rusty intro bowm

biosphere

describes any type of wide issue like pollution and global warming

Albedo

The reflectivity of a surface. Light surfaces (ice/snow) reflect more solar radiation than dark surfaces.

Ecosystem

All living (biotic) and nonliving (abiotic) components interacting in an area

Biotic components

Living parts of an ecosystem (plants, animals, fungi, bacteria).

Abiotic components

Nonliving environmental factors such as sunlight, water, soil, climate, and temperature.

Tundra

Cold, dry biome with permafrost, short growing seasons, mosses, lichens, and low shrubs.

Taiga (Northern Coniferous Forest)

Cold forest biome dominated by evergreen conifers; long winters, moderate precipitation.

Tropical Forest

Warm, wet biome near equator with extremely high biodiversity.

Rainforest vs Dry Forest

• Rainforest: heavy rainfall year-round

• Tropical dry forest: seasonal rainfall with wet/dry seasons

Rainforest Layers

• Emergent layer: tallest trees

• Canopy: dense upper layer with most biodiversity

• Shrub/understory layer: smaller plants/shrubs

• Forest floor: low light, decompositio

Temperate Broadleaf Forest

Moderate climate with deciduous trees that lose leaves seasonally

Savannah

Grassland with scattered trees; tropical wet/dry seasons.

Grassland

Biome dominated by grasses with low rainfall and few trees

Desert

Very dry biome with low precipitation and specialized organisms.

Chaparral

Shrub-dominated biome with hot dry summers and periodic fires.

Logistic Growth

Population growth that slows and stabilizes at carrying capacity (K). S-shaped curve.

Exponential Growth

Rapid population increase under unlimited resources. J-shaped curve.

Survivorship Curve

Graph showing survival rates across lifespan.

Iteroparity

Repeated reproduction throughout life

Semelparity

One-time reproduction before death

Resource Partitioning

Species divide resources to reduce competition.

Character Displacement

Evolutionary divergence of traits due to competition

Invasive Species

Non-native species that spread aggressively and outcompete natives.

Niche

Role of a species and how it uses resources in habitat

Competitive Exclusion

When two species compete for the exact same niche/resources, one species eventually outcompetes the other.

Keystone Species

Species with disproportionately large effects on ecosystem structure.

Venomous

Injects toxins through bites/stings.

Poisonous

Toxic when eaten or touched.

Batesian Mimicry

Harmless species mimics harmful species.

Müllerian Mimicry

Two harmful/unpalatable species resemble each other.

Aposematic Coloration

Bright warning coloration signaling toxicity/danger.

Cryptic Camouflage

Coloration/patterns that help organisms blend into environment.

Chromatophore

Pigment-containing cell that changes color in animals like octopus/chameleons.

Predation

One organism kills/eats another.

Competition

Two species use the same limited resource.

Facilitation

One species benefits another without close symbiosis.

Parasitism

One benefits, host harmed. (+/-)

Mutualism

Both species benefit. (+/+)

Commensalism

One benefits, other unaffected. (+/0)

Amensalism

One harmed, other unaffected. (0/-)

Omnivore

Consumes both plants and animals.

Detritivore

Consumes dead organic matter and decomposing material.

Species Richness

Number of species in a community.

Relative Abundance

Proportion of individuals represented by each species.

Species Evenness

How equally individuals are distributed among species.

Carrying Capacity

Maximum population environment can sustain (K).

Ecosystem Engineer

Species that physically modify environment (example: beaver).

Foundation Species

Species that create/define habitat structure.

Greenhouse Effect

Atmosphere traps heat radiated from Earth.

Greenhouse Gases

Heat-trapping gases: CO₂, CH₄, H₂O vapor, CFCs, ozone, NOx.

Primary Production

Energy/carbon fixed by producers.

Net Production (NPP)

Energy available after producer respiration.

Primary Consumer

Herbivore that eats producers.

Bioaccumulation

Build-up of substances within organism tissues

Biomagnification

Increase in toxin concentration up food chain.

Overexploitation

Excessive harvesting/use of organisms causing decline.

Trophic Levels

• Primary Producers (Autotrophs)

  • Plants, algae, phytoplankton

  • Convert sunlight into chemical energy through photosynthesis

• Primary Consumers

  • Herbivores

  • Eat producers

  • Examples: rabbits, zooplankton, deer

• Secondary Consumers

  • Carnivores that eat herbivores

  • Examples: snakes, frogs, small fish

• Tertiary Consumers / Apex Predators

  • Top predators

  • Eat secondary consumers

  • Examples: wolves, sharks, hawks

• Detritivores/Decomposers

  • Break down dead matter

  • Recycle nutrients

  • Examples: fungi, bacteria, earthworms

Energy Transfer Between Trophic Levels

10% of energy transfers to next trophic level.

