Emergence of seedlings of four alvar grassland species (Arenaria serpyllifolia, Festuca ovina, Filipendula vulgaris and Veronica spicata) in bryophyte and lichen carpets was analysed in a series of greenhouse experiments. The aspects investigated were: the influence of thickness of moss mats, both in dry and moist conditions, the effects of thick Cladonia spp. clumps, and of living vs dead moss shoots and lichen podetia. Overall, Festuca seedlings emerged best whereas the small‐seeded species, Arenaria and Veronica , had the lowest emergence. Moisture had a significant effect only on the emergence of Festuca seedlings, which emerged better in the dry treatment than in the moist. A thick moss cover negatively affected seedling emergence of Arenaria and Veronica but did not affect the emergence of Festuca. Filipendula showed lower seedling emergence in both thick and thin moss than on bare soil only in the dry treatment, whereas in the moist treatment emergence did not differ among the three substrates. Arenaria seedlings emerged less in thick and thin moss than on bare soil in the dry treatment, whereas in the moist treatment emergence in the thin moss was not different from bare soil. Thus, in relatively dry environments even a thin moss cover may inhibit rather than facilitate seedling emergence. The lichen clumps inhibited only the emergence of the forbs. Both living moss shoots and lichen podetia inhibited emergence of Veronica seedlings but did not affect Festuca. In contrast, emergence in the presence of dead mosses and lichens did not differ from emergence in their absence for both species. Hence, inhibition of seedling emergence by bryophytes and lichens of at least some vascular plant species may be mediated by some biotic factor. However, the effect of differences in substrate properties on germination cannot be excluded

Summary1 A glasshouse experiment was conducted with seven bryophyte species to determine the eects of competition. We tested whether competitive hierarchies varied with initial abundance (density and biomass) and between two dierent experimental approaches. 2 Relative competition intensities were calculated based on proportional growth (G) and relative biomass (R). The standards for comparison (i.e. no interactions) were species' performance in monocultures at one of two sowing abundances (the combined monocultures method; CM) and in a low-density mixture of equal proportions of all species (the community density series method; CDS). 3 Proportional growth decreased with increasing initial abundance for all species. Community eects (relative biomass of each species) were generally weaker and more variable than individual eects. R increased linearly with abundance for only one species, while three species showed a quadratic response (of which two were negative). 4 Competitive hierarchies derived by the CM method diered with abundance, and we argue that the CDS method is likely to provide a more reliable comparison. 5 With CDS, competitive hierarchies were similar along the community abundance gradient, implying that non-linear competitive eects are not likely to be a mechanism of coexistence in this community. 6 There were signi®cant competitive eects on community composition, but not on diversity as measured by evenness. At the community level individual species tended to show either competitive or positive eects throughout the gradient of initial community abundance, with decreasing values for most species at high initial community abundance, as were the eects of interactions on community composition.

This study has showed the difficulties of long-term clinical treatment of obese outpatients, even in a specialised obesity clinic. The findings demonstrate that educated and experienced staff together with an extended package of treatment options is not enough to keep patients in treatment for two years. However though the drop-out rate was high, two thirds of the included subjects reduced their weight, which is a satisfactory result in a clinical setting. The drop-out rate and the reasons for dropping out could give a clue in which direction the diagnostics and analysis of the subject's individual needs in health care should be directed.

No abstract

1999. Bryophytes, lichens and phanerogams in an alvar grassland: relationships at different scales and contributions to plant community pattern. -Ecography 22: 40-52.The relationship between bryophytes and lichens versus phanerogams has been investigated in three stands of a limestone grassland community, along three transects of 500 10 X 10 cm plots. Otdination axes resulting from Detrended Correspondence Analysis for bryophytes and lichens versus phanerogams were correlated using Spearman rank correlation coefficient. The effect of grain (sample plot) size on relationships between species along the gradient and on the correlation between the layers formed by bryophytes and lichens (cryptogams) and phanerogams, and with environmental variables has been as well exarnined. Values for light, moisture, pH and nitrogen have been derived from the vegetation itself with the help of Ellenberg indicator values. The relative position of species in the ordination space is more or less the same until grain size 3 (10 x 40 cm) for cryptogams and phanerogams and until grain size 2 (10 x 20 cm) for all-species together. Therefore, it is suggested that sample plot sizes of 10 x 10 cm to 10 x 20 cm are appropriate as units for field experiments testing interactions between cryptogams and phanerogams. The respective layers were weakly correlated and the correlation between them increased with increase in grain size. The correlation of DCA axis 1 frotn the ordination of cryptogams, phanerogams and all-species with the environmental factors was weak and similar in order of magnitude. Only the environtnental variables which were strongly correlated with the DCA axis 1 increased in correlation at larger grain sizes. The ordinations of cryptogams, phanerogams and all-species were correlated along DCA axis 1 with pH in all investigated stands and at almost all grain sizes. Multi-species patches have been detected by pattern analysis (PASFRAN) on DCA sample scores from ordinations of cryptogams, phanerogams and combined matrices. Multi-species patterns with sizes between 20-240 cm. composed by bryophytes and lichens and by phanerogams have been found. Complex patterns formed by cryptogams and phanerogams together, which are different in size than those in the separate layers, suggest that bryophytes + lichens and phanerogams may interact with each other.M. Zamfir (manuela.zamfir(a vaxthio.uu.se). X. Dai and E. van der Maarel.