EESC3310 Lecture Notes - Lecture 5: Chiang Rai Province, Perennial Plant, Traditional Ecological Knowledge
25 Apr 2017
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Exam: focus on lectures, use learning objectives as a guide, use examples to illustrate points. The role of fire in agroecosystems and the environmental complex. Surface fire: shallow, not too hot, quick, burns surface litter and vegetation. Crown fire: canopy is consumed, mature plant species are killed. Ground or subsoil fire: slow and destructive occurring in soil with high om. Subsurface also increases but more moderately and temporary (50-100 c) Nitrogen and organic acids are burned off returning inorganic cations (k, ca, mg) - little flush of availability after a fire -- allows quick access to nutrients for growth. Nitrogen becomes more available immediately, but long term availability declines. Some plants can regenerate from underground reserves. Some seeds die or break dormancy or germinate under new soil conditions. Higher patchiness in landscape (which can increase plant diversity) Serotiny - allows release of seeds triggered by fire because fire melts resin in pine cone and opens it up.
