How is this an HEI?

Reindeer herding is an HEI because people are herding reindeers and using them as a resource for food, clothing, trade, and labor; rather than letting them live in the wild by themselves.

Also the migration of reindeers (controlled by the herders) is making the land area harsh conditions for bushes, shrubs, or trees to grow due to the trampling of reindeers.

Reindeer herding is an example of adaptation and modification.

This is an example of adaptation because when people are herding, they have to adapt to the different seasons by moving herds to different areas.

This is an example of modification because; due to herders migrating their reindeers, the land area is becoming trampled, causing the land to be unhabitable by different kind of plants.