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Seasonal patterns of foliage respiration in dominant and suppressed Eucalyptus globulus canopies
journal contribution
posted on 2023-05-17, 02:25 authored by Anthony O'Grady, Alieta EylesAlieta Eyles, Worledge, D, Battaglia, MWe examined spatial and temporal dynamics of foliage respiration in canopies of dominant and suppressed Eucalyptus globulus trees to better understand processes regulating foliage respiration in a young fast-growing stand. Temperature response functions and seasonal measures of respiration (measured at a reference temperature of 15 ¡ÆC, R15) were studied for ¡1 year to (i) examine controls on respiration as a function of canopy position, foliar nitrogen and non-structural carbohydrate concentrations and (ii) assess the capacity for thermal acclimation within E. globulus canopies. The short-term temperature response of respiration varied both with canopy position and seasonally. Area-based R15 measurements declined with increasing canopy depth and were strongly related to foliar N concentrations, especially in upper-canopy positions. R15 was negatively correlated with the average temperature of the preceding 14 days, a pattern consistent with thermal acclimation. In suppressed canopies, R15 was higher than that at similar canopy heights in dominant trees. Similarly, foliar concentrations of non-structural carbohydrates were also relatively higher in suppressed canopies than dominant canopies, providing support for a substrate-based model of leaf respiration. Our data highlight the dynamic nature of foliar respiration within E. globulus canopies, which contrasts with the generally simplistic representation of respiration within most process-based models.
History
Publication title
Tree PhysiologyVolume
30Issue
8Pagination
957-968ISSN
0829-318XDepartment/School
School of Natural SciencesPublisher
Heron PublishingPlace of publication
202, 3994 Shelbourne St, Victoria, Canada, Bc, V8N 3E2Rights statement
The definitive publisher-authenticated version is available online at: www.oxfordjournals.orgRepository Status
- Restricted