A stable ecosystem in north america is disrupted greatly by a particular human stress. which trophic level would most likely be the first suffer?

The first trophic level that would likely suffer would be the primary producers. The first thing that usually occurs as humans move into or influence an area would be clearing the land fir the purpose of creating infrastructure for development or for agricultural purposes. This is the primary cause of deforestation globally. As the first trophic level is affected so too are the other levels in an ecosystem.