the vegetation have been extracted from the report of Buys (1987) This oceanic
mire complex consists mainly of bogs. In about 10 percent of the area fens have
developed under influence of more mineral‑rich water. This water originates
from the surrounding mountains, or is seeping out of the bogs and is probably
enriched by the subsoil of the bogs. Both fens and bogs show a wide morphological
variation. For desmids the most important feature is that many of the hollows
and flarks (the wet parts of the mire) are permanently filled with a few decimeter
of water forming an enumerable number of pools
Roughly two major fen types may be distinguished. (Chemical differences are schematic). One fen type is fed by springs from the surrounding mountains, chemically characterized by a 1:3 Mg:Ca ratio, morphologically by numerous occurrence of flark pools and strings, and botanically by the presence of Molinea caerulea, Carex panicea, Calliergon trifarium. Also Phragmites australis occurs frequently.
The second fen type is fed by springs in the middle of the mire, chemically characterized by a 1:5 in some cases 1:10 Mg:Ca ratio, morphologically by a smaller and less orderly arranged small relief, and botanically by species like Comarum palustre, Carex chordorrhiza, Equisetum fluviatile, Calamagrostis neglecta, Oxycoccus quadripetalus, Drepanocladus purpurascens, and others. Many of these species are characteristic for what Eurola and Kaakinen (1980) call swamp influence. Phragmites australis occurs in well defined plant communities. The transition between bogs (which show a Mg: Ca ratio of less then 2:3) and fens of the first type may be very subtile. It occurs in wide bands or narrow zones between the two.
On the wettest places, the major habitats for desmids, different combinations of mosses can be observed. These vegetations are so wet that all Ericaceae are lacking. In general the oligotrophic and meso‑eutrophic vegetation types are common, those in between less common. The vegetation types that have been sampled for desmids are listed below. The name of the type is preceded by the code number in Buys (1987).
Andromeda‑ Gymnocolea hollow vegetation, oligotrophic. This vegetation occurs on the transition between hummocks and hollows, or in pure lawns in oligotrophic mire expanse situations.
Sphagnum angustifolium vegetation, oligotrophic. This vegetation develops under mire‑margin conditions, as lawns or carpets. A slight minerotrophic influence is typical.
Oligotrophic wet hollow and pool vegetation. This vegetation grows on the wettest sites in bogs. Dwarfshrubs and herbs only occur incidentally. The vegetation is build up by an open graminoid layer, and a rich to very scanty moss layer that consists only of the most wet‑tolerant oligotrophic species.
Oligo‑mesotrophic wet flark vegetation. This vegetation concerns flarkpools and wet mudbottom‑like structures, in oligo‑mesotrophic areas. Characteristic moss species are: Sphagnum annulatum, S. plathyphyllum and Drepanocladus procerus. These species indicate a nutrient status intermediate between oligotrophic and mesotrophic situations. The field layer is better developed than in '10' and '11'. Of the dwarf shrubs only Andromeda polifolia occurs sporadically.
(Oligo)‑mesotrophic lawn and low hummock vegetation. This type of vegetation occurs on low strings or lawns in intermediate fens. Rich fen species occur only sporadically, and Sphagnum species dominate the moss layer. The two communities share a high frequency of Betula nana, Menyanthes trifoliata, Scapania sp., Calliergon stramineum and Viola palustris.
Meso‑eutrophic lawn and hummock vegetation. This vegetation includes lawns, hummocks and strings in meso‑eutrophic fens.
Mesotrophic to eutrophic vegetation with swamp character. Characteristic species are Comarum palustre, Calamagrostis neglecta, Drepanocladus purpurascens, Equisetum fluviatile, Oxycoccus quadripetalus, Sphagnum teres, Mnium rugicum/cinclidioides, and as for Andøya this list can be completed with Carex chordorrhiza, Calliergon sarmentosum and Pedicularis palustris, and maybe also more scarcely occurring species as Calliergon richardsohnii and Sphagnum contortum might be added.
giganteum community. The most nutrient rich (eutrophic) type of this
mire. Except for the species mentioned, and many swamp species, also Carex
diandra is characteristic. This community develops in springs in
the mire expanse, which occur as very deep pools.
19 Calliergon sarmentosum‑Drepanocladus purpurascens community. In addition to the species mentioned above it shows a very species‑ rich moss layer due to minor height differences around the waterline. Oligo‑mesotrophic as in '12' and '13' but notably more rich in sulphate. No Carex chordorrhiza, but a varying fieldlayer with regularly Phragmites australis, Triglochin palustre and Andromeda polifolia. It grows in very shallow pools, drier than '13'.
20 Sphagnum subsecundum‑Drepanocladus purpurascens community. Characterized by the above‑mentioned species, and a moderate swamp influence. It occurs on transitional places between 'normal' fens and swamp fens. The vascular plants are similar to those in the oligo‑mesotrophic types ('12' and '13'). Also the trophic status is comparable. It develops just above the water surface in shallow waters. It is periodically inundated. Slight swamp influence, less than '19' and '21'.
21 Carex chordorrhizza community. Characterized by the name giving species. The numerous swamp species are common, just as Andromeda polifolia. The trophic status varies from 'rich' oligo‑mesotrophic ('13') to meso‑eutrophic. This is the most common swamp comunity.
22 Narthecium‑Sphagnum papillosum community. Dominated by Narthecium ossifragum. It is a moist lawn community, which is permanently wet but rarely inundated. There is always a superficial water run‑off.
Spring and spring meadow vegetation.
27 Phylonotis community. The vegetation is quite heterogeneous, with many herbs and graminoids. Important mosses are Phylonotis fontana, Cratoneuron decipiens and Bryum pseudotriquetrum.
Fontinalis vegetation. Recorded once, near a spring with a constant temperature at a shady place.Mossless pool and lake vegetation. Many (bog) pools without mosses bear no vegetation at all. Lake shores may be mossless due to erosion. Here Carex rostrata, Phragmites australis, Equisetum fluviatile and Menyanthes trifoliata can form facies.