Читать книгу Collins Complete Guide to British Trees: A Photographic Guide to every common species - Paul Sterry - Страница 26

Birches are often viewed with disdain and dismissed as being little more than scrub trees. It is true that, in certain circumstances, Silver Birch, in particular, is an aggressively invasive species of heathland and newly cleared woodland on neutral to acid soils. However, in its favour is the fact that it plays host to a wide range of insects, in particular the larvae of many moth species. Most feed on birch leaves but the larva of the Large Red-belted Clearwing Synanthedon culiciformis feeds on wood, sometimes being discovered in cut stumps.

In the autumn, Silver Birches usually turn a spectacular golden yellow for a week or two. Around the same time, an amazing array of fungi put in an appearance as well, many of them only found growing in association with these trees. The best-known fungal association with Silver Birch is probably the Fly Agaric Amanita muscaria, an unmistakable and striking species. But dozens of other species are invariably associated with these trees, including several Boletus and Russula species as well as the Birch Polypore Piptoporus betulinus.

Silver Birches provide stunning autumn colours that lift the spirits.

Phil Green

The larvae of the Large Red-belted Clearwing feed beneath birch bark and the secretive, day-flying adults are sometimes spotted resting among the foliage.

The Buff-tip has an uncanny resemblance to a snapped birch twig: a convincing camouflage that increases the moth’s chances of avoiding detection by predators.

The Fly Agaric has a mycorrhizal association with the roots of birch trees (see p.), so you are unlikely to find this fungus growing anywhere else.

Downy Birch often grows alongside Silver Birch but comes to replace it in many western, northern and upland parts of the region. In terms of specifically associated wildlife, it has much in common with Silver Birch, particularly when it comes to fungi. However, in Scotland, in particular, superficially similar hardy Highland species often replace their southern counterparts. Look out for the intriguing Hoof Fungus Fomes fomentarius growing on stumps and trunks.