Tree of the Week: Eastern Hemlock (Tsuga canadensis)

Cooler, moist climate relict, Eastern Hemlock's Indiana range greatly shrank in warmer, drier periods after a peak following pine-fir-spruce-birch domination...after glaciation...

A magnificent, stately evergreen, Eastern Hemlock is sensitive to a warmer, drier climate & even a much warmer, wetter climate, as it is prone to aphids & fungus in a changing climate regime. It thrives in the cool, moist, misty, shady micro-climates, which are confined to deep canyons & ravines on the cool north sides of slopes south of the Northern Great Lakes or Northeast. The native populations of this species in Indiana are relicts from a period of warming, but still cool, much wetter climate following the Ice Age glaciations. It was the cool Summers of this time period that likely led it to flourish in the state. Highly-intolerant of fire, it is wiped out by a fire regime or persistent windy, dry, droughty long-term pattern.