Question

consider the following explanation for these data
once invertibrates arrive at a newly restored stream trajectory, they have to be able to settle and reproduce before they can be considered established. for this process to occur, favorable habitats must be present. the rapid increase in biodiversity after water flow began indicates that the formation of such habitats was not a limiting factor for species that recolonized the ecosystem. immediate habitat formation in the reconnected trajectories was most likely due to the high connectivity to upstream pools of organisms and the input of organic material from nearby areas.
adapted from westveer et al 2018 plos one licensed under cc by 4.0
based on the data, which of the following best describes a counterargument to the explanation above?
a. early colonizers like bivalves and insects were unable to persist in the ecosystem over time
b. the most rapid increase in the biodiversity in the restored stream habitats occurred during the second year after the tributaries were flooded
c. the early colonization of the restored streams by insects and bivalves may have helped formed habitats for crustacean species
d. the abundance of insects increased at a more rapid rate than did the abundances of worms, bivalves, and crustaceans

Explanation:

To find a counterargument, we analyze each option:

• Option A: The original explanation states that favorable habitats (not species persistence) are key. A counterargument would challenge this by suggesting early colonizers (bivalves, insects) couldn’t persist, undermining the "habitat availability" claim.
• Option B: Flooding is not mentioned in the original context, so it’s irrelevant.
• Option C: This supports the original idea (early colonization forming habitats), not counter it.
• Option D: Comparing insect and other species’ abundance rates doesn’t address the "habitat availability" explanation.

Answer:

A. Early colonizers like bivalves and insects were unable to persist in the ecosystem over time