Units 1-4 Resource
Unit 1: Ecosystems
Levels of Ecosystem
Individual: One specific organism.
Population: Individuals of the same species living in the same area.
Community: All biotic (living) organisms in an area.
Ecosystem: All biotic and abiotic factors (plants, animals, soil, bodies of water, etc.).
Types of Species Interactions
Mutualism: Relationship where both species benefit.
Commensalism: One species benefits; the other is unharmed.
Parasitism: One species benefits; the other is harmed.
Competition: Two species compete for the same resources.
Resource partitioning: Species change behavior to access resources.
Terrestrial Biomes
Tropical Forest: Hot, wet, acidic soil, found along the equator.
Savanna: Hot grassland with dry/seasonal rains (think "Lion King").
Desert: Hot, dry, lower biodiversity, typically around 30° N/S.
Chaparral: Warm and drier; fire-resistant species can regenerate.
Temperate Forest: Seasonal temperatures, higher precipitation.
Boreal Forest/Taiga: Cold temperatures, higher precipitation, lots of evergreen trees.
Tundra: Very cold, dry, with minimal vegetation.
Temperate Grassland: Seasonal temperatures and lower rains (think Great Plains in the US).
Page 2: Aquatic Biomes
Aquatic Biomes Overview
Estuary: Where freshwater meets ocean; organisms must tolerate salinity.
Deep Ocean: Limited sunlight beyond continental shelves.
Coral Reefs: Shallow, tropical waters with high biodiversity; threatened by ocean warming.
Salt Marshes: Temperate intertidal zones, covered in grasses.
Mangroves: Tropical areas; roots provide shelter and protect coastlines.
Nutrient Cycles
Carbon Cycle:
Emissions from burning fossil fuels; ocean is largest carbon sink.
Photosynthesis and respiration cycle carbon.
Nitrogen Cycle:
N-fixation by bacteria makes nitrogen available for plants.
Excess nitrogen from fertilizers causes eutrophication, leading to hypoxia.
Page 3: Phosphorus Cycle and Primary Production
Phosphorus Cycle:
Phosphorus is locked in rock and sediment; runoff causes eutrophication in freshwater.
Primary Production Definitions
Gross Primary Productivity (GPP): Total photosynthetic production.
Net Primary Productivity (NPP): Organic material remaining after plant respiration (GPP - respiration).
Page 4: Trophic Levels
Consumers: Organisms that consume other organisms (heterotrophs).
Primary Consumers: Eat producers (e.g., deer, grasshoppers).
Secondary Consumers: Eat primary consumers (e.g., robin, badger).
Tertiary Consumers: Eat secondary consumers (e.g., shark, falcon).
Energy Flow in Ecosystems
Energy decreases as it moves up trophic levels (loss of 90% energy).
Keystone Species: Critical for ecosystem stability (e.g., beavers).
Trophic Cascade: Changes triggered by the alteration of keystone species.
Unit 2: Biodiversity Overview
Biodiversity: Variety of life at all biological levels (species, genes, communities).
Measured by species richness and species evenness.
Page 5: Genetic and Ecosystem Diversity
Genetic Diversity: Total genetic variety within a species.
Population Bottleneck: Sharp reduction in population size, leading to decreased genetic diversity.
Global Hotspot: Regions rich in biodiversity but threatened.
Specialists vs. Generalists: Specialists need specific resources; generalists can thrive in various environments.
Ecosystem Services
Provisioning: Goods obtained from ecosystems.
Regulating: Maintenance of ecosystem quality.
Supporting: Providing habitats and maintaining biodiversity.
Cultural: Non-material benefits from ecosystems.
Page 6: Island Biogeography and Disturbances
Island Biogeography Theory: Balance of immigration and extinction rates affects species number.
Natural Disturbances: Changes in conditions impacting ecosystems; resistance and resilience define stability and recovery.
Forest Fires
Natural in some ecosystems, returning nutrients and triggering regeneration, but can devastate when not resilient.
Page 7: Natural Selection and Succession
Natural Selection Facts: Struggle for survival leads to reproductive success.
Ecological Succession: Gradual changes following a disturbance.
Pioneer Species: First to colonize disturbed areas.
Climax Community: Stable end stage of succession.
Page 8: Population Dynamics
Niche: Role of a species in its environment.
Fundamental Niche: Niche without competition.
Realized Niche: Actual niche in the presence of competition.
Population Factors
Carrying Capacity (K): Maximum population size supported by an ecosystem.
r-selected vs. K-selected species: r-selected species thrive in unstable environments; K-selected need stable conditions.
Page 9: Population Growth and Dynamics
Natality and Mortality: Birth and death rates.
Exponential Growth: Unlimited resources lead to rapid population increase (J-curve).
Logistic Growth: Resources become limited, growth levels off (S-curve).
Age Structure Diagrams
Graphs illustrating age distribution in populations; used to predict future changes.
Page 10: Demographic Transition
Stages of demographic transition from high birth/death rates to low rates:
Stage 1: High rates, stable population; often in rural communities.
Stage 2: High birth, declining death; rapid population increase.
Stage 3: Declining birth; stability in population growth.
Stage 4: Low birth and death rates; slight population decline.
Page 11: Earth Systems and Soil
Soil: Medium for plant growth; formed from weathering of rock.
Soil Horizons: Different layers with unique compositions.
Soil Erosion: Caused by deforestation, poor farming, and natural disasters.
Soil Key Points
Mature soil supports biodiversity; soil texture and structure affect agricultural practices.
Page 12: Plate Tectonics
Earth's Layers: Iron core, mantle, crust.
Plate Boundaries: Divergent, convergent (mountains, island arcs), and transform (earthquakes).
Page 13: Natural Disasters and Atmospheric Function
Tsunamis: Caused by seismic activities.
Atmosphere Functions: Provides oxygen, moderates climate, and recycles nutrients.
Page 14: Global Wind Patterns
Convective Circulation: Driven by temperature differences.
Climate and Rain Patterns: Affected by geography and ocean currents.
Page 15: Ocean Currents and Climate Regulation
Currents transport heat and regulate global climate.
El Nino: Alters global weather patterns; impacts fisheries.
Page 16: Land and Water Use
Tragedy of the Commons: Overuse of shared resources.
Green Revolution: Technological advancements to increase crop yields; also created unintended consequences.