Reductions in tree performance during hotter droughts are mitigated by shifts in nitrogen cycling

Plant, Cell & Environment
By: , and 



Climate warming should result in hotter droughts of unprecedented severity in this century. Such droughts have been linked with massive tree mortality, and data suggest that warming interacts with drought to aggravate plant performance. Yet how forests will respond to hotter droughts remains unclear, as does the suite of mechanisms trees use to deal with hot droughts. We used an ecosystem‐scale manipulation of precipitation and temperature on piñon pine (Pinus edulis) and juniper (Juniperus monosperma) trees to investigate nitrogen (N) cycling‐induced mitigation processes related to hotter droughts. We found that while negative impacts on plant carbon and water balance are manifest after prolonged drought, performance reductions were not amplified by warmer temperatures. Rather, increased temperatures for 5 years stimulated soil N cycling under piñon trees and modified tree N allocation for both species, resulting in mitigation of hotter drought impacts on tree water and carbon functions. These findings suggest that adjustments in N cycling are likely after multi‐year warming conditions and that such changes may buffer reductions in tree performance during hotter droughts. The results highlight our incomplete understanding of trees' ability to acclimate to climate change, raising fundamental questions about the resistance potential of forests to long‐term, compound climatic stresses.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Reductions in tree performance during hotter droughts are mitigated by shifts in nitrogen cycling
Series title Plant, Cell & Environment
DOI 10.1111/pce.13389
Volume 41
Issue 11
Year Published 2018
Language English
Publisher Wiley
Contributing office(s) Southwest Biological Science Center
Description 11 p.
First page 2627
Last page 2637