Effect of successional stages on the establishment of quercus calliprinos in an east mediterranean maquis

A sowing experiment was conducted to investigate whether and how secondary succession affects the establishment success of Quercus calliprinos, a leading species of East Mediterranean maquis. Acorns of Q. calliprinos were sown at equivalent densities in experimental plots representing three different stages of the succession: open patches (gaps) dominated by annual plants, patches of low woody vegetation dominated by the early-successional dwarf shrub Sarcopoterium spinosum, and patches of mature Q. calliprinos trees. These patch types represent early, middle, and late stages of the succession. Seedlings that emerged in the experimental plots were monitored for survival and growth during two successive years. Seedling emergence was lowest beneath the canopy of Q. calliprinos trees (2%), intermediate in patches of S. spinosum (54%), and highest in gaps (85%). Seedling survivorship exhibited an opposite pattern: 67% beneath the canopy of Q. calliprinos trees. 43% in patches of S. spinosum, and only 4% in gaps. The combined probability of pre-emergence and post-emergence survival was 23% in patches of S. spinosum, 3% in closed-canopy patches, and 1% in gaps. These results indicate that (I) secondary succession may have considerable effects on the establishment success of Q. calliprinos in Mediterranean maquis, and (2) post-emergence death of Q. calliprinos seedlings may modify patterns of establishment generated by earlier germination and emergence responses. The significance of these results for the natural dynamics and management of maquis dominated by Q. calliprinos is discussed with respect to the concepts of “regeneration niche” and “succession models”.