Answer: The field is experiencing Secondary succession.
Explanation:
Ecological communities change slowly over time. While primary succession is initiated by pioneer species in areas that haven't previously been colonized; secondary succession always follows other communities. Secondary succession follows major disruptions in communities like fires, storms, flooding and even human disturbance.
The field becoming overgrown is typical of secondary succession. After years of disuse, the field is being occupied by species more capable of thriving in changed conditions. The community may be on its way to becoming a stable climax community if no further disruptions occur.
