What causes the lower tree line in central Ontario lake shored to be straight?

The lower tree line along central Ontario lake shores tends to be straight due to a combination of environmental factors, including soil composition, moisture levels, and the influence of water bodies on microclimates. The consistent exposure to water, along with the relatively stable temperature and humidity conditions near lakes, creates a uniform habitat that supports tree growth up to a certain elevation. Additionally, human activities and land use can contribute to this straight line by limiting natural forest expansion.