OAK TREES Oak trees hold a special place in the hearts of the nation. One of the most widespread trees in the UK, their size and longevity symbolise strength and endurance. There are two native species of oak in Britain: the English oak and the Sessile oak. Telling them apart is simple, just take a close look at their leaves and acorns. English oak leaves have a very short stalk while Sessile oak leaves have a long one, and conversely, English oak acorns grow at the end of long stalks while Sessile oak acorns have no stalks.
Both species can reach a grand old age – oaks over 1,000 years old can be found around the country – and anything over 400 years old is classed as an ‘Ancient Tree’. With increasing age, oaks become shorter and wider, developing gnarly crevices and hollows. Oaks are well known for supporting a huge variety of wildlife, and as they age they attract even more species. Specialist insects feed on the dead and decaying wood within an aged oak, and many birds and bats use their holes and cavities for nesting and roosting.
Research published by the UK Centre for Ecology and Hydrology in 2019 revealed that mature oak trees support a staggering 2,300 different wild species. Throughout the year in every season, oaks offer valuable living accommodation, food and shelter for a wide variety of wildlife. Oaks flower in springtime, producing long, pollen-rich green catkins – these are the male flowers. Their pollen is dispersed by the wind, fertilising the small red female flowers, which then grow into acorns. Oak flowers and pollen provide food for a host of creatures, from squirrels to butterflies. The caterpillars of the dazzling purple hairstreak butterfly feast on oak flower buds and leaves, while many bee species rely on oak pollen to provide a springtime buffet. If you’ve ever seen an unusual shaped growth on an oak tree, you’ve probably stumbled across a gall. Oaks play host to a variety of galls, the most
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