Abstract
The influence of elevated CO2 concentration ([CO2]) during plant growth on the carbon:nutrient ratios of tissues depends in part on the time and space scales considered. Most evidence relates to individual plants examined over weeks to just a few years. The C:N ratio of live tissues is found to increase, decrease or remain the same under elevated [CO2]. On average it increases by about 15% under a doubled [CO2]. A testable hypothesis is proposed to explain why it increases in some situations and decreases in others. It includes the notion that only in the intermediate range of N-availability will C:N of live tissues increase under elevated [CO2]. Five hypotheses to explain the mechanism of such increase in C:N are discussed; none of these options explains all the published results. Where elevated [CO2] did increase the C:N of green leaves, that response was not necessarily expressed as a higher C:N of senesced leaves. An hypothesis is explored to explain the observed range in the degree of propogation of a CO2 effect on live tissues through to the litter derived from them. Data on C:P ratios under elevated [CO2] are sparse and also variable. They do not yet suggest a generalising-hypothesis of responses. Although, unlike for C:N, there is no theoretical expectation that C:P of plants would increase under elevated [CO2], the average trend in the data is of such an increase. The processes determining the C:P response to elevated [CO2] seem to be largely independent of those for C:N. Research to advance the topic should be structured to examine the components of the hypotheses to explain effects on C:N. This involves experiments in which plants are grown over the full range of N and of P availability from extreme limitation to beyond saturation. Measurements need to: distinguish structural from non-structural dry matter; organic from inorganic forms of the nutrient in the tissues; involve all parts of the plant to evaluate nutrient and C allocation changes with treatments; determine resorption factors during tissue senescence; and be made with cognisance of the temporal and spatial aspects of the phenomena involved.
Similar content being viewed by others
References
Arnone J A and Gordon J C 1990 Effect of nodulation, nitrogen fixation and CO2 enrichment on the physiology, growth and dry mass allocation of seedlings of Alnus rubra Bong. New Phytol. 116, 55–66.
Arp W J, Kuikman P J and Gorissen A 1997 Climate change: The potential to affect functions through changes in amount and quality of litter. In Driven by Nature: Plant Litter Quality and Decomposition. Eds Cadisch G and Giller K E. pp 187–200. Wallingford, CAB International. 409p.
Arp W J, Mierlo J E M, Berendse F and Snijders W 1998 Interactions between elevated carbon dioxide concentration, nitrogen and water: Effects on growth and water use of six perennial species. Plant Cell Environ. 21, 1–11.
Barrett D J and Gifford R M 1995 Acclimation of photosynthesis and growth by cotton to elevated CO2: Interactions with severe phosphate deficiency and restricted rooting volume. Aust. J. Plant Physiol. 22, 955–963.
Barrett D J, Richardson A E and Gifford R M 1998 Elevated atmospheric CO2 concentrations increase wheat root phosphatase activity when growth in limited by phosphorus. Aust. J. Plant Physiol. 25, 87–93.
Bassirad H, Tissue D T, Reynolds J F and Chapin, F S 1996 Response of Eriophorum vaginatum to CO2 enrichment at different soil temperature: Effects on growth, root respiration and PO -43 uptake kinetics. New Phytol. 133, 423–430.
Berntson G M and Bazzaz F A 1996 Belowground positive and negative feedbacks on CO2 growth enhancement. Plant Soil 187, 119–131.
Bettarini I, Calderoni G, Miglietta F, Raschi A and Ehleringer J 1995 Isotopic carbon discrimination and leaf nitrogen content of Erica arborea L. along a CO2 concentration gradient in a CO2 spring in Italy. Tree Physiol. 15, 327–332.
Cannell M G R and Thornley J H M 1998 N-poor ecosystems may respond more to elevated [CO2] than rich ones in the long term. A model analysis of grasslands. Global Change Biol. 4, 431–442.
Chu C C, Field G B and Mooney H A 1996 Effects of CO2 and nutrient enrichment on tissue quality of two California annuals. Oecologia 107, 433–440.
Coleman J S, McConnaughay K D M and Bazzaz F A 1993. Elevated carbon dioxide and plant nitrogen-use: Is reduced tissue nitrogen concentration size-dependent? Oecologia 93, 195–200.
Conroy J P, Milham P J, Reed M L and Barlow EW 1990 Increases in phosphorus requirements for CO2-enriched pine species. Plant Physiol. 92, 977–982.
