Ultimate Guide: AP Environmental Science (copy)

Interspecific

occurring between different species.

Community

Population of different species.

Ecological Niche

A particular area within a habitat occupied by an organism, as well as the function of that organism within its ecological community.

Physical Environment

non-living aspects of our surroundings that affect living organisms and ecosystems

Symbiosis

any type of close and long-term biological interaction between two different biological organisms of the same or different species

Amensalism

The interaction between two species whereby one species suffers and the other species is not affected.

Commensalism

The interaction between two species whereby one organism benefits and the other species is not affected.

Competition

Interaction between organisms when they share limited resources in an ecosystem

Intraspecific

Competition between members of the same species.

Mutualism

The interaction between two species whereby both species benefit.

Parasitism

The interaction between two species whereby one species is benefited, and the other species is harmed.

Specialist predators

organisms that are highly adept at hunting and consuming a specific prey species, or even just a specific life stage of that species.

Law of Tolerance

the existence, abundance, and distribution of species depend on the tolerance level of each species to both physical and chemical factors.

Limiting Factor

Any abiotic factor that limits or prevents the growth of a population.

Spatial Partitioning

When competing species use the same resource by occupying different areas or habitats within the range of occurrence of the resource

Temporal Partitioning

When two species eliminate direct competition by utilizing the same resource at different times

Deserts

A region characterized by extremely low precipitation

Arctic tundra

characterized by extremely cold temperatures, short growing seasons, permafrost, and treeless plains

Aestivation

summer hibernation

Forests

Covers about one-third of Earth's land surface and accounts for 75% of gross primary productivity and plant biomass.

Tropical Rainforests

Lush, evergreen forests found in warm, humid regions near the equator, characterized by tall trees, abundant rainfall, and incredible biodiversity.

Temperate Deciduous Forests

Vibrant ecosystems found in mid-latitude regions around the world, and characterized by distinct seasonal changes, with green foliage in spring and summer and display of colors and leaf loss in autumn.

Taiga

Largest terrestrial biome; found in northern Eurasia, North America, Scandinavia, and two-thirds of Siberia.

Savannas

Grasslands with scattered individual trees and cover almost half the surface of Africa and large areas of Australia, South America, and India.

Temperate Grasslands

Environment where grasses are the dominant vegetation, while trees and large shrubs are absent.

Tundra

Environment that has extremely low temperatures, low biotic diversity, and simple vegetation structure.

Permafrost

Layer of permanently frozen subsoil.

Krill

Key food source in arctic ecosystems and serves as food for many predators.

Photic Zone

The layer just above the depth where the rate of carbon dioxide uptake by plants is equal to the rate of carbon dioxide production by animals.

Barrier reefs

Reefs that grow parallel to the coastline and are separated by deeper, wider lagoons. At their shallowest point, they can reach the water’s surface, forming a “barrier” to navigation.

Littoral Zone

Ecological zone found in coastal environments where land and water meet

Profundal Zone

Deepest layer of freshwater ecosystems that lies below the photic zone (where sunlight penetrates) and is characterized by cold temperatures, darkness, and low oxygen levels.

Stratification

Formation of distinct layers within a body of water with varying densities due to differences in temperature and salinity

Wetlands

Areas that are covered with water at some point in the year and that support aquatic plants.

Carbon

fundamental element exchanged among the biosphere, geosphere, hydrosphere, and atmosphere and is the basic building block of life and found in carbohydrates, fats, proteins, and nucleic acids.

Ocean Acidification

The ongoing decrease in the pH of the Earth's oceans, disrupting the creation of coral reefs and the viability of externally fertilized egg cells; Occurs when atmospheric carbon dioxide reacts with seawater to form carbonic acid,

Nitrogen

Element that takes up 78% of the atmosphere. Needed for photosynthesis

Nitrogen Cycle

A biogeochemical process through which nitrogen is converted into many forms, consecutively passing from the atmosphere to the soil to organism and back into the atmosphere

Nitrogen Fixation

When atmospheric nitrogen is converted into ammonia (NH3) or nitrate ions (NO3–), which are biologically usable forms of nitrogen.

Natural Cycling of Nitrogen

Atmospheric nitrogen is converted to nitrogen oxides by lightning and deposited in the soil by rain, where it is assimilated by plants and either eaten by animals or decomposed back to elemental nitrogen by bacteria

Nitrification

When ammonia (NH3) is converted to nitrite (NO2–) and nitrate (NO3–), which are the most useful forms of nitrogen to plants.

Assimilation

When plants absorb ammonia (NH3), ammonium ions (NH4+), and nitrate ions (NO3–) through their roots.

Ammonification

When decomposing bacteria convert dead organisms and wastes, which include nitrates, uric acid, proteins, and nucleic acids, to ammonia (NH3) and ammonium ions (NH4+)—biologically useful forms.

