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Registros recuperados: 10 | |
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Bremer, P.. |
The major part of the valley of the river Overijsselse Vecht has been assigned to the Fluviatile District. Of the various species which are regarded as characteristic for this valley, many have suffered a decline since 1976. Their present distribution supports the upstream delimitation of this part of the Fluviatile District, between the villages Ommen and Hardenberg. |
Tipo: Article / Letter to the editor |
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Ano: 1993 |
URL: http://www.repository.naturalis.nl/record/526488 |
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Bremer, P.. |
Inula conyza DC. is still growing near the former island of Urk, where it was found for the first time in 1957. It grows mostly in a Prunus spinosa vegetation. The accompanying species differ from those of other populations in the Netherlands. Probably /. conyza reached this locality with saplings for the Urkerbos, a wood planted in 1954 – 1959. |
Tipo: Article / Letter to the editor |
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Ano: 1982 |
URL: http://www.repository.naturalis.nl/record/526784 |
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Hovenkamp, P.H.; Viane, R.L.L.; Bremer, P.. |
Dryopteris expansa was recently discovered at two localities in the Netherlands (Havelterberg, prov. of Drenthe; Kuinderbos, prov. of Flevoland). Its diagnostic characters and taxonomic status are discussed. The taxon is morphologically very similar to D. dilatata and can only be identified by means of microscopical research (microglands c. 80 µm against c. 110 µm in D. dilatata; the diploid chromosome number whereas D. dilatata is a tetraploid). Nevertheless it is concluded that it must be regarded as a separate species. In the field D. expansa resembles Athyrium filix-femina in the light green colour and the soft texture of the lamina. |
Tipo: Article / Letter to the editor |
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Ano: 1990 |
URL: http://www.repository.naturalis.nl/record/527546 |
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Bremer, P.. |
Gymnocarpium dryopteris is rather rare in the Netherlands. Distribution and ecology have been surveyed, especially for the period 1979-1991. In this period the species was detected with more than 670 individual stands, 90% at the Kuinderbos. In this article the Kuinderbos population is compared with other Dutch populations. Gymnocarpium dryopteris prefers shadowy ditches, but may grow in various other habitats as well. Especially in the western and southern part of the Netherlands it is growing on walls. The vegetation on the sites belongs to different syntaxa, with a preference for the Quercion (Fago-Quercetum) or plantations (Pseudotsuga) and in the Kuinderbos especially plantations of Picea sitchensis. Gymnocarpium dryopteris is often accompanied by... |
Tipo: Article / Letter to the editor |
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Ano: 1994 |
URL: http://www.repository.naturalis.nl/record/527632 |
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Bremer, P.. |
The Noordoostpolder is one of the polders in the former Zuiderzee, reclaimed in 1941 and 1942. A natural vegetation developed but was destroyed when the land was cultivated. Many adventitious species came into the area together with road construction materials and crop seeds. Nowadays these species have mostly disappeared, only a small number are still present. The polder consists of an area with sandy clay, bordered by an area with loam, sand and peat Calcareous sands are predominant here. It is shown that floristically this border area is quite different from the area with sandy clay, but also from the bordering part of the ‘old land’. 133 species characterize this border area. Many of these species show links with a number of different plant... |
Tipo: Article / Letter to the editor |
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Ano: 1980 |
URL: http://www.repository.naturalis.nl/record/527647 |
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Bremer, P.. |
In the Netherlands Ophioglossum vulgatum occurs in a wide variety of habitats, like dune slacks, wetlands, unfertilized grassy pastures and pits. Records from woodlands were scarce. After the reclamation of the IJsselmeer polders thousands of acres have been planted with trees; in these woodlands Ophioglossum has been recorded at 11 localities, mostly growing under a canopy of Ash, on calcareous soils consisting of fine sand, boulder clay or clay. |
Tipo: Article / Letter to the editor |
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Ano: 1988 |
URL: http://www.repository.naturalis.nl/record/526901 |
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Bremer, P.. |
In 1978 and 1979 Polystichum lonchitis (L.) Roth and Asplenium viride Huds. were found for the first time in the Netherlands. Both were growing on ditch-sides in the forest ‘Kuinderbos’ at 3-3,5 m below sealevel on calcareous sand. The former occurred in a plantation of Fraxinus excelsior, the latter in a plantation of Picea sitchensis. The nearest localities are in West-Germany, but it is possible that both were transported by western winds from Great Britain. |
Tipo: Article / Letter to the editor |
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Ano: 1981 |
URL: http://www.repository.naturalis.nl/record/526701 |
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Bremer, P.. |
Hieracium caespitosum appeared very soon (1948) after the reclamation (1942) of the IJsselmeerpolders. The species mainly flowers in June and it takes approximately thirteen days between fertilization and riping of the achenes; therefore, to enable proper dispersal, mowing of the populations should take place in the second half of June. The species is facultative apogamous and is frequently visited by insects, mainly Muscidae en Syrphidae. From the ecological point of view Hieracium caespitosum has been regarded to be a characteristic for Molinion-vegetations. However, on soils which are humous and lutum-rich, the species shows a preference for Arrhenatherion-vegetations; on poor soils it is part of vegetations that are related to the Thero-Airion. In fact... |
Tipo: Article / Letter to the editor |
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Ano: 1991 |
URL: http://www.repository.naturalis.nl/record/527751 |
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Registros recuperados: 10 | |
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