We examined species composition and diversity of vegetation and soil seed bank associated with different microhabitats in Mediterranean semiarid sand dune community, to identify which functional groups or species benefit from trampling, and to provide a basis for management. In this community microhabitats were found to significantly influence species abundance and biomass of dominant functional groups and dominant species. The open patches generally have the greatest species richness, diversity and productivity. The highest value of similarity occurred during June to September and the lowest value occurred in April when seedling emergence stopped but before new seeds dispersed. Shrubs did not benefit their understorey plant functional groups except for perennial forbs and Apiaceae due to their denser canopy and larger litter amount. Trampling decreased the species diversity of vegetation and did not facilitate the establishment of herbaceous plants, but was beneficial for some functional groups such as Apiaceae and Brassicaceae as well as some species such as Polycarpon succulentum. A positive relationship was found between productivity and diversity in this community and on the trail, but the relationship in the open area and shrub understorey was not significant. This work can provide a deeper understanding of smallscale vegetation processes and mosaic patterns of distribution.

Seedling emergence and establishment was monitored in 3 microhabitats during growing seasons in a Mediterranean coastal sand dune community in Poleg Stream Nature Reserve, Israel. Seedling emergence varied temporally among the 3 microhabitats, with a delay in the timing of seedling emergence in shrub understoreys due to lower soil average temperatures and lower irradiance. In contrast, seedling emergence on trails was advanced because of more intense irradiance and higher soil temperatures on their more exposed soil surfaces. Microhabitats showed significant differences in individual densities, species diversity, and species richness of total seedlings (P < 0.0001). Open areas generally possessed significantly greater total seedling densities, species diversity, and species richness compared to shrub understoreys and trails. Twelve key species and 5 functional groups showed significant microhabitat preferences. Seedling patterns indicated that emergence responses could account for observed patterns of variation in the 5 functional groups and dominant species populations. In this semi-arid ecosystem, negative interactions between the shrub canopy species (white weeping broom) and its understorey occurred for seedling establishment because of lower seed densities in the seed bank, a larger amount of litter on the soil surface, and the dense woody canopy. On the trails, trampling decreased plant diversity and discouraged the establishment of most functional groups and key species except annual grasses and 'Polycarpon succulentum' and 'Cutandia philistaea'. The variability in seedling response patterns for the different microhabitats will assist in understanding the patchy regeneration strategies of this coastal sand dune community and provide a basis for vegetation management.