Environmental Science Unit 1 Study Guide

Ecology

Study of interactions between organisms and their environment.

Rule of 70

Used to estimate doubling time.

ppb vs. ppm

Parts per billion (ppb) and parts per million (ppm) measure chemical concentration; 1 ppm = 1,000 ppb.

Per capita

Per person; often used in measurements like GDP per capita.

Economically depleted

Resources are not worth extracting due to high cost or low abundance.

Renewable vs. nonrenewable resources

Renewable resources can replenish naturally (e.g., solar energy, wind); non-renewable resources cannot (e.g., coal, oil).

Reuse vs. recycle

Reuse is using an item multiple times; recycling is reprocessing an item into new products.

Tragedy of the commons

Overuse of shared resources leads to depletion (e.g., overfishing).

Sustainable yield

The rate at which a resource can be used without depleting it.

Ecological footprint

A measure of human impact on the environment; reduce by lowering consumption and waste.

Pollution

Contaminants in the environment that harm health and ecosystems.

Point vs. nonpoint sources of pollution

Point source has a specific origin (e.g., factory waste); nonpoint source is diffuse (e.g., runoff).

Persistence

How long a pollutant remains in the environment.

Positive vs. negative feedback loops

Positive amplifies changes (e.g., melting ice); negative stabilizes (e.g., predator-prey dynamics).

Synergistic effect

When combined substances have a greater impact together than separately.

Acidity measurement

Measured by pH scale; lower pH means more acidic.

High vs. low quality energy

High-quality energy (electricity) can do more work; low-quality energy (heat) is less usable.

Fuel in nuclear reactors

Uranium-235 or Plutonium-239.

Fission vs. fusion

Fission splits atoms; fusion combines them.

First and second law of thermodynamics

Energy cannot be created/destroyed; energy disperses and increases entropy.

Law of conservation of matter

Matter cannot be created or destroyed, only changed in form.

Biome vs. ecosystem vs. community vs. population

Biome is a large region with distinct climate; ecosystem includes all living and nonliving components; community is interacting organisms; population is one species in an area.

Greenhouse gases

CO₂, CH₄, N₂O, H₂O vapor, O₃.

Greenhouse effect

Greenhouse gases trap heat, warming the Earth.

Biotic vs. abiotic factors

Biotic are living (plants); abiotic are non-living (temperature).

Zone of tolerance

Range of conditions a species can tolerate.

Producer vs. consumer

Producers (plants) make food via photosynthesis; consumers eat other organisms.

Biodegradable

Capable of being broken down by microorganisms.

Primary, secondary, tertiary consumers

Primary consume producers; secondary eat primary consumers; tertiary eat secondary consumers.

Primary productivity

Rate at which producers create biomass.

GPP vs. NPP

GPP is total photosynthesis; NPP is GPP minus respiration.

10% rule

Only 10% of energy is transferred to the next trophic level.

Most vs. least productive ecosystems

Most productive: tropical rainforests; least productive: deserts.

No till vs. crop rotation

No-till minimizes soil disruption; crop rotation alternates crops to maintain soil fertility.

Terracing vs. contour farming

Terracing creates steps on slopes; contour farming plows along slopes.

Eutrophication sequence

Nutrient runoff → algal bloom → oxygen depletion → dead zones.

Anthropogenic

Human-caused effects on the environment.

El Niño vs. La Niña

El Niño warms the Pacific Ocean, altering weather; La Niña cools it.

Coriolis effect

Deflection of moving air/water due to Earth’s rotation.

Soil horizons

Layers: O (organic), A (topsoil), B (subsoil), C (weathered parent material), R (bedrock).

N cycle

Nitrogen fixation, nitrification, assimilation, ammonification, denitrification.

P cycle

Movement of phosphorus through rocks, water, soil, and living organisms.

C cycle

Carbon moves through respiration, photosynthesis, decomposition, combustion.

Water cycle

Evaporation, condensation, precipitation, infiltration.

S cycle

Movement of sulfur through rocks, water, soil, air, and organisms.

Gas composition of Earth’s atmosphere

Mostly nitrogen (78%), oxygen (21%), argon, CO₂.

Legumes

Plants with root nodules housing nitrogen-fixing bacteria.

Mutations

Random changes in DNA due to errors or environmental factors.

Adaptation

Trait that increases survival or reproduction.

Coevolution

Species evolve in response to each other (e.g., predator-prey).

Gradualism vs. punctuated equilibrium

Gradualism is slow evolution; punctuated equilibrium is rapid bursts.

Weather vs. climate

Weather is short-term; climate is long-term average.

Rain shadow effect

Dry area on leeward side of mountain due to blocked rain.

Food web

Shows energy flow between organisms in an ecosystem.

Biomes

Identifiable by location or characteristics like climate and vegetation.

Deciduous plants

Examples include Oak, Maple, Birch.

Evergreen plants

Examples include Pine, Spruce, Fir.

Desert plants

Drought-resistant, often with thick stems and spines.

Resource partitioning

Species divide resources to reduce competition (e.g., birds at different tree heights).

Producers of the tundra

Lichens, mosses, low shrubs.

Climate and vegetation by altitude

Higher altitude/elevation has colder temperatures and different vegetation.

Exponential curve

J-shaped; rapid growth rate.

Tropical rainforest destruction

Caused by logging, agriculture, urbanization.

Carrying capacity

Maximum population size an environment can support.

Ecological services provided by forests

Carbon storage, habitat, water regulation.

Types of ecological services

Provisioning (food), regulating (climate), supporting (photosynthesis), cultural (recreation).

Sand, silt, clay

Differ in particle size; sand is largest, clay is smallest.

Sandy vs. clay soils

Sandy drains quickly; clay retains water well.

Seasons and Earth's tilt

Tilt affects sunlight, causing seasons.

Generalist vs. Specialist

Generalists have a broad niche; specialists have a narrow niche.