Answer
The increase in forest fragmentation results in the decrease of species richness, but white-footed mice population still exists in this condition. As the mice are the major host of B. burgdorferi, and the percentage of mice is high in the forest, there would be an increased incidence of Lyme disease.
Work Step by Step
The narrowing down of niche because of the forest fragmentation causes the eradication of the species like opossum. The species of white-footed mice have a broad range of niche, so they would exist in the population, in spite of forest fragmentation.
The mice are a reservoir of the bacterium Borrelia burgdorferi, which causes Lyme disease. Therefore, the presence of a greater percentage of mice in the forest fragments would result in the presence of B. burgdorferi. Thus, the increased incidence of Lyme disease would be observed.
