TITLE:
Effects of Nitrogen Supply on the Physiological and Morphological Responses to Elevated [CO2] in Yellow Birch (Betula alleghaniensis Britt.)
AUTHORS:
Piumi Maheshika Godakanda, Sahari Inoue, Binyam Tedla, Qing-Lai Dang
KEYWORDS:
Climate Change, Yellow Birch (Betula alleghaniensis Britt.), Elevated [CO2], Soil Nitrogen Availability, Growth, Biomass, Photosynthesis
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.16 No.1,
January
24,
2025
ABSTRACT: Climate change impacts soil nitrogen, influencing plant responses to elevated atmospheric [CO2]. Understanding the interaction between nitrogen supply and elevated [CO2] is crucial for predicting plant future performance. This study examined the interactive effects of elevated [CO2] and nitrogen supply on the eco-physiological performance of yellow birch. Seedlings were exposed to two [CO2] levels and five nitrogen supply levels for 4 months. Growth parameters such as seedling height and root collar diameter increased with higher nitrogen supply and elevated [CO2], while specific leaf area decreased. [CO2] elevation and increasing nitrogen supply also increased the total and stem, and leaf biomass. The elevated [CO2] increased the stem mass ratio but decreased the root-to-shoot ratio and root mass ratio. However, decreases in nitrogen supply increased root mass ratio and root-to-shoot ratio. The elevated [CO2] increased the maximum rate of Rubisco carboxylation (Vcmax) and photosynthetic electron transport (Jmax), but the effect on Jmax was statistically significant only at the two highest nitrogen supply levels. The results indicate that yellow birch may increase photosynthetic capacity, biomass, and growth in the future when [CO2] is higher.