How did the changes in ecosystem that you described result in changes to the tree frog population?

Amphibians are good indicators of significant environmental changes. Amphibians, unlike people, breathe at least partly through their skin, which is constantly exposed to everything in their environment. Consequently, their bodies are much more sensitive to environmental factors such as disease, pollution, toxic chemicals, ultraviolet radiation, and habitat destruction. The worldwide occurrences of amphibian declines and deformities could be an early warning that some of our ecosystems, even seemingly pristine ones, are seriously out of balance.

the speed increase from w to x due to increased gravity force

the speed decreases from x to y due to decrease in gravity