FRST 200 Lecture Notes - Lecture 21: Grafting, Permafrost, Light-Dependent Reactions
Document Summary
Type is characteristic of species, but it is influenced by environment. Taproot system (d-f: primary root system is well-developed, penetrates deeply into soil, laterals smaller. Flat sitka spruce: laterals well-developed, suitable for shallow soils, water logged, permafrost. Heart root system - intermediate to above. Base of tree usually more swollen on shallow soils. Result from extra wood growth on the upper root surface. Roots spread out up to 10x further than crown. They overlap and may graft to each other if the same species. On coast (at least) root growth peaks in spring, decreases in summer, peaks again in fall. Light reactions - absorption and conversion of light energy into chemical energy. Carbon/dark reactions - using that chemical energy to fix carbon into carbohydrates. Most light absorbed by chlorophyll, but also by carotenoids. Psi & psii and funnel energy into the photosystem centers.
