Question

Root competition among neighboring plants was studied by growing plants with their roots inside tubes of PVC pipes. Some tubes had holes of varying sizes, allowing their neighbors' roots to enter the tubes of a target plant. As the percentage of a target plant's tube open to neighbors' roots increased,

A) both target plant biomass and neighbor plant root biomass decreased.
B) target plant biomass decreased and neighbor plant root biomass increased.
C) target plant biomass increased and neighbor plant root biomass decreased.
D) both target plant biomass and neighbor plant root biomass increased.

Answer 1

As the percentage of a target plant’s tube open to neighboring plants’ roots increases, the target plant biomass will decrease due to competition for resources, and the neighbor plant root biomass will increase as they benefit from additional resources.

Step-by-step explanation:

The question is about how root competition affects plant biomass when the roots of neighboring plants are allowed to enter the tubes in which target plants are growing. When other plants' roots enter the tube, they compete with the target plant for nutrients and water from the soil. As the percentage of a target plant’s tube open to neighbors’ roots increases, the correct answer is B) target plant biomass decreased and neighbor plant root biomass increased. This occurs because the neighboring plants' roots, which now have access to new resources within the target plant's tube, can absorb those resources, thereby benefiting in terms of biomass. On the other hand, the target plant now faces competition for the same resources, which can potentially decrease its own biomass due to the shared resources being taken up by its neighbors.