Researchers investigated how intraspecific variation in big sagebrush shrub roots among subspecies and cytotypes could affect its ability to access surface water. Using an isotope tracer to examine plants’ belowground zone of influence, researchers found that lateral root development and activity is more strongly related to genetic variability within big sagebrush plants than to plant size. Contrary to expectations, plant crown volume was a weak predictor of water uptake. Subspecies adapted to deep soils generally had a smaller horizontal reach, and polyploid cytotypes were associated with greater water uptake compared to diploids. This study shows that variation in life strategies is linked to mechanisms of resource acquisition such as competition for water, not only how well adapted populations are to physical properties of the site. Findings can inform management practices and conservation of arid scrublands, particularly seed-transfer guidelines for big sagebrush.

Zaiats, A., Lazarus, B.E., Germino, M.J., Serpe, M., Richardson, B., Buerki, S., Caughlin, T., 2020, Intraspecific variation in surface water uptake in a perennial desert shrub: Functional Ecology, https://doi.org/10.1111/1365-2435.13546