HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Johnson, D. W. Articles by Walker, R. F. Search for Related Content PubMed Articles by Johnson, D. W. Articles by Walker, R. F. Agricola Articles by Johnson, D. W. Articles by Walker, R. F.

Effects of Carbon Dioxide and Nitrogen on Growth and Nitrogen Uptake in Ponderosa and Loblolly Pine

Desert Res. Inst., P.O. Box 60220, Reno, NV 89506 and Environ. and Resource Sciences, Univ. of Nevada-Reno, Reno, NV 89512;

R. B. Thomas

West Virginia Univ., Morgantown, WV 26506-6057;

K. L. Griffin

Lamont-Doherty Earth, Columbia Univ., Palisades, NY 10964;

D. T. Tissue

Dep. of Biological Sciences, Texas Tech Univ., Lubbock, TX 79409-3131;

J. T. Ball

Desert Res. Inst., P.O. Box 60220, Reno, NV 89506;

B. R. Strain

Dep. of Botany, Duke Univ., Durham, NC 27707;

R. F. Walker

Environ. and Resource Sciences, Univ. of Nevada-Reno, Reno, NV 89512.

^* Corresponding author (dwj{at}dri.edu).

ABSTRACT

The purpose of this paper is to summarize the results of a series of greenhouse and open- top chamber studies on the effects of N and elevated atmospheric CO₂ on ponderosa and loblolly pine (Pinus ponderosa Laws, and P. taeda L.) to evaluate common patterns of response. Growth response to elevated CO₂ ranged from zero to more than 1000%, depending largely upon N status. In both species, growth response to CO₂ was greater under moderate N deficiency than under extreme N deficiency or N sufficiency/excess. Elevated CO₂ generally caused lowered tissue N concentrations in many (but not all) cases, which in turn resulted in smaller increases in N uptake than in biomass. Growth response to N ranged from –50 (in ponderosa pine) to more than 1000%, depending upon the N status of the control medium. Growth response to N was enhanced by elevated CO₂ when N was in the extreme deficiency range but not when N was in the moderate deficiency range. In two separate studies, ponderosa pine responded negatively to high N inputs, and in each case this response was mitigated by elevated CO₂. Collectively, these results show that (i) N deficiency is a continuum rather than a step function, (ii) responses to elevated CO₂ vary across this continuum of N deficiency, and (iii) elevated CO₂ greatly enhances growth response to N additions when N is initially in the extremely deficient range.

This article has been cited by other articles:

				H. F. Causin, D. C. Tremmel, T. W. Rufty, and J. F. Reynolds Growth, nitrogen uptake, and metabolism in two semiarid shrubs grown at ambient and elevated atmospheric CO2 concentrations: effects of nitrogen supply and source Am. J. Botany, April 1, 2004; 91(4): 565 - 572. [Abstract] [Full Text] [PDF]