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Physiologic traits are promising indicators of population health in the face of rapidly changing environments. We obtained values of diverse physiologic parameters for Two-banded Plovers ( Charadrius falklandicus) in coastal sites in Patagonia, Argentina, with the objectives of determining the timeline in which these parameters become affected by the stress of capture and handling and of obtaining reference values for future monitoring of these populations. We analyzed packed cell volume, white blood cell profile, heterophil/lymphocyte ratio, bacterial agglutination titer, and total protein, glucose, triglyceride, and cholesterol levels in apparently healthy birds. Glucose, total white blood cell count, lymphocytes, and eosinophil levels showed changes with handling times >60 min after capture. The remaining parameters did not manifest significant alterations in response to capture and handling of up to 232 min (average=105.2, SD=56.7). Therefore, although researchers should attempt to obtain blood samples as soon as possible after capture, inclusion of physiologic parameters in monitoring studies of species not easily sampled in a few minutes, such as Two-banded Plovers and other shorebird species during migration, should not be discouraged. Here we provide a physiologic report for the species that can be considered as reference values during the nonbreeding season at Patagonian coastal sites. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mediterranean riparian forests are negatively impacted by drought. • Growth responses to climate and drought of four tree species were investigated. • Growth was reduced by drought and low spring-summer river flow. • Populus nigra and Fraxinus angustifolia were the most responsive species to drought. • Ash earlywood anatomy, and wood C and O isotopes also responded to drought. Mediterranean riparian forests have been altered by past use and are also negatively impacted by climate and hydrological droughts. However, we lack data on their historical changes in extent combined with multi-proxy, long-term assessments of tree growth and leaf gas exchange responses to climate, drought severity and river flow. These evaluations must also consider their current stand structure and the amount of lying deadwood which are proxies of river dynamics and forest maturity. To fill these research gaps, we studied four riparian tree species (Populus alba , Populus nigra , Fraxinus angustifolia and Ulmus minor) inhabiting a Mediterranean riparian forest located in north-eastern Spain. We quantified and analyzed: stand structure; lying deadwood; radial growth; relationships between growth, climate variables, the SPEI drought index and river flow; stable C (δ13C) and O (δ18O) isotopes in wood of P. alba , P. nigra and F. angustifolia ; and earlywood anatomy in F. angustifolia. Mature sites were dominated by P. nigra and F. angustifolia and showed the highest amount of decayed lying deadwood. Radial growth was reduced by drought and low spring-summer river flow. We found the highest growth responses to 3- (P. nigra , r = 0.62; P. alba , r = 0.46) or 12-month SPEI (F. angustifolia , r = 0.54; U. minor , r = 0.53). The coordinated decrease in δ18O and intrinsic water-use efficiency (WUE) in P. alba and P. nigra could involve an increase in stomatal conductance rate. P. alba and P. nigra were more enriched in δ18O than F. angustifolia , suggesting the former used more enriched shallow groundwater in dry periods. The F. angustifolia WUE and P. nigra δ18O series were positively and negatively correlated with the SPEI, respectively. The F. angustifolia hydraulic diameter decreased in response to drought, whereas its vessel density and WUE were positively associated. Overall, P. nigra and F. angustifolia were the species most responsive to drought. [ABSTRACT FROM AUTHOR]

Tree species inhabiting riparian forests under Mediterranean climate have evolved to face summer water shortage but may fail to cope with future increases in drought severity. Thus, understanding tree growth phenological variations in response to environmental conditions is necessary to assess the impact of seasonal drought in riparian forests. In this study, we investigated the response of stem radial growth to climate in the narrow-leaved ash (Fraxinus angustifolia) over its distribution in southern Europe. We simulated intra- and inter-annual growth patterns using the Vaganov-Shashkin (VS) model considering five sites subjected to summer drought but showing different climate conditions. The growth pattern in this species varied from unimodal in cool-wet sites to facultative bimodal in warm-dry sites. Bimodal patterns were characterized by two growth peaks coinciding with favorable climate conditions in spring and autumn. The spring growth peak occurs earlier (May) in warm-dry sites than in wet-cool sites (June–July). The variation in the season growth length and growth timing suggests different strategies adopted by this species to cope with summer drought. The VS model revealed different growth patterns across which would be relevant in predicting the response of this and other riparian tree species to climate warming and aridification. Differences in the length of the growing season, timings of growth peaks and the shift from unimodal to bimodal growth patterns should be considered when assessing growth adjustments to future climate scenarios. [Display omitted] • Ring-width and daily climatic data were used to adjust the VS model in narrow-leaved ash. • The ash growing season varied in length and pattern, but always showed a spring growth peak. • Ash growth shifted from unimodal in wet-cool sites to facultative bimodal in dry-warm sites. • The use of process-based models allows assessing intra-annual growth responses to climate. [ABSTRACT FROM AUTHOR]

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The article presents a study which examined whether reverse movements of red knots occurred during their migration in Argentina. Resightings of birds individually marked in San Antonio Oeste or the flyway at two staging sites in 2006, 2007, 2009 and 2010 were analysed to investigate whether reverse movements occurred between them. The movements were found to have occurred in all years of the study.

