Succession Part 4

Brainstorm How do Ecosystems Form?

Succession Ecosystems are constantly changing in response to natural and human activities or events. Ecosystems are constantly changing in response to natural and human activities or events.

Succession Sometimes, an ecosystem changes in response to an abrupt disturbance. Sometimes, an ecosystem changes in response to an abrupt disturbance.

Succession Ecosystems are constantly changing in response to natural and human activities or events. Ecosystems are constantly changing in response to natural and human activities or events. Sometimes, an ecosystem changes in response to an abrupt disturbance. Sometimes, an ecosystem changes in response to an abrupt disturbance. At other times, change occurs as a more gradual response to natural fluctuations in the environment. At other times, change occurs as a more gradual response to natural fluctuations in the environment.

Succession Ecosystems are constantly changing in response to natural and human activities or events. Ecosystems are constantly changing in response to natural and human activities or events. Natural Events Human Events

Succession Ecosystems are constantly changing in response to natural and human activities or events. Ecosystems are constantly changing in response to natural and human activities or events. Natural Events Human Events - Fires - Volcanic eruptions - Retreated Glacier - Flood - Storms - Fallen tree

Succession Ecosystems are constantly changing in response to natural and human activities or events. Ecosystems are constantly changing in response to natural and human activities or events. Natural Events Human Events - Fires - Volcanic eruptions - Retreated Glacier - Flood - Storms - Fallen tree - Logging - Land Clearing for Construction Construction - Live-stock Grazing in Farming in Farming

What is ecological succession? The series of predictable changes that occurs in a community over time, due to natural or human disturbances is called ecological succession. The series of predictable changes that occurs in a community over time, due to natural or human disturbances is called ecological succession.

There are two types of succession: There are two types of succession:

1. Primary Succession

There are two types of succession: There are two types of succession: 1. Primary Succession 2. Secondary Succession

Primary Succession Succession that occurs on surfaces where no soil exists. Succession that occurs on surfaces where no soil exists.

Primary Succession Succession that occurs on surfaces where no soil exists. Succession that occurs on surfaces where no soil exists.Examples:  Retreating Glaciers  Volcanic Eruptions

Primary Succession The first species to populate the area are called pioneer species. The first species to populate the area are called pioneer species.

Primary Succession Pioneer species physically break up the rocks, extract minerals, and provide organic matter that will decompose and become the soil for later species. Pioneer species physically break up the rocks, extract minerals, and provide organic matter that will decompose and become the soil for later species. The first species to populate the area are called pioneer species. The first species to populate the area are called pioneer species.

Pioneer Species Pioneer species share some of the following characteristics, which allow them to be the first to grow in an area. Pioneer species share some of the following characteristics, which allow them to be the first to grow in an area. –Reproduce quickly –Mechanisms for distant seed dispersal (birds, insects, wind –Shade Intolerant –Need little or no soil –Survive in harsh environments –Need little water

Pioneer Species Example of pioneer species: Example of pioneer species: –Lichen Two organisms (algae and fungus)

Stages of Primary Succession 1. Primary succession begins when lichens populate bare rock. Because lichens are the first species to live where no life has lived in the past, they are called pioneer species. As the lichens grow, they help break up the rocks and when they die their organic material helps to form soil in which plants can grow.

Stages of Primary Succession 2. Mosses may grow next and then grasses and small weeds will root in the soil trapping soil and organic matter that blows their way. In addition, the decomposition of grasses and weeds will accelerate the soil formation process.

Important NOTE As the vegetation begins to grow, animals begin to arrive in the area. As the vegetation begins to grow, animals begin to arrive in the area. These animals also die, decompose, and add to the soil being formed for other plants to take root and more organisms arrive as their habitats form. These animals also die, decompose, and add to the soil being formed for other plants to take root and more organisms arrive as their habitats form.

Important NOTE As the vegetation begins to grow, animals begin to arrive in the area. As the vegetation begins to grow, animals begin to arrive in the area. These animals also die, decompose, and add to the soil being formed for other plants to take root and more organisms arrive as their habitats form. These animals also die, decompose, and add to the soil being formed for other plants to take root and more organisms arrive as their habitats form.

