Sycamore (Acer pseudoplatanus L.) is a naturalised exotic species that grows well on a wide range of sites across Britain, usually as a minor component of mixed woodland. The time of introduction is uncertain, and it is currently thought to have arrived in Britain as late as the sixteenth century but has become well established in the last 200 years. Sycamore is a hardy species being tolerant of wind and salt-spray, late spring frosts, shade in earlier years and can also grow on sites contaminated with heavy metals. At present, it is threatened by no major pests or disease but is highly susceptible to damage by grey squirrel. It prefers cool, humid sites and can produce prolific amounts of seed, which often facilitates natural regeneration.
Sycamore has similar ecological requirements to ash (Fraxinus excelsior) and can support a high number of ash-associated species. As such, sycamore is considered as a potential replacement species in ash woodlands devastated by the fungal disease ash dieback. Sycamore hosts a wide range of lichen and aphid species, and the latter is an important food supply for many organisms. It has acquired a reputation for being an invasive species and this may be because it thrives where there has been disturbance. However, evidence suggests that it cannot dominate woodlands for long periods as it has difficulty regenerating under its own dense canopy.
A sycamore plus tree, the starting point of any tree improvement programme