ISSN:
0931-1890
Keywords:
Key words Betula pendula
;
Ozone
;
Nutrition
;
Photosynthesis
;
Stomatal conductance
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Cuttings of a single birch clone (Betula pendula) were grown in field fumigation chambers throughout the growing season in either filtered air (control) or 90/40 nl O3 l–1 (day/night). Both regimes were split into plants under high and low nutrient supply (macro- and micronutrients). The stomatal density of leaves was increased by ozone but was lowered at high nutrition, while the inner air space was hardly affected by the treatments. Ozone induced macroscopic leaf injury regardless of nutrition, but leaf shedding was delayed in the low-fertilized plants, despite O3 uptake being similar to that in high-fertilized plants. The leaf turn-over was enhanced in the O3-exposed high-fertilized plants, but length growth and leaf formation of stems were not affected by ozone in either nutrient regime. Leaves of high-fertilized plants showed O3-caused decline in photosynthetic capacity, water-use efficiency, apparent carbon uptake efficiency and quantum yield earlier as compared with low-fertilized plants, whereas chlorophyll fluorescence (FV/FM) and leaf nitrogen concentration were rather stable. CO2 uptake rate and rubisco activity of young leaves compensated for the O3 injury in the ageing leaves of the low-fertilized plants. In 8-week-old leaves, however, the O3-induced decline in CO2 uptake did not differ between the nutrient regimes and was associated with increased dark respiration rather than changed photorespiration. The balance between CO2 supply and demand was lost, as was stomatal limitation on CO2 uptake. High nutrition did not help leaves to maintain a high photosynthetic capacity and life span under O3 stress.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/PL00009692
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