Sowing seeds from a mighty oak on the ‘wood wide web’

On that September day, Jeremy, orchard curator at Irish Seed Savers – the heirloom seed charity based in Clare – his nursery team and local volunteers at Jim Cronin’s nearby organic farm found themselves sorting the proverbial wheat from the chaff.

Their goal was to pick the thousand best acorns to kick-start a two-year replanting project, transferring them into specials beds that mimic the woodland floor.

This December, the saplings will have reached a viable height and be considered fit for replanting in their forever homes.

In preparation, members of Irish Seed Savers are being offered the chance to plant one of these historically significant saplings and grow their own daughter of Brian Boru – the application deadline closes this month (see irishseedsavers.ie for details).

“We’ve had an astonishingly positive response from our supporters – from many of the country’s universities to plant in their grounds, local community groups to plant in their parks,” says Jeremy of the applications to date.

“We’ve had people looking to plant on their family farms and demesnes. From many ecological restoration and native woodland restoration projects and also from supporters who have an appropriate place to mark the special occasion of a birth, marriage or to remember a loved one who’s passed over.” 

The oak is among the most biodiverse of trees, capable of supporting more than 300 species and subspecies, from deer to lichen and fungi, each of which is integral to Ireland’s ancestral ecosystem.

“An oak’s life cycle is this: 300 years in the growing, 300 in the living and 300 in the dying,” says Jeremy.

The Brian Boru oak, located at Raheen Woods, Tuamgraney, is said to have been planted by Ireland’s last high king himself, who was born nearby.

That puts it at about 1,000 years old, a grand age for any oak and despite the ravages of weather, surrounding deforestation and, more recently, climate change, the tree appears to be in rude health.

“Different species age at different rates, but I would say ‘ancient’ means a tree trampling the foothills of old age in the third and final period of its life,” says Jeremy.

“However, some trees, if managed by pollarding [top pruning], are infinitely renewable and never lose their ‘sunshinyness’.”

The fact the oak dropped such an abundance of acorns in its twilight years speaks volumes of its vigour. Masting requires an extra effort from a tree, providing what’s called “predator satiation” for the many species that rely on it for food, such as squirrels, jays, mice and badgers.

But masting also ensures any leftovers can produce new trees – squirrels and jays can’t always remember where they hide each and every acorn.

Oaks synchronise their acorn drop, communicating with one another via an underground network, known as the “wood wide web”. This means all the oaks in an area drop at the same time – and therefore potentially across an entire region or country if there are enough green corridors linking them together – ensuring the long-term survival of the species.

But they can’t survive alone. It is human intervention that has historically disrupted the oak’s destiny and while the Irish government has a strategic plan to raise its forest cover to 18pc by 2046, it’s a moot point whether this figure is ambitious enough for a country that in 2019 declared a climate and biodiversity emergency.

It’s easy to be lulled into a false sense of security by the Sitka spruce swathing our landscape. However Sitka is an invasive species imported from America’s Pacific Northwest in the 1900s by Scottish-Irish plantsman and sinologist Augustine Henry, in the belief it would enliven Ireland’s “useless land”.

“Forest cover is only useful and meaningful to Ireland if it is native woodland,” says Jeremy. “Commercial conifer plantations are also considered ‘woodland cover’ yet are of no real value or benefit to the Irish public or our ecosystems. We need to rethink what a functioning woodland is. We are a forest people without a forest.”

In truth, the Brian Boru’s real age is shrouded in mystery, since coring and dating trees hasn’t been done much in Ireland. But what we do know is it’s far older than the average oak, which should serve its progeny well.

“This tree really is ancient but it isn’t showing signs of decline, where they invariably begin to die back to reserve their energy into the bowl of the tree,” Jeremy says.

“Perhaps in the case of the Brian Boru the scientists haven’t left room for magic…”