SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Janssen, C.R.; Hove, H.A. ten.

Three pollen diagrams from the Peel peatlands, a raised bog area in the southern part of The Netherlands reveal the post-Boreal vegetation history of that region. There are two or three land-occupation phases in the Neolithic and Bronze ages, that show but low values of terrestrial herbs. They are negatively correlated with Ulmus. The Fagus curve starts slightly below the first occupation phase at around 2500 B.C. In the Subatlantic there is an Iron age and a Medieval occupation phase with higher values of terrestrial herbs. Fagus shows two maxima, one at the beginning of our era and another at around 700 A.D. The trend of the pollen curves for bog species is discussed in relation to bog development.

Serpulinae (Polychaeta) from the Caribbean: I – The genus Spirobranchus

Ano: 1971

URL: http://www.repository.naturalis.nl/record/534844

After studying more than thousand Spirobranchus worms from Curaçao and other Caribbean Islands, and after comparison with the material from other tropical and subtropical regions, it appeared that in the West Indies 3 species and 1 variety of Spirobranchus could be recognized; viz: Sp. giganteus giganteus: large (45—66 mm), more or less solitary; operculum with 2 or 3 antler-like horns; branchiae in a spiral. Sp. tetraceros: smaller (30—40 mm), more or less gregarious; operculum as a rule with 3 groups of much branched horns, appearing as 6 or 8 distinct horns; branchiae not in a spiral. Sp. polycerus: small (about 15 mm), usually forming colonies; operculum in general with 7 small horns, sometimes small secondary spines; branchiae in a spiral. Sp....

The Ulmus fall at the transition Atlanticum-Subboreal in pollen diagrams

Ano: 1970

URL: http://www.repository.naturalis.nl/record/506140

The views of previous authors on the elm fall, especially backgrounded by Tauber’s (1965) theory on differential pollen dispersion, are discussed. Five possible explanations are given: climate, competition and edaphical factors, human influence, diseases, selective pollen filtering. For the time being the present author concludes that the most probable explanation for the elm fall is human influence, eventually in interaction with a change in climate. Depending on local, edaphic and ecological conditions, the various factors which may be held responsible for the elm fall, are probably of unequal importance for different regions.

Serpulinae (Polychaeta) from the Caribbean: II – The genus Sclerostyla

Ano: 1968

URL: http://www.repository.naturalis.nl/record/534969

The genus Sclerostyla is better known from fossil records than from recent material (WRIGLEY, 1951; MÜLLER, 1970). This is not surprising, since Sclerostyla ctenactis is difficult to find, the tube usually being imbedded in the substrate. Such material was studied only by MÖRCH (1863) in the Zoologiske Museum, København; by AUGENER (1922) in the zoological museums of Berlin and Hamburg; by TREADWELL (1929) in the American Museum of Natural History and by WRIGLEY (1951) in the Allan Hancock Foundation, Los Angeles. The specimens have been reexamined. Additional specimens were collected by Dr. P. WAGENAAR HUMMELINCK (1955, 1963—64) and by the author (1970). This material, as a rule, was preserved with formaldehyde and, after a short period, transferred to...

Serpulinae (Polychaeta) from the Caribbean: III – The genus Pseudovermilia (including species from other regions)

Ano: 1973

URL: http://www.repository.naturalis.nl/record/506077

In 1969 the author’s attention was caught by the variability of some species of the genus Vermiliopsis, sensu lato, so extreme, that at the time it was impossible to distinguish the various species. The present review is the third in a series of revisionary studies on the former genus Vermiliopsis. The first one dealt with the genus Metavermilia Bush (ZIBROWIUS, 1971), the second with the genus Bathyvermilia Zibrowius (ZIBROWIUS, 1973a). A study on the genus Vermiliopsis, sensu stricto, is in preparation. The material was collected mainly by dr. P. WAGENAAR HUMMELINCK, when sampling on various islands, in a number of habitats from the tidal zone down to a depth of about 2 m (1930, 1948/49, 1955, 1963/64, 1967); by the “Onderzoekingen Continentaal Plat...