Question

A farmer stops cultivating a large tract of farmland and abandons it. the natural changes taking place soon afterwards, such as the growth of wild grasses and weeds, can be considered secondary succession and not primary succession because

Answer 1

When a farmer stops cultivating farmland and abandons it, the growth of wild grasses and weeds can be considered secondary succession because of the presence of the existing soil. Secondary succession occurs in ecosystem when soil have been disturbed or disrupted by humans such in a way of farming.  Furthermore, the reason why it cannot be categorize as primary succession because primary succession only occurs in essentially lifeless areas, where soil is not capable of sustaining life. Specifically, this is called old-field succession where wild grasses and weeds represents a new plant species to colonize a bare soil after the farmer abandon the farmland.