A Comparison of Tree Growth in Two Sites near Schefferville, Quebec

Trees provide vital global ecosystem services, including carbon sequestration and biodiversity conservation, among others. Further, trees play an important role in regulating climate because of their role in complex water and carbon cycles, and other climate feedback mechanisms. Thus, understanding influences on their growth and productivity is important for gaining insight into current and future climatic conditions. Research has shown that tree height within forests is a significant indicator of the tree’s health as well as overall forest productivity. This study aims to add to understanding of how stress factors might influence tree growth and how trees might adapt to stressed conditions by comparing two sites in Canada’s sub-Arctic, near Schefferville, Quebec. The methodology involved collecting and analyzing tree core samples taken from trees in the two sites: one ‘stressed’ and a second ‘ideal’ or ‘non-stressed.’ Analysis of the tree cores found no statistically significant difference in trunk circumference (or diameter) growth between the stressed and ideal forests. This arguably indicates that trees in both plots had similar amounts of water to facilitate their annual growth. However, comparisons of annual average tree height and vertical growth found highly statistically significant differences. Trees in the stressed forest grew slower vertically (but not in thickness) than trees in the ideal forest, and they reached lower total height— by a factor of almost two. If it is assumed that the stressed forest under study constitutes a random sample of trees that comes from a population of “all stressed forests,” and similarly for the “ideal forest,” then we may conclude that stressed forests—ones exposed to heavy winds and facing unreliable water supply—tend to produce shorter and slower-growing trees than forests under “ideal” conditions. Equally, the non-significance of the width-growth variable can indicate that it is not necessarily true that tree-width and tree-width-growth-rate are adversely affected by a stressed environment.