Definition: Holarctic coniferous and boreo-subarctic birch forests on oligotrophic and leached soils in the boreal zone and at high-altitudes of mountains in the nemoral zone of Eurasia
Definition: Of plant duration, a plant whose life span extends over more than two growing seasons, c.f. annual, biennial, ephemeral, of flowering with respect to architecture, hapaxanthic, monocarpic, pleonanthic