Phenological Responses in Maple to Experimental Atmospheric Warming and CO sub(2) Enrichment

• Published in: Global change biology Vol. 9; no. 12; p. 1792
• Main Authors: Norby, Richard J, Hartz-Rubin, Jennifer S, Verbrugge, Maria J
• Format: Journal Article
• Language: English
• Published: 01.12.2003
• Subjects: Acer rubrum; Acer saccharum
• ISSN: 1354-1013; 1365-2486
• DOI: 10.1111/j.1365-2486.2003.00714.x

Young sugar maple Acer saccharum and red maple A. rubrum trees were grown for four growing seasons in open-top field chambers in Tennessee to explore phenological responses to increasing temperature and carbon dioxide enrichment. The phenological events were vegetative bud break in spring and leaf abscission in fall. Air temperature inside the chambers was maintained at +0 or +4 degree C relative to ambient air outside the chambers. Buds began swelling and opening earlier in chambers maintained at elevated temperature, and leaf expansion was significantly more advanced at the developmental midpoint, while the effects of CO sub(2) were small and inconsistent. For both species, the onset of leaf abscission was delayed each year in the warmer chambers, where trees retained significantly more leaf area during most of the fall.