Hydraulic adjustment of Scots pine across Europe

Abstract

Summary• The variability of branch-level hydraulic properties was assessed across 12 Scots pine populations covering a wide range of environmental conditions, including some of the southernmost populations of the species. The aims were to relate this variability to differences in climate, and to study the potential tradeoffs between traits.• Traits measured included wood density, radial growth, xylem anatomy, sapwoodand leaf-specific hydraulic conductivity (K S and K L ), vulnerability to embolism, leaf-to-sapwood area ratio (A L : A S ), needle carbon isotope discrimination (Δ 13 C) and nitrogen content, and specific leaf area.• Between-population variability was high for most of the hydraulic traits studied, but it was directly associated with climate dryness (defined as a combination of atmospheric moisture demand and availability) only for A L : A S , K L and Δ 13 C. Shoot radial growth and A L : A S declined with stand development, which is consistent with a strategy to avoid exceedingly low water potentials as tree size increases. In addition, we did not find evidence at the intraspecific level of some associations between hydraulic traits that have been commonly reported across species.• The adjustment of Scots pine's hydraulic system to local climatic conditions occurred primarily through modifications of A L : A S and direct stomatal control, whereas intraspecific variation in vulnerability to embolism and leaf physiology appears to be limited.

Comparative Drought Responses of Quercus ilex L. and Pinus sylvestris L. in a Montane Forest Undergoing a Vegetation Shift

“…Minimum values of Ψ were representative of extreme drought conditions for both species. For example, ΨMD for P. sylvestris (~−2.5 MPa) were in the lowest end of ΨMD reported across Europe [50] and ΨPD values were lower than those observed in other drought-exposed populations [51]. Likewise, Q. ilex reached values of ΨPD and ΨMD (~−5MPa and ~−6 MPa, respectively) that are among the most negative ones ever recorded for this species [33,52].…”

Transpiration and stomatal conductance of mistletoe (Loranthus europaeus) and its host plant, downy oak (Quercus pubescens)

“…The difference reflected the different leaf areas supported by each unit of sapwood area (Huber value). If this value can be considered a measure of a plant's adaptation to water stress (Martínez-Vilalta et al 2009), then mistletoe, having a 3.6 times smaller leaf : xylem area (Table 1), was much better adapted. In contrast, the similarity of the sap flow rates in the xylem of the two species do not support the findings of Ziegler et al (2009) The diurnal curves of transpiration ( Fig.…”

Modelling benzo[a]pyrene in air and vegetation for different land uses and assessment of increased health risk in the Iberian Peninsula

“…According to Anfodillo et al (2002) and Martínez-Vilalta et al (2009), this evidence is particularly seen in latitudinal and altitudinal gradients where the influence on climatic patterns is stronger than in longitudinal frameworks.…”