* ‘Silent killer’ air pollution and poor management have reduced floral richness by nearly 20% on verges
* Plantlife reveals the ‘dirty dozen’ plant marauders that are increasingly rampant on road verges
* Wildlife at risk: Red clover and lady’s bedstraw – two particularly wildlife-friendly plants – are experiencing the most rapid decline on verges
* BUT ALL IS NOT LOST; better management of our road verges could have spectacular results for wild flowers and wildlife, delivering an estimated 400 billion more blooms (or 6,000 flowers per person).
A marauding gang of invasive native plants including nettle and bramble are thriving on a diet of ‘junk food’ and taking over our once flower-rich road verges reveals Plantlife, Europe’s largest conservation charity dedicated to wildflowers and other flora.
Almost 90% of Britain’s wild flowers prefer lower-nutrient soil but they are being crowded out of the countryside as a result of air pollution creating unnaturally rich conditions, particularly on our road verges. Analysing trends since 1990, Plantlife has identified that our road verges are undergoing a dramatic change with plants that enjoy soil rich in nitrogen – much of it deposited from vehicle exhausts – spreading like wildfire including stinging nettle, bramble, rough meadow-grass, cow parsley, Yorkshire fog and creeping buttercup.
The boom of these ‘nitrogen guzzlers’ is crowding out wild flowers that had found a haven on our road verges, including some of our rarest and most threatened species such as fen ragwort and wood calamint which are now clinging on at a handful of verges, their last remaining habitat.
Victims of the changing verge include wild flowers like tufted vetch, bugle, tormentil, red clover, lady’s bedstraw, white campion and greater knapweed. Air pollution combined with decades of poor management has seen the floral richness of our verges decline by nearly 20%.
Dr Trevor Dines, Plantlife Botanical Specialist, commented: “Our once colourful and botanically diverse road verges are becoming mean, green thickets where only thuggish species can thrive and more delicate flowers are being driven to the brink of extinction.
“After the froth of cow parsley in May, many verges no longer enjoy a bountiful summer; for the 23 million people who commute to work by road, the verge can be their only daily contact with nature – a floral parade of pink orchids, sapphire-blue tufted vetch, white oxeye daisies and billowing yellow lady’s-bedstraw – that we know can boost health and wellbeing.”
Why road verges matter
- So often undervalued, road verges are home to over 700 species of wild flower – nearly 45% of our total flora – including 29 of 52 species of wild orchid.
- As other grassland habitats disappear – 97% of meadows have vanished since the 1930s (5) – verges are a last remaining refuge for many bees, butterflies, birds, bats and bugs as the wider countryside becomes increasingly hostile. Red clover and lady’s bedstraw, two of the top six verge species that support the highest number of invertebrates (6) – are amongst the plants experiencing the most rapid decline.
Dr Dines said: “The destructive impact of air pollution on human health is well documented but how pollution affects plantlife remains under-appreciated: vehicle exhausts can result in up to 2.5 kg of nitrogen per mile per year being dumped on our road verges – a rate that only a fraction of our wild flowers can cope with.
“Poor management has combined with pollution to create a perfect storm. Not only have councils adopted an over-eager regime that sees flowers cut down before they can set seed, but the mowings left on the verge simply add to the soil richness. Under this management, summer-flowering plants such as eyebright and harebell are disappearing and only the toughest of characters – like nettle and bramble – are prospering.”
Plantlife’s vision for Britain’s road verges is simple: verges remain safe for motorists but are managed for wildlife as a matter of course. Some strikingly simple changes – like cutting less and later in the year and harnessing the power of semi-parasitic yellow rattle to act as nature’s own lawnmower – can significantly improve the biodiversity on our verges, bringing benefits for wildlife, for us and for future generations.
Plantlife can reveal today the spectacular results a concerted regeneration of our road verges could deliver. Plantlife research estimates that if all of the road verges in the United Kingdom were managed for nature there would be a spectacular 418.88 billion more flowers, or 6,300 per person in the UK.
Dines added: “Verges are positively bursting with the untapped potential to arrest the alarming decline of our wildflowers and wildlife. If all our verges were managed for nature we would see an area the size of London, Birmingham, Manchester, Cardiff AND Edinburgh combined adorned with wildflowers.
“This surge in pollen and nectar would have a genuinely transformative effect on the prospects of wildlife – half of which we have tragically lost in the past 50 years alone. Re-enlivening our neglected roadside offers us a route away from biodiversity oblivion.”
Over 24,600 people have signed Plantlife’s petition calling for councils’ management to better benefit flowers and wildlife. Those councils that have already adopted our guidance have seen strong floral and financial results. Dorset Council estimates they have saved over £100,000 through, among other things, fewer cuts since 2004.
Pictures: Plantlife