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.
