1. Succession & Biodiversity
Chapter 3

2. Succession What is succession?
Succession- the process of life recolonizing after a disturbance in an ecosystem.
Primary succession- recolonizing an ecosystem with no soil
Stripping an ecosystem down to its bedrock and completely starting over or creating a brand new ecosystem that only has a rock surface.
Usually due to glaciers, volcanoes or new land forming
Secondary succession- recolonizing an ecosystem that still has its soil
This is where the living things have been erased but the soil is still intact.
Fires and agriculture clearing

3. Primary Succession
Primary succession- is recolonizing an ecosystem with no soil
2 ways primary succession can happen
New land can be created as in the formation of a volcano by lava erupting and creating new rock
Old land can be stripped down to rock when glaciers move and bulldoze away all of the plant life and soil
Over time in primary succession plants will colonize the area. How do plants grow there without any soil?

4. Primary Succession
Before plant life can grow in a new area, soil must be created. How is new soil created?
Lichen(the colored crusty stuff on rocks) start to grow on the rocks in the ecosystem. The lichen secrete a very weak acid that over time breaks down the rocks into smaller and smaller bits.
Natural wind and water erosion also takes place which breaks down the rocks into smaller bits.
Moss also starts to grow on the rocks which act as a sponge to trap particles and nutrients that are important for soil. Also, once that moss dies it becomes nutrient rich plant matter/compost that is a main component soil
Lichen, moss and erosion help create the soil needed for future plants to grow
This process of creating new soil could take thousands of years or longer

5. Primary Succession
After lichen, erosion and moss have created soil for plants to grow grasses start to colonize the area
The weeds are important because it prevents the soil created from washing away
Next come grass, flowers and other small plants. (annuals first then perennials)
Next come small shrubs and bushes.
Next come conifer trees like pines and then deciduous trees like oaks and depending on the ecosystem, it will determine which specific trees colonize the area.
Lichens/moss  weeds  grass/flowers  shrubs  evergreen trees  deciduous trees

6. Primary Succession
Pioneer species- the first species to inhabit an area after succession
Usually are lichen in primary succession and grasses in secondary succession
Climax community- the largest and last species to colonize an area
Usually are large hardwood trees that establish after all of the other trees have come in…lets you know that an ecosystem has completely gone through succession
Why are pine trees often needed for deciduous trees like oaks to grow?
Pines grow and provide shade for the deciduous seedlings who have a hard time growing in direct sunlight. The cover provided by the pine trees usually provides a good environment for the seedlings to grow below

7. Secondary Succession
Secondary Succession- recolonizing an ecosystem that still has its soil
Fires and agriculture clearing
weeds  grass/flowers  shrubs  evergreen trees  deciduous trees
This process can take a few hundred years, much shorter than primary succession because soil does not need to be created from scratch

8. Aquatic Succession
Aquatic Succession- the process of changing an aquatic ecosystem into a terrestrial ecosystem
How does it happen?
Streams and rivers that feed into lakes dump sediment and as soil erodes from hillsides it gets deposited in the lakes slowing building up the bottom soil layer until there is no water left
Aquatic succession turns lakes  wetlands  dry land
This process can take hundreds or thousands
of years but can be sped up by drought or
mass erosion events
As aquatic succession occurs aquatic species
retreat and terrestrial plant species colonize

9. Succession Good or Bad?
In what ways do you think succession might be bad for an ecosystem? 
Could eliminate rare plants
Make soil more susceptible to erosion
In what ways do you think succession might be good for an ecosystem?
Reset an ecosystem to allow new plants to grow
Can create more diversity
How do humans contribute to succession.
Agriculture and man made fires
It is sometimes said that ecosystems are always going through succession, why do you think that is?
How do we handle succession in the Black Hills?
Ecological upset- where one species experiences a population boom at the expense of another
Ecological collapse- where almost all of the species in an ecosystem die due to events like pollution, etc

10. ECOLOGY TEST Biomes Biogeochemical Cycles Species interactions
Know the characteristics of terrestrial and aquatic biomes.
How do humans impact aquatic biomes?
Be able to describe biotic and abiotic factors in an environment.
Be able to read a climate diagram.
Biogeochemical Cycles
Understand how matter flows through the water, carbon, nitrogen & phosphorus cycles.
What are the major sinks of each cycle?
Know who the key players are in each cycle, are there 1 or 2 crucial steps?
How are humans impacting each cycle?
Species interactions
Why do organisms want to have niches?
What are the various types of species interactions?
What is the principle of allocation?
Populations
What are limiting factors?
Be able to draw and describe logistical population growth?
Be able to read a predator/prey graph.
Energy Flow
Be able to identify the 4 trophic levels and organisms that would be in each.
Be able to read a food web.
What is an invasive species and how do they impact an ecosystem?
Succession
Be able to describe the processes of primary and secondary succession. What colonizes 1st, 2nd, 3rd.