Ecology What are the changes that occur in a community over time Ecology What are the changes that occur in a community over time? How can life begin again SB5.e. Construct explanations that predict an organism’s ability to survive within changing environmental limits (e.g., temperature, pH, drought, fire).

Types of succession: 1. Primary Succession Life starts from scratch Ex. Volcanic eruptions and drop in sea levels cause new land to form Always starts with rock (new or old)

2. Secondary succession Life starts over again Ex. Fire or natural disaster Starts with soil there already

Changes in Communities over time Ecological Succession –the natural replacement of one community with another until a climax stage is reached. Succession can occur when: a) Migration - populations move in or out of an area b) a natural disaster c) human actions destroy an existing habitat

Order of Succession A community starts with the pioneer species-the first species that lives in the area. Examples: Bacteria and Lichen(fungus and bacteria or algae) and mosses

Order of Succession 2. Next come the grasses, small plants. The animals that would inhabit(live in) the area would be insects, small rodents

Order of Succession 3. Next come the small shrubs. The animals that would inhabit the area would be small animals, rodents, rabbits, snakes, fox

Order of Succession 4. Next come the small trees(pines, spruces). The animals that would inhabit the area would be deer, coyote, wolves

Order of succession 5. Last come the large trees(maple, oak). The animals that would inhabit the area would be all animals, lions, tigers and bears, OH MY!!

Process of succession: How does succession happen? The above organisms live, some will die, and decomposers will break them down to return nutrients to the soil, which makes the soil richer. This changes the environment to a better environment for different species life. When succession slows down, a diverse, stable and mature community develops. This is called the climax community.