One of the UK's most spectacularly insignificant plants seems to about to become extinct in this country but in its death throes it is providing researchers from the University of Warwick with important information about the pace of climate change in the UK.
The Iceland Purslane plant is found in only two localities in he UK, the Storr on the Isle of Skye, and on the Ardmeanach Peninsula on Mull - although it is widely distributed in the higher latitudes of the northern hemisphere - in Norway, the Faroes, and Iceland. It also occurs around the south pole in places such as Tierra del Fuego.
Dr Barry Meatyard from the University of Warwick's Institute of Education is directing a project to monitor the growth of the plant over a number of years and to relate that information to climate change and other biological factors. In the last few years numbers of plants have declined dramatically, in one area there has been a 80% reduction since 1994.
This decline seems to be an indicator of long term climatic change. The Mull Purslane plant population is remotely situated and therefore is unlikely to be affected by herbicides or other direct human influence, however, it is the most southerly situated of the plants and is currently probably at the limit of its climatic range. Any changes in the population over the long term are thus possibly caused by climate change.
What is certain is that the early part of the year has been much drier on the west coast of Scotland in recent years and this spring (1997) many of the burns had dried up by the end of June giving many remote houses cause for concern. By studying the plant the researchers will be able to determine if aberrations in weather are becoming part of a longer term pattern. If climate change is occurring and these weather patterns become more long term it seems likely that the Iceland Purslane could become extinct in Britain. The loss of such an insignificant little plant is not likely to cause high drama in the same way that the loss of 'sexy' species such as orchids does, but it is an indication that climatic change will have measurable effects on our plant life.
In the UK the Iceland Purslane is regarded as a relic from the last glaciation. As a member of our arctic alpine flora it is unusual in that it is an annual and its abundance from year to year thus depends on the quality of the seed bank in the soil. It appears to have very specific ecological requirements and grows on open basalt gravel terraces where there is little competition from other species. It is a small member of the Dock family with large specimens being 4 cms high with tiny greenish flowers about 3 mm across.
Note for editors: Dr Meatyard is working with the following organisations in connection with this project:- Scottish National Heritage, the National Trust for Scotland and the Royal Botanic Garden in Edinburgh.