How is the ph altered in an ecosystem? (both terrestrial and aquatic)

The pH of a substance refers to the degree of acidity or alkalinity of that substance, that is, pH is a measure of how acidic or basic a substance is. The pH scale ranges from 0 to 14. Point 1 [very acidic] to 6 [slightly acidic] is considered to be acidic while point 8 [very basic] to point 14 [slightly basic] is considered to be basic. Point 7 is neutral. 
In an ecosystem, the pH of the terrestrial or the aquatic environment can be altered by pollution such as mining erosion, radioactive materials, oil spillage, excess nutrients, etc.

Cartificial intelligence

Hydrosphere is the correct answer