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Whole-plant approaches allow quantification of the temporal overlap between primary and secondary growth. If the amount of time available to grow is short, there may be a high temporal overlap between shoot growth and wood formation. We hypothesise that such overlap depends on the duration of the growing season and relates to wood anatomy. We evaluated wood anatomy, shoot longitudinal and radial growth rates, fine root production and the concentrations of non-structural carbohydrates (NSC) in the wood of six sub-shrub species growing in sites with contrasting climatic conditions (Lepidium subulatum, Linum suffruticosum, Salvia lavandulifolia, Satureja montana, Ononis fruticosa, Echinospartum horridum). Sub-shrub species living in sites with a short growing season displayed a high overlap between aboveground primary and secondary growth and formed wide vessels, whereas species from the warmest and driest sites presented the reverse characteristics. The highest overlap was linked to a rapid shoot extension and thickening through the enhanced hydraulic conductivity provided by wide vessels. The reductions in NSC concentrations when growth peaked were low or moderate, indicating that sub-shrubs accumulate NSC in excess, as do trees. The temporal overlap among primary and secondary growth in woody plants may be connected to the duration and rates of shoot and wood growth, which in turn depend on the vessel lumen area. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands. ; We thank Elena Lahoz and Arben Q. Alla for help with histological and image analyses. This work was supported by the Spanish Government and FEDER (European Social Fund) projects [grant nos. CGL2007-66066-C04-02/BOS, CGL2008-04847-C02-01, CGL2010-16880/BOS, CGL2011-26654]. S.P. and J.J.C. acknowledge support from a 'Juan de la Cierva' grant and from ARAID, respectively. ; Peer Reviewed

8 páginas, 4 tablas.-- El PDF es la versión post-print. ; [Question]: This study analysed the effect of severe soil erosion on species composition of plant communities by favouring species showing certain growth forms, root-sprouting and clonal growth abilities. [Location]: The study area was located between the middle Ebro Valley and the Pre-Pyrenees (northeastern Spain). [Methods]: Root-sprouting and shoot-rooting abilities, clonal reproduction and growth form were assessed for the 123 most common plant species from eroded lands in the study area. We obtained 260 vegetation relevés in three different substrata (gypsum outcrops, Miocene clays and Eocene marls) on areas with different degrees of soil erosion. The frequency of every plant trait in each relevé was estimated according to species presence. The effect of soil erosion on the frequency of plant attributes was assessed by correlation analyses. [Results]: Bipolar, non-clonal plants and annual species decreased their frequency with increasing soil erosion in the three substrata analyzed, whereas root-sprouters and woody plants (mostly sub-shrubs) increased their frequency in most of the substrata analysed. [Conclusions]: Woody sub-shrubs, root-sprouters and clonal species are favoured in eroded lands in NE Spain. Bipolar species and annual plants might not be plastic enough to survive the high stress and frequent disturbances prevailing in such eroded areas. ; This study was supported by the research projects RTA 2005-00100 from the MEC (INIA) and CGL2006- 11619/HID, CGL2004-04919-C02-01/HID, REN2003-08678/ HID from the MCT, Spanish Government. J.G.C. was supported by a grant from the Government of Aragon (BMA 15/93). ; Peer reviewed

10 páginas, 4 figuras, 3 tablas.-- El PDF es la versión post-print. ; [Background and aims]: Mediterranean woody plants have a wide variety of phenological strategies. Some authors have classified the Mediterranean phanaerophytes into two broad phenological categories: phenophase-verlappers (that overlap resource-demanding activities in a short period of the year) and phenophase-sequencers (that protract resource-demanding activities throughout the year). In this work the impact of both phenological strategies on leaf nutrient accumulation and retranslocation dynamics at the level of leaves and branches was evaluated. Phenophase-overlappers were expected to accumulate nutrients in leaves throughout most of the year and withdraw them efficiently in a short period. Phenophase-sequencers were expected to withdraw nutrients progressively throughout the year, without long accumulation periods. [Methods]: To test this hypothesis, variations in phenology and leaf NPK in the crown of a phenophase-overlapper Cistus laurifolius and a phenophase-sequencer Bupleurum fruticosum were monitored monthly during 2 years. [Key Results]: Changes in nutrient concentration at the leaf level were not clearly related with the different phenologies. Nitrogen and phosphorous resorption efficiencies were lower in the phenophase-overlapper, and accumulation–retranslocation seasonality was similar in both species. Changes in the branch nutrient pool agreed with the hypothesis that the phenophase-overlapper accumulated nutrients from summer until the bud burst of the following spring, recovering a large nutrient pool during massive leaf shedding. The phenophase-sequencer did not accumulate nutrients from autumn until early spring, achieving lower nutrient recovery during spring leaf shedding. [Conclusions]: It is concluded that phenological demands influence branch nutrient cycling. This effect is easier to detect by assessing changes in the branch nutrient pool rather than changes in the leaf nutrient concentration. ; This study was supported by the "Comisión Interministerial de Ciencia y Tecnología" (Spanish government) project REN 2000-0163-P4-05, REN2002-02635/GLO and the Thematic Network GLOBIMED (REN 2001-4841-E/GLO); and 2) the "Gobierno de Aragón" project P-024/2001 and financial support to R. M. ; Peer reviewed

