the entire coast of Europe.

I went to learn about reinstating the original habitat, with fewer conifers, more broad-leaved trees, and - as a result - a greater diversity of other plants and wildlife.

Rhodri, from the National Trust at Ganllwyd, introduced us to the basics of laying a hedge, using an overgrown relic of the 1930s.

The old line of the hedge could still be made out by a row of mature hazel trees: we started at the top end because hedges are laid uphill, as this is the direction in which trees grow. We took out the dead wood and removed large branches or trunks pointing in the wrong direction.

One by one the branches were bent in the desired direction. Using a billhook, the bottom end (about 6 cm off the ground) was cut into, downwards, until it could be "laid" at an angle of about 30° to the ground. The important thing is to retain a sufficient core of the branch and its bark to form a hinge so that life can flow from the roots.

Stakes were driven into the ground every 60 cm or so through which the laid branches were twisted, to provide strength and a straight line.

Quite a few gaps needed to be filled with cut branches and these were supplemented with freshly-cut pieces of willow. Cut willow has a 99% success rate of growing when stuck into the ground.

Our dormice tutor was Jack Grasse. Nocturnal, and asleep for up to three quarters of their life, their numbers have fallen dramatically in recent years, probably because of disappearing hedgerows and ancient woodlands. Jack is a veteran of dormice conservation and he has invented a special dormice nesting box on a tall pole.

Our newly laid hedge would be a vital corridor for dormice. They spend 99% of their time above the ground to avoid the predators that lurk below. Without corridors it is difficult for dormice to move to other areas, limiting their ability to feed and breed. Hedges also retain food. Having laid a section of hedge to act as a corridor we planted young hazels in the gaps from which conifers had been removed - treeless ground is a dormice desert. Dormice eat about 14 hazelnuts a night and take about 20 minutes with each one. It's quite an effort for a small creature to break into the tough shells and they leave a distinctive pattern. Jack showed us how to differentiate between these and nuts eaten by wood mice, squirrels, bank voles and nuthatches.

The course I attended was an EU-funded project organised by Meirionnydd Oakwoods at Tan-y-Coed near Corris.