Temperature adjustments in sugar maple - acclimation and adaptation of photosynthesis and respiration
- Oak Ridge National Lab., TN (United States)
The assumptions underlying predictions of forest redistribution with climate change generally do not include the potential for adaptation or acclimation. Populations from the southern extreme of a species` range may have higher temperature optima, or individuals may be able to physiologically acclimate to temperature increases. Sugar maple (Acer saccharum) seedlings from a southern and a central geographic source were grown at either 27{degrees}/14{degrees} or 31{degrees}/18{degrees}C (day/night). Photosynthesis and respiration were measured across a range of cuvette temperatures to assess physiological acclimation and pre-existing genetic adaptation. The temperature response curves of photosynthesis had no sharp optima, but rates declined above 31{degrees}C. Curves did not differ with geographic source. Photosynthetic rates were somewhat higher in trees acclimated to the higher temperature, which could help compensate for reductions in assimilation at superoptimal temperatures. Respiration increased with increasing cuvette temperatures, and relationships were similar in trees from both sources. The temperature response for respiration shifted downward in seedlings grown at 31{degrees}, such that respiratory carbon losses at elevated growing temperatures were less than that predicted by relationships from ambient grown plants. These results suggest that for these sugar maple populations acclimation was more important than geographic source in determining the temperature responses of carbon dynamics.
- OSTI ID:
- 95796
- Report Number(s):
- CONF-9507129-; ISSN 0012-9623; TRN: 95:004728-0061
- Journal Information:
- Bulletin of the Ecological Society of America, Vol. 76, Issue 2; Conference: 80. anniversary of the transdisciplinary nature of ecology, Snowbird, UT (United States), 30 Jul - 3 Aug 1995; Other Information: PBD: Jun 1995
- Country of Publication:
- United States
- Language:
- English
Similar Records
Growth and physiology of woody plants in response to elevated CO{sub 2} and defoliation in an open-top field study
Foliar amino acid accumulation as an indicator of ecosystem stress for first-year sugar maple seedlings