Effects of CO 2 enrichment and nutrition on growth, photosynthesis, and nutrient concentration of Alaskan tundra plant species

• Published in: Canadian Journal of Botany
• Main Authors: Oberbauer, Steven F., Sionit, Nasser, Hastings, Steven J., Oechel, Walter C.
• Format: Article in Journal/Newspaper
• Language: French
• Published: Canadian Science Publishing 1986
• Subjects: Plant Science; Betula nana; Carex bigelowii; Tundra
• Online Access: http://dx.doi.org/10.1139/b86-396; http://www.nrcresearchpress.com/doi/pdf/10.1139/b86-396

Three Alaskan tundra species, Carex bigelowii Torr., Betula nana L., and Ledum palustre L., were grown in controlled-environment chambers at two nutrition levels with two concentrations of atmospheric CO 2 to assess the interactive effects of these factors on growth, photosynthesis, and tissue nutrient content. Carbon dioxide concentrations were maintained at 350 and 675 μL L −1 under photosynthetic photon flux densities of 450 μmol m −2 s −1 and temperatures of 20:15 °C (light:dark). Nutrient treatments were obtained by watering daily with 1/60- or 1/8- strength Hoagland's solution. Leaf, root, and total biomass were strongly enhanced by nutrient enrichment regardless of the CO 2 concentration. In contrast, enriched atmospheric CO 2 did not significantly affect plant biomass and there was no interaction between nutrition and CO 2 concentration during growth. Leaf photosynthesis was increased by better nutrition in two species but was unchanged by CO 2 enrichment during growth in all three species. The effects of nutrient addition and CO 2 enrichment on tissue nutrient concentrations were complex and differed among the three species. The data suggest that CO 2 enrichment with or without nutrient limitation has little effect on the biomass production of these three tundra species.