Bryophytes are the second most diverse group among land plants after the flowering plants (Magnoliophyta, ~350 000 described species; Glime 2007). Defining the number of species of bryophytes worldwide is difficult, since new ones are discovered constantly and different textbooks give different estimates. However, a conservative estimate would be between 15000-25000 species (Glime 2007, Shaw et al. 2011). 

Many bryophyte species are very sensitive to certain environmental conditions – both naturally occurring and imposed by anthropogenic activity. Bryophytes are used as indicators and we distinguish between bioindication and biomonitoring. Bioindication Bioindication involves a qualitative response recording species presence or absence. E.g. acidic contamination on Svalbard was identified by the presence of Mielichhoferia elongata

Bryophytes have many important ecosystem functions in the Arctic. These include: Regulation of hydrology In many habitats, bryophytes control soil and vegetation hydrology (Beringer et al. 2001). This is mainly due to their large capacity to absorb and retain water. Especially Sphagnum is known for its capacity to retain water in both intra- and extracellular spaces, even

Bryophytes are found throughout the world from the harsh environments of Antarctica to the lush conditions of the tropical rainforests. Despite their small size, they can dominate with extensive carpets in mires, bogs, woodland, oceanic heath vegetation, or as epiphytes on trees and bushes, especially where soil and/or air moisture is high. Bryophytes’ contribution to

Bryophytes are very resilient and have a unique ability to recover from long-lasting extreme environmental conditions (La Farge et al. 2013, Procter et al. 2007). Bryophytes show a high degree of phenotypic plasticity as well as a remarkable ability to photosynthesise whenever conditions are favourable. Both these traits enable them to survive in cold regions (Turetsky