Crown thinning in canopy trees of two temperate deciduous species: Implications for light transmission in tolerant hardwood forests.
Published: 2006
Language: eng
Number of pages: 72
ISBN-13: 9780494211755
Description: Leaf area index (LAI) often increases with stand age and subsequently declines following canopy closure in monospecific forests. Typically, these declines in stand-level LAI are attributed to population processes that decrease canopy cover, such as tree mortality and crown abrasion. However, recent evidence of age-related changes in allocation and leaf morphology suggest that intra-crown LAI may also decline late in ontogeny. Using vertical line transects, the intra-crown LAI for canopy trees of two temperate deciduous species was directly quantified. Intra-crown LAI declined from 7 to 4 for  Acer saccharum and from 9 to 5 for Betula alleghaniensis  across the size range (15--72 cm dbh). For A. saccharum , tree age was a better predictor of LAI decline than dbh (range 30--160 y.). These results indicate that ontogenetic declines in intra-crown LAI are underappreciated and may significantly contribute to light transmission in mature forests, potentially influencing tree regeneration.
Notes: Source: Masters Abstracts International, Volume: 45-03, page: 1338.

Supervisor: John Caspersen.

Thesis (M.Sc.F.)--University of Toronto, 2006.

Electronic version licensed for access by U. of T. users.

ROBARTS MICROTEXT copy on microfiche.