Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.14/90679
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- Title
- Carbon budget of Pinus sylvestris saplings after four years of exposure to elevated atmospheric carbon dioxide concentration
- Related
- Tree physiology, Vol. 25, No. 3 (2005), p.325-337
- DOI
- 10.1093/treephys/25.3.325
- Publisher
- Heron Publishing
- Date
- 2005
- FoR/RFCD Code(s)
-
070500 Forestry Sciences
- Author/Creator
- Janssens, Ivan A
- Author/Creator
- Medlyn, Belinda
- Author/Creator
- Gielen, Birgit
- Author/Creator
- Laureysens, Ilse
- Author/Creator
- Jach, M. Ewa
- Author/Creator
- Van Hove, Ditske
- Author/Creator
- Ceulemans, Reinhart
- Description
- To study the responses of Scots pine (Pinus sylvestris L.), a commercially important tree species in Europe, to future increases in atmospheric CO2 concentration ([CO2]), we grew saplings for 4 years in the ground in open-top chambers in ambient or ambient + 400 μmol mol− CO2, without supplemental addition of nutrients and water. Carbon (C) budgets were developed for trees in both CO2 treatments based on productivity and biomass data obtained from destructive harvests at the end of the third and fourth years of treatment, and simulations of annual gross photosynthesis (Ptot) and maintenance respiration by the model MAESTRA. Simulated Ptot was enhanced by elevated [CO2], despite significant down-regulation of photosynthetic capacity. The subsequent increase in C uptake was allocated primarily to tissues with limited longevity (needles and fine roots), which explains why the measured annual increment in woody biomass did not differ between CO2 treatments. Thus, our results suggest that accelerated stem growth only occurs in the first 2 years in the presence of elevated [CO2] and that forest rotations will not be shortened significantly in response to increasing [CO2]. In elevated [CO2], a higher proportion of available C was allocated below ground, resulting in altered biomass distribution patterns. In trees of equal size, measured ratios of fine root/needle biomass and belowground/aboveground biomass were almost twice as large in the elevated [CO2] treatment. Although there are uncertainties in scaling from saplings to mature canopies, the data indicate that, in nutrient-limited Scots pine forests, elevated [CO2] is unlikely to accelerate tree growth significantly, but is likely to increase C inputs to soil.
- Description
- 13 page(s)
- Subject Keyword
- 070500 Forestry Sciences
- Subject Keyword
- allocation
- Subject Keyword
- construction respiration
- Subject Keyword
- elevated CO2
- Subject Keyword
- MAESTRA
- Subject Keyword
- maintenance respiration
- Subject Keyword
- photosynthesis
- Subject Keyword
- productivity
- Resource Type
- journal article
- Organisation
- Macquarie University. Dept. of Biological Sciences
- Identifier
- http://hdl.handle.net/1959.14/90679
- Identifier
- ISSN:1758-4469
- Identifier
- mq-rm-2006011630
- Language
- eng
- Reviewed
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