Why is it hard to set static boundaries for regions?

Atown located beside a river derives a large percentage of its revenues each year from the local logging industry. however, heavy traffic to and from the logging sites has increased pollution and contributed to soil erosion. this has also resulted in the loss of native bird species in the logged forests. which of the following is the most sustainable solution to this problem? protecting certain forested areas to allow the birds to recover relocating the equipment and vehicles to new forests for logging relocating the birds to new forests away from the town introducing new bird species to replace the species that have been lost reducing the number of trucks traveling through the forest by 10 percent