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13 pages, 3 figures, 2 tables, 57 references. I am most indebted to Regino Zamora and José María Gómez for their invaluable intellectual and logistical support during this study. I thank the Consejería de Medio Ambiente (Junta de Andalucía) and the Directors of the Sierra Nevada National Park and the Sierra de Baza Natural Park for permission to do fieldwork. Many thanks also to Sergio de Haro, Elena Baraza and José Antonio Hódar for field assistance. David Nesbitt improved the English version. This research is part of REDBOME (www.ugr.es/~redbome/) and GLOBIMED (www.globimed.net) networks on forest ecology., 1. Plant recruitment is a multiphase process that takes place in environments that are heterogeneous in space and time. In this work, I analyse how environmental heterogeneity in Mediterranean forests affects dynamics of early recruitment at different scales, using the wind-dispersed tree Acer opalus subsp. granatense as a case study. 2. Seed dispersal and viability, post-dispersal predation, seedling emergence and seedling and sapling survival were evaluated in different habitats (regional scale) and microhabitats (local scale). Simultaneously, a review of the literature on spatial dynamics of plant recruitment in Mediterranean systems was conducted to look for general patterns and investigate their fit to the Acer system. Nineteen woody and herbaceous species were included in the review. 3. At the regional scale, Acer recruitment dynamics strongly converged among sites of the same habitat. This was mainly due to large seedling emergence and survival differences among habitats. Although most of the studies reviewed analyzed only one site per habitat type, they also support strong regional variation (either site- or habitat-specific) in recruitment patterns. 4. At the local scale, Acer recruitment was microhabitat-specific, a result shared by almost all the reviewed species independently of their life form and dispersal syndrome. This was mostly due to spatial differences in seed arrival (higher under conspecifics) and seedling survival (higher under nurse shrubs). 5. Spatial discordance among seed rain and recruitment was found in 60% of the reviewed species at the regional scale, and in 67% at the local scale. Acer results supported this predominant lack of concordance. Discordance among seed rain and recruitment suggests that regeneration is largely limited by safe sites than by seed availability. Because seedling survival was the limiting process with a larger impact on the magnitude and spatial pattern of recruitment, safe sites might be defined as those where seedlings have a higher survival probability. 6. Synthesis : This study indicates that the influence of seed dispersal on the spatial patterns and demography of plant species could be limited in heterogeneous and stressful environments (as are found in the Mediterranean), where recruitment is restricted to a small fraction of the landscape. If we are to preserve the distribution and abundance of Mediterranean species in the face of environmental changes, we need to explicitly consider the strong patch-specificity that characterizes their recruitment process at all scales., This study was supported by a grant PFPU-MECD to L.G.A., the Andalusian government grant (PAI) rnm-220 and by the coordinated Spanish MEC projects HETEROMED (REN2002-04041-CO2-01/GLO) and DINAMED (CGL2005-05830-C03-03).

6 páginas, 2 figuras., Dormancy in seeds of Acer opalus is shown to be mainly caused by the seed coats, although a slight embryo dormancy exists in fresh seeds. The ability to germinate after drying indicates that seed storage behaviour is orthodox. Recalcitrant seeds were heavier than orthodox seeds not only within section Acer but also within the whole genus after statistical control of phylogeny, through a phylogenetic ANOVA with data from two different Acer phylogenies. An evolutionary change from orthodox to recalcitrant behaviour is postulated for genus Acer, but this change appears not to have been accompanied by a change in seed dormancy, at least in the taxonomic section in which Acer opalus belongs., We would like to thank Patricio García-Fayos and Hugh W. Pritchard for their suggestions and helpful comments and Lorena Gómez, Regino Zamora and José M. Gómez for the useful data concerning germination response in the field. Funding was provided by a Ramón & Cajal grant from the Spanish Ministerio de Ciencia y Tecnología to Miguel Verdú.

6 páginas, 2 figuras, 1 tabla., 1. Theory predicts that plants that achieve fitness more through male function may be less tolerant of herbivory than those that achieve fitness through the female function. We tested this hypothesis by measuring the degree of infection and damage inflicted by the gall-forming eriophyid mite Aceria macrorhynchus on three different sexual morphs (males, protandrous bisexuals and protogynous bisexuals) of the Mediterranean tree Acer opalus., 2. The dependence of each morph on male function, estimated by registering gender changes over 5 years and quantifying male function, decreased in the order males, protandrous, protogynous., 3. The same decreasing order was found in the degree of gall infection produced by the mite, and in the reduction of photosynthetic rates and shoot growth, but not in the carbon-isotope discrimination caused by the mites., 4. Mites attack the morphs of A. opalus that rely more on the male function more often and more harmfully than they do other morphs. Male-biased herbivory is a selective force that could have been driving the separation of sexes in the genus Acer., We especially thank T. L. Ashman, D. C. Freeman and A. Traveset for their comments on the manuscript. I. Pérez-Moreno identified the mite. P. Cámara, S. Cosín, I. Gimeno and D. Montesinos helped in data collection. J. L. Ferrándiz and the staff of the Park gave us permission to work in the Parque Natural de la Font Roja. The project 1FD97-0551 supported this research. M.V. was granted with contracts of the Reincorporación de Doctores y Tecnólogos del Ministerio de Educación y Ciencia and Programa Ramón y Cajal del Ministerio de Ciencia y Tecnología during this study.