Summary1. An international group of scientists has built an open internet data base of life-history traits of the Northwest European flora (the LEDA-Traitbase) that can be used as a data source for fundamental research on plant biodiversity and coexistence, macro-ecological patterns and plant functional responses. 2. The species-trait matrix comprises referenced information under the control of an editorial board, for ca. 3000 species of the Northwest European flora, combining existing information and additional measurements. The data base currently contains data on 26 plant traits that describe three key features of plant dynamics: persistence, regeneration and dispersal. The LEDA-Traitbase is freely available at www.leda-traitbase.org. 3. We present the structure of the data base and an overview of the trait information available. 4. Synthesis. The LEDA Traitbase is useful for large-scale analyses of functional responses of communities to environmental change, effects of community trait composition on ecosystem properties and patterns of rarity and invasiveness, as well as linkages between traits as expressions of fundamental trade-offs in plants.

Question: Can seeds in the seed bank be considered as a potential source of material for the restoration of European plant communities including forest, marsh, grassland and heathland? Methods: This study reviews seed bank studies (1990–2006) to determine if they provide useful and reliable results to predict restoration success. We formally selected 102 seed bank studies and analyzed differences between four plant community types in several seed bank characteristics, such as seed density, species richness and similarity between seed bank and vegetation. We also assessed the dominant genera present in the seed bank in each plant community. Results: We observed remarkably consistent trends when comparing seed bank characteristics among community types. Seed density was lowest for grassland and forest communities and highest in marshes, whereas species richness, diversity and evenness of the seed bank community was lowest in heathland and highest in grassland. Similarity between seed bank and vegetation was low in forest, and high in grassland. There was a lot of overlap of the dominant genera of seed bank communities in all studies. Conclusions: The absence of target species and the high dominance of early successional species, in particular Juncus spp., indicate that restoration of target plant communities relying only on seed germination from the seed bank is in most cases not feasible. The exceptions are heathland and early successional plant communities occurring after temporally recurring disturbances. Restoration of plant communities composed of late successional species, such as woody species or herbaceous species typical of woodland or forest rely mainly on seed dispersal and not on in situ germination.

Contents SummaryHabitat fragmentation is one of the major threats to species diversity. In this review, we discuss how the genetic and demographic structure of fragmented populations of herbaceous forest plant species is affected by increased genetic drift and inbreeding, reduced mate availability, altered interactions with pollinators, and changed environmental conditions through edge effects. Reported changes in population genetic and demographic structure of fragmented plant populations have, however, not resulted in large-scale extinction of forest plants. The main reason for this is very likely the long-term persistence of small and isolated forest plant populations due to prolonged clonal growth and long generation times. Consequently, the persistence of small forest plant populations in a changing landscape may have resulted in an extinction debt, that is, in a distribution of forest plant species reflecting the historical landscape configuration rather than the present one. In some cases, fragmentation appears to affect ecosystem integrity rather than short-term population viability due to the opposition of different fragmentation-induced ecological effects. We finally discuss extinction and colonization dynamics of forest plant species at the regional scale and suggest that the use of the metapopulation concept, both because of its heuristic power and conservation applications, may be fruitful.

Global circulation models predict an increase in mean annual temperature between 2.1 and 4.6 °C by 2080 in the northern temperate zone. The associated changes in the ratio of extinctions and colonizations at the boundaries of species ranges are expected to result in northward range shifts for a lot of species. However, net species colonization at northern boundary ranges, necessary for a northward shift and for range conservation, may be hampered because of habitat fragmentation. We report the results of two forest plant colonization studies in two fragmented landscapes in central Belgium. Almost all forest plant species (85%) had an extremely low success of colonizing spatially segregated new suitable forest habitats after c. 40 years. In a landscape with higher forest connectivity, colonization success was higher but still insufficient to ensure large‐scale colonization. Under the hypothesis of net extinction at southern range boundaries, forest plant species dispersal limitation will prevent net colonization at northern range boundaries required for range conservation.