The Effects of Species and Genus on Leaf Senescence

Abstract

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.