Ecology Chapter 3 Notes
Section 1 How Ecosystems Change
A. Ecological ____________________—normal, gradual changes that occur in the types of species that live in an area
1. Primary succession begins in a place without ________.
a. Starts with _________________________ such as _________________, that can grow on rock
b. New ______________ forms as weather and erosion break down rock.
c. Decaying plants add __________________________ to new soil.
2. ______________________________ begins in a place that has soil and once had living organisms
a. Examples: after a ______________ or removal of buildings
b. Occurs faster and has different pioneer species than primary succession
B. __________________________—stable stage of ecological diversity and balance
Section 2 Biomes
A. Factors that affect biomes’ climates
B. Major ________________—large areas with similar climates and ecosystems
1. ________________—cold, dry, treeless region
a. Permanently frozen soil called ____________________
b. Average winter temperature: _______________
c. Average precipitation is _________________________ 25 cm per year.
d. Plants: ________________, grasses, small shrubs, lichens
e. Animals: insects, ducks, geese, other birds, mice, arctic ______________, reindeer
2. _______________— cold forest of mostly evergreen trees
a. Soil _______________ in the short summer.
b. Precipitation: mostly snow, _____________________ per year
3. ________________________ forests—region with four seasons, mostly trees that lose their leaves in autumn
a. Temperatures range from ________________________ in winter to _______________________ in summer.
b. Precipitation: throughout the year, _________________ per year
4. ________________________ forest—tall trees with needlelike leaves
a. Average temperature: _____________________
b. Precipitation: _____________________ per year
5. ________________________ forests—the most biologically diverse of all biomes
a. Average temperature: _______________
b. Precipitation: ______ per year
c. Four _____________: forest floor, understory, canopy, emergents
d. Human impact: habitats being _____________________ by farmers and loggers
6. ________________—driest biome, supports little plant life
a. Temperatures: vary from _____________ to ______________
b. Precipitation: less than ______ cm per year
c. Soil: thin, _______________, or gravelly
d. Plant: cactus
e. Animal: kangaroo ______
7. ____________________—prairies or plains, dominated by grasses
a. Temperatures: temperate or _______________
b. Precipitation _____________________ per year; dry season
Section 3 Aquatic Ecosystems
A. ____________________ ecosystems—include flowing and standing water, low or no salt
1. Rivers and streams—_________________ water
a. Most ___________________ washed into water from land.
b. The faster the flow, the greater the ________________ content.
2. Lakes and ponds—very little ______________
a. Sunlight warms and lights pond ________________ supporting plant and animal life.
b. Deeper lakes support life along _________________ shoreline or surface
3. Water ___________________—a problem caused by fertilizer-filled runoff and sewage
4. __________________—regions wet all or most of year
a. Lie between __________________ and water
b. Very _________________ ecosystems
B. Saltwater ecosystems—95% of Earth’s water contains high concentration of salt, or
1. Open oceans—divided into lighted and dark life _______________
a. _________________—upper 200 m and home of plankton
b. ______________—below 200 m where animals feed on material that floats down or prey on each other
2. _____________________—diverse and fragile ecosystems formed from coral shells of calcium carbonate
3. Seashores—along ____________________
a. _________________________—covered with water at high tide and exposed to air at low tide
b. Drastic _________________ in temperature, moisture, salinity, and wave action
4. ___________________—where a river meets an ocean; called bays, lagoons, harbors, inlets, sounds
a. Rich in ___________________
b. Changing _________________ of salt water and freshwater.