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Nitrogen supply as a limiting factor determining the sensitivity of Populus tremuloides Michx. to ozone stress
Author(s) -
PELL E. J.,
SINN J. P.,
JOHANSEN C. VINTEN
Publication year - 1995
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1995.tb01838.x
Subject(s) - ozone , biomass (ecology) , nitrogen , shoot , growth rate , limiting , relative growth rate , horticulture , botany , biomass partitioning , agronomy , chemistry , biology , zoology , mathematics , mechanical engineering , geometry , organic chemistry , engineering
summary 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. The biomass of plants stressed by ozone (O 3 ) 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 3 on biomass 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 of N supplied, and O 3 ‐induced reductions in total biomass were highly correlated with growth rate. We concluded that when growth rate was small as a result of N limitation, compensatory responses to O 3 stress were sufficient to prevent detectable losses in biomass.