Identifying Plant Physiological and Climatic Drivers in the Woody Shrub Prosopis strombulifera: Effects of Spring Traits on Flower Sprouting and Fruit Production

Prosopis strombulifera is a widely distributed woody species distributed along arid ecosystems in America. The interannual evolution of ecophysiological parameters and their effects on fruit production and flower sprouting in Prosopis strombulifera were studied for three years in a natural population distributed in the Atacama Desert. Xylem water column tension, pressure–volume curves, specific leaf area (SLA), and chlorophyll fluorescence parameters were assessed. Flower sprouting was assessed in different weeks using tagged flowers. To assess fruit production, four small containers were placed under twenty-five individuals, allowing the estimation of total annual production and individual production. We found considerable variability between years and between individuals. Positive relationships were found between plant water parameters, SLA, and chlorophyll variables measured in spring at flower sprouting and during fruit production. A negative correlation was found between the mean of the minimum temperatures in spring and flower sprouting. These results suggest that spring ecophysiological parameters strongly affect the reproductive status of P. strombulifera. The results also reflect the potential of this species to adapt to a hyperarid climate by preserving a high relative water content before flower sprouting.