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Trade-offs in low-light CO2 exchange: a component of variation in shade tolerance among cold temperate tree seedlings.
- Source :
-
Functional Ecology . Apr2000, Vol. 14 Issue 2, p155-165. 11p. - Publication Year :
- 2000
-
Abstract
- Abstract1. Does enhanced whole-plant CO2 exchange in moderately low to high light occur at the cost of greater CO2 loss rates at very-low light levels? We examined this question for first-year seedlings of intolerant Populus tremuloides and Betula papyrifera, intermediate Betula alleghaniensis, and tolerant Ostrya virginiana and Acer saccharum grown in moderately low (7·3% of open-sky) and low (2·8%) light. We predicted that, compared with shade-tolerant species, intolerant species would have characteristics leading to greater whole-plant CO2 exchange rates in moderately low to high light levels, and to higher CO2 loss rates at very-low light levels. 2. Compared with shade-tolerant A. saccharum, less-tolerant species grown in both light treatments had greater mass-based photosynthetic rates, leaf, stem and root respiration rates, leaf mass:plant mass ratios and leaf area:leaf mass ratios, and similar whole-plant light compensation points and leaf-based quantum yields. 3. Whole-plant CO2 exchange responses to light (0·3–600 µmol quanta m-2 s-1) indicated that intolerant species had more positive CO2 exchange rates at all but very-low light (< 15 µmol quanta m-2 s-1). In contrast, although tolerant A. saccharum had a net CO2 exchange disadvantage at light > 15 µmol quanta m-2 s-1, its lower respiration resulted in lower CO2 losses than other species at light < 15 µmol quanta m-2 s-1. 4. Growth scaled closely with whole-plant CO2 exchange characteristics and especially with integrated whole-plant photosynthesis (i.e. leaf mass ratio × in situ leaf photosynthesis). In contrast, growth scaled poorly with leaf-level quantum yield, light compensation point, and light-saturated photosynthetic rate. 5. Collectively these patterns indicated... [ABSTRACT FROM AUTHOR]
- Subjects :
- *PLANT photorespiration
*CARBON dioxide
*POPULUS tremuloides
*PAPER birch
Subjects
Details
- Language :
- English
- ISSN :
- 02698463
- Volume :
- 14
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- Functional Ecology
- Publication Type :
- Academic Journal
- Accession number :
- 5471777
- Full Text :
- https://doi.org/10.1046/j.1365-2435.2000.00415.x