ENV100Y5 Lecture Notes - Lecture 24: Habitat Conservation, Rainforest, Reforestation
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ENV100Y5 Full Course Notes
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Lecture 24 notes: session 35: finishing up forests (30-11-15) Agriculture is the major cause of conversion of forests. Agriculture now covers more of the planet"s surface than forest. Swidden agriculture = small area of forest cleared and crops planted: sustains only one or two seasons of planting, soil depleted quickly, 7 years required to replenish soil in original clearings to support crops or forests. Swidden agriculture = slash and burn agriculture. Only support a couple of years of crop production; abandoned to restore fertility. 7 years required to replenish soil in original clearings to support crops or forests. Why it"s bad to clear tropical forests Huge competition for nutrients so whenever there is some, it gets used quickly, most of the nutrients are in biomass. So when you cut down a tropical forests, you"re essentially taking a huge portion of the nutrients. Deforestation is proceeding rapidly in many developing nations. Plantation forestry has grown in north america.
