The darkening of the atmosphere caused by meteorites would have reduced the sizes of some ecosystems due to less solar energy being available to plants.
This is the form of energy which is derived from the sun and is usually trapped by plants during photosynthesis.
Plants being primary producers will have less photosynthetic activity thereby leading to less food production and oxygen availability.
Read more about Meteorites here https://brainly.com/question/7993266
#SPJ4