The scenario described in the question pertains to primary succession. In primary succession, a barren landscape such as the park with unmowed grass after a catastrophic event like a zombie apocalypse begins the process of ecological succession from scratch, as opposed to secondary succession which occurs on previously colonized, but disturbed, soil.
In the next 100 years following the cessation of grass mowing in the park, various stages of primary succession will occur:
Stage 1: Pioneer Species Establishment - Initially, pioneer species like flowering plants may start colonizing the area. These plants are hardy and can thrive in harsh conditions, helping to break down rocks and organic matter to create soil.
Stage 2: Soil Development - As the pioneer species grow and die, they contribute organic matter to the soil, aiding in its development. The soil becomes more fertile and capable of supporting a wider range of plant species.
Stage 3: Intermediate Species Colonization - With improved soil conditions, a diverse array of plants, shrubs, and small trees may begin to populate the area. These species further enrich the soil and provide habitat for animals.
Stage 4: Establishment of Big Trees - Over time, larger trees like oak, maple, or pine may take root in the park. These big trees create a canopy that alters light availability, moisture levels, and temperature, shaping the local ecosystem and supporting a more complex community of plants and animals.
Each stage in this primary succession process plays a crucial role in transforming the landscape from a grassy park to a diverse and mature ecosystem over the span of 100 years.
