Definition:
Lichens:
Linchens-Pioneer Species:
Climax Community:
- Natural, gradual changes in the type of species that live in an area and can be primary or secondary.
- Gradual replacement of one plant community by another through natural process over time.
- Begins in a place without soil. Sides of volcanoes, landslides and flooding.
- It starts with the arrival of living things such as lichens do not need soil to survive called pioneer species.
- Soil starts to from as lichens and the forces of weather and erosion help break down rock into smaller pieces.
- When lichens die, they decompose adding small amounts of organic matter to the rock to make soil.
Lichens:
- Symbiotic relationship between algae and fungus.
- Algal or cyanobacterial cells are photosynthetic and as in plants they reduce atmospheric carbon dioxide inorganic carbon sugars to feed both symbionts .
- The fungus The fungus provides support water and minerals from the substrate fro the algae.
Linchens-Pioneer Species:
- Help break down hard substrate providing nutrients to the soil.
- When they die they help create new rich soil also known as "indicator species", sensitive to change in the environment.
- Simple plants like mosses and ferns can grow in the new soil.
- Simple plants die, adding more organic material. Soil layer thickens and grasses, wildflowers begin to take over. Plants die adding more nutrients into other soil(shrubs and trees can survive now).
- Insects, small birds and mammals have begun to move in. What was once bare rock now supports varieties of life.
- Places where soil was once the home of living organisms.
- Occurs faster and has different pioneer species than primary succession(example after forest fires).
Climax Community:
- Stable group of plants and animals in the end result of succession process.
- Does not always mean big trees
- Grasses in prairies
- Cacti in deserts