GEOG 1200 Chapter Notes - Chapter 8: Agroforestry, Water Cycle, Transpiration
Document Summary
Forest cover 31% of the earths land surface. Trees are autotrophs as they provide themselves with their own food. For photosynthesis to occur and the tree to survive there are several fundamental requirements: Nutrients for the tree to grow are provided through the trees roots from the soil. Macronutrients for trees include nitrogen, phosphorous, potassium, magnesium, calcium and sulphur, in addition to carbon. Trees acquire much of their nitrogen from the atmosphere, by the way of the soil. Nitrogen can also be provided through the decomposition of organisms. Micronutrients for trees are iron, manganese, zinc, copper, boron, chlorine and molybdenum. Water acts as a solvent, dissolving mineral constituents from particles in the soil. Water transports chemicals form one part of the tree to where they are needed to carry out the metabolic process. Transpiration occurs when solar energy causes water to evaporate from leaf surfaces, resulting in negative internal water pressure.
