U.S. Department of Energy Office of Biological and Environmental Research

Searchable Research Highlights



A Multi-Species Synthesis of Physiological Mechanisms in Drought-Induced Tree Mortality
Published: August 07, 2017
Posted: September 05, 2017

The Science  
This is the first paper to synthesize the results on mechanisms of mortality from all known drought manipulation studies, and found that hydraulic failure is a universal component of death while carbon starvation is frequent but not universal.

The Impact
This paper 1) tests a contentious hypothesis regarding hydraulic failure and carbon starvation, for the first time, at a global scale, 2) provides modelers a direct path to improving vegetation dynamics simulations.

Summary
About half of carbon dioxide emissions are absorbed by plants, but this service is threatened by increasing frequency of hot droughts. One of the largest uncertainties in land surface modeling is how vegetation will respond to greater exposure to life-threatening droughts. One of the most contentious theories in ecology today regards the mechanisms of responses e.g., how plants regulate hydraulic failure and carbon starvation (if they even occur at all) during drought. Hydraulic failure is where plants experience partial or complete interruption of the water transporting xylem tissue function from stress induced embolisms that inhibits water transport, leading to desiccation. Carbon starvation is a phenomena where an imbalance between carbohydrate demand and supply leads to an inability to meet osmotic, metabolic and defensive carbon requirements. This study reviewed and synthesized the findings on all known drought studies that killed trees and found the occurrence of hydraulic failure was a universal characteristic proceeding plant death, and co-occurring carbon starvation occurred in approximately 50% of studies. The most advanced land-surface models today simulate mortality via carbon starvation but not via hydraulic failure. Therefore, current model development should incorporate hydraulic failure as a trigger to plant mortality to improve our understanding and predictions of ecosystems and vegetation.

Contacts
(BER PM)

Daniel Stover
SC-23.1
Daniel.Stover@science.doe.gov (301-903-0289)

(PI Contact)
Nate McDowell
Pacific Northwest National Lab
nate.mcdowell@pnnl.gov

Funding
Funding was provided by DOE, Office of Science, NGEE-Tropics, via the Los Alamos and the Pacific Northwest National Lab’s LDRD program, and via NSF.

Publications
Adams et al. (61 co-authors). A multi-species synthesis of physiological mechanisms in drought-induced mortality.. Nature Ecology & Evolution 1, 1285-1291 (2017). [doi:10.1038/s41559-017-0248-x] (Reference link)

Topic Areas:

  • Research Area: Terrestrial Ecosystem Science
  • Research Area: Next-Generation Ecosystem Experiments (NGEE)
  • Mission Science: Climate

Division: SC-23.1 Climate and Environmental Sciences Division, BER

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Nov 01, 2017
Rapid Characterization of Northern Cold-Region Soil Organic Matter
Infrared spectroscopy discriminated variations in soil properties and extent of organic matter d [more...]

Sep 06, 2017
Terrestrial Biosphere Models Underestimate Photosynthetic Capacity and CO2 Assimilation in the Arctic
New measurements of photosynthesis in the Arctic demonstrate that current models underestimate k [more...]

Sep 05, 2017
A New Approach to Represent Multi-Consumer, Multi-Species Soil Biogeochemical Reactions for Earth System Models
A new kinetics formulation (SUPECA) scales mixed reaction networks. < [more...]

Aug 25, 2017
Shaking Up Atmospheric Assumptions
Researchers used long-term ARM data to gain a new understanding of the vertical structure of tur [more...]

Aug 07, 2017
A Multi-Species Synthesis of Physiological Mechanisms in Drought-Induced Tree Mortality
The Science   This is the first paper to synthesize the results on m [more...]