Our Campaign to help the critically endangered Arran Whitebeam Tree

One of our conservation projects includes helping to save the Arran Whitebeam tree which is critically endangered. We have so far planted up 20 of them in a fenced area (to keep the deer from eating them!).  Here’s local expert Henry Murdo talking about the Arran Whitebeam.

Since 1869 when they were first mentioned in journals, the three species of whitebeam tree growing on the Isle of Arran have entranced naturalists and tree lovers. This is because Arran, and specifically the north end of Arran, is the only place in the world where they are found growing naturally. They are a hybrid of the rock whitebeam, and the oft sung of rowan tree, and have pretty leaves with a soft white underside, which show the mix quite clearly. Lovely white blossoms are produced after the snow melts, and red-orange berries come before winter. They are considered close to extinction by the World Wildlife Fund and although they have been studied and protected sporadically by various environmental organisations, including the Nature Conservancy Council who ran a reserve around them in Glen Diomhan from 1973-1991, (sadly it no longer has reserve status), there are far fewer left than in the 1950s.  Deer prefer nibbling them to almost any other native tree and sheep have been known to die for them: the trees that are left mainly live precariously between 100 and 300 feet up on craggy steep-sided rocks and visitors to the island are generally unaware of them.  Apart from deer and enthusiastic chain-saw wielders, both of which the island has in roaming herds, other threats to sorbus arranensis and her sisters the catacol whitebeam, (sorbus pseudomeinichii) and the delightfully named bastard whitebeam or cut leaved whitebeam, (sorbus pseudofennica) include habitat loss, overgrazing by sheep and the inevitable severe weather event, which could still wipe out the entire wild population.

This would be a shame, as the species seems to be incredibly old –  isolated here since the last glaciation period 11,500 years ago. Seedlings are clones of the parent tree, producing asexually, reducing genetic variation which makes them vulnerable to changes in the environment. There are, however, quite a few whitebeams in what you could call ‘captivity’. In fact, the sorbus arranensis is a bit of a must- have in some Arran gardens. They are useful for schools when teaching about the mechanics of evolutionary diversity in trees.  Their rarity has given them value in other respects with them being used as an interesting and thought-provoking  international gift. Four years ago, in twin ceremonies at Edinburgh Botanical Gardens, and in Knoxsville Tennessee, saplings were exchanged and planted by ‘Trees 4 Two Nations’. Arran got the beautiful rock chestnut oak, and Knoxsville got the lovely whitebeam, to symbolise shared ‘deep historical and cultural roots’ and the continued friendship between the two nations.

Henry Murdo of Corriegills on Arran runs his own tree-propagating nursery in his garden and knows all there is to know about these trees having busily collected and propagated seed and tended the saplings for years, in hopes of helping to stabilise and raise the population of these beautiful tenacious survivors on Arran. He explains that they they are extremely hard to propagate from seed and he has been experimenting to find its ideal germination conditions. Some of his trees go to enclosures on the Brodick Castle Estate on Arran but he is keen to see more planting in a variety of locations and explained to ACLI trustees that these trees are equally suited to lower land not just the craggy rocks in remote burns. Arran Community Land Initiative hopes to plant and protect several on their land lying above the coastal village of Whiting Bay.