Bell Work Imagine you have been hired to oversee the maintenance of a forest. How would you evaluate the health of the forest? What actions would you take to keep the forest healthy? What might be a threat to the health of the forest?

Today’s Schedule 5 minutes Bell Work 10 minutes Review 30 minutes Primary Succession Mini-break Secondary Succession 5 minutes Succession Video Exit Ticket

Predation Niche Biotic Factor Biological Community Commensalism Review Predation Niche Biological Community Biotic Factor Commensalism Ecology Abiotic Factor Food web Biome Food web Ecosystem Population omnivore Symbiosis Biosphere Habitat Mutualism

Ecological Succession In 1988 large areas of Yellowstone Park burned to the ground. How do you think the park looked the following spring?

Ecological Succession The “dead” forest began to change New plant growth began

ECOLOGICAL SUCCESSION Ecosystems tend to change with time until a stable system is formed. The stable system that will form depends on climatic limitations.

Ecological Succession The replacement of one community by another until a stable stage is reached is called ecological succession.

Climax Community The final stage of succession is called the climax community. The climax community in New York State is an oak-hickory forest or a maple-beech forest.

Succession Gradual development of a community of organisms over time Takes place in all communities Takes place over time

Succession occurs BECAUSE Each community changes the conditions so that they are more favorable to other organisms that replace them. For example, some types of trees need a lot of sun and their saplings cannot grow under the shade of their own species. They will be replaced by the types of trees whose saplings can grow in shade of other trees.

Primary Succession Primary succession occurs where there was no previous community, such as on bare rock or sand. Primary succession begins with pioneer organisms.

Pioneer Organisms Pioneer organisms can tolerate extreme conditions: hot and cold; dry and wet. Moss, dune grass, and lichens are pioneer organisms.

Lichens Lichens are algae and fungus growing together in a mutualistic relationship. Algae make the food; fungus anchor and capture water.

Pioneer organisms Soil is produced over hundreds of years by pioneer organisms. These organisms break apart rock, add humus as they die and decompose, and hold water This allows other organisms to grow there.

Primary Succession Example: volcanic eruption There is no soil in this area, usually just bare rock

Steps in Primary Succession After an volcanic eruption, lava covers the land and hardens into rock

Primary Succession 2. Lichens begin to form on rocks Acids from the lichens begin to break down the rock These pieces of broken rock and the remains of dead lichens start forming soil 3. Pioneer species appear- first organisms to grow in a succession example-lichens

Primary Succession 3. After many years The soil is deep enough for mosses to grow Mosses replace lichens Tiny organisms like insects live the in the lichens and mosses Their remains add to the soil

Primary Succession 4. After hundreds or even thousand of years The soil may be deep enough to support a forest The final stage of succession is the climax community

Primary Succession

Secondary Succession Changes that takes place after an environment is disrupted in some way (the soil must remain intact) Disruption may be from fire, farming, wind, foresting

Secondary Succession The community begins again where the former community was disrupted. Soil is already present.

Steps of Secondary Succession 1. fast growing grasses and non-woody plants appear

Secondary Succession 2. Larger shrubs move in

Secondary Succession 3. Fast growing trees (such as pines) move in 4. These are followed by slower-growing hardwood trees

Secondary Succession 5. animals begin moving back in the ecosystem Succession ends with a climax community

Secondary Succession

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