TY - JOUR

T1 - Species richness of vascular plants, bryophytes and lichens in dry grasslands

T2 - The effects of environment, landscape structure and competition

AU - Lobel, Swantje

AU - Dengler, Jürgen

AU - Hobohm, Carsten

N1 - Funding Information: Acknowledgements: We thank Lennart Agren and Eje Rosrn for providing useful information during the field work; Eddy van der Maarel gave important information when we started to plan this study. Thomas Becker, Werner H~irdtle, and H~kan Rydin gave useful comments on the manuscript, and Bill Meek improved the English language. The field work was supported by a grant of the Universit~itsgesellschafl Liineburg.

PY - 2006/12/1

Y1 - 2006/12/1

N2 - We studied the relative importance of local habitat conditions and landscape structure for species richness of vascular plants, bryophytes and lichens in dry grasslands on the Baltic island of Öland (Sweden). In addition, we tested whether relationships between species richness and vegetation cover indicate that competition within and between the studied taxonomic groups is important. We recorded species numbers of vascular plants, bryophytes and lichens in 4 m 2 plots (n = 452), distributed over dry grassland patches differing in size and degree of isolation. Structural and environmental data were collected for each plot. We tested effects of local environmental conditions, landscape structure and vegetation cover on species richness using generalized linear mixed models. Different environmental variables explained species richness of vascular plants, bryophytes and lichens. Environmental effects, particularly soil pH, were more important than landscape structure. Interaction effects of soil pH with other environmental variables were significant in vascular plants. Plot heterogeneity enhanced species richness. Size and degree of isolation of dry grassland patches significantly affected bryophyte and lichen species richness, but not that of vascular plants. We observed negative relationships between bryophyte and lichen species richness and the cover of vascular plants. To conclude, effects of single environmental variables on species richness depend both on the taxonomic group and on the combination of environmental factors on a whole. Dispersal limitation in bryophytes and lichens confined to dry grasslands may be more common than is often assumed. Our study further suggests that competition between vascular plants and cryptogams is rather asymmetric.

AB - We studied the relative importance of local habitat conditions and landscape structure for species richness of vascular plants, bryophytes and lichens in dry grasslands on the Baltic island of Öland (Sweden). In addition, we tested whether relationships between species richness and vegetation cover indicate that competition within and between the studied taxonomic groups is important. We recorded species numbers of vascular plants, bryophytes and lichens in 4 m 2 plots (n = 452), distributed over dry grassland patches differing in size and degree of isolation. Structural and environmental data were collected for each plot. We tested effects of local environmental conditions, landscape structure and vegetation cover on species richness using generalized linear mixed models. Different environmental variables explained species richness of vascular plants, bryophytes and lichens. Environmental effects, particularly soil pH, were more important than landscape structure. Interaction effects of soil pH with other environmental variables were significant in vascular plants. Plot heterogeneity enhanced species richness. Size and degree of isolation of dry grassland patches significantly affected bryophyte and lichen species richness, but not that of vascular plants. We observed negative relationships between bryophyte and lichen species richness and the cover of vascular plants. To conclude, effects of single environmental variables on species richness depend both on the taxonomic group and on the combination of environmental factors on a whole. Dispersal limitation in bryophytes and lichens confined to dry grasslands may be more common than is often assumed. Our study further suggests that competition between vascular plants and cryptogams is rather asymmetric.

KW - alvar

KW - biodiversity

KW - dispersal limitation

KW - environmental heterogeneity

KW - fragmentation

KW - soil pH

KW - spatial autocorrelation

KW - Biology

KW - Ecosystems Research

UR - http://www.scopus.com/inward/record.url?scp=33749074827&partnerID=8YFLogxK

U2 - 10.1007/BF02806555

DO - 10.1007/BF02806555

M3 - Journal articles

VL - 41

SP - 377

EP - 393

JO - Folia Geobotanica

JF - Folia Geobotanica

SN - 1211-9520

IS - 4

ER -