David Nash Annely Juda Gallery, London Andy Goldsworthy Michael Hue-Williams, London

Autumn in London always makes me have thoughts of rural escape. I yearn for the last warmth of the sun and the first whiff of wood smoke on the air. Romantic nonsense perhaps, but the seasonal mood suits a couple of sculpture shows that are currently on view in the capital.

An exhibition of new work by Andy Goldsworthy, at Michael Hue-Williams, is less pretty than some shows of his work that we have seen in recent years, but is all the better for it. Goldsworthy's gift is an ability to alter and re-shape natural things in consistently surprising ways. He is best known for his photographs but this show takes a tougher line with a series of autumnally inspired installations including a very beautiful lattice screen of chestnut stems and a giant ball of stacked sticks. Around the walls a string of rushes pinned by thorns makes sense of Paul Klee's definition of drawing as "taking a line for a walk". Goldsworthy calls the show Wood, a title that would equally suit a show of David Nash's recent sculpture at the Annely Juda Gallery.

Nash works with wood, only wood, and always from a single piece of fallen tree. If Goldsworthy's strength is the element of surprise, Nash's is in a feeling of inevitability. A sense that once he has seen the shape, and started sawing, carving and burning his way towards it, there is only one way that it can go. His contribution is the next logical step in a natural process. Nature makes the tree, the tree grows, the tree falls over and then comes Nash to give it another life.

His early works tended to be huge and roughly hewn and were often left in the woodland site where the tree had fallen. Big outdoor sculptures still feature in his repertoire, but gradually he has begun to look equally at home in a gallery context, working on a smaller more sophisticated scale.

At Annely Juda the installation Cube, Sphere, Pyramid dominates one room with three giant lumps of elm that have been gashed and burnt on the inside. The basic shapes are replicated in charcoal drawings on the wall, like black shadows, ethereal yet incredibly dense. It's an impressive piece: massive, yet elegant, and with an unsettling quality resonant of Neolithic stone circles.

The strength of these larger sculptures is a blend of simplicity and presence, but even on a smaller scale his best work has an air of domestic monumentality. It doesn't always work, but when it works well it defies the boundaries of time and place.

If Nash and Goldsworthy share anything, it is the drive of a powerful imagination. Goldsworthy is probably the more inventive, a sort of magician working minor miracles with sticks and twigs, but Nash seems more of a mystic who looks deep into the tree and releases something that was already there.

Both men have popular appeal. Their work has a direct and understandable appeal, but in certain influential corners there has been a reluctance to take them as seriously as some of their contemporaries. Neither of them were included in the landmark exhibition A Century of British Sculpture held recently in Paris, nor has either been invited to show in the prestigious British Pavilion at the Venice Biennial. This is a shame. One senses that in the past the environmental label that their work attracts has counted against them, but it is time for that to change. These are two of the best small shows of the autumn and increasingly Nash and Goldsworthy look like two of the finest British sculptors of their generation.

Andy Goldsworthy at Michael Hue-Williams, 21 Cork Street, London (0171-434 1318). To 22 Nov; David Nash at Annely Juda Gallery, 23 Dering Street, London (0171-629 7578). To 21 Dec