Co-occurring woody species have diverse hydraulic strategies and mortality rates during an extreme drought.

Published

Journal Article

From 2011 to 2013, Texas experienced its worst drought in recorded history. This event provided a unique natural experiment to assess species-specific responses to extreme drought and mortality of four co-occurring woody species: Quercus fusiformis, Diospyros texana, Prosopis glandulosa, and Juniperus ashei. We examined hypothesized mechanisms that could promote these species' diverse mortality patterns using postdrought measurements on surviving trees coupled to retrospective process modelling. The species exhibited a wide range of gas exchange responses, hydraulic strategies, and mortality rates. Multiple proposed indices of mortality mechanisms were inconsistent with the observed mortality patterns across species, including measures of the degree of iso/anisohydry, photosynthesis, carbohydrate depletion, and hydraulic safety margins. Large losses of spring and summer whole-tree conductance (driven by belowground losses of conductance) and shallower rooting depths were associated with species that exhibited greater mortality. Based on this retrospective analysis, we suggest that species more vulnerable to drought were more likely to have succumbed to hydraulic failure belowground.

Full Text

Duke Authors

Cited Authors

  • Johnson, DM; Domec, J-C; Carter Berry, Z; Schwantes, AM; McCulloh, KA; Woodruff, DR; Wayne Polley, H; Wortemann, R; Swenson, JJ; Scott Mackay, D; McDowell, NG; Jackson, RB

Published Date

  • March 2018

Published In

Volume / Issue

  • 41 / 3

Start / End Page

  • 576 - 588

PubMed ID

  • 29314069

Pubmed Central ID

  • 29314069

Electronic International Standard Serial Number (EISSN)

  • 1365-3040

International Standard Serial Number (ISSN)

  • 0140-7791

Digital Object Identifier (DOI)

  • 10.1111/pce.13121

Language

  • eng