The remaining ~90% is lost because:

• organisms use energy for metabolism

• movement

• respiration

• heat production

• waste

This is due to the 2nd Law of Thermodynamics.

Why Apex Predators Are Rare

Very little energy remains at top trophic levels, so ecosystems can support only small numbers of apex predators.

Example:

• Few wolves compared to deer

• Few sharks compared to fish

Trophic Cascade

A trophic cascade occurs when changes at the top predator level affect all lower trophic levels.

Wolf Example (Yellowstone) of trophic cascade

Before wolves:

• Elk population exploded

• Elk overgrazed vegetation

• Riverbanks eroded

• Biodiversity declined

After wolves reintroduced:

• Elk numbers dropped

• Elk avoided certain areas

• Trees/shrubs recovered

• Beavers returned

• River ecosystems improved

Predators indirectly controlled vegetation and ecosystem structure.

(Sea otter/urchin/kelp forests are another example from class.)

Levels of Ecology

Hierarchy from smallest to largest:

1. Organism

2. Population

3. Community

4. Ecosystem

5. Landscape

6. Biosphere

Gaia Hypothesis

The Gaia Hypothesis states Earth behaves like a self-regulating system where living organisms help stabilize conditions for life.

Evidence

1. Oxygen Regulation

Plants and algae maintain atmospheric oxygen through photosynthesis.

2. Carbon Regulation

Organisms absorb and store carbon.

3. CLAW Hypothesis

Marine plankton release sulfur compounds that help form clouds, affecting climate.

4. Daisyworld Model

Black and white daisies regulate planetary temperature by changing albedo.

Weather

Short-term atmospheric conditions.

Examples:

• rain today

• storm this week

• temperature tomorrow

Climate

Long-term average weather patterns.

Examples:

• deserts are dry

• tropics are warm/wet

Two Main Climate Factors that determine biome type

• Temperature

• Precipitation

Coastal vs Inland Climate

Water heats and cools slowly.

Coastal Areas

• milder temperatures

• cooler summers

• warmer winters

• more humidity

Inland Areas

• larger temperature swings

• hotter summers

• colder winters

Example:
San Francisco is cooler than inland California.

Why does the equator have more heat than the poles?

Sunlight strikes equator directly but hits poles at low angles.

At poles:

• energy spreads over larger area

• more reflected by ice/snow

Why do we have seasons?

Caused by Earth’s 23.5° axial tilt.

NOT caused by Earth being closer to the Sun.

Summer

Hemisphere tilted toward Sun:

• more direct sunlight

• longer days

Winter

Hemisphere tilted away:

• less direct sunlight

• shorter days

What are the characteristics of high and low pressure mentioned in class?

High Pressure

• cool dense air sinks

• dry conditions

• clear skies

Associated with deserts near 30° latitude.

Low Pressure

• warm moist air rises

• clouds/rain form

Associated with equator and rainforests.

What is a convection cell?

Warm air rises, cool air sinks, creating circular air movement.

This drives:

• global wind patterns

• rainfall distribution

• atmospheric cells

What are the three atmospheric cells and how do they flow?

1. Hadley Cell (0°–30°)

• Warm air rises at equator

• Rainforests form

• Dry air sinks at 30°

• Creates deserts

2. Ferrel Cell (30°–60°)

• Moderate climates

• Many temperate forests

3. Polar Cell (60°–90°)

• Cold dry air

• Tundra/polar deserts

What is the ITCZ and how does this relate to dry and wet seasons of jungles/tropical rainforests?

Intertropical Convergence Zone:

• low-pressure zone near equator

• intense heating

• rising moist air

• heavy rainfall

As Earth tilts seasonally, ITCZ shifts north/south causing tropical wet and dry seasons.

How are biomes affected by latitude and atmospheric cells?

Latitude & Biomes:

0° Equator

• Warm + wet

• Tropical rainforests

30°

• Dry descending air

• Deserts

60°

• Rising moist air

• Temperate forests/taiga

90°

• Cold dry air

• Tundra/polar deserts

How can trees increase rainfall independent of latitude?

Trees release water vapor through transpiration.

Large forests:

• increase humidity

• form clouds

• promote rainfall

Rainforests partially create their own rain cycles.

What is a biome and how is it related to climate?

Biomes are large ecological regions determined mainly by:

• climate

• temperature

• precipitation

What are all the major biomes and be able to understand how they are classified due to relative amounts of precipitation and temperature?

Tropical Rainforest

• hot/wet

• highest biodiversity

• layered structure

Savanna

• grass with scattered trees

• wet/dry seasons

Desert

• low precipitation

• extreme temperatures

Chaparral

• Mediterranean climate

• fire-adapted shrubs

Temperate Grassland

• grasses dominate

• fertile soil

Temperate Broadleaf Forest

• deciduous trees

• moderate rainfall

Taiga

• coniferous forest

• cold winters

Tundra

• permafrost

• short growing season

What are the major zones of the rainforest? 

