ENV234H1 Lecture Notes - Lecture 9: Holland Marsh, Solonetz, Acri
Document Summary
Lecture 1 soils: interface between geology and biology. Support plants: basis of life on earth, agriculture. Determine the fate of water in the hydrologic system and its quality. Recycle organic wastes and nutrients: nature"s recycling system. Basic medium in human-built ecosystems: building material, support. Factors controlling soil formation: parent material (geology, weathering of parent material over very long periods of time, physical weathering. Sand, rain, thermal expansion and contraction, water freezing: chemical weathering. Tree roots and lichens: weathering sequence (from cations that weather very quickly, easily depleted and a lot in the soil to the least) Cl > so4 > na > ca > mg > k > si > fe > al: organisms (plant, animals, microbes, plant type and environment matter. Desert: very small layer of organic soil; not a lot of input. Grassland: grasses have smaller roots; organic matter and soil very deep. Temperate deciduous forest: a large layer of organic soil from decomposition and mixing.