Conference poster
Seasonal variation in leaf respiration: The temperature response of leaf respiration and leaf characteristics of Quercus rubra L.
Ecological Society of America (ESA) Annual Meeting, 89th (Portland, United States, 01-Aug-2004–06-Aug-2004)
2004
Abstract
We measured the responses of leaf respiration to temperature and leaf characteristics of Quercus rubra in two sites with different soil water availability, at two canopy heights,for four times throughout the 2003 growing season in the Black Rock Forest, New York. The response of respiration to temperature was strongly seasonal. Q. rubra leaves displayed higher area based respiration (R area ) in mid-June and late-October than in late-July and mid-September. Overall, leaves from the upper canopy of trees had higher Rarea then those from lower canopy, and leaves from trees growing at the drier (upper) site had higher Rarea than those from wetter (lower) site. However, E0, a model variable representing the over-all energy of activation for CO2 efflux, varied only slightly (a range of 52±5 kJ mol-1 K-1), and was not influenced by season, site, or canopy height. When expressed on a leaf mass or nitrogen basis (Rmass, RN), the effects of site and canopy were offset to some degree, but the seasonal patterns did not change. The leaf characteristics (specific leaf area, nitrogen, soluble sugar and starch) also displayed significant seasonal variations. When expressed on a leaf area basis, nitrogen (Narea) and soluble sugar (sugararea) had significantly positive correlation with Rarea for all samples. In contrast, SLA was negatively correlated to Rarea. The correlations between Rarea and these leaf characteristics were also strong within each sampling period throughout the season, which indicates that SLA, Narea and sugararea all involved in the regulation of the site and canopy level variation in respiration. However, only soluble sugar explained the seasonal variation of the samples across all sites and canopy positions. Overall, our findings suggest that significant simplifications may be made when modeling respiratory carbon fluxes in Q. rubra, by assuming a single temperature coefficient (E0) across multiple spatial and temporal scales. The base respiration rate to which this temperature response will be applied may be predictable from the soluble sugar concentration or other physiological varibles.
Details
- Title
- Seasonal variation in leaf respiration: The temperature response of leaf respiration and leaf characteristics of Quercus rubra L.
- Authors
- Cheng Yuan Xu (Author) - Lamont Doherty Earth Observatory, United StatesK L Griffin (Author) - Lamont Doherty Earth Observatory, United States
- Conference details
- Ecological Society of America (ESA) Annual Meeting, 89th (Portland, United States, 01-Aug-2004–06-Aug-2004)
- Date published
- 2004
- Organisation Unit
- University of the Sunshine Coast, Queensland
- Language
- English
- Record Identifier
- 99450038502621
- Output Type
- Conference poster
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