Refine
Year of publication
- 2005 (6) (remove)
Document Type
- Article (5)
- Part of Periodical (1)
Language
- English (6)
Has Fulltext
- yes (6)
Is part of the Bibliography
- no (6)
A guide to bryological hotspots in Europe : [Part 2: The Rur Valley, Eifel Mountains, Germany]
(2005)
The Rur valley is situated in the extreme west of Germany in the western part of the Eifel Mountains, close to the Belgian border. The Rur valley harbours several interesting, mainly bryopyhtes. Most of the interesting species are aquatic species. Very obvious is the oceanic element, which is represented by species such as Platyhypnidium lusitanicum, Hyocomium arnoricum, and Isothecium holtii.
The diversity of bryophytes on the different islands of the Azores varies much between 104 and 324 species. Attempts have been made to explain the heterogenity of the bryoflora. There is a correlation between species numbers and age of the islands in the way that the youngest islands (Pico) has the lowest species numbers in spite of the fact that it is the highest island. The species numbers of the other islands are correlated with the maximum elevation and with the size of the islands. The liverwort-moss ratio varies between 1.21 and 1.67 and shows a distinct humidity gradient between the islands. The floristic affinities between the islands are calculated by a cluster analysis. They show no correlation with the location of the islands (nearest neighbour), size, age, elevation or species numbers, which indicates that the species composition is mainly determined by chance. Ten species (2,3%) are endemic to the Azores and 14 species (including one genus) are endemic to the Macaronesian Islands. Some of the endemics are questionable, others may occur elsewhere in the tropics under a different name, but there is fossil prove that the others are relicts from the Tertiary which survived extinction during Quaternary in Europe.
An account of the bryological activities on the Azores is given. Three phases can be distinguished: one at the end of the 19. century, when first collections of non-bryologists were made, which resulted in the discovery of less than one third of the presently known species and the description of many so called endemics. A second phase in the thirties of the 20. century is characterized by an intensive collecting activity of some bryologists, which enormously raised the species numbers. In a third phase at the end of the 20. century, tourism as well as activities of local bryologists raised again the species numbers. Revisions of genera reduced the number of endemic species and revisions of herbarium specimens of doubtful records even reduced the species numbers of hepatics.
Lepidozia stuhlmannii, L. pearsonii, Atrichum tenellum, Bryum lanatum, Campylopus subulatus, Ceratodon stenocarpus, Polytrichum commune var. humile and Thuidium delicatulum are reported as new to the Azores. The record of Sphagnum pylaisii from Terceira is referred to a monoclade expression of S. denticulatum. The presence of the North American Leucobryum albidum on the Azores is confirmed and the distinguishing characters between this species and Leucobryum juniperoideum are discussed. The recently described Thamnobryum rudolphianum is reported another time from Terceira. Campylopus brevipilus and Racomitrium aquaticum are reported as new to Pico.
Book Reviews
(2005)