Smith Lab News
Jan. 19, 2025: Alissar, Lizz, Evan, and Risa lead paper showing that leaf nitrogen demand helps determine leaf nitrogen responses to soil nitrogen, out now in Ecology Letters
Alissar led a
new study published in Ecology Letters titled “Soil nitrogen supply
exerts largest influence on leaf nitrogen in environments
with the greatest leaf nitrogen demand."
The paper uses leaf chemistry data (Firn et al., 2019) from the Nutrient Network to show that sites that have the greatest leaf nitrogen response to soil nitrogen fertilization are those where we would expect there to be the greatest demand for photosynthetic leaf nitrogen.
From theory (see review by Stocker et al. (2024)) we can predict how climatic factors should drive photosynthetic leaf nitrogen demand. This theory predicts that leaf nitrogen demand should increase with aridity and sunlight, and decrease with temperature. The new paper shows that the responsiveness of leaf nitrogen to soil nitrogen across the network increases with these factors (see figure below).
This study provides a novel confirmation of our theoretical understanding of plant nitrogen dynamics. This can serve as a baseline for developing new models (e.g., Stocker et al. (2024)) for simulating these responses, ultimately improving simulations of terrestrial carbon-nitrogen cycle interactions.
As an aside, it is with pleasure to note that this paper was the result of many years of work by the PhUnFETTy lab and our collaborators within the NutNet. The first four authors are current or former PhUnFETTy lab members, all of whom contributed significant effort towards the analyses in this paper. Although, a huge shout out goes to Alissar for bringing many years of thinking together to craft a cohesive suite of analyses and resulting narrative.
This work was primarily supported by the National Science Foundation.
Cheaib, AC*, EF Waring*, RM McNellis*, EA Perkowski*, JP Martina, EW Seabloom, ET Borer, PA Wilfahrt, N Dong, IC Prentice, IJ Wright, SA Power, EK Hersch-Green, AC Risch, M Caldeira, C Nogueira, QQ Chen, and NG Smith (2025). Soil nitrogen supply exerts largest influence on leaf nitrogen in environments with the greatest leaf nitrogen demand. Ecology Letters 28(1): e70015. link.
