When a canary died in a coal mine it was a strong warning to get out. The canary was a sensitive meter, a living organism with all its strengths and frailties warning of toxic gas, usually methane or CO2.

A new warning organism has been found in northern Sweden, Diapensia, a dwarf, white-flowered, evergreen shrub that hugs the ground and looks like a small greenish-reddish igloo. It grows in cold habitats in the circum-arctic region, throughout much of Newfoundland-Labrador and also Mt. Marcy and Mt. Washington in New England and the Cape Breton Highlands of Nova Scotia.

My correspondent Prof. Ulf Malau, of Sweden's Gotborg University, has observed a mass die-off, of these plants, about 20%, in 5 years of observation. Findings were published in Ecological Bulletins (V.45) in 1996 and the Nordic Journal of Botany (Vol.17) in 1997 and in a Swedish government press release on the internet (Marianne.Lillieskold@environ.se).
Prof. Malau has estimated that large Diapensia plants are as much as 700 years old. These are some of the oldest organisms on the planet and very sensitive to transplanting and trampling by hikers. This die-off devastates the population and is non-reversable because new plants are not becoming established.

The cause of the die-off is known...early spring thaws caused by global warming. Yes, global warming like evolution, are measurable and no longer theories.

Dr. A.W.H. Damman (at Storrs Connecticut) and I found evidence for Diapensia's heat intollerance in studies conducted in Newfoundland (Federal Forestry and Memorial Univ. respectively) between 1976-85. The Diapensia populations in Canada, New England and Alaska may also be dying out at unknown rates. I reported a low frequency of young Diapensia plants and the dying of larger plants in the 1980s at Holyrood's Hawke Hills, southeast Newfoundland.
An extract from my Atlas of Labrador Plants (p.xx) reads:
"Diapensia is a compact, dwarf evergreen shrub, widespread in Labrador on foggy hill tops and exposed coastal site that remaim cool in summer. I spent a number of years studying this plant (Day 1978 etc.) and found it very difficult to keep alive after transplanting. It is remarkably intolerant of high temperatures as it is known to have poor internal water transport and seems unable to cool or rehydrate itself in strong sunlight. These two related hypotheses need experimental testing. Anybody interested?"

Is the decline of Diapensia the only effect we are to expect from global warming? What could happen to our natural resource sectors? The Swedish press release indicates we should expect permafrost melting in the north allowing landslips, slow growing arctic and mountain evergreen plants may decline while grasses and dwarf birch and willow espand. Eratic weather we have experienced in recent years. Lack of snow cover exposes many sensitive plants and animals and they may decline as well. Forest trees may actually show a boosted growth rate with global warming but ice storms could subtract this with increased breakage and frost damage to shoots. Midsummer drought can also depress tree growth.

Nobody is certain what is going to happen, but change is happening and more is on the way.
Plant die-offs, massive ones, are well known in Newfoundland and Labrador as in other parts of the world. Acid rain around Sudbury Ontario and in Chekoslovakia killed off large forests, massive damming and flooding around Lake Michikamau in Labrador created the huge Smallwood Reservoir in the 1970s. Forest fires sweep over north Canada and Siberia each year and a meteor or comet hit the sea at Yucatan Mexico, killing most forest and dinosaurs, ending the Cretaceous age. Our world vegetation changes and something always grows back as "nature abhors [an ecological] vacuum". All this means nothing to most people. The big scares are still to come. The Arctic and Antarctic sea ice IS melting. This will drastically change world sea level and the Labrador Current. Will this current run hotter or colder in the next 20 years and how will this affect our way of life? Hefty questions yes. Computer models of ice and water movement should tell us a lot.

When I studied Diapensia in the 1980s at Memorial U. with my ever-helpful teacher Peter Scott we saw it as an attractive but obscure and not very useful wildflower. Nobody is more surprised than me to find it now viewed as a canary of global warming. Next time readers go out to pick blueberries on the hills and mountains you may be lucky to see a white-flowered Diapensia. It could be the first you have seen and soon be gone from much of Canada-Alaska.

A draft of this article was published a couple of yars ago in Rural Delivery magazine, Nova Scotia, Canada.

Copyright 2006 Robin Day