Sycamore (Acer pseudoplatanus)
Sycamore

The real home of the sycamore is high ground in southeast Europe and the Caucasus. It is uncertain when it was introduced to Britain - It may have been brought by the Romans, but the first definite written record in England dates from 1578. Sycamore was still scarce here in the 16th century, and has only really become established in the last 200 years. This tree is very tough, being tolerant of salty coastal winds, and growing higher on hills than any native broadleaf tree except for rowan. It is also highly invasive, propagating from its copious winged seeds, and is still spreading vigorously throughout the UK. Sycamore is now more geographically widespread than any native tree except ash and hawthorn.

When sycamore invades birch, ash and other lightly-shading woodland, the extra shade beneath its large leaves suppresses the ground flora. Bird numbers also decline once the sycamore canopy closes. Sycamore supports only 19 insect species despite its long history in Britain, compared to 423 recorded on oaks and 450 on willows. However, it supports similar numbers of lichens to native trees, and its flowers provide springtime food for bees. Wood mice will eat the fallen seeds, but only if acorns and beech nuts are scarce. The relatively unpalatable seeds may be one reason why sycamore is such a successful coloniser. It also supports very high aphid populations, an important food source for birds.

Sycamore seedlings don't establish well in established grassland, but readily colonise bare soils and existing woodland - a problem in the woods around the edges of the commons, and in the bare areas where roads and runways have been removed. Sycamore is controlled by felling and stump treatment, but some large specimens are left because of their potential for nest sites.

Interesting fact:

Sycamore wood is very hard and was used in prehistory for spear points. “Acer” is latin for sharp !