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Background:Seedling recruitment following fire is an infrequent yet critical demographic transition for woody plants in Mediterranean ecosystems. Aims:Here we examine whether post-fire seedling recruitment of three widespread Californian chaparral shrubs is affected by local adaptation within an edaphically and topographically complex landscape. Methods:We reciprocally transplanted 6-month-old seedlings ofAdenostema fasciculatum,Ceanothus cuneatusandEriodictyon californicumto serpentine and sandstone soils, and cool northerly and warm southerly slopes. Results:At the age of 2 years, none of the species manifested higher survival or growth on ‘home’ compared with ‘away’ soils or slopes, indicating an absence of local adaptation with respect to seedling recruitment in these environments. Seedlings of all species manifested lower survival and relative growth on serpentine soils regardless of seedling source, as well as a variety of other destination and source effects. Conclusions:The ability of these three species to recruit in new environments, such as in restoration settings or in response to shifting climates, is unlikely to be impeded by a need for seeds from sources that closely match their edaphic or topographic destination. [ABSTRACT FROM PUBLISHER]

The mechanical resistance of leaves has key ecological implications but its basis has not been well understood, particularly at the tissue scale. We tested the hypotheses that leaf mechanical resistance should be a function of tissue density, increasing from the lamina to the midrib, and higher in drought-tolerant than drought-avoiding species., In a common garden study, we quantified nine leaf biomechanical traits, including measurements of material and structural resistance, and in addition 17 morphological traits, at the tissue and whole-leaf scales, for 21 species from three semi-arid communities of California, USA., The mechanical properties of leaves depended strongly on tissue density. Material resistance was significantly greater in the midrib than in the leaf lamina, and tissue resistances were significantly correlated among tissues, lower in deciduous coastal sage species and higher in evergreen drought-tolerant chaparral species. The proportion of the biomass invested in the midrib was lower in species bearing midribs and laminas of high material resistance., Our results support the hypothesis of a hierarchical partitioning of leaf mechanical resistance among leaf tissues reflecting the investment of dry mass. Also, our data indicated a mechanical compensation in leaf design, where leaves with high material resistance and density deploy a relatively minor proportion of support tissue in the midrib. Finally, our results establish a quantitative basis for differences among communities in leaf biomechanics. Our results supported the classical characterization of the mediterranean-climate flora of California according to the dramatic increase in the mean leaf mechanical resistance from species of coastal sage to chaparral, with diverse leaf types in the Mojave Desert species. [ABSTRACT FROM AUTHOR]