Stages of Primary Succession 3. Small shrubs and pine trees can now grow amongst the grasses and weeds.

Stages of Primary Succession 4. The community then moves from a scrubby one to a pine dominated forest.

Stages of Primary Succession 5. Hardwood trees such as Maple, Beech and Oak grow in the shade of the pines and eventually grow taller than the pines shading them and ultimately resulting in their death and replacement by the hardwood forest. the hardwood forest.

This is called the climax community. If nothing changes, which in nature is highly unlikely, this community will be stable.

PRIMARYSUCCESSIONEXAMPLES

Secondary Succession What happens if a community is disturbed at some stage of succession?

Secondary Succession What happens if a community is disturbed at some stage of succession? If a community is disturbed, without removing the soil, it will be set back to an earlier stage and succession will start over from there.

Secondary Succession Secondary succession proceeds much quicker than primary succession, because there is soil present and often even seeds.

Secondary Succession Secondary succession proceeds much quicker than primary succession, because there is soil present and often even seeds. Results after a disturbance such as: – – abandoning a plowed field – –a wildfire or clear cutting a forest

Secondary Succession Secondary succession proceeds much quicker than primary succession, because there is soil present and often even seeds. Results after a disturbance such as: – – abandoning a plowed field – –a wildfire or clear cutting a forest

Secondary Succession Secondary succession proceeds much quicker than primary succession, because there is soil present and often even seeds. Results after a disturbance such as: – – abandoning a plowed field – –a wildfire or clear cutting a forest Pioneer species: Grasses and weeds.

Secondary Succession

Primary or Secondary Succession?

_____ As these plants live and die, the soil continues to develop to the point that grasses can successfully grow and grassland community forms. _____ As these plants live and die, the soil continues to develop to the point that grasses can successfully grow and grassland community forms. _____ The shrub community may be replaced by a forest. _____ The shrub community may be replaced by a forest. _____ Bare rock is first colonized by lichens* and bacteria. _____ Bare rock is first colonized by lichens* and bacteria. _____ Over time, the soil level increases to point that shrubs can grow in the grassland. The grassland is replaced by a shrub community. _____ Over time, the soil level increases to point that shrubs can grow in the grassland. The grassland is replaced by a shrub community. _____ The small amount of soil formed by the lichens* is colonized by mosses and ferns, which do not have roots and require little soil. _____ The small amount of soil formed by the lichens* is colonized by mosses and ferns, which do not have roots and require little soil.

__3__ As these plants live and die, the soil continues to develop to the point that grasses can successfully grow and grassland community forms. __3__ As these plants live and die, the soil continues to develop to the point that grasses can successfully grow and grassland community forms. __5___ The shrub community may be replaced by a forest. __5___ The shrub community may be replaced by a forest. __1__ Bare rock is first colonized by lichens* and bacteria. __1__ Bare rock is first colonized by lichens* and bacteria. __4__ Over time, the soil level increases to point that shrubs can grow in the grassland. The grassland is replaced by a shrub community. __4__ Over time, the soil level increases to point that shrubs can grow in the grassland. The grassland is replaced by a shrub community. __2___ The small amount of soil formed by the lichens* is colonized by mosses and ferns, which do not have roots and require little soil. __2___ The small amount of soil formed by the lichens* is colonized by mosses and ferns, which do not have roots and require little soil.

Arrange the species below in order of their appearance in succession from bare rock to forest: Softwoods (conifer) LichenMossFerns Hardwoods (oak)

Arrange the species below in order of their appearance in succession from bare rock to forest: Lichen Softwoods (conifer) Softwoods (conifer)MossFerns Hardwoods (oak)

Arrange the species below in order of their appearance in succession from bare rock to forest: LichenMoss Softwoods (conifer) Ferns Hardwoods (oak)

Arrange the species below in order of their appearance in succession from bare rock to forest: LichenMoss Ferns Ferns Softwoods (conifer) Softwoods (conifer) Hardwoods (oak)