THE tree mallow was once described by a naturalist as "the glory of Craigleith" - but this pretty Mediterranean plant has turned from rare and exotic beauty into a rampaging weed that has almost driven puffins on the Firth of Forth island to extinction.
From 28,000 pairs of birds in 1999, the population has plummeted to just a few thousand today as the mallow has covered virtually the entire island, blocking up the birds' burrows and allowing few other plants to grow.
However, it was announced yesterday that 235,000 - from the proceeds of a tax on rubbish dumped in landfill sites - has been given to the Scottish Seabird Centre to help fund an extensive "SOS Puffin" campaign to hack back the tree-mallow jungle on Craigleith.
After conservation efforts were kickstarted last autumn by the Channel 4 programme Wild Thing, I Think I Love You, featuring comedian Bill Bailey, a major programme of work will now be carried out over a five-year period to enable plant and animal to live together in relative harmony.
The cash will pay for regular boat trips to the island to take squads of volunteers to cut back the mallow, which has spread rapidly, partly because of fewer winter frosts as the climate warms.
Ironically, the plant has also benefited from the puffins' previous success. As puffin numbers on the island rose, their guano fertilised the soil and their burrows made it easier for the mallow to take root.
Dr Rene Van Der Wal, an ecologist at the Centre for Ecology and Hydrology at Banchory, who studies the puffins on Craigleith, said: "They dug their own graves effectively, which is a bit sad.
"It was very dramatic, it changed the whole landscape - last year 75 per cent of the area was covered with tree mallow and as soon as the plant is in there, the puffins have to move out.
"We lost over half of the pairs in a five-year period and the situation has got worse ever since."
The extra funding of the SOS Puffin campaign, he said, would enable the removal of large numbers of plants so "puffins and tree mallow can live happily together".
The money will also be used to set up four solar-powered cameras on the island to monitor the birds and similar work will be carried out on the island of Fidra in the firth.
Puffins, highly sociable birds which mate for a life that can last 20 years, tend to return to the same burrow.
Large numbers arriving at Craigleith have been seen in the water off the island, unable to find a place to congregate and burrow.
This makes them more vulnerable to predators like peregrines and great black-backed gulls as well as herring gulls, which do not eat them but will kill puffins to steal their sand-eel catch.
Maggie Sheddan, a seabird centre volunteer who runs boat trips to Craigleith, said the fast-growing mallows had "exploded" since the 1980s and had created an almost impenetrable jungle. The "wonderful" award of money would enable regular boat trips to the island.
She added: "I've seen gulls caught up in the mallow which have just died because they have got in a tangle. I don't think we'll ever get rid of it completely, but we can pull it back dramatically."
• LIKE many seabirds, the fate of the puffin is closely linked with its favourite food - the sandeel. Populations of sandeels, which are fished on an industrial scale to make fertiliser, feed farmed fish and even to be burned in power stations on the Continent, are going through a turbulent period. Experts say the tiny fish will have a bad year, causing extinction for many seabirds, and then a good year, with no clear pattern.
Sandeel fisheries have been closed and reopened periodically amid concern about their numbers, but it is difficult to develop a clear picture of what is actually going on.
What does appear certain from studies of sandeels eaten by seabirds is that the average size of the adult fish is getting smaller. This means puffins and other seabirds must work harder and expend more energy to provide their chicks with the required amount of calories.