Land Ecosystems
Ecological succession – the process of one ecological community gradually changing into another.
Climax community – a stable community that no longer goes through major ecological changes
Examples: lava flow, sand dunes, exposed rock
Pioneer species – The first species that colonize new or undisturbed land.
Examples: lichens and mosses
Secondary succession – Ecological succession in areas where existing ecosystems have been disturbed or destroyed.
Example – cleared forests
Climax community – a stable community that no longer goes through major ecological changes
- Differ depending on biome
- Usually stable for hundreds of years
- As plants die – new plants grow
- Will continue as long as climate stays the same
Examples: lava flow, sand dunes, exposed rock
Pioneer species – The first species that colonize new or undisturbed land.
Examples: lichens and mosses
Secondary succession – Ecological succession in areas where existing ecosystems have been disturbed or destroyed.
Example – cleared forests
Freshwater Ecosystems
Freshwater ecosystems change over time in a natural predictable process called aquatic succession.
Aquatic succession
Aquatic succession
- Sediments carried by rainwater and streams accumulate on the bottoms of ponds, lakes, and wetlands.
- The decomposed remains of dead organisms add to the buildup of soil.
- As time passes – more soil accumulates
- Eventually – so much soil – water disappears and the area becomes land.
- Decaying organisms fall to the bottom of a pond, lake, or wetland and add nutrients to the water.
- Natural part of aquatic succession
- Humans contribute with fertilizers and waste from farm animals.
- When fertilizers and pollution run off into a pond or lake, nutrient concentrations increase.
- High nutrient levels support large populations of algae and microscopic organisms.
- Organisms use most of the dissolved oxygen which leave less oxygen for fish.
- Many of the fish then die and decay speeding up succession.