Empirical evidence for resilience of tropical forest photosynthesis in a warmer world

Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

Fersiynau electronig

Dangosydd eitem ddigidol (DOI)

  • Marielle Smith
    Michigan State UniversityUniversity of Arizona, Tucson
  • Tyeen C. Taylor
    University of Arizona, Tucson
  • Joost van Haren
    University of Arizona, Tucson
  • Rafael Rosolem
    University of Bristol
  • Natalia Restrepo-Coupe
    University of Arizona, Tucson
  • John Adams
    University of Arizona, Tucson
  • Jin Wu
    University of Hong Kong
  • Raimundo C. de Oliveira
    Embrapa Amazônia Oriental, Santarém, Brazil
  • Rodrigo da Silva
    University of Western Pará
  • Alessandro C. de Araujo
    National Institute of Amazonian Research (INPA), Manaus
  • Plinio Barbosa de Camargo
    Departamento de Ecologia, Universidade de São Paulo
  • Travis E. Huxman
    University of California, Irvine
  • Scott R. Saleska
    University of Arizona, Tucson
Tropical forests may be vulnerable to climate change1,2,3 if photosynthetic carbon uptake currently operates near a high temperature limit4,5,6. Predicting tropical forest function requires understanding the relative contributions of two mechanisms of high-temperature photosynthetic declines: stomatal limitation (H1), an indirect response due to temperature-associated changes in atmospheric vapour pressure deficit (VPD)7, and biochemical restrictions (H2), a direct temperature response8,9. Their relative control predicts different outcomes—H1 is expected to diminish with stomatal responses to future co-occurring elevated atmospheric [CO2], whereas H2 portends declining photosynthesis with increasing temperatures. Distinguishing the two mechanisms at high temperatures is therefore critical, but difficult because VPD is highly correlated with temperature in natural settings. We used a forest mesocosm to quantify the sensitivity of tropical gross ecosystem productivity (GEP) to future temperature regimes while constraining VPD by controlling humidity. We then analytically decoupled temperature and VPD effects under current climate with flux-tower-derived GEP trends in situ from four tropical forest sites. Both approaches showed consistent, negative sensitivity of GEP to VPD but little direct response to temperature. Importantly, in the mesocosm at low VPD, GEP persisted up to 38 °C, a temperature exceeding projections for tropical forests in 2100 (ref. 10). If elevated [CO2] mitigates VPD-induced stomatal limitation through enhanced water-use efficiency as hypothesized9,11, tropical forest photosynthesis may have a margin of resilience to future warming.
Iaith wreiddiolSaesneg
Tudalennau (o-i)1225–1230
CyfnodolynNature Plants
Cyfrol6
Rhif y cyfnodolyn10
Dyddiad ar-lein cynnar12 Hyd 2020
Dynodwyr Gwrthrych Digidol (DOIs)
StatwsCyhoeddwyd - Hyd 2020
Cyhoeddwyd yn allanolIe
Gweld graff cysylltiadau