Photosynthesis-Ecology-2
Leaf Anatomy favors Light Absorption.
Epidermal cell walls can act like Lenses that Focus incoming Light on the photosynthetic Mesophyll cells below.
This has an amplifying effect on the amount of light reaching these cells.
| In many cases, there are
several Palisade Layers which
absorb most of the incident irradiation. The number of Palisade layers is related
to the amount of light reaching the leaves. Many Palisade layers are present in bright light environments
while one or two are found in dim light.
Palisade Cells have small intercellular spaces. Their shape provides a lot of surface area for gas exchange without excessive air spaces. Consequently, they have the Best Shape
& Organization for photosynthetic efficiency. Multiple
Palisade layers are
found in plants which inhabit Dry environments. These environments are usually highly
illuminated. This can be seen when Leaves grown under high light (Sun Leaves) are compared to those grown under low
light on the same plant (Shade Leaves). |
 Upper Epidermis and Palisade Layer from a Dicot Leaf Sun Leaves have many Palisade Layers while the Shade Leaves have 1-2 Palisade Layers.
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 Edge of a Larea tridentata (Creosote Bush) Leaf. This is a desert shrub. Note the abundance of Palisade Mesophyll on both sides of the Leaf. This occurs with plants that grow in high light, dry environments. |
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Creosote Bush Habitat |
