Answer:
1. changes in climate
2. strong nomadic leadership wanting to expand their lands
Explanation:
The pastoral society is a nomadic group of people who travel with a herd of domesticated animals, which they rely on for food while the agrarian society, or agricultural society, is any community whose economy is based on producing and maintaining crops and farmland.
Having defined what both societies represent, there's a need to state the possible reasons for interaction between these two societies.
The changes in climate, especially increased atmospheric CO2, temperature and precipitation had great impacts on the agarian and pastoral societies as there was a need to balance the atmospheric conditions in other for both plants and animals to survive.
Normadic leadership whereby a fixed habitation which regularly moves to and from the same area in other to settle down also led to the interaction between these two societies.
