Upland spruce-fir forests may lose suitable habitat to other forest types as snowfall decreases, growing seasons lengthen, and temperatures increase.

Submitted by sdhandler on

Within northern Michigan, upland spruce-fir forests are typically confined to areas with shorter growing seasons and lake-effect snow and fog. Water temperatures of the Great Lakes are increasing faster than air temperatures, so lake-effect fog may become less common during the growing season. Uncertainty exists for snowfall levels in northern Michigan, particularly for lake-effect snow, but it is projected that snowfall will decline by the end of the century. Additionally, several species in this system are limited by high growing-season temperatures, so projected warming in the assessment area may exceed the physiological limits of this forest type. Prolonged droughts and warmer temperatures expected under climate change will also be particularly stressful for this forest type. Other forest types may have historically been prevented from competing in cold, snowy areas with short growing seasons. Poor soils and comparably colder temperatures may still limit the ability of some hardwoods to outcompete boreal conifers on these sites.