Facilitation of Quercus ilex recruitment by shrubs in Mediterranean open woodlands

Uppsala

2008

2 Abb., 3 Tab., zahlr. Lit. Ang.

Unselbständiges Werk

12599

200145396

Three months after sowing, 199 of 512 acorns were removed, predominantly by rodents. Acorn removal occurred at each treatment but was highest under shrubs. Eight months after sowing, seedling survival was highest under shrubs (50%), followed by shaded cages (16%), open grassland (4%) and cages (0%). Main mortality cause was drought (90%), killing most seedlings between June and July. No seedlings died from ungulate browsing. Conclusion: Shrubs demonstrated clear net facilitative effects for Quercus ilex recruitment, despite higher seed removal. Shading appears the crucial factor facilitating seedling survival. We therefore propose that lack of shrubs contributes largely to tree recruitment failure in Mediterranean open woodlands; management should aim at conserving shrubs.