Woolly willow  (Salix lanata)

Most of the populations of woolly willow in Scotland are very small, comprising fewer than one hundred plants. Four of the sites consist of a single individual, and this makes the plant vulnerable, especially as it is a dioecious species. Individual trees therefore have no close source of cross-pollination for them to reproduce successfully. The increase in grazing over the willows’ habitat has reduced the populations to those that cannot be reached by sheep, cattle or deer. Here, they are also vulnerable to rock-falls, avalanches and general erosion.

The woolly willow is listed as a priority species in the UK Biodiversity Action Plans. Many of the sites where it survives in Scotland have statutory protection, and the action plan specifies a number of conservation measures to further improve its chances of survival. The two agencies responsible for the woolly willow in Scotland, Scottish Natural Heritage and The National Trust for Scotland, are currently implementing these measures.

On some of the sites, grazing pressure is being reduced, especially that from red deer, by fencing. It has also been recommended that where plants exist in isolation, new individuals, propagated from wild seed, should be planted close to the existing specimen. This would improve the chances of successful insect pollination.

It is believed that before humans began modifying the upland, woolly willow occupied at least 2000 hectares. This has been discovered through vegetation mapping. It would certainly be a worthwhile aim to stabilise the populations of woolly willow at least to the level that they are naturally sustainable.