Denitrification

When anaerobic bacteria convert ammonia into nitrites (NO2–), nitrates (NO3–), nitrogen gas (N2), and nitrous oxide (N2O) to continue the cycle.

Nitrous oxide (N2O)

A greenhouse gas breaks down and destroys atmospheric ozone in the stratosphere.

Phosphorus

Element essential for the production of nucleotides, ATP, fats in cell membranes, bones, teeth, and shells.

Water cycle

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

Condensation

The conversion of a vapor or gas to a liquid

Evaporation

The process of turning from a liquid into vapor

Evapotranspiration

The process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plants

Infiltration

The process by which water on the ground surface enters the soil

Runoff

Part of the water cycle that flows over land as surface water instead of being absorbed into groundwater or evaporating

Capillary Action

A result of hydrogen bonding, helps tree roots take up water, allowing trees to grow as large as they do.

Photosynthesis

When plants remove carbon dioxide from the atmosphere and use light energy to produce carbohydrates and other organic compounds

Trophic Level

The position an organism occupies in a food chain; the number of steps it takes from the chain's start.

Food web

The natural interconnection of food chains.

Second Law of Thermodynamics

States that as energy is transferred or transformed, more and more of it is wasted.

Heterotrophs

Organisms dependent on photosynthetic organisms.

Cellular Respiration

the process by which organisms break down glucose and other organic molecules to release energy

10% Rule

States that energy is lost mostly as heat from one stage to the next.

Productivity

The rate of generation of biomass in an ecosystem (mass per unit surface area (or volume) per unit time)

Biomass pyramid

Shows how much organic mass is within each trophic level.

Gross primary production (GPP)

The rate at which plants capture and fix a given amount of chemical energy as biomass in a given length of time.

Net primary production (NPP)

The remaining fixed energy is the rate at which all the plants in an ecosystem produce net useful chemical energy.

Genetic Diversity

The range of all genetic traits, both expressed and recessive, that make up the gene pool for a particular species

Species Diversity

Number of different species that inhabit a specific area

Population Bottleneck

Large reduction in the size of a single population due to a catastrophic environmental event

Generalist Species

Species that live in different types of environments and have varied diets

Specialist Species

Species that require unique resources and often have a very limited diet

Species Richness

The number of different species (diversity) represented in an ecological community or region

Theory of Island Biogeography

Proposes that the number of species found on an "island" is determined by immigration and extinction of isolated populations

Pioneer Species

Earlier successional plants, generalists

r-Strategists

Mature rapidly; short-lived species; number of organisms within a species is high; low biodiversity; niche generalists

K-Strategists

Mature slowly; long-lived; number of organisms within a species is lower; greater biodiversity; niche specialists

Ecological succession

The process of change in the species structure of an ecological community over time, which can be millions of years in the case of primary succession or decades in the case of secondary succession

Primary succession

The evolution of a biological communitys ecological structure in which plants and animals first colonize a barren, lifeless habitat

Secondary succession

A type of ecological succession in which plants and animals recolonize a habitat after a major disturbance

Keystone species

A species whose presence contributes to a diversity of life and whose extinction would lead to the extinction of other forms of life

Indicator Species

Organisms whose presence, absence, or abundance reflects a specific environmental condition and can indicate the health of an ecosystem

early stages of succession

Stage in succession when gross productivity is low due to the initial environmental conditions and low numbers of producers.

Carrying capacity (K)

Refers to the number of individuals that can be supported sustainably in a given area

Population Dispersal Pattern

How individuals or species of animal become distributed in different spaces over certain periods

Biotic potential

The maximum reproductive capacity of an organism under optimum environmental conditions

Environmental Resistance

Any factor that inhibits an increase in the number of organisms in the population

J-Curve

A curve that represents population growth occurs in a new environment when the population density of an organism increases rapidly in an exponential or logarithmic form, but then stops abruptly as environmental resistance or another factor suddenly impacts the population growth

S-Curve

A curve that represents when, in a new environment, the population density of an organism initially increases slowly but then stabilizes due to the finite amount of resources available

Density-dependent limiting factors

Factors whose effects on the size or growth of the population vary with the density of the population

Density-independent factors

Factors that limit the size of a population, and their effects are not dependent on the number of individuals in the population

Doubling time

Amount of time it takes for a population to double in size [70/% growth rate]

Birth Rate (%)

[(total births/total population)] × 100

Crude Birth Rate (CBR)

[(b ÷ p) × 1,000]

Death Rate (%)

[(total deaths/total population)]× 100

Crude Death Rate (CDR)

[(d ÷ p) × 1,000]

Emigration

number leaving a population

Global Population Growth Rate (%)

[(CBR – CDR)]/10

Immigration

number entering a population

National Population Growth Rate (&)

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

Percent Rate of Change

[(new # - old #)/old #] × 100

Population Density

Total population size/total area

Population Growth Rate (%)

[(births + immigration) - (deaths + emigration)]/total population