9 páginas, 4 figuras, 2 tablas.-- El PDF es la versión post-print. ; [Background and Aims]: The objective of this study was to test whether the mean values of several root morphological variables were related to the ability to develop root-borne shoots and/or shoot-borne roots in a wide range of vascular plants. [Methods]: A comparative study was carried out on the 123 most common plant species from eroded lands in north-east Spain. After careful excavations in the field, measurements were taken of the maximum root depth, absolute and relative basal root diameter, specific root length (SRL), and the root depth/root lateral spread ratio on at least three individuals per species. Shoot-rooting and root-sprouting were observed in a large number of individuals in many eroded and sedimentary environments. The effect of life history and phylogeny on shoot-rooting and root-sprouting abilities was also analysed. [Key Results]: The species with coarse and deep tap-roots tended to be root-sprouting and those with fine, fasciculate and long main roots (which generally spread laterally), tended to be shoot-rooting. Phylogeny had an important influence on root system morphology and shoot-rooting and root-sprouting capacities. However, the above relations stood after applying analyses based on phylogenetically independent contrasts (PICs). [Conclusions]: The main morphological features of the root system of the study species are related to their ability to sprout from their roots and form roots from their shoots. According to the results, such abilities might only be functionally viable in restricted root system morphologies and ecological strategies. ; This study was supported by the Spanish Ministry of Science and Technology, projects AMB93-0806, REN2002-02635/ GLO and RTA 2005-00100. J. G. C. and S. P. were supported by a grant from the Government of Aragon (BMA 15/93) and a FPU scholarship (AP-2001-2311, MEC, Spain), respectively. ; Peer reviewed

12 páginas, 3 figuras, 2 tablas. ; Few studies have examined the effects of plant growth on nutrient remobilization in phenologically contrasting species. Here we evaluated the consequences of above-ground seasonality of growth and leaf shedding on the remobilization of nutrients from branches in eight evergreen Mediterranean phanaerophytes that differ widely in phenology. Vegetative growth, flower bud formation, flowering, fruiting, leaf shedding, and the variations in nitrogen (N), phosphorus (P) and potassium (K) pools in branches throughout the year were monitored in each species. Nitrogen and P remobilization occurred in summer, after vegetative growth and synchronously with leaf shedding. Despite the time-lag between growth and remobilization, the branches that invested more nutrients in vegetative growth also remobilized more nutrients from their old organs. Potassium remobilization peaked in the climatically harshest periods, and appears to be related to osmotic requirements. We conclude that N and P remobilization occurs mainly associated with leaf senescence, which might be triggered by factors such as the replenishment of nutrient reserves in woody organs, the hormonal relations between new and old leaves, or the constraints that summer drought poses on the amount of leaf area per branch in summer. ; This study was supported by the Comisión Interministerial de Ciencia y Tecnología (Spanish government) projects REN 2000-0163-P4-05, REN2002-02635/GLO, and the Thematic Network GLOBIMED (REN 2001–4841-E/GLO. The 'Gobierno de Aragón' project P-024/2001 provided financial support to R. M. ; Peer reviewed

11 páginas, 3 figuras, 5 tablas. ; [Background and Aims]: Plants from gypsum habitats are classified as gypsophiles and gypsovags. The former include both narrow endemics limited to small gypsum areas and regionally dominant gypsophiles growing in gypsum areas of large regions, whereas gypsovags are plants that can grow both in gypsum and non-gypsum soils. Factors controlling the distribution of gypsum plants are still not fully understood. [Methods]: To assess how the different types of gypsum plants deal with the stressful conditions of gypsum substrates, comparisons were made of the leaf chemical composition of four gypsovags, five regionally dominant gypsophiles and four narrow gypsum endemics growing in two massive gypsum areas of the Iberian Peninsula. [Key Results]: The chemical composition of gypsovags was clearly different from regionally dominant gypsophiles, while the chemical composition of narrow-gypsophile endemics was more similar to the chemical composition of gypsovags than to that of regionally dominant gypsophiles. Regionally dominant gypsophiles showed higher concentrations of ash, Ca, S, N, Mg P and Na, whereas gypsovags and local gypsophile endemics displayed higher concentrations of C and greater C : N ratios. [Conclusions]: Such differences suggest that the three groups of gypsum plants follow diverse ecological strategies. It is suggested that regionally dominant gypsophiles might fit the 'specialist' model, being species specifically adapted to gypsum, whereas both gypsovags and narrow-gypsophile endemics might fit the 'refuge' model, being stress-tolerant species that find refuge on gypsum soils from competition. The analysis of the leaf chemical composition could be a good predictor of the degree of plants specialization to gypsum soils. ; R.M. and S.P. were funded by a Post-doctoral and a FPU fellowship, respectively (SEUI – MEC, Spain). This study was supported by the MEC (Spanish Government; research project RTA 2005–00100), the MCT (Spanish Government; research projects CGL2006–11619/HID, CGL2004– 04919-C02-01/HID, REN2003–08678/HID) and by REMEDINAL, a research network financed by the Autonomous Government of Madrid. ; Peer reviewed