How ecosystem change?

What  happens when people abandon a city? Nature takes over. Example: From farmland to forest.

• Abandoned  farm : the pionner species take place things like grass, insects, adn crabgrass.
• Second a third year: tall weeds, small mammals like mice and rabbits, insects, and eatin-birds seed and insect form a pionner community.
• Four to six years: more birds are join to the community, pine trees, small mammals like opossums adn skunks.
• Twenty-five yars later: a pine forest has replaced the old farm field. Seeds of a decidious trees such as maple, hickory, larger animal like raccons and foxes.
• One hundread years later: the forest is now mostly decidious trees. This trees are the habits of many animals like birds and small mammals like squirrels. Deers, raccons, and foxes also live in the forest.

The gradual replacement of one coummunity bu another is called ecological succesion. The ecological succesion can begin in two different kinds of places. It can begin where community already exists. Ecological succesion in a place where  a community alraedy exist is called secondary succesion. The ecological succesion can also happen where thre few, if any, living things. This is called primary succesion.