The effect of elevated CO₂ on the chemical composition and construction costs of leaves of 27 C₃ species

Abstract

We determined the proximate chemical composition as well as the construction costs of leaves of 27 species, grown at ambient and at a twice-ambient partial pressure of atmospberic CO2. Tbese species comprised wild and agricultural berbaceous plants as well as tree seedlings. Botb average responses across species and tbe range in response were considered. Expressed on a total dry weigbt basis, tbe main cbange in cbemical composition due to CO2 was tbe accumulation of total non-structural carbobydrates (TNC). To a lesser extent, decreases were found for organic N compounds and minerals. Hardly any cbange was observed for total structural carbobydrates (cellulose plus bemicellulose), lignin and lipids. Wben expressed on a TNC-free basis, decreases in organic N compounds and minerals were still present. On tbis basis, tbere was also an increase in tbe concentration of soluble pbenolics.In terms of glucose required for biosynthesis, tbe increase in costs for one cbemical compound -TNCwas balanced by a decrease in tbe costs for organic N compounds. Tberefore, tbe construction costs, tbe total amount of glucose required to produce 1 g of leaf, were ratber similar for tbe two CO2 treatments; on average a small decrease of 3% was found. Tbis decrease was attributable to a decrease of up to 30% in tbe growtb respiration coefficient, tbe total CO2 respired [mainly for N AD(P)H and ATP] in tbe process of constructing 1 g of biomass. Tbe main reasons for tbis reduction were tbe decrease in organic N compounds and tbe increase in TNC.

Tissue chemistry and carbon allocation in seedlings of Pinus palustris subjected to elevated atmospheric CO2 and water stress

“…Few studies have examined CO 2-induced changes in plant chemistry, and these have mostly been restricted to foliar responses (Lindroth et al 1993, Lindroth 1996, O'Neill and Norby 1996, Pritchard et al 1997, Williams et al 1997) and have shown high variability among plant species (Pefiuelas et al 1996, Poorter et al 1997. Plants subjected to water stress had increased concentrations of needle FWO.…”

The nitrate and ammonium nitrate supply have a major influence on the response of photosynthesis, carbon metabolism, nitrogen metabolism and growth to elevated carbon dioxide in tobacco

“…The organic nitrogen concentration decreases in elevated [CO 2 ] (Wong 1979;Curtis, Drake & Whigham 1989;Garbutt, Williams & Bazzaz 1990;Coleman et al 1991;Hocking & Meyer 1991a, 1991bColeman & Bazzaz 1992;Gries, Kimball & Idso 1993;Pettersson et al 1993;Körner & Miglietta 1994;Pettersson & MacDonald 1994; FerrarioMery et al 1997;Poorter et al 1997), indicating that nitrate assimilation fails to keep pace with growth. There is conflicting evidence with respect to the effect of elevated [CO 2 ] on nitrate reductase (NR) activity.…”

“…However, in many other studies with a range of species including wheat (Hocking & Meyer 1991a;Mitchell et al 1994;McKee & Woodward 1994;Rogers et al 1996b;Fangmeier et al 1997), cotton (Wong 1979;Rogers et al 1996a), Xanthium occidentale (Hocking & Meyer 1985), Eucalyptis grandis (Conroy, Milham & Barlow 1992), oak seedlings (Norby, O'Niell & Luxmore 1986), loblolly pine seedlings (Gebauer, Reynolds & Strain 1996) and Influence of nitrogen on response to elevated CO 2 in tobacco 1179 birch (Pettersson et al 1993) the relative and absolute stimulation of growth in elevated [CO 2 ] was much smaller in nitrogen-limited plants than in well-fertilized plants. In soybean (Sionit 1983), Agrostis capillaris and Nardus strictus (Bowler & Press 1996), loblolly pine (Griffin, Thomas & Strain 1993;Thomas, Lewis & Strain 1994;Johnson, Ball & Walker 1995), chestnut (El-Kohen & Mousseau 1994) and several woody species (Eamus & Jarvis 1989) (Wong 1979;Hocking & Meyer 1991a, 1991bPettersson et al 1993;Rogers et al 1993;McKee & Woodward 1994;Jacob et al 1995;Poorter et al 1997), elevated [CO 2 ] should promote more growth in nitrogen-limiting conditions. Although the increased nitrogen use efficiency in elevated [CO 2 ] is partly due to a decrease of the nitrate content (Purvis et al 1974;Yelle, Gosselin & Trudel 1987;Hocking & Meyer 1985;Hocking & Meyer 1991b;Poorter et al 1997), growth in elevated [CO 2 ] also typically leads to a lower organic nitrogen concentration (see above), indicating that organic nitrogen u...…”

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ABSTRACTThe nitrogen concentration usually decreases in elevated [CO 2 ] (Wong 1979;Hocking & Meyer 1985;Hocking & Meyer 1991a, 1991bColeman et al 1993;Pettersson, MacDonald & Stadenburg 1993;Rogers et al 1993;McKee & Woodward 1994;Jacob, Greitner & Drake 1995;Nie et al 1995;Poorter et al 1997), indicating that nitrogen uptake lags behind carbohydrate synthesis and growth in elevated [CO 2 ]. The effect of elevated [CO 2 ] on the nitrate uptake rates per unit root weight is rather variable and apparently depends on the nitrogen concentration supplied (Larigauderie, Reynolds & Strain 1994) and the species.

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“…Although nitrate uptake might be improved in elevated [CO 2 ] because plants possess more roots and exploit a larger soil volume (see, e.g. Stulen & den Hertog 1993;Pettersson et al 1993;Jackson & Reynolds 1996), the decreased water flow in elevated [CO 2 ] will tend to decrease the root surface concentrations of nitrate (Van Vuuren et al 1997).The organic nitrogen concentration decreases in elevated [CO 2 ] (Wong 1979;Curtis, Drake & Whigham 1989;Garbutt, Williams & Bazzaz 1990;Coleman et al 1991;Hocking & Meyer 1991a, 1991bColeman & Bazzaz 1992;Gries, Kimball & Idso 1993;Pettersson et al 1993;Körner & Miglietta 1994;Pettersson & MacDonald 1994; FerrarioMery et al 1997;Poorter et al 1997), indicating that nitrate assimilation fails to keep pace with growth. There is conflicting evidence with respect to the effect of elevated [CO 2 ] on nitrate reductase (NR) activity.…”