Inland Rainforest

The same maritime air masses that create the coastal rainforest of the Pacific Northwest of North America are responsible for a second rainforest, located far to the interior. These moist air masses, having deposited rain on the west coast, continue to move east and rise up again over a second, higher mountain range the Rocky Mountains. On the western flanks of the Rockies they deposit rain in the summer and snow in the winter. These low to mid-elevation forests are kept moist through the summer not only by rain, but also by groundwater from melting snow at higher elevations.


The inland rainforest phenomenon stretches from northern Idaho, Washington and Montana (about 46 N latitude) to about 54 N in central British Columbia, but here we focus on the portion that is north of about 5030' N the coolest, wettest portion, where the expression of the phenomenon is most pronounced. Because of the wet climate and moist soils, lightning strikes more often result in small canopy gaps than in large, stand-destroying fires. Some stands get very old and the trees become very large, especially on moist, productive sites at the base of slopes.


Mist blowing through western hemlock trees at the Ancient Forest Trail nourishes rich canopy lichen communities. Forest floor soils are covered with Devil's Club shoots (foreground).

The inland rainforest, generally dominated by western redcedar and western hemlock, is made up of a peculiar combination of interior and coastal elements. Here you can find the mountain caribou, a distinctively interior animal, in the same stand as the netted specklebelly (Pseudocyphellaria anomala), one of many coastal lichen species that also occur in the inland rainforest. And coastal elements also make their way into the inland rainforest when salmon that spend most of their lives in the ocean swim upriver to inland rainforest streams to spawn and die. Some species groups, such as stubble lichens, reach their highest levels of diversity in the inland rainforest. This may be, at least in part, because the favourable reflective light conditions created by the snowpack last so much longer in the inland rainforest than in the coastal rainforest.

Globally, temperate rainforests are rare, and the inland rainforest may be unique. A few hundred years ago, tropical rainforests covered about 11% of the land area of the earth, but temperate rainforests covered only about 0.3%. More than 98% of the temperate rainforest area was coastal. Today, less than half of the earth's temperate rainforest mostly in western North America, Chile and Argentina, New Zealand, and Tasmania -- remains in a naturally forested condition.

For more information on the northern portion of the inland rainforest, see British Columbia's Inland Rainforest: Ecology, Conservation and Management

For more information on temperate rainforests of the world, see Temperate and Boreal Rainforests of the World

 
 
 

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Deep snowpack blankets inland rainforest stands in the winter period, providing vital groundwater recharge as it melts during the spring. Image from the Ancient Forest Trail.

Netted specklebelly (Pseudocyphellaria anomala) grows in both coastal and inland temperate rainforests of British Columbia.

The University of Northern British Columbia