Is it a myth that moss always grows on the north side of trees?

Understanding the Northern Aspect Myth

The notion that moss grows predominantly on the north side of trees stems from the fact that trees in temperate climates often have a more shaded north side due to the sun’s lower angle. This reduced sunlight allows mosses and other epiphytes to thrive, creating a dense, green layer. In regions with consistent north-facing shading, mosses like Hypnum and Polytrichum can form extensive colonies on tree trunks.

Factors Influencing Moss Growth

While the northern aspect myth holds some truth, other factors significantly influence moss growth, making it less predictable. For instance, trees growing in shaded valleys or near bodies of water often have more extensive moss growth due to higher humidity and reduced sunlight. Conversely, trees in coastal areas or exposed to strong winds may have sparse moss cover due to the abrasive effects of salt and sand.

Measuring Moss Growth on Trees

To assess the validity of the northern aspect myth in your local area, measure the height of moss growth on multiple trees. Take note of the tree species, exposure to sunlight, and surrounding microclimate conditions. Compare the moss heights on the northern, southern, eastern, and western aspects of each tree. You may find that moss growth is indeed more pronounced on the north side of trees in your area, but with significant variations depending on local conditions.