BIO120H1 Lecture Notes - Lecture 17: Sclerophyll, Volumetric Heat Capacity, Larix Laricina

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12 Jul 2017
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BIO120H1 Full Course Notes
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BIO120H1 Full Course Notes
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Stresses on plants are especially challenging because plants can"t evade stress by moving. Plants solve problems by growth and development, not behaviour, carbon balance central. Tradeoffs on photosynthesis: compromises involving 3 necessities (light, temperature, water) Desert: plant roots in dry matrix of sandy soil. Photosynthetic bark on trunks and branches, can grow without incurring heat load and water loss through leaves. Microphylly: highly reduced leaves, fairly thick (thermal inertia), don"t heat up much beyond air around them. Mesquite: more common shrub, doesn"t have photosynthetic bark, greatly reduced leaves keep plant from overheating. E. g. prickly pear: expanded stems, no leaves, leaves modified into thorns that protect plants from animals that would like to get at pads (full of water) Episodic patterns of h2o availability: rillito river, arizona. Grows to 15m, 200 years old, 5+ tonnes (wet weight) Can absorb 800l of water from one storm, use it gradually for growth.