Conroy J P, Milham P J and Barlow E W R 1992 Effect of nitrogen and phosphorus availability on the growth response of Eucalyptus grandis to high CO2. Plant Cell Environ. 15, 843–847.
Cotrufo F M, Ineson P and Scott A 1998 Elevated CO2 reduces the nitrogen concentration of plant tissues. Global Change Biol. 4, 43–54.
Cure J D, Rufty TW and Israel DW 1988 Phosphorus stress effects on growth and seed yield responses of non-nodulated soybean to elevated carbon dioxide. Agron. J. 80, 897–902.
De Lucia E H, Callaway R M, Thomas E M and Schlesinger W H 1997 Mechanisms of phosphorus acquisition for ponderosa pine seedlings under high CO2 and temperature. Ann. Bot. 79, 111–120.
Franck V M, Hungate B A, Chapin F S III and Field C B 1996 Decomposition of litter produced under elevated CO2: Dependencies on plant species and nutrient supply. Biogeochemistry 36, 223–237.
Gebauer R L E, Strain B R and Reynolds J P 1998 The effect of elevated CO2 and N-availability on tissue concentrations and whole plant pools of carbon-based secondary compounds in loblolly pine (Pinus taeda). Oecologia 113, 29–36.
Gifford R M 1980 Carbon storage by the biosphere. In Carbon Dioxide and Climate: Australian Research. Ed. G I Pearman. pp 167–181. Australian Academy of Science, Canberra. 217p.
Gifford R M 1992 Interaction of carbon dioxide with growthlimiting environmental factors in vegetation productivity: Implications for the global carbon cycle. Adv. Bioclim. 1, 25–59.
Gifford R M 1994 The global carbon cycle: a view point on the missing sink. Aust. J Plant Physiol. 21, 1–15.
Gifford R M, Lutze J L and Barrett D J 1996 Global atmospheric change effects on terrestrial carbon sequestration: Exploration with a global C-and N-cycle model (CQUESTN). Plant Soil 187, 360–387.
Gifford R M, Barrett D J, Lutze J L and Samarakoon A B 1996 Agriculture and global change: Scaling direct carbon dioxide impacts and feedbacks through time. In Global Change and Terrestrial Ecosystems. Eds B Walker and W Steffen. pp 229–259. Cambridge University Press, Cambridge. 619p.
Gifford R M and Rawson H M 1994 Investigation of wild and domesticated vegetation CO2 enriched greenhouses. In Proc, IGBP Workshop on Design and Execution of Experiments on CO2 Enrichment, Weidenberg, Germany Oct 26-30. Eds E-D Schulze and H A Mooney. pp 147–165. Publication no. EUR 15110 EN of the Office for the Official Publication of European Communities, Luxembourg. 420p.
Gries C, Kimball B A and Idso S B 1993 Nutrient uptake during the course of a year by sour orange trees growing in ambient and elevated atmospheric carbon dioxide concentrations. J. Plant Nut. 16, 129–147.
Griffin K L, Winner W E and Strain B R 1996 Construction cost of loblolly pine leaves grown with varying carbon and nitrogen availability. Plant Cell Environ. 19, 729–739.
Griffin K L, Thomas R B and Strain B R 1993 Effects of nitrogen supply and elevated carbon dioxide on construction cost in leaves of Pinus taeda (L.) seedlings. Oecologia 95, 575–580.
Hartwig U A, Zanetti S, Hebelson T, Lüscher A, Frehner M, Fischer B, Van Kessel C, Hendrey G R, Blum H and Nosberger J 1996 Symbiotic nitrogen fixation: One key to understanding the response of temperate grassland ecosystems to elevated CO2? In Carbon Dioxide, Populations, Communities. Eds C Körner and F Bazzaz. pp 253–264. Academic Press, San Diego.
Hattenschwiler S, Schweingruber F H and Korner C 1996 Tree ring responses to elevated CO2 and increased N-deposition in Picea abies. Plant Cell Environ. 19, 1369–1378.
Henning F P, Wood C W, Rogers H H, Runion G B and Prior S A 1996 Composition and decomposition of soybean and sorghum tissues grown under elevated atmospheric carbon dioxide. J. Environ. Qual. 25, 822–827.
Hewitt E J 1966 Sand and water culture methods used in the study of plant nutrition. 2nd Edn. Commonwealth Agricultural Bureaux. 547p.
