Succession is a series of regular, predictable changes in the structure of a community over time. Primary succession takes place on bare mineral soils and rocks or water. Secondary succession begins with the destruction or disturbance of an existing ecosystem.
A climax community is a relatively stable, long-lasting, complex and interrelated group of many different organisms. A successional community is a stage in the successional process. It is generally short-lived and unstable.
Tropical rainforest: high diversity, high rainfall, and no frost
Desert: low rainfall, sparse vegetation, and high evaporation
Tundra: permafrost, low rainfall, and short growing season
Taiga: coniferous trees, soil freezes in winter, and bogs
Savanna: occasional or patches of trees, seasonally structured ecosystem, and mound-building termites
Grassland: low rainfall, few trees, and grazing animals
Temperate deciduous forest: deciduous trees, evenly distributed rainfall, and migrating birds
The two primary factors in determining biomes are temperature and precipitation.
As elevation increases, the average temperature decreases. The change in biomes from sea level to mountaintop is similar to the change which occurs from equator to the North Pole.
The areas which are most productive are those where light and nutrients are most abundant. These include areas where currents bring nutrients up from the bottom of the ocean or where currents or rivers deposit sediment.
Sand tends to shift making it difficult for plants and algae to become attached, although burrowing worms, clams, and crustaceans find it suitable. Mud is more suitable for some plants and algae and many burrowing organisms. Rocks are a good substrate for plants and large algae that in turn make a good habitat for a variety of motile and attached animals.
Phytoplankton: free-floating photosynthetic primary producers in the euphotic zone.
Zooplankton: free-floating primary consumers found deeper than phytoplankton.
Algae: attached primary producers in shallow, coastal water.
Coral organisms: mutualistic relationship between coral and algae; form calcareous substrate for other organisms.
Fish: nektonic higher order consumers.
Freshwater ecosystems differ from marine by having much less salt, greater temperature variability, and different rganisms.
An estuary consists of a shallow, partially enclosed area where freshwater enters the ocean. Estuaries are high in transported sediment from up-river and their salinity varies with the change in tides. They are important because they are nursery sites for fish and crustaceans like flounder and shrimp.
