The Effects of Species and Genus on Leaf Senescence


  • Seura Jang
  • Dongha Kim


Deciduous trees undergo leaf degradation every year through a process known as autumn
leaf senescence. This integral life history stage in deciduous trees is usually signalled by harsh
environmental conditions which cause the trees to store more energy to survive. As a response to
the harsh winter temperatures, deciduous trees will reduce production of chlorophyll in leaves to
conserve energy which leads to the browning of the leaves and the ensuing falling of leaves. The
aim of this study was to determine if the species of the trees were an important factor in the rate
of leaf senescence. It was hypothesized that since all deciduous trees undergo leaf senescence,
there won’t be a significant difference observed between the groups. We analyzed three Prunus
avium trees and one Salix nigra tree everyday from October 22nd, 2020 till November 13th,
2020. The percent canopy cover of the 4 tree samples were taken daily through the use of the
Canopeo phone application and were later implemented into a dataset. A decline in percent
canopy cover was found in the four tree samples indicating the process of leaf senescence. The
dataset of percent canopy cover was transformed into the rate of change in percent canopy cover
by obtaining the difference between one canopy cover reading with the canopy cover reading of
its preceding date. An ANOVA single factor statistical test was done to determine if the rate of
change in the percent canopy cover of the 4 tree samples were significantly different. Given a pvalue
of 0.948, it was concluded that there was no significant difference in leaf senescence for
the 2 tree species.