Ecosystems

Ecosystem – all the organisms in an area along with their environment (habitat) - includes biotic (living) and abiotic (nonliving) factors Biotic factors: organism → population (all org of one species) → community (all species in the area)

Abiotic factors: temperature, water (rainfall), sunlight, oxygen levels, wind, soil temperature and water (climate) - most important factors determining types of life an ecosystem can support

Biodiversity – variety of organisms in an ecosystem – Tropical rainforest – most biodiverse land ecosystem – Coral reef – most biodiverse aquatic ecosystem

Succession Succession – change in an ecosystem – Replacement of one type of community by another over a period of time – Two types: 1. Primary – occurs in a newly made habitat (EX: new volcanic island) 2. Secondary – occurs in habitat that has been disturbed (EX: after forest fire or manmade change)

Succession (Cont) Communities involved in succession – Pioneer community – first species in habitat (EX: lichens, mosses) – Intermediate species – follow pioneer – Climax community – final species to appear; will remain as long as ecosystem is stable EX: lichens → grass → shrubs → pine trees →deciduous trees

Biome Biome – large region characterized by specific kind of climate and certain kinds of plant and animal life – Terrestrial biomes: tundra, taiga (coniferous forest), temperate (deciduous) forest, grassland (prairie, savanna), desert, tropical rainforest – Aquatic ecosystems: lakes and rivers, wetlands, estuaries, marine