Environmental Science 1021F/G Lecture Notes - Lecture 6: Heracleum Mantegazzianum, Habitat Fragmentation, Shelterwood Cutting
25 Feb 2016
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Document Summary
Forests classified by age and structure: old-growth forests (22%) dark, canopy coverage, second-growth forests (63%) brighter, after damage by humans or natural disasters, tree farms/plantations (5%) human made. Erosion and disturbance protection (natural disasters: prevents landslides (large scale soil erosion) on slopes because of roots, protects from windstorms ex. Boreal largest: temperate-northern and southern hemisphere, or in temperate regions. Main characteristics include: wide leaves, large and tall trees and non seasonal vegetation: boreal (taiga) northern hemisphere, largest forest system in canada and the world. Most threatened landscape: 33% of canada"s species-at-risk, 25% of canadians live in region, 2. uneven-aged management: maintain trees at many ages and sizes, biodiversity high, shade tolerant and shade intermediate, natural regeneration, long-term sustainable production; selective cutting choosing ones you want. Harvesting methods: selective cutting (sustainable, uneven- aged)a. High grading: shelterwood cutting (even-aged, seed tree cutting (even-aged) more sparce then shelterwood, good genetic stock/healthy to reproduce, clear cutting (even-aged, strip cutting.