Hocking P J and Meyer C P 1985 Responses of Noogoora burr (Xanthium occidentale Bertol.) to nitrogen supply and carbon dioxide enrichment. Ann. Bot. 55, 835–844.
Hungate B A, Canadell J and Chapin F S III 1996 Plant species mediate changes in soil microbial N in resyonse to elevated CO2. Ecology 77, 2505–2515.
Körner C and Miglietta F 1994 Long term effects of naturally elevated CO2 onMediterranean grassland and forest trees. Oecologia 99, 343–351.
Kuehny J S, Peet M M, Nelson P V and Willis D H 1991 Nutrient dilution by starch in CO2-enriched Chrysanthemum. J. Exp. Bot. 42, 711–716.
Larigauderie A, Hilbert D W and Oechel W C 1988 Effect of CO2 enrichment and nitrogen availability on resource acquisition and resource allocation in a grass, Bromus mollis. Oecologia 77, 544–549.
Li J H, Dijkstra P, Hinkle C R, Wheeler R M and Drake B G 1999 Photosynthetic acclimation to elevated atmospheric CO2 concentration in the Florida scrub-oak species Quercus geminata and Quercus myrtifolia growing in their native environment. Tree Physiol. 19, 229–234.
Loehle C 1995 Anomalous responses of plants to CO2 enrichment. Oikos 73, 181–187.
Lovelock C E, Kyllo D, Popp M, Isopp H, Virog A and Winter K 1997 Symbiotic vesicular-arbuscular myccorrhizae influence maximum rates of photosynthesis in tropical tree seedlings grown under elevated CO2. Aust. J. Plant Physiol. 24, 185–194.
Lutze J L 1996 Carbon and nitrogen relationships in swards of Danthonia richardsonii in response to carbon dioxide enrichment and nitrogen supply. PhD Thesis, Australian National University, Canberra, Australia. 281p.
Lutze J L and Gifford R M 1998a Acquisition and allocation of carbon and nitrogen by Danthonia richardsonii in response to restricted nitrogen supply and CO2 enrichment. Plant Cell Environ. 21, 1133–1141.
Lutze J L and Gifford RM1998b Carbon accumulation, distribution and water use of D. richardsonii swards in response to CO2 and nitrogen supply over four years growth. Global Change Biol. 4, 851–861.
Lutze J L and Gifford R M in press Nitrogen accumulation and distribution in Danthonia richardsonii swards in response to CO2 and nitrogen supply over four years growth. Global Change Biol.
Lutze J L, Gifford R M and Adams H N in press Litter quality and decomposition in Danthonia richardsonii swards in response to CO2 and nitrogen supply over four years growth. Global Change Biol.
Luxmoore R J 1981 CO2 and phytomass BioScience 31, 326.
Makino A, Harada M, Sato T, Nakano H and Mae T 1997 Growth and N allocation in rice plants under CO2 enrichment. Plant Physiol. 115, 199–203.
McGuire D A, Melillo J M and Joyce L A 1995 The role of nitrogen in the response of forest net primary production to elevated atmospheric carbon dioxide. Ann. Rev. Ecol. Syst. 26, 473–503.
Medlyn B E 1996 The optimal allocation of nitrogen within the C3 photosynthetic system at elevated CO2. Aust. J. Plant Physiol. 23, 593–603.
Melillo J M, Prentice I C, Farquhar G D, Schulze E-D, Sala O E and 29 others 1996 Terrestrial Biotic responses to environmental change and feedbacks to climate. In Climate Change 1995: The Science of Climate Change. Eds J T Houghton, L G Miero Filho, B A Callander, N Harris, A Kattenberg and K Maskell. pp 446–481. Cambridge University Press, Cambridge.
Moorehead D L and Linkins A E 1997 Elevated CO2 alters belowground exoenzyme activities in tussock tundra. Plant Soil. 189, 321–397.
Nakano H, Makino A and Mae T 1997 The effect of elevated partial pressure of CO2 on the relationship between photosynthetic capacity and N content in rice leaves. Plant Physiol. 115, 191–198.
Newbery R M, Wolfenden J, Mansfield T A and Harrison A F 1995 Nitrogen, phosphorus and potassium uptake and demand in Agrostis capillaris: The influence of elevated CO2 and nutrient supply. New Phytol. 130, 565–574.
Norby R J 1987 Nodulation and nitrogenase activity in nitrogen-fixing woody plants stimulated by CO2 enrichment of the atmosphere. Physiol. Plant. 71, 77–82.
