Seedling photosynthesis and leaf respiration under climate change

Climate change is expected to bring warmer temperatures and more variable precipitation patterns worldwide, patterns that will depend on the ability of the world’s flora to take up carbon under these new conditions. In a recent study published in AoB PLANTS, Smith et al. subjected deciduous tree seedlings growing in an old-field ecosystem in Massachusetts, USA to warming and altered precipitation.

Leaf gas exchange measurements being performed at the Boston Area Climate Experiment (BACE).
Leaf gas exchange measurements being performed at the Boston Area Climate Experiment (BACE). Visible are ceramic infrared heaters used to heat the plant canopy as well as clear plastic polycarbonate slats used to remove ambient rainfall. Photo credit: Nick Smith.

They found that leaf carbon uptake was greatest under the coolest, wettest conditions, an effect driven by increased soil water availability in these plots. Their findings suggest that warming may reduce leaf carbon uptake by decreasing soil moisture, an effect that will be exacerbated during drought periods.

Reference

Smith, N. G., Pold, G., Goranson, C., & Dukes, J. S. (2016). Characterizing the drivers of seedling leaf gas exchange responses to warming and altered precipitation: indirect and direct effects. AoB Plants, 8, plw066. http://dx.doi.org/10.1093/aobpla/plw066