Aspen Bibliography

Title

Nitrogen supply as a limiting factor determining the sensitivity of Populus tremuloides Michx. to ozone stress

Document Type

Article

Journal/Book Title/Conference

New Phytologist

Volume

130

Issue

3

First Page

437

Last Page

446

Publication Date

1995

Abstract

Seedlings of trembling aspen {Populus tremuloides Michx.) were grown at six rates of supplemental nitrogen (N). Five of the N rates were sub-optimal to optimal for growth, whilst the sixth provided an excess of N with no additional growth benefit. T h e biomass of plants stressed b y ozone (O3) in open-top chambers was significantly reduced at optimal rates of N. Plants which received sub-optimal or excess N showed no significant effects of O., on hiomass accumulation. Ozone induced two compensatory responses; increased shoot/root ratio and accelerated senescence, at all N rates. Growth rate was strongly influenced by the amount o f N supplied, and O.,-induced reductions in total biomass were highly correlated with growth rate. W e concluded that when growth rate was small as a result of N limitation, compensatory responses to O,, stress were sufficient to prevent detectable losses in biomass.