Emergent Layer

Tallest trees above canopy.

Canopy

Most biodiversity; receives most sunlight.

Understory/Shrub Layer

Shade-tolerant plants.

Forest Floor

Low light; decomposition dominant.

What three factors determine biomes and microclimates within California?

Three major factors:

1. Latitude

2. Elevation

3. Ocean influence

Mountains also create rain shadows.

What are adaptations of desert organisms?

Plants

• waxy cuticle

• CAM photosynthesis

• spines instead of leaves

• water storage

Animals

• nocturnal behavior

• burrowing

• concentrated urine

• large ears for heat release

Globally and statistically, where are the highest amounts of diversity?

Near equator/tropical rainforests because:

• stable climate

• high productivity

• abundant sunlight/water

Species richness decreases toward poles.

How can we measure population densities? Know how to do the math for the mark/recapture method

Mark-Recapture Formula

N=MCRN=RMC​

Where:

• M = marked initially

• C = second capture total

• R = recaptured marked individuals

What would cause uniform vs. clumped vs random distributions of organisms?

Uniform=Even spacing due to competition/territoriality.

Example:Penguin nesting colonies

Random=No strong interactions.

Example:Some wildflowers

Clumped=Most common.
Resources patchy or social behavior.

Example:
Schools of fish

What are the three types of survivorship curves? 

Type I

Low early death; high old-age death.

Examples:
Humans, elephants

Type II

Constant death rate.

Examples:
Birds

Type III

High juvenile death.

Examples:
Fish, insects, oysters

What are the characteristics of r vs K strategists?

r-selected Species:

• many offspring

• little parental care

• unstable environments

• fast reproduction

Examples:
flies, weeds

K-selected Species:

• few offspring

• high parental care

• stable environments

• populations near carrying capacity

Examples:
humans, elephants

Carrying Capacity

Maximum population environment can sustain indefinitely. (k)

K-selected species level off near carrying capacity.

density dependent population factors

Effects increase as population density rises.

Examples:

• disease

• competition

• predation

• waste buildup

Density-Independent Factors

Affect populations regardless of density.

Examples:

• floods

• fires

• droughts

• volcanoes

Fundamental vs realized niche. Which one accounts for competition?

Fundamental Niche

Potential conditions species COULD occupy.

Realized Niche

Actual conditions occupied after competition/predation.

Competition reduces realized niche.

What are the four types of symbioses and examples of each that we went over in class?

Mutualism (+/+) - Both benefit.

Example:
Bees pollinating flowers

Parasitism (+/-) - Parasite benefits, host harmed.

Example:
Ticks on dogs

Commensalism (+/0) - One benefits, other unaffected.

Example:
Barnacles on whales

Amensalism (0/-) - One harmed, other unaffected.

Example:
Penicillin killing bacteria

Lotka-Volterra dynamics (predator-prey curves) what causes it?

Prey increases first → predators increase later → prey declines → predators decline.

Cycles repeat.

Example:
lynx and snowshoe hare data from class

Why are predators ecologically important? diversity, disease, genetics.

• maintain biodiversity

• prevent overgrazing

• remove weak/sick individuals

• strengthen genetics through natural selection

What is succession and how does it work?

Gradual ecosystem change over time.

primary succession

Starts without soil.

Example:
lava flow or retreating glacier

Pioneer species:

• lichens

• mosses

secondary succession

Soil already present.

Example:
forest regrowth after fire

Much faster than primary succession.

What are ecosystem phase shifts?

Abrupt change from one stable ecosystem to another.

Example:
healthy coral reef → algae-dominated reef

Often difficult to reverse.

What two factors does the Shannon diversity index account for? (calculate for extra credit)

Measures:

1. species richness

2. species evenness

Higher SDI = greater biodiversity.

How does diversity make ecosystems more resilient?

Diverse ecosystems:

• resist invasive species

• recover faster after disturbance

• maintain ecosystem functions better

What are keystone species examples?

Sea Otters

• Eat sea urchins

• Protect kelp forests

• Without otters → urchins destroy kelp

Wolves

• Control elk populations

• Prevent overgrazing

• Increase biodiversity

Pisaster Sea Stars

• Eat mussels

• Prevent mussels from taking over tide pools

Beavers

• Build dams

• Create wetlands/habitats

• Alter water flow

Flying Foxes (Fruit Bats)

• Pollinate plants

• Disperse seeds

• Help forests regenerate

What does DDAM mean?

D = Disturbance

• Ecosystem disruption

• Examples: fires, floods, habitat destruction

D = Disease

• Pathogens harming populations

• Example: fungal diseases in amphibians

A = Alien Species (Invasive Species)

• Non-native species outcompeting natives

• Examples: lionfish, invasive algae

M = Modification

• Human alteration of ecosystems

• Examples: pollution, dams, deforestation