Biology A-level Energy Transfers Question

Biology question: Hi, could someone please help me understand this question? I understand that more trees will block light, but surely that light is mostly hitting leaves which can photosynthesise? So it would not decrease GPP? Thanks

Here is the answer:

(ii) 1. Less light / more shading / more competition for light;
Neutral: references to animals
2. Reduced photosynthesis.
Accept: no photosynthesis

(edited 1 year ago)

Question.png128.0KB

Reply 1

JJ <3

The light would only be hitting a few of the leaves at the top

Reply 2

Matt Lee

From the image, it is clear the dip occurs around the 100-year mark.
By this time the all the available land would have been occupied by trees, and no new area would be available for growth.
The plants below will compete for sunlight and also other resources like water etc. The animals might also be affected but probably at a later stage.