Mean cover and frequencies of vascular plant species during three decades around Abisko Scientific Research Station

Plant species distributions are expected to shift and diversity is expected to decline as a result of global climate change, particularly in the Arctic where climate warming is amplified. We have recorded the changes in richness and abundance of vascular plants at Abisko, sub-Arctic Sweden, by re-sampling five studies consisting of seven datasets; one in the mountain birch forest and six at open sites. The oldest study was initiated in 1977-1979 and the latest in 1992. Total species number increased at all sites except for the birch forest site where richness decreased. We found no general pattern in how composition of vascular plants has changed over time. Three species, Calamagrostis lapponica, Carex vaginata and Salix reticulata, showed an overall increase in cover/frequency, while two Equisetum taxa decreased. Instead, we showed that the magnitude and direction of changes in species richness and composition differ among sites.

Vegetation in the coastal area of East Greenland

This paper deals with the syntaxonomy and ecology of debris, scree and alluvium vegetation of the Ammassalik district, Southeast Greenland, on more or less moist soil. The Oxyria digyna- and Chamaenerion latifoliumvegetation types are classified as Saxifrago-Oxyrietum digynae (Böcher 1933 ap. Nordh. 1943) Gjaerevoll 1950 respectively Chamaenerietum latifolii Böcher 1933 in the class Thlaspietea rotundifolii Br.-BI. ap. Br.-BI. et al. 1947. The chionophytic Saxifrago-Oxyrietum digynae and the Chamaenerietum latifolii occurring on river-banks are classified in the alliance Saxifrago stellaris-Oxyrion digynae Gjaerevoll 1950. This alliance belongs to the order Androsacetalia alpinae Br.-BI. ap. Br.-BI. & Jenny 1926, Thlaspietea rotundifolii Br.-BI. ap. Br.-BI. et al. 1947. The following syntaxa are described as new: Saxifrago-Oxyrietum digynae stellarietosum humifusae and typicum with two variants and one variant of the subassociation inops De Molenaar 1976, and the Chamaenerietum latifolii typicum with two variants and salicetosum herbaceae with three variants.

Abundance of plant macrofossils, mollusca and ostracoda in sediments obtained near Tessin, north Germany

A depression filled with Late Glacial and Holocene sediments was excavated during the geological exploration and recovery of a dump area near Tessin close to Rostock, and initiated the studies of the present paper. Pebble analysis of three exposed or respectively drilled till horizons as well as pollenanalytical, carpological and faunistical studies carried out allow the stratigraphical subdivision of the Quaternary sequence of the dump area. The basal till was probably the result of dead ice decay, and was lithostratigraphically assigned to the Pomerian Stage (qw2). The palynological results of boreholes RKS 19/93 and A/92 reveal pre-Allerod and other sediments instead of the expected interweichselian deposits. Based on the palynological and carpological findings, we correlated the beginning of the late glacial development in the locality with the end of the Meiendorf-lnterstadial sensu Menke in Bock et al. (1985, doi:10.3285/eg.35.1.18). The limnic-telmatic sedimentation could be observed pollen floristically probably starting with the Meiendorf-lnterstadial (Hippophae-Betula nana-phase) followed by the Bolling-(Betula nana-B. alba s.l.-Artemisia-Helianthemum-Poaceae-phase) and the Allerad-lnterstadial [Betula alba s.l.-(Pinus)-Cyperaceae-phase] lasting up to the Younger Dryas (Juniperus-Artemisia-Poaceae-phase). Sedimentation closed during the Younger Dryas with the accumulation of fine sands. It was reactivated later during the Holocene due to the anthropogene influence (Older and Younger Subatlantic, dampness of the depression by clearing).