Diverse ecosytem

The ecosystem of Pacific temperate rain forests is so productive that the biomass in the best sites is at least four times greater than that of any comparable area in the tropics (Davis 2000). In sheer mass of living and decaying material - trees, mosses, shrubs, and soil - these forests are more massive than any other ecosystem on the planet. In part, this is due to the rarity of fire. Unlike drier forests, which burn periodically, temperate rain forests are naturally subject to only small-scale disturbances, such as blow-downs and avalanches.

source: wikipedia