BIOL 3753 Lecture 2: BIOL3753, lecture 2 midterm 1
Document Summary
Makes up the majority of the arctic (treeless, underlain by permafrost) There is not enough moisture for bacteria to use organic, decaying material so it just sits there and is referred to as peat. Energy and nutrients in the form of dead organic material. Talik unfrozen ground in permafrost region often hydrological. Active layer top layer of soil that thaws during the summer and freezes again in the autumn. Closed talik pocket of unfrozen earth surrounded by frozen ground under a bog. Through talik from underlying layer of unfrozen ground to the surface usually under a large lake. Open talik small pocket of unfrozen ground surrounded by continuous permafrost, under a small lake no active layer above it. Periglacial features are associated with glaciers or with repeated freeing and thawing of the ground. Giant ice piles covered in soil - uncommon. Freeze/thawing of ground and water penetration resulting in surface expression.
