02275nas a2200301   4500008004100000020001400041245011700055210006900172260002900241300001200270490000800282520134500290653002101635653001401656653001801670653001401688653002201702653001901724653002501743653002101768100002301789700001901812700002201831700002401853700002501877700002701902856004401929       2012                        eng d  a1365-274500aStabilizing selection for within-season flowering phenology confirms pollen limitation in a wind-pollinated tree0 aStabilizing selection for withinseason flowering phenology confi  bBlackwell Publishing Ltd  a758-7630 v1003 a1. We examined the fitness consequences of pollen limitation in the valley oak (Quercus lobata Née, Fagaceae), a wind-pollinated, predominantly outcrossing tree endemic to California, by examining the relationship between within-year phenology and acorn production over an 8 year period. 2. We predicted that pollen limitation should result in trees flowering relatively early and late in the season, when fewer trees are in flower, to experience reduced reproductive success compared to trees flowering during the middle of the season. 3. Despite considerable variation in acorn production from year to year, analyses confirmed this prediction and indicated that there was significant overall stabilizing selection on budburst date consistent with the pollen limitation hypothesis. 4. Analyses including herbivory and pre-budburst temperatures at individual trees revealed significant correlations with acorn production, but we still found significant stabilizing selection on budburst date even when considering these variables. 5.Synthesis.  Pollen limitation, as indicated by stabilizing selection on within-year flowering phenology, significantly affects acorn production by individual trees in Q. lobata and has the potential to influence other key life-history features including masting behaviour and spatial synchrony.10aacorn production10aherbivory10amast-fruiting10aphenology10apollen limitation10aQuercus lobata10areproductive ecology10awind-pollination1 aKoenig, Walter, D.1 aFunk, Kyle, A.1 aKraft, Thomas, S.1 aCarmen, William, J.1 aBarringer, Brian, C.1 aKnops, Johannes, M. H.  uhttps://quercus.myspecies.info/node/14503605nas a2200277   4500008004100000020001400041245010800055210006900163260002900232300001200261490000800273520272800281653002503009653001603034653002403050653001803074653002303092653002503115653001403140653002903154100003003183700002403213700002303237700002303260856004403283       2012                        eng d  a1365-274500aOntogenetic conflicts and rank reversals in two Mediterranean oak species: implications for coexistence0 aOntogenetic conflicts and rank reversals in two Mediterranean oa  bBlackwell Publishing Ltd  a467-4770 v1003 a1. In heterogeneous environments, species segregate spatially in response to selective abiotic and biotic filters occurring throughout plant ontogeny. Ontogenetic conflicts in recruitment may lead to spatially discordant patterns of regeneration among microhabitats with different plant cover. In addition, species differing in seed size may be subjected to opposing ecological and evolutionary pressures throughout the life cycle of the plant. 2. We used a multi-stage demographic approach aimed at characterizing the main stage-specific probabilities of recruitment (seed survival, seed germination, seedling emergence and survival during the first 3 years of life) in two Mediterranean oak species coexisting at southern Spain. We calibrated linear and nonlinear likelihood models for each of these consecutive life history stages and calculated overall probabilities of recruitment along a wide range of plant cover and seed size variation. 3. Seed predation and seedling mortality over the dry season were the most limiting processes for the two studied oak species. However, species ranking diverged substantially through the life history stages considered in this study due to different ontogenetic trends among species. 4. At the intraspecific level, recruitment-driving processes during the seed and the seedling stages showed opposing tendencies along the explored range of plant cover and seed size. Thus, small-sized acorns and open areas were favoured for the seed stage, whereas large acorns and dense microhabitats did for the seedling stage. 5. The existence of opposing selective pressures on seed mass and their differential influence on the two studied oak species determined the occurrence of species-specific optimal seed sizes (small acorns for Quercus canariensis vs. acorns of large or intermediate size for Quercus suber). 6. The spatial patterns predicted by our overall-recruitment models provided some evidence of regeneration niche partitioning in the two coexisting oak species, supporting their current distribution patterns as saplings and adults at the study area. 7. Synthesis. We conclude that within- and among-species differences through plant ontogeny, arising from species differential response to microhabitat heterogeneity and seed size variation, could be of great importance for oak species niche segregation, driving stand dynamics and spatial pattern distribution along the landscape. The information provided by this study could be also applied to optimize management and restoration programmes since it has enabled us to identify the most favourable conditions and traits for recruitment in oak species that exhibit serious constraints for natural regeneration.10aMediterranean forest10aplant cover10aQuercus canariensis10aQuercus suber10aregeneration niche10areproductive ecology10aseed size10aseed–seedling conflict1 aPérez-Ramos, Ignacio, M.1 aUrbieta, Itziar, R.1 aZavala, Miguel, A.1 aMarañón, Teodoro  uhttps://quercus.myspecies.info/node/150