Chapter 26 Ecosystems

Section 1- How Ecosystems Change  Succession  The normal, gradual changes that occur in the types of species that live in an area.  Primary succession  The process of succession that begins in a place previously WITHOUT plants.  Pioneer species  The first to inhabit an area. Ex. Lichens  Deciduous trees are not pioneer species.  Secondary Succession  A pasture that gradually returns to its forested state.  Likely areas for secondary succession would be:  Flooded land, abandoned logging areas, the land after a forest fire.

Biomes  Biomes- large geographic areas that have similar climates and ecosystems.

Tundra  Cold, dry, treeless biomes in far north  Populated by caribou, reindeer, snowy owls, geese  Latitudes just south of the north pole.

Taiga  Dominant plants are cone-bearing evergreen trees.  Populated by moose, bears, lynx, shrews, foxes.  Found in Canada, northern Europe, and Asia.

Temperate Deciduous Forest  Usually have 4 distinct seasons.  Dominant plants loose their leaves every autumn  New England States

Temperate Rain Forest  Dominant plants are firs, spruces, and cedars that grow very high.  Populated by black bear, cougar, bobcat, and endangered northern spotted owl.  Pacific Northwest.

Tropical Rain Forest  Consists of forest floor, understory, canopy, and emergents.  Has greatest variety of organisms on Earth.  Located near the equator.

Desert  Populated by cacti and kangaroo rats  Northern Africa  Southwestern States

Grassland  Dominant plants and grasses  Perfect for growing crops and raising cattle and sheep  Have the same latitudes as deciduous forests, but receive less precipitation  Plains of North America  Savannas of Africa

Rainfall  Temperature & Precipitation are the two most important climatic factors that affect life in an area.  Desert- Lowest <25cm per year  Grassland cm per year  Taiga cm per year  Temperate Deciduous forest cm  Tropical Rain forest- Highest- at least cm.

Section 3- Aquatic Ecosystems  Freshwater ecosystems include  Lakes  Ponds  Swamps  An estuary is not a freshwater ecosystem because it contains freshwater and saltwater.