The Sycamore (Acer pseudoplatanus) is one of the most common and recognizable features of the British landscape. Standing up to 35 metres tall, it can live for 400 years.  It’s not native to the UK, as it was introduced from central Europe in the 15th/16th century. Most environmentalists in the UK think negatively of the tree due to its dominating self-seeding habits and its tendency to crowd out native species. But sycamores can be a vital lifeline for an incredible variety of insects, birds and mammals, especially since the recent loss of so many ash trees. Our native oak supports a greater diversity of insect species, but the sycamore wins on sheer volume.

Sycamores flower relatively early, producing clusters of small, green-yellow flowers, providing pollen and nectar just as many species of bees are emerging from winter hibernation and starting to forage.

Sticky stuff! In summer, a single tree can host up to 2.5 million sycamore aphids! These tiny green insects feed on sap in the leaves and secrete masses of honeydew, which is is a rich source of food for ants, flies, wasps and bees. The abundance of aphids attracts predatory insects such as ladybirds, hoverfly larvae and lacewings. Adding to this insect menagerie, there are many species of moth caterpillars that devour the leaves. This includes the miniscule Sycamore-seed Dot.

The aphids are also an important food source for many species of birds, especially in providing a supply of readily digestible high energy food for the young. Chiffchaffs, tits, sparrows, wrens and many other birds can be seen searching the undersides of leaves for this valuable resource.

Like other trees, sycamores provide nesting sites for birds, and may develop hollows providing shelter to bats and small mammals. The fat rich, winged seeds in autumn are another good food source, for small mammals and seed-eating birds such as greenfinches and goldfinches.

The tree can be also be an environmental indicator. In late summer, you may notice large black "tar spots" on sycamore leaves. Caused by the specialized fungus Rhytisma acerinum, these spots are entirely harmless to the tree but are a fascinating indicator of clean, low-pollution air.

After a devastating loss of ash trees in the UK, the Forestry England agency has pointed out that sycamores grow in very similar conditions and can act as an ecological proxy. They are capable of hosting many of the same insect and lichen communities that would otherwise lose their homes.

Hardy, pollution-tolerant, and resilient against strong winds, the sycamore is proving that it is far more than an invasive nuisance.