This month the oak has been calling out for me to spotlight its majesty in our rewilding species of the month series.  Every step I take along a favourite pathway in our local woodland is currently carpeted with a mass of acorns so that they rarely leave my imagination when I take my daily dose of nature.

But just as oak trees seem to have firmly entwined themselves with my wanderings lately, they have always been entwined with human life, building our ships, flavouring our whisky, and structuring our steeples for centuries. Throughout history, the great oak has sheltered both our princes and our paupers and thousands of non-human species too.

Life in Abundance

The two oak species native to the UK, the English and Sessile Oak, support a massive 2,300 different species of mammals, invertebrates, birds, fungi and mosses. Throughout its life, the oak supports these species in different ways, whether it’s a 40 year old nourishing nature via its acorns or a dying oak giving a place for bats to roost in its hollow core. Even a dead oak tree has a role to play in nature abundance. There’s an important lesson for our policy makers here. We need to look beyond totting up a tally of saplings planted. Tree planting certainly has its place in supporting nature recovery but the worth of an action does not lie in it being easy to quantify on paper or boast about in soundbites. We must be led by the evidence and therefore also look to protect and restore the dynamism of existing broadleaf woodlands. The worth of an oak wood goes beyond the number of trees: it reaches both far into the soil and up into the canopy.

For anyone who would like to see how important the oak is, putting just one fresh oak leaf under a microscope can reveal a whole ecosystem in itself – with various insects all making their way about: there will be tiny ones feeding on the leaf; larger ones feeding on the leaf eaters; and other insects making a home where their larvae can thrive.  Move along an oak tree from its leaves and you will find a branch decked in lichens and fungi including ones which will only survive here such as little tufts of Oak Moss Lichen or clusters of Oak Polypore. Continue down the branch and trunk and within the bark of the tree you will find even more invertebrates scurrying around. Perhaps within the bark you may also find a nesting pied flycatcher overlooking a forest floor which, in the autumn, creates a leaf mould nurturing stag beetle larvae and millipedes which in turn provide a feast for the blackbirds. All this, and we haven’t even mentioned the catkins and the acorns which sustain still more life from butterflies to finches to squirrels.

The Humble Acorn

The Ancient Celts believed that the acorn held within it the knowledge of the universe and though discerning all the mysteries of life from an oak seed may be a bit of a stretch, there’s certainly a lot of wisdom that can unravel when reflecting on how “mighty oaks from little acorns grow”.  Each small thing within a forest has its part to play whether it’s holding the potential of a thousand forests or sacrificing itself to a squirrel so that others might live.

As mentioned above, in the UK many of our woodland floors are currently carpeted with acorns. This is because this year is a mast year for our oak trees. For those who aren’t aware, oak trees vary the number of acorns that they produce each year. There are a few theories as to why this is (and there may be some truth in them all) but the most popular idea is that producing more acorns every few years leads to ‘predator satiation’. Pacing itself with austere years not only requires fewer resources, but also ensures that the population of predators are kept in check. Thus, in a mast year many acorns will be eaten, but others will be able to survive as the predators simply cannot eat them all. Some of those predators might feel optimistic though. They’ll squirrel them away somewhere else where they will grow uneaten, free from the shade of their mother tree. In the case of jays, they may even plant an entire woodland!

Herein lies important wisdom from the acorn and the jay on the whole topic of rewilding – sometimes, rather than trying to control everything, you just need to let nature do her thing. This was shown to be the case by a number of scientists (including one of Wild Card’s co-founders Professor James Bullock) in a study which explored woodland restoration through passive rewilding. The study found that half the trees in two new English woodlands were planted by jays! 

Given that there are plenty of acorns around this year, I would recommend picking one up and putting it in your pocket. It can act as a reminder to trust the great wisdom of the natural world; or that even small things deserve our respect; or that it’s sometimes good to pace yourself rather than trying to do everything at once. And, if that isn’t enough, it’s also a folklore tradition that carrying an acorn with you will protect you and bring you good fortune.

The Royal Oak

The connection between the oak and protection does not end with this little tradition. The strength of oak timber has, throughout our history, provided protection from the storm. Whether you were sheltering in a Medieval cathedral, a Tudor cottage, or on Lord Nelson’s ship, you could rely on its durable wood. Unfortunately, this is one of the main reasons why our country is not as wooded as it once was. It took over 5,500 oak trees to build HMS Victory and our Royal Navy needed a lot more ships than this. So, although oak trees have a potential life span of over 1,000 years, we do not have as many ancient oak trees as we might otherwise have had.  Whilst there was a trend for replanting oak trees during the Victorian era, our need for local timber in the first and second world wars depleted our oak trees still further. The decision to replace these ancient broadleaf woodlands with fast growing pine forests has been a disaster for the species which rely on oak. As these plantations come to the end of our life span, we hope that a better understanding of the ecology of our woodlands will lead those with Plantations on Ancient Woodland Sites (PAWS) to Rewild these Ghost Woods to restore the habitats that we have lost.

Those individual great oaks that did manage to survive through the ages have become legendary. Unsurprisingly so, since rare ancient oak trees like The Big Belly Oak in Wiltshire date back to an age when William the Conqueror first claimed these lands for himself and his noblemen. The Major Oak in Sherwood Forest is even of an age where it may well have sheltered Robin Hood and his Merry Men.

Though no longer with us, another legendary oak tree is the Royal Oak at Boscobel which gave King Charles II a hiding place from the Roundheads. Readers of an age to enjoy the TV series, Horrible Histories, may know this king as the king that brought back partying and, true to form, on his return to the throne Charles II instigated a party day in celebration known as Royal Oak Day which was held on 29^th May each year and officially lasted until 1859.

It is, of course, a little anachronistic to celebrate the restoration of King Charles II but having a day to celebrate the oak tree is certainly something that could be supported. If the royal connection to an oak day celebration leaves you a little lack lustre, then you may like to know that marble galls from an oak tree provided the indelible ink on the Magna Carta (which establishes the principle that even the royal family must be subject to the law). Oaks also provided the groves where Welsh druids prayed; the Gospel Oaks under which English villagers read the Bible at rogation-tide; the Church of the Oak ‘or ‘Cill-dara’ where St Brigid founded her abbey; and, to this day, they provide the rich oak tones of the best Scotch Whisky. Our islands have had a relationship with the oak that has gone through some rocky patches but given all that it has given to us and all that it provides for our native wildlife, it is definitely time to restore our love for the oak.