Ecological Succession

Succession  Primary succession:  development of a new community with no previous life.  No soil is initially present.  Very slow!  Examples:  Bare rock, volcanic island

Primary succession 1.Lichens colonize the bare rock. Lichens are a mutualistic relationship between fungi and algae. 2.Dead and decaying lichen forms a layer of soil for grasslike plants to grow. 3.Dead plants add to organic soil, so mosses and larger plants can grow.

Secondary succession  Existing community is cleared by a disturbance, but soil is present.

1.Weeds, like annual grasses, dandelions, colonize first. Seeds are carried by wind or animals. Grow quickly, but die each year. 2.Perennial grasses and shrubs colonize later. Grow slower, but last longer. 3.Large trees, like oak, eventually colonize

 Pioneer species: first species to predominate in succession. Tend to be small, and grow quickly.

 Climax community: stable point that remains constant until a disturbance occurs.

Summarize 1.How are populations related to communities? 2.Describe the difference between a habitat and a niche. 3.An abandoned farm would be an example of primary or secondary succession?