THE discovery of the Lake District’s smallest tree could help monitor climate change.

Since the start of its search in 2012, Cumbria Wildlife Trust has mapped the location of the dwarf willow to 54 Wainwright summits.

Mike Douglas, the trust’s upland plant expert, said: “Although records provided a good basis for our survey, this is the first time that anyone has attempted to quantify and map the whereabouts of dwarf willow.

“Our volunteers have found it down to an altitude of 535 metres on Buck-barrow, an outlying fell to the south west of the Lakes, and on the summit of Scafell Pike.”

He added that it was also discovered in previously unknown places like Black Combe, near Millom.

The charity said this hardy tundra species was adapted to extreme condi-tions and short growing seasons.

It was only found on high mountains in the UK, with the Lake District being its last stronghold in England.

The low-growing, carpet-forming plant was usually less than five centimetres high and came into leaf in late May, throwing out male and female catkins which would later be spread by the wind.

The trust said its niche on cold mountain tops meant that it might be a good indi-cator of climate change, gaining altitude with higher temperatures or disappearing from some summits entirely.

Mr Douglas said: “Many of the locations have just a few scattered plants measuring less than 0.1 metres squared, but large carpets were found on Red Pike at Buttermere, Grasmoor, Crag Hill and St Sunday Crag, where it covers almost three hectares of the summit plateau.

“Our surveyors will carry on the survey to complete the search of Wainwright summits and gather more details at key populations.”