Arctic Plants

Arctic Plants

In the Arctic, growing conditions for vegetation are very varied. In the southern reaches of the Arctic, plant communities can be vigorous, with small trees and stands of low growing shrubs. The further north one travels, the shorter and more sparse the ground cover becomes until in the high arctic, which is a true desert, the plants are scattered across rocky ground and the most numerous plants are the lichens. Here the carpets of flowers are only found below bird cliffs or other areas of high fertility.

During the winter months the plants need to rest under the blanket of snow and be ready for a quick getaway as soon as the temperature gets high enough. Nearly all arctic plants grow their flower buds in late summer, then they overwinter and are ready for an early start the next spring. In order to survive the low temperatures and cold winds the plants grow close to the ground and many of then have small leaves to stop evaporation. I was fascinated to see, on a summer visit to Franz Josef Land, how plants that I was familiar with further south, that had flowers on longish stems like the Alpine saxifrage, Saxifraga nivalis, in the very marginal conditions on Franz Josef Land the flower was nestled within the rosette of the leaves, there is safety in keeping your head down! By growing in clumps the plants are protected from the wind and the dark green foliage of some of the plants, warm up quickly and then the air within the canopy of the plant warms up, sometimes it is as much as 20C above the ambient air temperature, giving that plant an advantage.

Purple Saxifrage in snow
Different plants have different coping strategies, Moss campion has a deep taproot and colonises ground, giving cover to less robust plants. The Arctic Willow in its many forms is found all over the Arctic, its stems, although not thick could be hundreds of years old. A forest less than 6 cm high. The bowl shaped flowers of the Arctic Avens and the Arctic Poppy follow the sun around the sky to optimize the warmth from it. They are a popular resting place for pollinating insects because of the warmth focused into the centre of the flower. Arctic bell heather thrives in hollows where a covering of snow protect it from sharp driving snow in winter, the price it pays for this blanket of snow is a shorter growing season, while it waits for the snow to melt. Mountain Sorrel can survive under snow patches for several years, during summers when some of the snow doesn’t melt.

Grasses and rushes do well in the boggy tundra soils with cotton grass flowering conspicuously in the damp land close to streams and lakes, but a closer look will reveal that there are often sedges and Poa grasses growing alongside it

Plants in Thermal Underwear

The Wooly Lousewort and the Hairy Lousewort both protect their precious flowers with a lot of silvery hairs giving the impression of wearing thermal underwear but the plant with the most impressive thermal underwear is a large groundsel found in the subarctic. The Mastadon Flower, Senecio congestus grows to about 1m in height and is covered in long white fur.

Mosses and Lichens

Bear Flower & Lichen
Conditions do appear to favour the mosses and lichens and there are frequently areas with no sign of any vascular plants but with a wide variety of lichens and mosses. But these are slow growing and any damage to them takes many decades to regrow. Sometimes in the very far north the ground is covered in a coating of black lichen. The delicate Reindeer Moss, which is actually a lichen, grows best in the low arctic where it can cover the whole ground with its spongy light coloured threads. There are often bright orange sheets of lichen close to bird activity where generations of bird poo has fertilized the rock face. This is Elegant Orange, Xanthoria elegans. Another common lichen in the Arctic is Map Lichen, Rhizocarpon geographicum which has bright greenish yellow plates surrounded by a black line of spores. Map lichen is used by climatologists to determine the age of a rock deposit, by knowing the rate of growth, they can judge the age of the largest piece of lichen on a rock and assume that the rock was in place when the lichen started to grow.

 


Text © B & C Alexander