Norby R J, O'Neill E G and Luxmoore R J 1986 Effects of atmospheric CO2 enrichment on the growth and mineral nutrition of Quercus alba seedlings in nutrient-poor soil. Plant Physiol. 82, 83–89.
Owensby C E, Coyne P I and Auen L M 1993 Nitrogen and phosphorus dynamics dynamics of a tallgrass prairie ecosystem exposed to elevated carbon dioxide. Plant Cell Environ. 16, 843–850.
Penuelas J and Estiarte M1997 Trends in plant carbon concentration and plant demand for N throughout this century. Oecologia 109, 69–73.
Penuelas J and Estiarte M 1998 Can elevated CO2 affect secondary metabolism and ecosystem function. Trends Ecol. Evol. 13, 20–24.
Poorter H, Berkel Y, Baxter R, Hertog J, Dijkstra P, Gifford R M, Griffin K L, Roumet C, Roy J, Song S C, Van Berkel Y and den Hertog J 1997 The effects of elevated CO2 on the chemical composition and construction costs of leaves of 27 C3 species. Plant Cell Environ. 20, 472–482.
Rawson H M, Gifford R M and Condon B N 1995 Temperature gradient chambers for research on global environmental change. I. Portable chambers for research on short stature vegetation. Plant Cell Environ. 18, 1048–1054.
Rouhier H and Read D J 1998 The role of mycorrhiza in determining the response of Plantago lanceoloata to CO2 enrichment. New Phytol. 139, 367–373.
Saxe H, Ellsworth D S and Heath J 1998 Tree and forest functioning in an enriched CO2 atmosphere. New Phytol. 139: 395–436.
Silvola J and Ahlholm U 1992 Photosynthesis in willows (Salix x dasyclados) grown at different CO2 concentrations and fertilization levels. Oecologia 91, 208–213.
Sims D A, Luo Y and Seemann J R 1998 Comparison of photosynthetic acclimation to elevate CO2 and limited nitrogen supply in soybean. Plant Cell Environ. 21, 945–952.
Soussana J F and Hartwig U A 1996 The effects of elevated CO2 on symbiotic N2 fixation: a link between the carbon and nitrogen cycles in grassland ecosystems. Plant Soil 187, 321–332.
Staddon P L and Fitter A H 1998 Does elevated atmospheric carbon dioxide affect arbuscular mycorrhizas? Trends Ecol. Evol. 13, 455–457.
Stiling P, Rossi A M, Hungate B, Dijstra P, Hinkle C R, Knott W M and Drake B 1999 Decreased leaf-miner abundance in elevated CO2: Reduced leaf quality and increased parasitoid attack. Ecol. Applic. 9, 240–244.
Stitt M and Krapp A 1999 The interaction between elevated carbon dioxide and nitrogen nutrition: The physiological and molecular background. Plant Cell Environ. 22, 583–621.
Swift M J, Heal O W and Anderson J M 1979 Decomposition in Terrestrial Ecosystems. Blackwell Scientific, Oxford. 372p.
Van Ginkel J H, Gorissen A and Van Veen J A 1997 Carbon and nitrogen allocation in Lolium perenne in response to elevated atmospheric CO2 with emphasis on soil carbon dynamics. Plant Soil 188, 299–308.
Webber A N, Nie G-Y and Long S P 1994 Acclimation of photosynthetic proteins to rising atmospheric CO2. Photosyn. Res. 39, 413–425.
Woodrow I E 1994 Optimal acclimation of the C3 photosynthetic system under enhanced CO2. Photosyn. Res. 39, 401–412.
Xu D-Q, Gifford R M and Chow W S 1994 Photosynthetic acclimation in pea and soybean to high atmospheric CO2 partial pressure. Plant Physiol. 106, 661–671.
Zak D R, Pregitzer K S, Curtis P S, Teeri J A, Fogel R and Randlett D L 1993 Elevated atmospheric CO2 and feedback between carbon and nitrogen cycles. Plant Soil 151, 105–117.
Rights and permissions
About this article
Cite this article
Gifford, R.M., Barrett, D.J. & Lutze, J.L. The effects of elevated [CO2] on the C:N and C:P mass ratios of plant tissues. Plant and Soil 224, 1–14 (2000). https://doi.org/10.1023/A:1004790612630
Issue Date:
DOI: https://doi.org/10.1023/A:1004790612630