Riparian ash forests subjected to seasonal drought are among the most endangered ecosystems in Europe. They are threatened by climate warming causing aridification and by land-use changes modifying river flow. To assess the impacts of these two stress factors on riparian forests, we studied radial growth and xylem anatomical traits in five narrow-leaved ash (Fraxinus angustifolia) stands across wide climatic and ecological gradients from northern Italy to southern Portugal. Radial growth rates and earlywood hydraulic diameter (Dh) were directly correlated, whilst earlywood vessel density and growth rates were inversely associated. Ash growth positively responded to precipitation. Higher and lower rates of growth increase in response to precipitation were found in dry (annual precipitation 357–750 mm, annual water balance −39 to −48 mm) and wet (annual precipitation 1030 mm, annual water balance 27 mm) sites, respectively. Wet conditions in autumn and winter of the year prior to tree-ring formation lead to larger Dh values, except in the wet site where warmer conditions from prior autumn to current spring were positively associated to wider vessels. Growth was also enhanced by a higher river flow, reflecting higher soil moisture due to elevated groundwater table levels. Peaks in river flow from late winter to early spring increased Dh in dry-continental sites. Growth and potential hydraulic conductivity in drought-prone riparian ash forests are differently impacted by climate variability and river flow depending on site and hydrological conditions. Nevertheless, covariation between radial growth and the earlywood vessel diameter was found, regardless of site specific differences. Wood production and hydraulic conductivity are coordinated through the production of large earlywood vessels which may allow reaching higher growth rates. • Mediterranean riparian forests are threatened but understudied ecosystems. • We quantified radial growth and earlywood anatomy in Fraxinus angustifolia. • Growth rate and the earlywood hydraulic diameter (Dh) covaried. • Growth increased in response to higher precipitation. • Earlywood Dh increased in response to wet prior autumn-winter conditions. [ABSTRACT FROM AUTHOR]

Abstract: This study was carried out in eight stands of wetland woods located in the north-western part of the Iberian Peninsula. The number of sampling sites per stand depended on the physical heterogeneity and area of each stand. Biological data recorded per site included species composition and a list of structural parameters (relative cover in each forest layer, tree height, tree diameter at breast height, number of live and dead trunks and individuals, and morphological adaptations to flooding). Hydro-geomorphologic, geological and climatic variables were also obtained. The floristic data set was subjected to a non-hierarchical cluster analysis and a principal component analysis, which provided an overall image of vegetation grouping based on community composition that only considered perennial species (trees, shrubs, non-annual herbaceous plants and climbers). Three groups of plant communities were distinguished, with an overstorey that was dominated by Betula alba, Salix atrocinerea and Alnus glutinosa, respectively, which presented different environmental drivers. The structural features of each group that was characterised by a different overstorey species were analysed and differences were tested. The number of trunks per individual, number of dead trunks, canopy height and the presence of adaptations to flooding were the structural parameters that best separated the wetland wood groups. Environmental variables were correlated with the ordination axis to analyse community distribution trends and the hydrological regime was found to be the key environmental factor controlling both floristic and structural patterns. [Copyright &y& Elsevier]

• We analyzed climate, drought and hydrology effects on Fraxinus angustifolia growth. • Diverse growth responses to climate and drought reflected the large bioclimatic range of the study. • Growth responses intensified in warmer sites and at longer time scales. • Growth was more coupled with hydrologic regime in sites with least human alteration. • Climate warming will negatively impact Mediterranean riparian ash forests. Mediterranean riparian forests are among the most threatened ecosystems in Europe. These ecosystems are exposed to land-use changes threatening their reduced habitat and by global warming, which is already triggering aridification processes. To assess the impact of these major threats, we studied the radial-growth responses to climate and drought in the narrow-leaved ash (Fraxinus angustifolia). This riparian tree species presents a relatively large ecological spectrum in its habitat preference in the Mediterranean Basin. We studied five sites arranged across a wide geographical range from Iberia to Italy, subjected to contrasting climatic conditions and located in hydrographic basins with different sizes and water regimes. We found diverse growth responses to climate and drought across the Mediterranean distribution range of the narrow-leaved ash at the individual and site levels. The growth of this species increased in response to wet and cool conditions in the prior winter and spring. The response to summer conditions was only observed in the coldest and wettest site (Ticino). Growth responded negatively to 2–14 month droughts that occurred from previous winter up to summer, particularly in the warmest-driest sites. Growth responses to drought peaked in the warmest-driest sites in terms of climate water balance (Odelouca, Doñana), but not in the driest sites in terms of annual precipitation (Tudela, Zaragoza). Hydrological conditions also affected the narrow-leaved ash with high discharges in the prior winter and early spring enhancing wood production. Considering projected aridification and increased hydrological alteration, implying limited water supply in the Mediterranean region, climate warming will negatively impact productivity of narrow-leaved ash riparian forests. Further research should combine analyses of growth responses to climate and hydrology from tree to basin scales to disentangle their relative roles as drivers of productivity under different scenarios of climate and hydrological changes, in order to aid adaptive management of these key ecosystems. [ABSTRACT FROM AUTHOR]