Ultimate Guide: AP Environmental Science

Ecosystem

A community of living organisms interacting with the non-living components of their environment through various cycles.

Organism

A living thing capable of independent function.

Species

Organisms with similar genetic makeup, able to interbreed and produce fertile offspring.

Population

Organisms of the same species interacting in a specific area.

Community

A group of populations of different species.

Ecological Niche

Area occupied by an organism and its function in the ecosystem.

Symbiosis

Close, long-term interaction between different biological organisms.

Competition

Interaction where organisms vie for resources.

Mutualism

Interaction where both species benefit.

Parasitism

Interaction where one species benefits at the expense of another.

Predation

Interaction where predators hunt and kill prey.

Saprotrophism

Obtaining nutrients from dead organisms.

Law of Tolerance

Species abundance depends on tolerance to physical and chemical factors.

Limiting Factor

Abiotic factor restricting population growth.

Predator-Prey Relationship

Relationship based on feeding between two species.

Biomes

Major biotic communities characterized by plant life and climate.

Deserts

Areas with low rainfall and specific plant and animal adaptations.

Succulents

Plants storing water in fleshy leaves or stems.

Forests

Biomes covering a significant portion of Earth's land surface.

Grasslands

Lands dominated by grasses rather than trees or shrubs.

Tundra

Cold biome with low temperatures, limited nutrients, and simple vegetation.

Alpine Tundra

Located on mountains at high altitudes where trees cannot grow, characterized by a short growing season and well-drained soil.

Aquatic Biomes

Include Antarctic, marine, lakes, wetlands, rivers, and streams, where organisms get nutrients from water and water's thermal capacity affects temperature regulation.

Corals

Marine invertebrates living in colonies of polyps, obtaining energy from photosynthetic dinoflagellates, with types like fringing reefs, barrier reefs, and atolls.

Lake Zones

Benthic, limnetic, littoral, and profundal zones, each with distinct characteristics and supporting different organisms.

Wetlands

Areas periodically covered with water supporting diverse plant and animal life, providing ecological services like flood control, carbon sequestration, and habitat for wildlife.

Hydric Soil

Soil that is permanently or seasonally saturated by water, leading to anaerobic conditions.

River Zones

Different sections of rivers with distinct characteristics like the source zone, transition zone, and floodplain zone.

Riparian Areas

Lands adjacent to water bodies supporting water-loving vegetation.

Carbon Cycle

The movement of carbon among the biosphere, geosphere, hydrosphere, and atmosphere.

Nitrogen Cycle

The process by which nitrogen is converted and circulated in the environment.

Phosphorous Cycle

The movement of phosphorus through the environment and its impact on ecosystems.

Hydrologic Cycle

The continuous movement of water on, above, and below the surface of the Earth.

Aquifers

Underground geological formations holding water that can be extracted for human use.

Primary Productivity

The process by which plants use sunlight to produce food through photosynthesis.

Trophic Levels

The position of an organism in a food chain and the concept of ecological pyramids.

Cellular Respiration

The process where cells oxidize glucose to produce carbon dioxide, water, and ATP.

Adenosine Triphosphate (ATP)

Molecule where energy from cellular respiration is stored.

10% Rule

Only about 10% of energy is transferred between trophic levels due to energy loss as heat.

Primary Productivity

Rate of biomass generation in an ecosystem, with autotrophs having primary productivity.

Secondary Productivity

Biomass generation by heterotrophic consumers through assimilated food.

Biomass Pyramid

Illustrates the organic mass at each trophic level in an ecosystem.

Energy Pyramid

Shows energy transfer between trophic levels in an ecosystem.

Gross Primary Production (GPP)

Rate at which plants convert chemical energy into biomass.

Net Primary Production (NPP)

Rate at which plants produce useful chemical energy after using some for respiration.

Population Bottleneck

Large reduction in population size leading to decreased genetic diversity.

Specialist Species

Organisms with specific habitat and diet requirements.

Species Richness

Number of different species in an ecological community.

Island Biogeography

Study of factors influencing species richness on isolated habitats.

Law of Tolerance

Species abundance depends on tolerance to environmental factors.

Ecological Succession

Gradual process of ecosystem development due to changes in community composition.

Inhibition

When one species modifies the environment to an extent that is not suitable for another species.

