Drought-induced xylem embolism limits the recovery of leaf gas exchange in scots pine

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Romy Rehschuh - , Karlsruhe Institute of Technology (Author)
  • Angelica Cecilia - , Karlsruhe Institute of Technology (Author)
  • Marcus Zuber - , Karlsruhe Institute of Technology (Author)
  • Tomáš Faragó - , Karlsruhe Institute of Technology (Author)
  • Tilo Baumbach - , Karlsruhe Institute of Technology (Author)
  • Henrik Hartmann - , Max Planck Institute for Biogeochemistry (Author)
  • Steven Jansen - , Ulm University (Author)
  • Stefan Mayr - , University of Innsbruck (Author)
  • Nadine Ruehr - , Karlsruhe Institute of Technology (Author)

Abstract

Climate change increases the occurrence of prolonged drought periods with large implications for forest functioning. Scots pine (Pinus sylvestris) is one of the most abundant conifers worldwide, and evidence is rising that its resilience to severe drought is limited. However, we know little about its ability to recover from drought-induced embolism. To analyze postdrought hydraulic recovery, we investigated stress and recovery dynamics of leaf gas exchange, nonstructural carbohydrates, and hydraulic properties in 2.5-year-old Scots pine seedlings. We quantified the degree of xylem embolism by combining in vivo x-ray microtomography with intrusive techniques including measurements of hydraulic conductivity and dye staining during drought progression and short-term (2 d) and long-term (4 weeks) recovery. Seedlings were grown under controlled conditions, and irrigation was withheld until stomata closed and xylem water potential declined to 23.2 MPa on average, causing a 46% loss of stem hydraulic conductivity. Following drought release, we found a gradual recovery of leaf gas exchange to 50% to 60% of control values. This partial recovery indicates hydraulic limitations due to drought-induced damage. Whereas xylem water potential recovered close to control values within 2 d, both x-ray microtomography and intrusive measurements revealed no recovery of stem hydraulic conductivity. Moreover, we did not find indications for nonstructural carbohydrate reserves limiting hydraulic recovery. Our findings demonstrate that Scots pine is able to survive severe drought and to partially recover, although we assume that xylem development during the next growing season might compensate for some of the hydraulic impairment. Such drought-induced legacy effects are important when considering vegetation responses to extreme events.

Details

Original languageEnglish
Pages (from-to)852-864
Number of pages13
JournalPlant physiology
Volume184
Issue number2
Publication statusPublished - Oct 2020
Peer-reviewedYes
Externally publishedYes

External IDs

PubMed 32820065

Keywords

Sustainable Development Goals

ASJC Scopus subject areas