BLG 567 Lecture Notes - Lecture 7: C4 Carbon Fixation, C3 Carbon Fixation, Carbon Fixation
Document Summary
Heritable variation in leaf shape has evolved for: optimal water use efficiency, minimization of the damage done by foraging animals, reducing the likelihood of overheating. Not all the variations in leaf shape are heritable, though: many are responses by the individual to its intermediate environment. Leaves of sun plants commonly exposed at acute angles to the midday sun and are typically superimposed into a multilayered canopy where even lower leaves may have a positive rate of net photosynthesis. Leaves are thicker and have greater photosynthetic capacity (more nitrogen and chlorophyll) Incident radiation per area of leaf is higher in shade plants than sun plants. Some water is consumed in photosynthesis, with the hydrogen incorporated into organic matter. Terrestrial plants serve as wicks, conducting water from the soil and releasing it into the air. If there is more release than uptake, wilting occurs due drying out.
