This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (59) Citing Articles via Google Scholar Google Scholar Articles by Conroy, J. P. Articles by Barlow, E. W. Search for Related Content PubMed PubMed Citation Articles by Conroy, J. P. Articles by Barlow, E. W. Agricola Articles by Conroy, J. P. Articles by Barlow, E. W.

Environmental and Stress Physiology

Increases in Phosphorus Requirements for CO₂-Enriched Pine Species ¹

School of Biological Sciences, Macquarie University, N.S.W., 2109, Australia, N.S.W. Agriculture and Fisheries, N.S.W., 2116, Australia

Pinus radiata D. Don (half-sib families 20010 and 20062) and Pinus caribaea var hondurensis (an open-pollinated family) were grown for 49 weeks at seven levels of phosphorus and at CO₂ concentrations of either 340 or 660 microliters per liter, to establish if the phosphorus requirements differed between the CO₂ concentrations and if mycorrhizal associations were affected. When soil phosphorus availability was low, phosphorus uptake was increased by elevated CO₂. This may have been related to changes in mycorrhizal competition. When the phosphorus concentration in the youngest fully expanded needles was above 600 milligrams per kilogram the shoot weight of all pine families was greater at high CO₂ due to increases in rates of photosynthesis. More dry weight was partitioned to the stems of P. radiata family 20010 and P. caribaea. At foliar phosphorus concentrations above 1000 milligrams per kilogram (P. radiata) and 700 milligrams per kilogram (P. caribaea), growth did not increase at 340 microliters of CO₂ per liter. Soluble sugar levels in the same needles mirrored the growth response, but the starch concentration declined with increasing phosphorus. At 660 microliters of CO₂ per liter, shoot weight and soluble sugar concentrations were still increasing up to a foliar P concentration of 1800 milligrams per kilogram for P. radiata and 1600 milligrams per kilogram for P. caribaea. The starch concentrations did not decline. These results indicate that higher foliar phosphorus concentrations are required to realize the maximum growth potential of pines at elevated CO₂.

This article has been cited by other articles:

				E. Chang and V. J. Terwilliger The effects of air pollution on vegetation from a geographic perspective Progress in Physical Geography, March 1, 2000; 24(1): 53 - 74. [Abstract] [PDF]

				J. L. Innes and J.L. Innes High-altitude and high-latitude tree growth in relation to past, present and future global climate change The Holocene, January 1, 1991; 1(2): 168 - 173. [Abstract] [PDF]