Swamp National Nature Monument

The Swamp NNM was declared in 1972 on an area of 1.45ha, with a buffer zone of 12ha, to protect unique littoral flora and fauna on a marsh with a fenny character and Pleistocene alluvial sands. This territory is of great significance for its algae populations. Part of the territory belongs to the Českolipsko-Dokeské pískovce a mokřady SPA – Bird Area ad to the Jestřebsko-Dokesko proposed Site of Community Importance.

The protected area lies in the Liberecký kraj – Liberec Region, by the town of Doksy on the Máchovo jezero Lake, and covers part of the south-western bank of the lake. The monument lies at elevations of around 265 metres above sea level. The geological basement is built of Upper Cretaceous sandstones from the Middle Turonian period and sandy floodplain deposits. The humolite formed after the groundwater levels rose when the Velký rybník Fishpond (Máchovo jezero Lake) was founded in the 14th century during the reign of King Charles IV. A thin layer of peat developed and transition peatbogs formed in the shallow bays of the glacial lake which lay on this site. Swamp NNM lies in a mildly warm climatic region and in a subdistrict with a mild, damp winter. The mean annual precipitation is 650mm.

The majority of the protected area is covered with oligotrophic water, transition peatbogs and wet forests. The littoral growths around the lake are of species-poor reedbeds, although one of the strongest populations of greater spearwort (Ranunculus lingua) in the Czech Republic can be found here. In drier areas the biotope type passes into sandy pine forests. Peaty pine stands with bog whortleberry and moor-grass have developed where the moisture level is higher. Significant peat-loving species which grow here include the critically endangered white beak-sedge (Rhynchospora alba) and the brown beak-sedge (Rhynchospora fusca) which grows at Swamp NNM on its last locality in Bohemia. Abundant populations of round-leaved sundew (Drosera rotundifolia), common cotton-grass (Erophorum angustifolium) and slender sedge (Carex lasiocarpa) can be found here. Lesser bladderwort (Utricularia minor) dominates the terrain depressions and pools. The leaves of the white water lily Nymphaea candida can be seen on the surface of the open water.

Swamp NNM is a notable algological locality. The richest and dominant group at the locality are the conjugating algae (Conjugatophyceae). By far the largest number of species belong to the green algae of the Desmidiales – 200 species, although the highest biomass is probably created by the filamentous conjugating algae of the Zygnematales order (especially from the Zygogonium and Spirogyra families). Other groups with a high species diversity are the diatoms, blue-green algae and green algae (of which a large number of species of the filamentous algae of the Microspora order can be found here). Groups such as the Euglenophyta, Craptophyta, Dinophyta, Chrysophyta and Raphidiophyta do not have such an important ecological function, but a whole range of interesting and rare species from these groups can also be found at Swamp NNM.
A total of 112 taxons of diatoms (including varieties and forms) have been recorded at the locality. Nineteen of these diatoms were recorded for the first time in the Czech Republic here, including Adlaphia bryophila, Cymbopleura subaequalis, Diatoma chrenbergii, Encyonema neogracile var. neogracile, Navicula antonii, neidium bisculatum var. subampliatum, Psammothidium subatomoides, Pinnularia anglica, Pinnularia lokana and Pinnularia neomajor.

Several rare green algae species grow more or less abundantly at Swamp NNM: Eremosphaera viridis, Botryosphaerella sudetica (found in the Czech Republic for the third time), Dicranocaete sp., Geminella mutabils (found in the Czech Republic for the third time), Oedogonium itzigsohnii (found in the Czech Republic for the first time here) and Oocystis solitaria. Of the 200 green algae species at Swamp NNM, 99 are regarded as rare and 35 as very rare taxons on a central European scale. The rarest species at the monument are Micrasterias oscitans, Pleurotaenium simplicissimm and Eustrum pinnatum, all of which are now probably extinct, or on the verge of extinction in most of Europe.

We may see an adder (Vipera berus) on the transition peatbog or in the pine stands. Birds which have been observed here include the bittern (Botaurus stellaris) and marsh harrier (Circus aeroginosus), and the crane (Grus grus) or white-tailed eagle (Haliaeetus albicilla) can also be seen here occasionally. Many significant invertebrate species are also at home in the Swamp NNM, including the rare dragonflies – eastern white-faced darter (Leucorrhinia albifrons) and large white-faced darter (Leucorrhinia pectoralis).

The territory is separated from the Máchovo jezero Lake by a low causeway, which serves to prevent the movement of nutrients from the lake, which is used for recreational activities, into the oligotrophic(more acidic) waters of the Swamp.