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Dormice, bats and carbon storage: Why we should be 'health-checking' the nation’s hedgerows 

PTES
Madeleine Howell meets a conservationist who is campaigning to preserve Britain’s hedgerows  Credit: John Lawrence

You might have considered the importance of planting a tree (the Woodland Trust has announced a new campaign, the Big Climate Fightback, to get a million people to plant a tree on Nov 30): but have you also considered the humble hedgerow?

Not only are they carbon storage powerhouses, but the hedges which criss-cross Britain are also vital havens for sheltering and connecting wildlife, says The People’s Trust for Endangered Species (PTES). Hedgerow health is important for different reasons to Warners Gin: the company recently launched a new raspberry gin with hedgerow fruits and has created a new charity partnership to support the work of PTES.

So, what can you do to help hedges thrive? This year, the charity has launched a Great British Hedgerow Survey, encouraging landowners, farmers and wildlife enthusiasts in the UK to "health-check" the nation’s hedgerows. It’s the brainchild of the charity’s Key Habitats project officer Megan Gimber, 32.

“If I look like I’ve just been through a hedge backwards, it’s because I have!” she jokes, when we meet at Hill Farm in Steventon in Oxfordshire. She is here to show me how a hedge health-check is done and, in the autumn light, we both admire a berry-laden example of what she refers to approvingly as a “non-interventionist” hedge (i.e. not trimmed or stripped of its fruit too soon).

“You shouldn’t be able to look over a hedge or under it – you should have to look through it, bear-hunt style,” she explains with a custom-made measuring stick in hand, as we wade gung-ho into the thorns.

Hazel dormice use hedges for connectivity, and as a secondary habitat

The charity’s aim is to research and test the best ways to protect endangered species in their natural environment, then put what works into action – and Gimber’s mission is to create a living database of the nation’s hedgerows. Historically, we’ve lost about half our hedgerows since WWII.

“It’s not just hedgehogs which live in them and which are under threat: one study named 2,070 different species in one 85m stretch of hedge,” Gimber tells me. “One of my favourite examples is the song thrush.

"It nests in the shrubby thickets of hedgerows, forages for slugs and snails in the base of it and, later in the season, switches to berries. Hedges are also essential for bats, which need a linear structure in order to navigate, and if it’s windy, they provide shelter for butterflies.”

The initiative sprang from another conservation project – an attempt to reintroduce hazel dormice (a mammal, not a rodent, despite its furry tail) to counties where they’d been lost, such as Warwickshire and Yorkshire.

“Dormice were introduced into two separate woods, and although they are arboreal, it was necessary to survey the hedgerows in between to make sure they could travel across safely and use them as a secondary habitat.

"We had all this data, and didn’t know where to put it – and we realised that if people doing hedgerow surveys up and down the country could gather all the data in one central place, at a national level, it could be key for future conservation projects.”

The UK is in danger of losing a quarter of its mammal population, according to the recent State of Nature Report 2019, conducted by 70 British wildlife charities in partnership with the government.

The hazel dormouse is just one of those at risk of decline and threatened with extinction, and the loss of hedgerows (along with changes in woodland management and farming practices) is listed as one reason why they’ve declined by a third since 2000.

The UK is in danger of losing a quarter of its mammal population according to the recent State of Nature Report 2019: the loss of hedgerows is cited as one reason for the decline Credit: John Lawrence

The results of each survey will help landowners and communities to make better decisions for wildlife conservation, and to optimise the benefits hedgerows have to offer to both animals and humans (did someone say sloe gin?). 

Here at Hill Farm (which plays host to “miniature Glastonbury” Truck Festival in summer), farmer Alan Binning has laid his hedges with a variety of species: blackthorn, dogwood, hazel, field rose and field maple – Gimber explains that a hedge of mixed plant species is much more wildlife friendly than a homogenous hedge.

But the first task of our survey is to identify the hedge structure and to select what state it is in from 12 options, ranging from over trimmed with gnarled, rotting base, perhaps invaded by elder or sycamore, to recently coppiced or laid in an attempt at rejuvenation, right up to leggy, tall and overgrown (at this stage, the hedge may have developed into a line of trees, with very little if any of the desired woody undergrowth). A diagram provided by PTES illustrates what it is you’re looking for. 

The dream scenario and an optimum stage in the “life cycle” of a hedge, says Gimber, is for it to be dense and managed, perhaps with a straggly appearance and protruding branches.

Happily, the hedge we look at is exactly that, with a margin of long grasses providing further shelter and a natural divide between  hedge and crops.

A mix of species, such as blackthorn, dogwood, hazel, field rose and field maple, makes for a better wildlife habitat Credit: John Lawrence

Next, we measure the height and width (which is where the measuring stick comes in useful); this one is 3.5 by 3.5 metres, which Gimber says is good news. Other tasks include looking for gaps, checking the number of connecting hedgerows, looking for nettles, cleavers and docks, checking whether there is a ditch or fence running alongside, and ticking off the woody species present. 

As long as you ask the landowner for permission first, I can report that taking part makes for a pleasant way to spend an afternoon in the great outdoors: and after conducting a survey, you may never look at a hedge in quite the same way again.

Happily, there are also ample opportunities for foraging along the way. Look for late season fruits, such as bullace, throughout November. According to Christine Iverson, author of The Hedgerow Apothecary (Summersdale, £14.99), hedgerow fruits in season from October until December include chestnuts, chickweed, crab apples, hawthorn berries, horseradish, nettles, rosehips, sheep’s sorrel, sloes, spearmint and walnuts. 

To survey a hedge using your smartphone or a tablet for instant feedback, or to print a paper copy, visit hedgerowsurvey.ptes.org