Plant Atlas 2020 is the most in-depth survey of British and Irish flora ever undertaken, and the results show a devastating loss.


Building on two previous Atlas surveys from the twentieth century, thousands of botanists from the Botanical Society of Britain and Ireland (BSBI) have spent twenty years collecting data on changes in British and Irish flora.

Their findings have shown that four main trends have emerged since the 1950s:

  • 53 per cent of native plants have declined in Britain due to human impacts.
  • Non-native plants now outnumber native plants in the wild.
  • Many montane plants have declined due to climate change.
  • Some non-native species have become invasive and are disrupting ecosystems.

Julia Hanmer, Chief Executive of BSBI said the study presented a "powerful and concerning insight into the changing distributions of our wild plants."

3,445 different plant species were recorded; 1,692 are native to Britain and 1,753 non-natives were found that have been deliberately or accidentally introduced to the wild by humans.

Changes in agriculture since the 1950s have had a large impact on the habitats that our wild plants depend on. Nitrogen enrichment, habitat degradation and changes in grazing pressure have led to the decline of species such as heather and harebell, whereas the draining of damp meadows has led to substantial declines in devil's-bit and scabious. Traditional grasslands have been reseeded or over-fertilised and 62 per cent of ancient arable wildflowers such as corn marigold have declined as a result of this.

© Kevin Walker

Climate change is likely to be the leading cause of the decline of some mountain plants such as alpine lady-fern, alpine speedwell and snow pearlwort. Peatlands, which will be essential in our efforts to combat climate change, are being affected by species such as Sitka spruce which regenerate into these habitats and reduce their ability to sequester carbon.

Recording on Colonsay. Image by Pete Stroh
© Pete Stroh

Moving forwards, Plant Atlas 2020 data can help to guide land-use management decisions and BSBI have already been working with Natural England through the Natural Capital and Ecosystem Assessment Programme and with The Wildlife Trusts who helped fund the publication of the study.


Head of Science at BSBI, Dr Kevin Walker said of the findings "There’s lots we can do to reverse these declines, but the most important are to increase the protection plants receive, extend the habitat available to them, and to place their needs at the very heart of nature conservation."


Molly Blair
Molly Blaireditorial and digital assistant

Molly is the Gardens Illustrated's editorial and digital assistant. She has a roof garden and has her RHS level 2.