Question

Members of a city planning committee want to designate over 100 hectares of greenspace in the city limits as protected, natural areas. One committee member, a biologist, tries to convince the other committee members to implement a plan that maximizes biodiversity in the greenspace while reducing the likelihood of invasion by a nonnative species. Which proposals would support the biologist committee member's ideas? Select ALL that apply.
Responses
A A large, continuous section of greenspace equaling 100 hectares should be conserved.A large, continuous section of greenspace equaling 100 hectares should be conserved.
B One hundred small, one-hectare size areas should be conserved across the city's limits.One hundred small, one-hectare size areas should be conserved across the city's limits.
C Native species should be maintained or planted within the greenspace to promote biodiversity.Native species should be maintained or planted within the greenspace to promote biodiversity.
D Exotic species should be cultivated and planted to increase biodiversity in the protected greenspace.Exotic species should be cultivated and planted to increase biodiversity in the protected greenspace.
E The majority of the secondary consumers should be removed from the greenspaces to promote an increase in lower levels of the food chain.

Answer 1

Correct choices: A and C.

Why:
- A (large, continuous 100 ha): Larger, contiguous reserves support more species (lower extinction risk), reduce edge effects, and are less easily invaded than many small fragments.
- C (use/restore native species): Native-dominated plantings promote local biodiversity and provide biotic resistance to nonnative invasions.

Why not the others:
- B (many 1‑ha patches) increases fragmentation and edge habitat, which lowers native biodiversity and makes invasion easier.
- D (plant exotics) can harm native communities and encourage invasions.
- E (remove most secondary consumers) would disrupt food webs and likely decrease biodiversity (trophic cascades).