Elevated photosynthetic potential in Polylepis reticulata trees from the Andean tree line.

Polylepis reticulata is a vulnerable Andean páramo endemic tree species that grows at the highest altitude in the world. Despite having abundant available water year-round, P. reticulata trees face extreme environmental conditions, namely low temperatures and frequent persistent clouds and fog, which create extremes of solar irradiance.

Legacies from early-season hot drought: how growth cessation alters tree water dynamics and modifies stress responses in Scots pine.

Tree responses to drought are well studied, but the interacting effects of drought timing on growth, water use, and stress legacy are less understood. We investigated how a widespread conifer, Scots pine, responded to hot droughts early or late in the growing season, or to both. We measured sap flux, stem growth, needle elongation, and leaf water potential (Ψ) to assess the impacts of stress timing on drought resilience in Scots pine saplings.

Overcoming drought: life traits driving tree strategies to confront drought stress.

This insight article comments on: Ziegler C, Cochard, H, Stahl C, Bastien Gérard LF, Goret J, Heuret P, Levionnois S, Maillard P, Bonal D, Coste S. 2024. Residual water losses mediate the trade-off between growth and drought survival across saplings of 12 tropical rainforest tree species with contrasting hydraulic strategies.

Relationships between xylem embolism and tree functioning during drought, recovery, and recurring drought in Aleppo pine.

Recent findings suggest that trees can survive high levels of drought-induced xylem embolism. In many cases, the embolism is irreversible and, therefore, can potentially affect post-drought recovery and tree function under recurring droughts. We examined the development of embolism in potted Aleppo pines, a common species in hot, dry Mediterranean habitats.

Anatomical adjustments of the tree hydraulic pathway decrease canopy conductance under long-term elevated CO2.

The cause of reduced leaf-level transpiration under elevated CO2 remains largely elusive. Here, we assessed stomatal, hydraulic, and morphological adjustments in a long-term experiment on Aleppo pine (Pinus halepensis) seedlings germinated and grown for 22-40 months under elevated (eCO2; c. 860 ppm) or ambient (aCO2; c.