Tolerance

When species are not affected by the presence of other species.

Pioneer Species

Earlier successional plants, generalists.

Characteristics of Succession within Plant Communities

Describes the changes in biomass, nutrient cycling, impact of macro-environment, life span of seed, life strategy, location of nutrients, NPP, plant structure complexity, recovery rate of plants, seed dispersal, species diversity, and stability of ecosystem during succession.

Primary Succession

The evolution of a biological community’s ecological structure in barren habitats.

Secondary Succession

The recolonization of a habitat after a major disturbance.

Keystone Species

Species crucial for ecosystem diversity and whose extinction would lead to the extinction of other forms of life.

Indicator Species

Organisms reflecting specific environmental conditions and indicating ecosystem health.

Generalists

Species adaptable to a wide range of environments.

Specialists

Species with specific resource needs and low adaptability.

r-Strategists

Species with high reproductive rates and short life spans.

K-Strategists

Species with low reproductive rates and long life spans.

Survivorship Curve

Graphical representation of age-distribution characteristics of species.

Carrying Capacity

Maximum sustainable population size in a given area.

Population Dispersal Patterns

Clumped, random, or uniform distribution of individuals in a habitat.

Biotic Potential

Maximum reproductive capacity of an organism under optimal conditions.

J-Curve

Rapid population growth followed by a sudden stop due to environmental resistance.

S-Curve

Population growth stabilizes due to limited resources.

Feedback Loops

Positive and negative mechanisms influencing ecosystem stability.

Limiting Factors

Resources or conditions restricting population growth.

Rule of 70

Formula to estimate doubling time of a population.

Important Population Formulas

Equations for birth rate, death rate, and doubling time calculations.

Emigration

The number leaving a population.

Global Population Growth Rate (%)

Calculated as [(CBR – CDR)]/10.

Immigration

The number entering a population.

National Population Growth Rate (%)

Calculated as [(CBR + immigration) – (CDR + emigration)]/10.

Percent Rate of Change

Calculated as [(new # - old #)/old #] × 100.

Population Density

Calculated as total population size/total area.

Population Growth Rate (%)

Represents the change in population over time.

Biodiversity

Essential for agriculture and medicine, but two-thirds of species are declining due to human activity.

Coastlines and Oceans

Stressed by high population densities, leading to overexploitation of fisheries and habitat destruction.

Forests

Significant loss impacting ecosystems and economy, with demand potentially exceeding sustainable consumption.

Food Supply and Malnutrition

25% of the world malnourished, with population growth outpacing food supply in many regions.

Freshwater

Finite supply facing increasing demand due to population growth.

Global Climate Change

Caused by greenhouse gas emissions, leading to various environmental disruptions.

Public Health

Significant impacts on health due to dirty water, poor sanitation, air pollution, and other contaminants.

Age-Structure Diagrams

Represent population demographics based on birth rate, death rate, generation time, and sex ratios.

Total Fertility Rate (TFR)

Average number of children each woman will have during her lifetime.

Human Population Dynamics

Factors influencing population growth and historical surges in growth.

Demographic Transition

Transition from high to lower birth and death rates as regions develop economically.

Plate Tectonic Theory

Earth's lithosphere divided into plates that move independently, leading to seismic activity at plate boundaries.

Soil Formation and Erosion

Processes involving the development of soil profiles and movement of soil components due to various factors.

Soil Erosion

Poor agricultural techniques like improper plowing, monoculture, overgrazing, and removing crop wastes instead of plowing organic material back into the soil lead to soil erosion.

Landslides

Masses of rock, earth, or debris moving down a slope, often triggered by heavy rains, droughts, earthquakes, or volcanic eruptions.

Mudslides

Fast-moving landslides flowing in channels, often starting on steep slopes and triggered by natural disasters or vegetation destruction.

Igneous Rocks

Formed by cooling, classified by silica content, with intrusive igneous rocks solidifying deep underground and extrusive igneous rocks solidifying on or near the surface.

Metamorphic Rocks

Formed by intense heat and pressure, high quartz content, examples include diamond, marble, asbestos, slate, and anthracite coal.

Sedimentary Rocks

Formed by piling and cementing various materials over time in low-lying areas, where fossils form.

Soil Components

Gravel, sand, loam, silt, clay, and humus, each with distinct properties affecting soil quality and plant growth.