Most people visiting the Arctic hardly recognise the bryophytes at all. At the very best, they distinguish a green or yellowish carpet of “mossy things”. If you find yourself in a polar environment apparently without vegetation, just kneel down and take a closer look. The probability that you will observe one or more specimens of bryophytes is very high.
The collective term bryophytes includes mosses (Bryophyta), liverworts (Marchantiophyta) and hornworts (Anthocerotophyta). While hornworts are not represented in the Arctic, liverworts and mosses are commonly distributed. The branch of botany devoted to the scientific study of bryophytes is called bryology.
Bryophytes belong to an ancient, primitive evolutionary plant group consisting of mosses, liverworts and hornworts. They appeared before flowering plants.
Although bryophytes are considered simple in structure and they are the most primitive plant group, they are highly successful from an evolutionary point of view. They are small, but highly successful in establishment and survival all over the earth. We can find them growing on house walls, in gardens, on trees, stones, close to the ocean and high up in mountains, from warm to cold climates and under both wet and dry conditions. Bryophytes are often the first plants to colonise newly exposed ground, and tend to dominate or survive as the only plants under stressful environmental conditions such as extremely exposed ridges, dry substrate or saline environments. Several bryophyte species are specific for particular micro-environments and they are sensitive to certain environmental conditions, making them suitable as environmental and ecological bioindicators.
The ability of bryophytes to survive where no other plant seems to thrive is related to the bryophytes’ amazing ability to withstand desiccation, their high phenotypic plasticity, and their ability to adjust net assimilation rates with temperature. Bryophytes also have a high ability to retain water, due to their internal structure (especially the genus Sphagnum).
Bryophyte-rich vegetation habitats, such as peatland and moss tundra, are important carbon sinks from Arctic to temperate zones, and contain some of the globe’s largest carbon reservoirs. Their overall contribution to vegetation productivity becomes more important in Arctic ecosystems as their cover and diversity increases relative to that of vascular plants. Especially in the Arctic, they are very important in terms of vegetation cover, abundance and biodiversity. Due to their insulating properties, they are important in maintaining the permafrost.
In a warming climate, the major effects on bryophytes are likely to be induced through hydrological changes in their habitats and shifts in competition pressure as vascular plant growth forms and plant cover changes.