This title appears in the Scientific Report :
2014
Please use the identifier:
http://hdl.handle.net/2128/7815 in citations.
Please use the identifier: http://dx.doi.org/10.3389/fpls.2014.00012 in citations.
The effect of irradiance on the carbon balance and tissue characteristics of five herbaceous species differing in shade-tolerance
The effect of irradiance on the carbon balance and tissue characteristics of five herbaceous species differing in shade-tolerance
The carbon balance is defined here as the partitioning of daily whole-plant gross CO2 assimilation (A) in C available for growth and C required for respiration (R). A scales positively with growth irradiance and there is evidence for an irradiance dependence of R as well. Here we ask if R as a fract...
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Personal Name(s): | Pons, T. L. (Corresponding author) |
---|---|
Poorter, Hendrik | |
Contributing Institute: |
Pflanzenwissenschaften; IBG-2 |
Published in: | Frontiers in plant science, 5 (2014) 12, S. 1 - 14 |
Imprint: |
Lausanne
Frontiers Media
2014
|
DOI: |
10.3389/fpls.2014.00012 |
PubMed ID: |
24550922 |
Document Type: |
Journal Article |
Research Program: |
Plant Science Sustainable Bioproduction |
Link: |
OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.3389/fpls.2014.00012 in citations.
The carbon balance is defined here as the partitioning of daily whole-plant gross CO2 assimilation (A) in C available for growth and C required for respiration (R). A scales positively with growth irradiance and there is evidence for an irradiance dependence of R as well. Here we ask if R as a fraction of A is also irradiance dependent, whether there are systematic differences in C-balance between shade-tolerant and shade-intolerant species, and what the causes could be. Growth, gas exchange, chemical composition and leaf structure were analyzed for two shade-tolerant and three shade-intolerant herbaceous species that were hydroponically grown in a growth room at five irradiances from 20 μmol m−2 s−1 (1.2 mol m−2 day−1) to 500 μmol m−2 s−1 (30 mol m−2 day−1). Growth analysis showed little difference between species in unit leaf rate (dry mass increase per unit leaf area) at low irradiance, but lower rates for the shade-tolerant species at high irradiance, mainly as a result of their lower light-saturated rate of photosynthesis. This resulted in lower relative growth rates in these conditions. Daily whole-plant R scaled with A in a very tight manner, giving a remarkably constant R/A ratio of around 0.3 for all but the lowest irradiance. Although some shade-intolerant species showed tendencies toward a higher R/A and inefficiencies in terms of carbon and nitrogen investment in their leaves, no conclusive evidence was found for systematic differences in C-balance between the shade-tolerant and intolerant species at the lowest irradiance. Leaf tissue of the shade-tolerant species was characterized by high dry matter percentages, C-concentration and construction costs, which could be associated with a better defense in shade environments where leaf longevity matters. We conclude that shade-intolerant species have a competitive advantage at high irradiance due to superior potential growth rates, but that shade-tolerance is not necessarily associated with a better C-balance at low irradiance. Under those conditions tolerance to other stresses is probably more important for the performance of shade-tolerant species. |