Species-specific drought effects on flower and fruit production in a Mediterranean holm oak forest

7 páginas, 3 figuras, 1 tablaA holm oak forest was exposed to an experimental drought (reduction of 15 per cent soil moisture\udas predicted for this area for the next decades by General Circulation Models and ecophysiological\udmodels) during 7 years to elucidate the reproductive responses of the dominant species Quercus\udilex L., Arbutus unedo L. and Phillyrea latifolia L. Soil moisture was partially reduced by plastic\udstrips intercepting rainfall and by ditch exclusion of water runoff. During the period studied,\udmeteorological conditions and soil moisture were continuously monitored, together with fl ower and\udfruit production in the three dominant species. In Q. ilex and A. unedo, fl ower and specially fruit\udproduction were strongly correlated with annual rainfall, but not in P. latifolia. The experimental\uddrought reduced fl ower and fruit production in Q. ilex by 30 per cent and 45 per cent, respectively.\udReductions in fl ower and fruit production were not signifi cant in A. unedo and were not observed\udin P. latifolia. A decrease in production of reproductive structures and the different response of the\udspecies studied to a decrease in water availability could induce important changes in the competitive\udability of the different species and in the long term in the community species composition and future\uddistribution of these Mediterranean species.This research\udwas fi nancially supported by CGL 2004-01402/BOS\udand GCL 2006-04025/BOS grants from the Spanish\udGovernment, a Fundación Banco Bilbao Vizcaya 2004\udgrant, a Catalan Government SGR2005-00312 grant\udand the European project Assesing Large scale Risks\udfor biodiversity with tested Methods (contract 506675,\udEuropean Union sixth framework programme).Peer reviewe