Why are Some Plant Species of Fragmented Continental Dry Grasslands Frequent and Some Rare?

Restoration of Species Richness in Abandoned Mediterranean Grasslands: Seeds in Cattle Dung

“…Results from our greenhouse germination experiment resembled those of other authors in similar habitats (Malo & Suárez 1995b) and indicated that almost 50% of the species pool in the grazed pastures (Traba 2000) were dispersed despite the fact that the sampling dates prevented the collection of early and late-fruiting species. The decline in richness and the disappearance of the introduced species in the fourth year suggests that single inputs are not enough to ensure the definitive establishment of viable populations and that these types of species need more or less constant contributions to guarantee the survival of the population (Willson 1992;Jackel & Poschlod 1996;Strykstra et al 1998a;Dieckmann et al 1999) and prevent rapid local extinctions of at least the species that lack sufficiently large and persistent seed banks (Fischer et al 1996). The lack of persistent banks for many of the introduced populations could indicate such a process, particularly clear in annual-dominated communities that have higher extinction rates than perennials (Ehrlén & van Groenendael 1998).…”

Quantification of plant dispersal ability within and beyond a calcareous grassland

“…These processes are especially important in small communities, where populations suffer from increased extinction risk (Joshi et al. ), and may be essential for persistence (Jackel & Poschlod ; Willems & Bik ; Pywell et al. ; WallisDeVries et al.…”

“…In addition to habitat loss and fragmentation, which have reduced the capacity of species to disperse between habitat patches (Soons et al. ), many traditional dispersal vectors that were provided by transhumance sheep herding or sowing of hayseed have disappeared (Jackel & Poschlod ; Poschlod et al. ; Poschlod & WallisDeVries ).…”

“…Dispersal within a community may decrease extinction risk by increasing connectivity and reducing population vulnerability to disturbance. These processes are especially important in small communities, where populations suffer from increased extinction risk (Joshi et al 2006), and may be essential for persistence (Jackel & Poschlod 1996;Willems & Bik 1998;Pywell et al 2002;WallisDeVries et al 2002).…”

“…In addition to habitat loss and fragmentation, which have reduced the capacity of species to disperse between habitat patches ), many traditional dispersal vectors that were provided by transhumance sheep herding or sowing of hayseed have disappeared (Jackel & Poschlod 1996;Poschlod et al 1998;Poschlod & Wallis-DeVries 2002). Current management practices might not promote diaspore dispersal to the same extent as traditional practices, since diaspores are not easily attached to the machinery used or transported over long distances (Fenner & Thompson 2005).…”