KNP is one of the most biologically richest territories in Latvia that results from interaction among various factors such as geographic location, geological structure and soil bedrocks, hydrological regime and land use in the past and present. Totally 897 vascular plant, 206 moss (36 liverworts and 171 hornworts), 148 lichen and 586 fungus species had been found in KNP.
Vascular plants
Totally 114 vascular plant species should be written into the red list of KNP taking into account all species which had been found at least once. However, only 2/3 of this number had been repeatedly found within the last decades, while several have gone extinct not only from the flora of KNP, but also vanished from all the territory of Latvia.
Extinctions are greatly related both to natural processes and human-caused pressures. Changes in land use and agricultural practise over the last century are among the most important affecting factors. As an example, relatively small arable lands within the current national park provided suitable habitats for several plant species such as common corncockle Agrostemma githago, Camelina alyssum and small fleabane Pulicaria vulgaris. Until the 19th century they were reported as common tillage weeds throughout the country, while for the time being they are going extinct in all Europe which results from current agricultural practices. Most probably, several species previously found in KNP have vanished due to natural vegetation change and change of hydrological regime (e.g. Sisymbryum supinum and allseed Radiola linoides).
Meadow plants are among the most endangered also in the territory of KNP, since many of the formerly regularly mown grassland and pastures are abandoned. The originally diverse meadow vegetation is becoming poorer in species due to competition by tall grasses, herbs and shrubs that tend to dominate after abandonment. Up to now, the meadow species had been promoted by regular interaction of nature, humans and livestock, while cessation of mowing and pasturing causes degradation of this ecosystem. At the moment, there are big efforts in several areas of the national park in restoring meadows by clearing shrubs, re-establishing regular mowing and pasturing.
Calcareous fens and moist calcareous meadows are rare protected habitat types in Latvia, while they are relatively frequent in KNP. In some areas on dolomite bedrocks large patches of fens with great fen sedge Cladium mariscus and alkaline fens with Schoenus ferrugineus are present as well as fens with bog myrtle Myrica gale, purple moor grass Molinia caerulea and blue moor grass Sesleria caerulea dominated meadows. Calcareous fens and meadows provide suitable conditions for several ecologically specific rare species, e.g. common butterwort Pinguicula vulgaris, bird’s-eye primrose Primula farinosa, Buxbaum’s sedge Carex buxbaumii, fen orchid Liparis loeselii, several orchids (Dactylorhiza sp.), bog rush, great fen sedge, bog myrtle etc.
Some shallow lagoon lakes with dolomite or muddy grounds are rich in stonewort (Chara) species. Several rare aquatic species grow in the lakes of the national park – spiny naiad Najas marina, horned pondweed Zannichellia palustris, soft hownwort Ceratophyllum submersum and narrow leaf bur-reed Sparganium angustifolium.
There are several floristic peculiarities in KNP, e.g. one of two known localities of a regionally endemic species Estonian sawwort Saussurea esthonica is found in KNP. Some plant species in Latvia are rare not only due to negative impacts, but they reach the boundary of their distribution range: gladiolus Gladiolus imbricatus‚ Hungarian sainfoin Onobrychis arenaria‚ bog spurge Euphorbia palustris‚ bog myrtle Myrica gale.
The dunes along the southwest coast of the Riga Gulf provide habitats for several species adapted only to coastal habitats, e.g. halberdleaf orach Atriplex calotheca, sand pink Dianthus arenarius, goat’s-beard Tragopogon heterospermum, Anthylis maritima, Peucedanum oreoselinum, Corispermum intermedium.
Rich deciduous and spruce forests host one the Latvia’s largest populations of yellow lady’s-slipper Cyperipedium calceolus; there are several known localities with rattlesnake grape-fern Botrychium virginianum, lesser hairy-brome Bromopsis benekenii. Dry pine forests are suitable habitats for flattened clubmoss Diphasiastrum complanatum, stag’s-horn clubmoss Lycopodium clavatum, meadow and spreading pasqueflowers Pulsatilla pratensis and P. patens and Hungarian sainfoin Onobrychnis arenaria.
Mosses
The most interesting and rare moss species had been found in natural undisturbed deciduous or mixed forests with trees of various age, large-size wind-fallen and decaying trees. Particular moss, lichen and fungus species are excellent indicators for naturalness and biological value of the forest. Specific moss flora had been found also in calcareous fens and in fens surrounding sulphurous and calcareous springs. 34 of moss species found in KNP are under protection. Large variety of natural habitats still provides opportunities for ecologically specific, rare mosses, e.g. one of two known localities of Harpanthus flotovianus takes place in KNP. A moss species listed in the Annex II of the EU Habitats’ Directive – Dicranum viride had been found here.
Fungi
In KNP, 39 species had been noted as rare by the researchers including species found only in KNP. Grifola umbellata‚ Xerocomus parasiticus‚ Geastrum quadrifidum‚ G. pectinatum‚ G. rufescens‚ G. triplex‚ Gyrodon lividus‚ Ganoderma lucidum‚ Sparassis crispa‚ Xylobolus frustulatus and Phellinus nigrolimitatus are mentioned as red list fungi species in KNP in many cases requiring specific habitats, mostly woodlands. Some of them are Junghuhnia collabens‚ Hapolopilus salmonicolor‚ Dichomitus campestris‚ Perenniporia subacida‚ Polyporus badius‚ Pycnoporellus fulgens‚ Oligoporus guttulatus‚ Tyromices fissilis‚ Ceriporiopsis pannocincta, Onnia tomentosa and Elaphomyces levellei. The black truffle which grows under the soil had been found and is thought to be still present in the national park as well as the rare smut Entorrhiza aschersoniana, a parasite dwelling on the roots of toad rush Juncus buffonius. Six new species for Latvia were found in 1997 on the beach in Ragaciems on organic deposits: Ceriosporopsis tubulifera‚ C. halima‚ Corollospora intermedia‚ C. maritima‚ Marinospora calyptrata and Amylocarpus encephaloides, while 16 new species for Latvia were found in sulphurous springs on decaying leaves.
Lichens
The large habitat variety in KNP provides suitable habitats for ca. 34% of the total number of lichens in Latvia. Perhaps the number is larger than known at the moment. KNP host the only known locality of Cladonia incrassata in Latvia, while 3 new lichen species for Latvia were found in the vicinity of Kaņieris Lake: Buellia griseovirens‚ Calicium glaucellum and Stenocybe pullatula. Among the lichen rarities of the national park also Opegrapha viridis and Thelotrema lepadinum (red list species) should be mentioned. Chaenotheca cinerea also being present in KNP had been rarely found in old-age coniferous woodlands.
Lichens Thelotrema lepadinum and Calicium quercinum which grow only in old-age undisturbed deciduous and mixed forests are of high conservation value due to their vulnerability to environmental change. Their abundance and number of localities are evidently decreasing due to air pollution and forest management.
Trees under protection
In Latvia, unusually large trees or trees of unusual shape are considered under national or local protection. The criterion for being a protected tree for birches, pines and spruces is perimeter larger than 3 m at breast height, for oaks – 5 m.
In KNP, two native, two introduced trees are under protection, while some others with their large-size stems or unusual shapes are worth to mention and are potentially protected. The largest birch in the Baltics may be found in the vicinity of Valgums Lake. A large, impressive pine tree can be easily found in the coastal village in Bigauņciems by the bus stop. Some interesting introduced trees grow in Kemeri Park in the vicinity of the former hotel ‘Ķemeri’ – a large Mandschurian walnut tree with twisted branches, unusually-shaped European white birch and Karelian birch.
Last revision 23-10-2008
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