DOI
https://doi.org/10.25772/FJWZ-CT71
Defense Date
2011
Document Type
Thesis
Degree Name
Master of Science
Department
Biology
First Advisor
Donald Young
Abstract
It is important to understand mechanisms that facilitate expansion of two common shrubs, Morella cerifera and Baccharis halimifolia in coastal environments. The purpose of my study was to investigate the physiological and structural changes that occur as leaves age. Photosynthesis, incident light, chlorophyll, and leaf C:N ratios were quantified for young, intermediate, and old leaves (distal, central and proximal leaves, respectively). Leaf structural differences were also compared. Leaves did not change morphologically with age. Light decreased with leaf age and during winter months. Photosynthesis showed no seasonal or age related patterns. Chlorophyll increased initially and then declined with age due to self shading. Nitrogen content was highest during spring. Seasonality and leaf age had unique effects on the two study species. Understanding senescence adaptations of these two shrubs can help explain their abundance in coastal ecosystems.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
July 2011