Late growing season carbon subsidy in native gymnosperms in a northern temperate forest
File version
Author(s)
Xu, C
Li, Z
Feng, J
Tissue, DT
Griffin, KL
Pereira, J
Griffith University Author(s)
Primary Supervisor
Other Supervisors
Editor(s)
Date
Size
File type(s)
Location
License
Abstract
Evergreen tree species that maintain positive carbon balance during the late growing season may subsidize extra carbon in a mixed forest. To test this concept of ‘carbon subsidy’, leaf gas exchange characteristics and related leaf traits were measured for three gymnosperm evergreen species (Chamaecyparis thyoides, Tsuga canadensis and Pinus strobus) native to the oak-hickory deciduous forest in northeast USA from March (early Spring) to October (late Autumn) in a single year. All three species were photosynthetically active in Autumn. During the Summer–Autumn transition, photosynthetic capacity (Amax) of T. canadensis and P. strobus increased (T-test, P < 0.001) and was maintained in C. thyoides (T-test, P = 0.49), while dark respiration at 20 °C (Rn) and its thermal sensitivity were generally unchanged for all species (one-way ANOVA, P > 0.05). In Autumn, reductions in mitochondrial respiration rate in the daylight (RL) and the ratio of RL to Rn (RL/Rn) were observed in P. strobus (46.3% and 44.0% compared to Summer, respectively). Collectively, these physiological adjustments resulted in higher ratios of photosynthesis to respiration (A/Rnand A/RL) in Autumn for all species. Across season, photosynthetic biochemistry and respiratory variables were not correlated with prevailing growth temperature. Physiological adjustments allowed all three gymnosperm species to maintain positive carbon balance into late Autumn, suggesting that gymnosperm evergreens may benefit from Autumn warming trends relative to deciduous trees that have already lost their leaves.
Journal Title
Tree physiology
Conference Title
Book Title
Edition
Volume
39
Issue
6
Thesis Type
Degree Program
School
Publisher link
Patent number
Funder(s)
Grant identifier(s)
Rights Statement
Rights Statement
Item Access Status
Note
Access the data
Related item(s)
Subject
Ecology
Plant biology
Forestry sciences
carbon subsidy
evergreen species
photosynthesis
respiration
temperate forest
Persistent link to this record
Citation
Li, X; Xu, C; Li, Z; Feng, J; Tissue, DT; Griffin, KL, Late growing season carbon subsidy in native gymnosperms in a northern temperate forest, Tree physiology, 2019, 39 (6), pp. 971-982