The effect of soil water retention and rainfall on annual growth of generalist and specialist tree species in the Douglas Lake Area.

Abstract

This study is an analysis of the effect that different soil types and annual precipitation have on annual growth of both generalist, (Pinus strobus L), and specialist, (Pinus resinosa and Acer saccharum), tree species. We expected to see a positive correlation between annual growth and annual precipitation on all sites except the swamp (due to it already being saturated). We predicted that the correlation would be higher on the sandier soil types due to the greater necessity for water. We found instead that correlations between annual rainfall and growth on both the swamp and the moraine were significant but negatively correlated. We also performed proportional analyses between annual ring growth and annual precipitation, and for this the specialist Pinus resinosa had a positive correlation that was statistically significant. For the rest of the data, there were positive correlation's between rainfall and tree growth, but these comparisons were not statistically significant.