GEOG Exam 3 Content Review

Biosphere Levels

-Habitat

-Ecosystems/Ecoregions

-Biome

Individual, Population, Community

Individual: survival & reproduction, unit of natural selection

Population: Unit of evolution

Community: Interactions amongst populations

Ecosystem

Self-sustaining association of living plants & animals and their non-living physical environment

Ecoregions

areas where ecosystems are generally similar.

Fields of Study

-Ecology

-Biogeography

Ecology: study of relationships between organisms & their environment

Biogeography: study of distribution of plants & animals over space and time

Taxonomy

• Classified by a Hierarchical system

• Classification based on evolutionary relationships

• First physical similarity, later genetic similarity

Put the following Kingdoms (6 total) in order:

• Class

• Order

• Family

• Species

• Genius

• Phylum

• Phylum,

• Class,

• Order,

• Family,

• Genus,

• Species

Scientific Binomial Names are always _______ or ______________

Italicized or underlined

Define the following:

Family, Genus, Species

Family

• share a common ancestor in the geologic past from which they evolved

Genus (plural=genera)

• hare a common ancestor in the recent geologic past

Species

• most closely related

The biological species concept (3 parts)

• Morphologically look similar/look alike

• are capable of mating and producing viable offspring (who can go on to also reproduce)

• Normally do so in the wild

While members of closely related species may be able to mate and produce offspring, the offspring are sterile

Types of Biodiversity

genetic diversity: variation of genes within species

species diversity: number of species in an ecosystem

ecosystem diversity: variety of ecosystems or habitats

Types of species

Endemic Species: unique to a defined geographic location

Native Species: either endemic or indigenous; may live in numerous locations

Introduced Species: living outside its native distributional range, which has arrived there

by human activity

Invasive Species: non-native/introduced to the ecosystem and causes/is likely to cause economic, environmental harm orharm to human health

biodiversity results in greater _______ = ability to recover from change

Resilience

What are primary drivers of Biodiversity loss?

• Habitat Loss

• Invasive Species

• Overexploitation

• Pollution

• Climate Change associated with global warming

Stenotopic

A species adapted to a narrow range of conditions

Eurytopic

A species adapted to a wide range of conditions

Abiotic

• Non-living

• Abiotic factors: SWATS

  • Soil

    Water

    Air

    Temperature

    Sunlight

Biotic Definitions, Roles, and Interactions

• Biotic=Living

• Roles

  • Producers

  • Consumers

  • Decomposers

• Interactions

  • Predators/Prey

  • Competitors

  • Symbionts

  • Pathogens

Limiting Factor

Component that most inhibits biotic operations through either lack or excess

Niche

Function of a life form within its community

Symbiosis

overlapping relationships

Commensalism, Parasitism, and Mutualism

Commensalism: One is benefited

Parasitism: One is benefited, one is harmed

Mutualism: Both benefit

Trophic Level

position organism occupies in a food chain (what it eats and what eats it)

Producers (autotrophs)

“self feeders”, use solar energy & CO2 for food, always plants

Consumers: (heterotrophs)

“feed on others”, depend on producer

Primary consumers = _________

Secondary consumers = ___________

Tertiary consumers = _________

Primary consumers = herbivores

Secondary consumers = carnivores

Tertiary consumers = carnivores

Omnivores

Eat both plants and animals

Decomposers (fungi/bacteria & detritivores)

Feed on dead organic debris left by living processes

Food Chain Efficiency

Only ~10% of the energy consumed at one trophic level passes up the food chain to the next

Biological magnification of persistent toxins

Concentration of toxic substances (like pesticides or heavy metals) multiplies as they move up the food chain

Grassland Biome

• Grassland biomes dominated by a single class of plant

  • Grass = a non-woody plant, containing a hollow stem for strength, bladed leaves for photosynthesis and a flowering bundled seed head for reproduction

• Evolved since end of Cretaceous, 66 million years ago

• >10,000 species today

Prior to human modifications, grasslands covered _____ to ______ of the

earth's land surface. Grasslands exist on every continent except ______

24 to 45%

Antarctica

Tropical Savanna Biomes

grasslands with interspersed trees

Tropical Savanna Biome Abiotic Characteristics

S) Tropical latitudes;high insolation

(T) Warm year-round

(W) Seasonal rainfall (9-150 cm; 4-60 in)

• Drought & fire are common

Mid Latitude Grassland Names in various continents

North America: Prairies

South America: Pampas

Eurasia: Steppes

Mid-Latitude Grasslands Abiotic Characteristics

(S) 25°-50° mid-latitudes; seasonal isolation

(T) Warm summers, cold winters

(W) Seasonal rainfall (25-75 cm; 10-30 in)

• Periodic drought & fire

Mollisols

• Thick organic A horizon

• Long-term addition of organic matter from grasses & roots

• High fertility ➡ productive agricultural soils

Mollisols Biotic Characteristics

• Moderate Biodiversity

Grasslands are relatively simple in ________ but rich in ________. However, most areas of the prairie have experienced serious declines in ___________.

structure, # of species, biodiversity

Annual Grass Definition and Examples

• Definition: Grow new from seed

• Examples

  • Rice, Wheat, Oats and Corn

Prennial Grass Definition and Examples

• Definition: Grow back from roots

• Examples

  • Kentucky Bluegrass, Sugar Cane, Switchgrass

Native Prairie herbivores

• bison

• pronghorn

• elk

• deer

• rabbits

• mice

________ of most prairie plants are below the ground.

Some roots die each year and decompose ➡ carbon sink in soil.

2/3

Threats to Mid Latitudes and Tropical Savanna

• Fire suppressions

• Desertification

Solution to Fire Suppressions

Controlled burns

Solutions to Desertification

Mimic nature with planned grazing

“restorative ranching”?

Keystone Species

Definition: species that has a disproportionately large effect on the communities in which it occurs

Example: Prairie Dogs

Photosynthesis - Respiration = ______

Biomass

Biomass

Dry weight of organic material

Net Primary Productivity (NPP)

• Net photosynthesis

• Stored chemical energy

• Fixed carbon per unit area per unit time

• Biomass

Carbon Source

Anything that releases MORE carbon than it stores

Carbon Sink

Anything that absorbs MORE carbon than it releases

Short-term Carbon Cycles

can take months to centuries

Composting

Using decomposers to make soil

Soil is made of

• Mineral particles

• Air

• Water

• Organic matter (humus)

• Plant roots

• Living organisms

Soil Development

• Weathering

• Translocation

  • Physical/chemical movement by water

• Organic Activity

  • Rooting: Plants

  • Bioturbation: Worms, rodents, insects, birds mixing soil

  • Decomposition: Fungi, Bacteria, Worms

Soil Development Steps

1. Rock begins to disintegrate by physical and chemical weathering

2. Plants facilitate weathering and add organic matter

3. Soil develops a layered structure, water moves dissolved minerals

4. Fully developed soil can support thick vegetation

Soil Formation Factors: CLORPT

CLimate

Organisms

Relief

Parent material

Time

Earthworms

• Accidentally introduced by European settlers in 1800s

• Altered forest soils and forest structure

Soil Classification: Soil Horizon

Soil layers, differences used to classify soils

Pedon

Description unit ~1m2 column from surface to bedrock

Soil Degradation

Human induced or natural processes that negatively affects soil functions (Accepting, storing, and recycling water, energy, and nutrients)

• Erosion (Wind, water)

• Chemical degradations (Contamination, Salination)

• Physical Degradation (Compaction)

• Biological Degradation (Loss of organic matter)