On the variability of the ecosystem response to elevated atmospheric CO2 across spatial and temporal scales at the Duke Forest FACE experiment
File(s)
Accepted version
Author(s)
Paschalis, Athanasios
Katul, Gabriel G
Fatichi, Simone
Palmroth, Sari
Way, Danielle
Type
Journal Article
Abstract
While the significance of elevated atmospheric CO2 concentration on instantaneous leaf-level processes such as photosynthesis and transpiration is rarely disputed, its integrated effect at ecosystem level and at long-time scales remains a subject of debate. In part, the uncertainty stems from the inherent leaf-to-leaf variability in gas exchange rates. By combining 10 years of leaf gas exchange measurements collected during the Duke Forest Free Air CO2 Enrichment (FACE) experiment and three different leaf-scale stomatal conductance models, the leaf-to-leaf variability in photosynthetic and stomatal conductance properties is examined. How this variability is then reflected in ecosystem water vapor and carbon dioxide fluxes is explored by scaling up the leaf-level process to the canopy using model calculations. The main results are: (a) the space-time variability of the photosynthesis and stomatal conductance response is considerable as expected. (b) Variability of the calculated leaf level fluxes is dependent on both the meteorological drivers and differences in leaf age, position within the canopy, nitrogen and CO2 fertilization, which can be accommodated in model parameters. (c) Meteorological variability is playing the dominant role at short temporal scales while parameter variability is significant at longer temporal scales. (d) Leaf level results do not necessarily translate to similar ecosystem level responses due to indirect effects and other compensatory mechanisms related to long-term vegetation dynamics and ecosystem water balance.
Date Issued
2016-09-17
Date Acceptance
2016-09-12
Citation
Agricultural and Forest Meteorology, 2016, 232, pp.367-383
ISSN
0168-1923
Publisher
Elsevier Masson
Start Page
367
End Page
383
Journal / Book Title
Agricultural and Forest Meteorology
Volume
232
Copyright Statement
© 2016 Elsevier B.V. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000389089800030&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Life Sciences & Biomedicine
Physical Sciences
Agronomy
Forestry
Meteorology & Atmospheric Sciences
Agriculture
Ecohydrological modeling
Elevated CO2
FACE
Stomatal conductance model
Spatio-temporal variability
WATER-USE EFFICIENCY
LONG-TERM EXPOSURE
PROGRESSIVE NITROGEN LIMITATION
MESOPHYLL DIFFUSION CONDUCTANCE
MODELING STOMATAL CONDUCTANCE
TERRESTRIAL CARBON-CYCLE
GLOBAL VEGETATION MODEL
VAPOR-PRESSURE DEFICIT
PLANT FUNCTIONAL TYPES
LOBLOLLY-PINE FOREST
Publication Status
Published