Article

 

Evaluating theories of drought-induced vegetation mortality using a multimodel– experiment framework Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/articles/8p58pd52z

Descriptions

Attribute NameValues
Creator
Abstract
  • Model–data comparisons of plant physiological processes provide an understanding of mechanisms underlying vegetation responses to climate. We simulated the physiology of a pi~non pine–juniper woodland (Pinus edulis–Juniperus monosperma) that experienced mortality during a 5 yr precipitation-reduction experiment, allowing a framework with which to examine our knowledge of drought-induced tree mortality. We used six models designed for scales ranging from individual plants to a global level, all containing state-of-the-art representations of the internal hydraulic and carbohydrate dynamics of woody plants. Despite the large range of model structures, tuning, and parameterization employed, all simulations predicted hydraulic failure and carbon starvation processes co-occurring in dying trees of both species, with the time spent with severe hydraulic failure and carbon starvation, rather than absolute thresholds per se, being a better predictor of impending mortality. Model and empirical data suggest that limited carbon and water exchanges at stomatal, phloem, and below-ground interfaces were associated with mortality of both species. The model–data comparison suggests that the introduction of a mechanistic process into physiology-based models provides equal or improved predictive power over traditional process-model or empirical thresholds. Both biophysical and empirical modeling approaches are useful in understanding processes, particularly when the models fail, because they reveal mechanisms that are likely to underlie mortality. We suggest that for some ecosystems, integration of mechanistic pathogen models into current vegetation models, and evaluation against observations, could result in a breakthrough capability to simulate vegetation dynamics.
  • Keywords: carbon starvation, hydraulic failure, process-based models, cavitation, dynamic global vegetation models (DGVMs), die off, photosynthesis
Resource Type
DOI
Date Available
Date Issued
Citation
  • McDowell, N. G., Gehres, N., Limousin, J. M., Macalady, A., Martínez-Vilalta, J., Mencuccini, M., . . . Dickman, L. (2013). Evaluating theories of drought-induced vegetation mortality using a multimodel-experiment framework. The New Phytologist, 200(2), 304-321. doi:10.1111/nph.12465
Journal Title
Journal Volume
  • 200
Journal Issue/Number
  • 2
Academic Affiliation
Rights Statement
Funding Statement (additional comments about funding)
  • We thank the New Phytologist Trust and Trustees for funding insupport of the workshop ‘A multi-scale model investigation of themechanisms of drought-induced vegetation mortality’ held inSanta Fe,NewMexico, in November 2011. Additional support wasprovided by the Department of Energy-Office of Science, andLANL-LDRD.
Publisher
Peer Reviewed
Language
Replaces

Relationships

Parents:

This work has no parents.

Items