Plant genetic variation drives geographic differences in atmosphere-plant-ecosystem feedbacks

Area of Science:

• Ecology
• Hydrology
• Plant Physiology

Background:

• Geographic variation in plant traits can drive large-scale land-atmosphere feedbacks.
• Understanding these feedbacks is crucial for predicting ecosystem responses to climate change.

Purpose of the Study:

• To investigate how genetic variation in Populus angustifolia affects land-atmosphere mass and energy exchange.
• To examine geographic differences in plant population traits and their influence on hydrologic processes.

Main Methods:

• Utilized a physical hydrology model.
• Conducted paired field and greenhouse observations of plant traits.
• Analyzed stable isotope compositions of soil, stem, and leaf water.

Main Results:

• Observed local adaptation in traits related to hydrologic functioning, with significant differences in stomatal density (47%) and stomatal ratio (74%).
• Identified differences in water use among populations, linked to historical landscape hydrologic functioning (evapotranspiration, streamflow).

Conclusions:

• Populus angustifolia populations exhibit local adaptation in traits influencing water use.
• Populations from diverse hydrologic histories will vary in their water balance maintenance under changing atmospheric conditions.
• These differences have significant ecosystem-level consequences.