Hallagerbakken 82 b

Oslo, Norway

Hallagerbakken 82 b

Oslo, Norway
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Several calcareous lakes were investigated in Nordland in August 2012. From a marble area in the municipality of Vefsn we describe two lakes, Lake Øvertjønna and Lake Stortjønna and in more detail a third locality, Lake Staultjønna which is different from the two others. This lake is different by having broad, dense mats of cyanobacteria which have loosened from the bottom, due to this mosaic structure on the bottom and dense stands of a Chara species which probably is a monstrous form of Chara aculeolata. Lake Staultjønna is evaluated to be of special interest and given the highest possible status according to «Action plan for calcareous lakes». The mosses found in and on the mires around the two lakes Stortjønna and Staultjønna have been surveyed. This is the first time the moss vegetation of Norwegian calcareous lakes has been studied.


Langangen A.,Hallagerbakken 82 b
Flora Mediterranea | Year: 2012

In this article charophytes are reported from the island of Crete, the largest island in Greece. On 9 visited localities, charophytes have been found in six. All localities, except one (loc. 6) are freshwater. Totally six different species were found: Chara aspera, C. connivens, C. corfuensis, C. vulgaris, Nitella hyalina and N. tenuissima. The most interesting locality is Lake Kournas which is an eutrophic Chara-lake with rich vegetation of four species: Chara corfuensis, C. aspera and the two species of Nitella.


In the summer and autumn of 20091 surveyed 25 small lakes in the vicinity of Oslo's main airport, Gardermoen, with the primary goal to map the occurrence of charophytes. I found such algae in eight lakes, but they were not found at three former localities. One reason for this can be changes in water quality e.g. due to eutrophication. In the area there is only one Chara-lake (dystrophic) with rich growth of Chara aculeolata. This species is red listed. Other redlisted charophytes are Nitella flexilis (Aurtjern and Vollnesputten), Chara strigosa (Norbytjern) and C. aspera (Svarttjern). Other species found are Chara virgata (Bonntjern and Ljøgottjern) and C. globularis (Skånetjern). Generally, the growth of charophytes is poor, except for at three lakes, Vollnesputten (Nitella flexilis), Bonntjern (Chara virgata) and Vesletjern (Chara aculeolata).


The Hadeland area is known for its calcareous lakes and many Chara-lakes. The author investigated some of the lakes in 1968-69. A new investigation was carried out in 2007(Gran municipality) and 2008 (Lunner and Jevnaker municipalities). This article refers to Lunner and Jevnaker municipalities. A total of 53 different waters have been investigated in the two municipalities. The lakes can be divided according to nutrient level, in eutrophic, mesotrophic to oligotrophic. Most of the lakes have rich vegetation of different helophytes and nymphaeids. Some are also more dystrophic and surrounded by rich mires. Charophytes were found in 34 of the lakes. At three lakes where charophytes were found earlier, none were found in 2008. Most of the 19 lakes without charophytes were highly eutrophic, and often rich with filamentous algae. 9 localities (Korsrudputten, Orentjemet, Velotjernet, Virstadputten, Galtedalsputten, lgedstadputten, Storetjemet, Muttatjernet, and Elgsjøen) have rich vegetation of charophytes, but are, for several reasons, not classified as Chara-lakes. Galtedalsputten, lgedstadputten, Muttatjernet are of special interest because of their dystrophic character. In Lunner and Jevnaker 12 Chara-lakes were surveyed (Høybytjernet, Øyskogtjernet, Korsrudtjernet, Østre og Vestre Galtedalstjernet, Vassjø, Nyborgtjemet, Karusputten, Finnerudputten, Vesletjernet, Kalven, and Nedre Småtjenet). Each one of them have their own characteristics, with a rich vegetation of charophytes as a common element.


Sundsfjordfjellet (Glomfjellet) is a mountainous area close to the coast in Nordland, situated north of the Arctic Circle. The area is the biggest marble-karst area in Scandinavia, and has generated many lakes of different sizes. The growth season is relatively short, temperatures low and precipitation very high. These are important factors in the development of the lakes. In total, we have investigated 24 lakes, of which 20 have vegetation composed of charophytes. The charophytes found were Nitella opaca, Tolypella canadensis and Chara contraria. In Lake Seglvatnet Tolypella canadensis has been found down to 17 m, and at this depth there were few fertile specimens. We have described five Chara lakes in the area (Table 2, Figure 2). In these lakes Chara contraria dominates. In six lakes without Chara contraria, the unencrusted Tolypella canadensis dominates. We have named such lakes Tolypella lakes. In these lakes, Chara contraria has developed several forms in which the cortication of the branchlets are either totally lacking or only partly developed. This may lead to difficulty in separating it from Tolypella canadensis. In Lake Saravatnet it was difficult to separate the two species in the field (Figure 13 C, 14 C). These may be ecotypes specially adapted to the abiotic factors in the lakes. In our opinion Sundsfjordfjellet is an interesting area to study the two species, Tolypella canadensis and Chara contraria, which in many of the lakes have developed similar growth forms (ecotypes). We believe that Northern Norway can be a source area for Tolypella canadensis. Its known distribution is limited to areas that were covered by ice during the Ice Age, and it is therefore a young species. Studies at lakes in Sundsfjordfjellet may provide information on the variation and the relations between these two species.


The genus Coleochaete is briefly described, based on information from literature and my own observations. Ecological observations are given for the genus and results of observations and experiments are given. Eleven species are reported from Norway, Coleochaete pulvinata, C. divergens, C. conchata. C. scutata, C. soluta, C. siemenskiana, C. circularis, C. echinocystis, C. andreae, C. irregularis and C. nitellarum. General information on the ecology of these algae is given and as well as a description of each species with information on reproduction, ecology and distribution.

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