GPHY 104 Lecture Notes - Lecture 5: Sphagnum, Soil Horizon, Podzol
24 Dec 2016
School
Department
Course
Professor
Document Summary
The boreal forest covers ~1/3 of the earth"s forested area (~14% of earth"s land: 55% russia, 30% canada, 10% scandinavia, 5% u. s. Changes in climates have shifted boreal forest species north and south through time: the current extent of the boreal forest was covered by glaciers until ~12, 000 years ago. Soils are young and roots are shallower. There are open & closed canopies among wetlands, rivers and lakes. A network of poorly drained areas (fens, peat bogs, marshes) Muskegs: low lying, water lled depressions or bogs: spongy sphagnum moss mat over ponded water. Open canopy forest: colder, shorter growing season, father-spaced trees and lichen ground cover. Closely spaced mixed trees: shade-tolerant shrubs with herbs and feathers oors. Closed canopy: longest and warmest season. Extreme temperature ranges: extremely cold winters and warm summers. Severe winter temperatures, short growing season, cold soils and permafrost are more prevalent as you go north.
