BIO120H1 Lecture Notes - Lecture 17: The Leaves, Sclerophyll, Redneck
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BIO120H1 Full Course Notes
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Sessile problems for plants and this produces constraints and tradeoffs centered around light, temperature, and water. Plants solve problems by growth and development, not behavior, so carbon balance is central. Tradeoffs on photosynthesis: compromises involving 3 necessities. Adaptations to extreme habitats and lifestyles i. e. deserts and epiphytes. Extreme deserts located where the pharrell cells descend. Palo verde trees exemplify a reduction in leaf area to reduce the amount of heat the leaves pick up. These barks are useful because if you have too much leaf surface, you have extreme water loss. In extreme dry seasons, they drop the leaves too and survive off of their barks. Mesquite, a common desert plant, does not have photosynthetic bark, but has small microphyllic leaves which shed in the dry season. In the santa rita prickly pear, the leaves have repurposed as defense mechanisms against herbivores. In the opuntia, the stems have been flattened to provide sa for photosynthesis.
