Final answer:
After 300 years of abandonment, the vegetation on the farmlands in Illinois and New York would undergo ecological succession, with pioneer plants and small seedlings colonizing the area and gradually building up the soil quality. This would lead to the development of a forest ecosystem.
Step-by-step explanation:
After 300 years of abandonment, the vegetation on the farmlands in Illinois and New York would likely undergo a process called ecological succession. Initially, the land would be bare with little life left behind. However, over time, small seedlings would establish themselves and gradually a forest ecosystem could develop.
Ecological succession is the process of gradual change in an ecosystem over time. It occurs in two main types: primary succession, which happens on newly formed or exposed land where no soil exists, and secondary succession, which occurs on land that has been previously occupied by vegetation but has been disturbed or cleared.
In this case, the farmlands would likely experience secondary succession. As the land is abandoned and left undisturbed for 300 years, pioneer plants and small seedlings would start colonizing the area. These plants, which are adapted to harsh conditions, would slowly build up the soil quality and create more favorable conditions for larger plants to establish. Eventually, the ecosystem would reach a climax community, which is a stable and self-sustaining community of plants and animals.