Final answer:
Photosynthetic light response curves of pioneer and late-successional tree species differ in their response to light intensity.
Step-by-step explanation:
Photosynthetic light response curves illustrate how the rate of photosynthesis varies with different light intensities. Pioneer and late-successional tree species have different responses to light due to their adaptations to different environments.
A pioneer species, such as grasses, birch trees, and fireweed, is one of the first plants to colonize a barren or disturbed area. These species are adapted to high light intensities and can photosynthesize efficiently even at high light levels. Their photosynthetic light response curve shows a rapid increase in photosynthesis with increasing light intensity, reaching a plateau at a high light saturation point.
On the other hand, a late-successional tree species, like oak or hickory, is adapted to shaded environments. These species have lower light requirements and a lower light saturation point. Their photosynthetic light response curve shows a slower increase in photosynthesis with increasing light intensity, reaching a lower maximum rate of photosynthesis compared to pioneer species.