Winner of the audience award at this year’s Glasgow film festival, Lizzie MacKenzie’s tender documentary debut about the simplicities of life far from so-called civilisation proves especially poignant in our hyper-connected time. Ken Smith, the “hermit of Treig”, has spent the past 40 years living alone in the wilderness, outside Kinlochleven in the Scottish Highlands. Such a lifestyle may be unusual, but Smith is far from an eccentric recluse; he is a gentle soul with a moving appreciation for his environment. Just as how he talks to his roses as they grow, Smith believes that when human beings care for Mother Nature, she will provide us with all that we need.

The life of a hermit demands a lot of hard work. Smith fishes for food, forages for vegetables and chops his own wood; all of this is no small feat for a man who is now in his 70s. In the cabin that he built himself, there is no electricity – or indeed any sign of technology except for a small GPS device he can use to pick up weather reports. The gadget comes in handy when Smith suffers a stroke, and he can send a signal to emergency services. Suddenly, the film’s soundscape of babbling brooks and rustling trees is interrupted by the ominous sound of helicopter blades, as Smith is taken to the hospital.

A dilemma springs from Smith’s health crisis: how much longer can he possibly live in this isolated condition? While the latter half of the film grapples with this conundrum, the thousands of photographs that Smith has taken over the years conjure up how much of his serendipity is tied up with his natural surroundings. Crisp in terms of running time, the film is elevated by the tender rapport between MacKenzie and Smith; when a film-maker is clearly captivated by their subject, the film can compel viewers to fall in love as well.

• The Hermit of Treig is released on 25 March in cinemas.