Thursday, August 18, 2016
Scotland's rare mountain plants disappearing as climate warms, botanists find
Let us assume that the fieldwork described below is entirely accurate and adequate. Let us also assume that there has been some warming in Scotland and that the warming is having an adverse effect. That still tells us nothing about WHY the warming is happening. Is it local warming or is it anthropogenic global warming? It is NOT anthropogenic global warming. Why? Because there has been none of that this century.
So could it be due to the recent warming caused by El Nino? As it happens, no. Why? Because they tell us below that there has been unusually heavy snow in recent winters. El Nino missed Scotland, apparently. So what we are left with is that plants WERE retreating during a period of NO anthropogenic global warming but are not retreating now. It would take the wisdom of Solomon to make something out of that
There is clear evidence that some of Britain’s rarest mountain plants are disappearing due to a steadily warming climate, botanists working in the Scottish Highlands have found.
The tiny but fragile Arctic plants, such as Iceland purslaine, snow pearlwort and Highland saxifrage, are found only in a handful of locations in the Highlands and islands, clustered in north-facing gullies, coires and crevices, frequently protected by the last pockets of late-lying winter snow.
A series of studies by the National Trust for Scotland (NTS), the historic building and landscape charity, has found these plants – relics from the last period of glaciation, are retreating higher up the mountainside or disappearing entirely. In some cases they are being replaced by grasses previously found at lower, warmer altitudes.
Iceland purslane, an Arctic species which is extremely rare in the UK and found only on the Hebridean islands of Skye and Mull, nestles in protected spots on areas of volcanic basalt at heights above 400m.
Surveying on the Burg peninsula of Mull had found the tiny annual plant was being severely hit by increasingly warm springs, which had also led to increased growth by other plants competing for space.
On Bidean nam Bian next to Glencoe in Argyll, the latest field surveys found a 50% decline in Highland saxifrage at lower altitudes compared to the numbers detected in 1995.
Their surveys on Ben Lawers, a 1,214m high peak on Loch Tay in Perthshire which is regarded as a mecca for botanists, had found “a very worrying decline” in the numbers of snow pearlwort. An inconspicuous cushion-forming flowering plant, it which only survives in the UK on Ben Lawers and several places in the surrounding Breadalbane mountains at heights above 900m.
Sarah Watts, a seasonal ecologist for NTS, said the plant was at the southern limit of its natural range on Ben Lawers. Half of the sites found in 1981 had now become extinct, although heavy snow in the recent winters had helped halt the effects of climate change.