Hydraulic efficiency in two Patagonian trees keeps constant across a precipitation gradient

Generalist tree species growing across broad climatic gradients pose an intriguing question about how they can deal with such strong variations in climate. Studying the conductive system of trees may give a clue about their strategies to face rainfall variations.

Location of the study areas (wet, mesic and dry), sites (four per area) and climatic diagrams for each study area.
Location of the study areas (wet, mesic and dry), sites (four per area) and climatic diagrams for each study area. Ak, Aiken Park; At, Atravesado Lake; Ci, Baguales; Cl, Claro River; Cu, Cuervo River; Ib, Puerto Ibáñez; Lv, Levicán Peninsula; Pa, Pangal Valley; Pf, head of Pangal Valley; Rc, Reserva Coyhaique; Ro, Rosado Mountain; Sa, Ibáñez River waterfall. Note that central months in climatic diagrams correspond to summer in the southern hemisphere. Climatic data were obtained from the Climate Forecast System Reanalysis (CFSR) data set, compiled by the National Center for Environmental Prediction (NCEP), USA (Globalweather 2016). The scale bar in the region map represents 50 km.

In southern Chile, García-Cervigón et al. examine hydraulic adjustments at the branch anatomical level in Nothofagus antarctica (Nothofagaceae) and Embothrium coccineum (Proteaceae) across a precipitation gradient from 500 to 2500 mm. Both species maintained hydraulic efficiency but combined with different levels of safety against embolism, which suggests the existence of alternative internal adjustments in coexisting species of temperate forests to face unpredictable climate changes.

Further reading

García-Cervigón, A. I., Olano, J. M., von Arx, G., & Fajardo, A. (2018). Xylem adjusts to maintain efficiency across a steep precipitation gradient in two coexisting generalist species. Annals of Botany, 122(3), 461–472. https://doi.org/10.1093/aob/mcy088