Unit 4: EcosystemsAPES Period 4

Terrestrial and Aquatic BiomesKaris Heidebrecht

What is a Biome?

Definition: A major biological community, such as a grassland or desert, characterized chiefly by the dominant forms of plant life and the prevailing climate.

Terrestrial Biomes Includetropical rainforest, temperate rainforest, deciduous forest, taiga, savanna,temperate grasslands, alpine and tundra.

Aquatic Biomes Include

estuaries, oceans, lakes, rivers, ponds, coral reefs and wetlands.

Energy Flow Through Ecosystems

McKenna

Biogeochemical CyclesDaniel Monsalve

Carbon Cycle

Nitrogen CycleNitrogen makes up 78% of the atmosphere it is also an essential nutrient for all life.

Nitrogen fixation - Most organisms can’t use atmospheric oxygen, but certain bacteria transfer it into other compounds like ammonia (NH4). Ammonia can then be used as a source of nitrogen for other organisms. Lightning also fixes a small amount of nitrogen.Assimilation - Nitrogen that is fixed can then be used by plants where it is then transferred to animals who eat the plants.Nitrification - Is the process of turning ammonia into nitrates or nitrites. It is carried out by b acteria.Denitrification - Other bacteria take organic nitrogen and nitrates and turn it back into gaseous nitrogen.

Effects of Excess Nitrogen

The burning of fossil fuels and the use of

manufactured fertilizers increase nitrogen on

land in the atmosphere and in oceans.

Ammonia (NH3) in the atmosphere has tripled

from human activity. This has led to water and

air pollution and in some cases acid rain.

Nitrogen Cycle Video

Phosphorus Cycle

Sulfur Cycle Phosphorus Cycle Animation

Water Cycle

Population Dynamics

Geoffrey Ashton

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Natural Ecosystem Change

Michaela Brost

Succession

The process by which one natural community changes into another over a time scale of years to centuries is called succession.Succession represents a natural transition from r- K-selected species.

Primary Succession

Referring to colonization of a newly exposed landform, such as sand dunes or lava flows after a volcanic eruption.

Secondary Succession

Describing the return of an area to its natural vegetation following a disturbance such as fire, treefall, or forest harvesting.

Autogenic Succession

Change driven by the inhabitants of an ecosystem, such as forests re-growing on abandoned agricultural fields.

Allogenic Succession

Change driven by new external geophysical conditions such as rising average temperatures resulting from global climate change.

Key Terms

Victoria Owen

Key Terms (Continued) Maribeth Villanueva

Adaptation- make (something) suitable for a new use or purpose; modify.

Adaptive trait- a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection.

Age structure- A population pyramid, also called an age pyramid or age picture diagram, is a graphical illustration that shows the distribution of various age groups in a population, which forms the shape of a pyramid when the population is growing

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Age distributions- the distributions of age in a population