AP Environmental Science Review

First Law of Thermodynamics

Energy is neither created nor destroyed, but may be converted from one form to another.

El Niño (ENSO)

prevailing winds in the Pacific weaken and change direction every few years which results in above average warming of eastern Pacific waters, which changes distribution of plant nutrients and alters earth's weather for 2-3 years

Reason for seasons on Earth

Tilt of the axis ~23.5°

Second Law of Thermodynamics

When energy is changed from one form to another, some useful energy is always degraded into lower quality energy (usually heat).

Nuclear Fission

nuclei of isotopes split apart when struck by neutrons.

Leaching

removal of dissolved materials from soil by water moving downwards through soil.

Soil Conservation Methods

conservation tillage, crop rotation, contour plowing, organic fertilizers.

Soil Salinization

in arid regions, water evaporates leaving salts behind. (ex. Fertile crescent, southwestern US)

Hydrologic Cycle Components

evaporation, transpiration, runoff, condensation, precipitation, and infiltration.

Watershed

all of the land that drains into a body of water

Aquifer

any water-bearing layer in the ground.

Salt Water Intrusion

near the coast, overpumping of groundwater causes saltwater to move into the aquifer.

La Nina

"Normal" year, easterly trade winds and ocean currents pool warm water in the western Pacific, allowing upwelling of nutrient rich water off the West coast of South America.

Nitrogen Fixation

because atmospheric N cannot be used directly by plants, it must first be converted into ammonia by bacteria.

Ammonification

decomposers covert organic waste into ammonia.

Nitrification

ammonia is converted to nitrate ions (NO -).

Assimilation

inorganic N is converted into organic molecules such as DNA/amino acids & proteins.

Denitrification

bacteria convert ammonia back into N.

Phosphorus

does not exist as a gas; released by weathering of phosphate rocks, it is a major limiting factor for plant growth. Phosphorus cycle is slow, and not atmospheric.

Soil Profile

Photosynthesis

plants convert CO2 (atmospheric C) into complex carbohydrates (glucose C6H12O6).

Aerobic Respiration

oxygen consuming producers, consumers & decomposers break down complex organic compounds & convert C back into CO2.

Biotic

living components of an ecosystem.

Abiotic

nonliving components of an ecosystem

Producer/Autotroph

organisms that make their own food—photosynthetic life.

Trophic Levels

producers → primary consumer → secondary consumer → tertiary consumer.

Energy Flow through Food Webs

10% of the usable energy is transferred to the next trophic level. Reason: usable energy lost as heat (2nd law), not all biomass is digested & absorbed, predators expend energy to catch prey.

Primary succession

development of communities in a lifeless area not previously inhabited by life (ex. lava).

Secondary succession

life progresses where soil remains (ex. clear-cut forest, old farm).

Mutualism

symbiotic relationship where both organisms benefit (e.g. clownfish and anemone)

Commensalism

symbiotic relationship where one organism benefits & the other is unaffected (e.g. epiphytic plants, such as many orchids, that grow on trees)

Parasitism

relationship in which one organism (the parasite) obtains nutrients at the expense of the host (e.g. mosquitoes and humans)

Carrying Capacity

the number of individuals that can be sustained in an area.

r-strategist

reproductive strategy in which organisms reproduce early, bear many small, unprotected offspring (ex. insects, mice).

K-strategist

reproductive strategy in which organisms reproduce late, bear few, cared for offspring (ex. humans, elephants).

Natural Selection

organisms that possess favorable adaptations (through mutations) pass them onto the next generation.

Thomas Malthus

The human population grows faster than food production unless kept in check by war, famine & disease. Did not foresee advancements in agriculture.

Doubling Time

(rule of 70) doubling time equals 70 divided by average growth rate. (ex. a population growing at 5% annually doubles in 70 ÷ 5 = 14 years)

Replacement Level Fertility

the number of children a couple must bear to replace themselves (2.1 developed, 2.7 developing).

World Population

slightly over 7.6 billion.

Demographic Transition Model

preindustrial, transitional, industrial, and postindustrial stages

Preindustrial stage

birth & death rates high, population grows slowly, infant mortality high.

Transitional stage

Aid from other countries and increase in industrialization lowers death rates (infant mortality). Birth rates high (from of the amount of people in the reproductive stage).

Industrial stage

decline in birth rate, population growth slows.

Postindustrial stage

low birth & death rates.

Age Structure Diagrams

broad base → rapid growth; narrow base → negative growth (NPG); uniform shape → zero growth (ZPG)

Most populous nations

1)China 2)India 3)US 4)Indonesia

Low Economic/Social Status of Women

Most important factor keeping population growth rates high.

Methods to Decrease Birth Rates

Family planning, contraception, economic rewards & penalties.

Composition of Water on Earth

97.5% seawater, 2.5% freshwater. 0.023% readily available freshwater for use.

Aquaculture

farming aquatic species, commonly salmon, shrimp, tilapia, oysters.

Point Source

from specific location such as pipe or smokestack

Non-Point Source

from over an area such as agricultural (farm) runoff, traffic.

Eutrophication

rapid algal growth caused by an excess of nitrogen & phosphorus.

Keystone Species

species whose role in an ecosystem is important for the ecosystem's stability (manatee, alligator, sea otter, etc). Impact outweighs relative abundance

Indicator Species

species that serve as early warnings that an ecosystem is being damaged (amphibians).

Pesticide Cons

genetic resistance, pesticide treadmill, persistence, bioaccumulation, and biological magnification.

Genetically Modified Organisms (GMOs)

new organisms created by altering the genetic material (DNA) of existing organisms; usually in an attempt to remove undesirable or create desirable characteristics in the new organism.

Electricity Generation

steam, from water boiled by fossils fuels or nuclear energy, or falling water is used to turn a turbine and generate a generator.

Coal Formation

prehistoric plants buried undecomposed in oxygen-depleted water of swamps/bogs converted by heat and pressure.

Nuclear Reactor

consists of a core, control rods, moderator, steam generator, turbine, containment building.

Alternate Energy Sources

wind, solar, waves, biomass, geothermal, fuel cells

Troposphere

first layer of atmosphere 0-10 miles above the Earth's surface. Contains weather, greenhouse gases (bad ozone)

Stratosphere

second layer of atmosphere 10-30 miles above the Earth's surface. Contains protective ozone layer (good ozone)

Temperature Inversion

a warm layer of air above a cooler layer traps pollutants close to the Earth's surface.

Divergent plate boundaries

tectonic plates spreading apart, new crust being formed (Mid Ocean Ridge)

Convergent plate boundaries

tectonic plates with the oldest crustal material on Earth moving together, one moving under another. Mineral deposits and volcanoes are most abundant at convergent plate boundaries (Volcanic arc like Japan)

Transform Fault

tectonic plates sliding past one another (San Andreas Fault Line)

Most Endangered species

have a small range, require large territory, have long generations, have very specialized niche, or live on an island

Biome

large distinct terrestrial region having similar climate, soil, plants & animals.

Tropical Rain Forests

characterized by the greatest diversity of species, believed to include many undiscovered species. Occur near the equator. Soils tend to be low in nutrients. Distinct seasonality: winter is absent, and only two seasons are present (rainy and dry).

Temperate Forests

occur in eastern North America, Japan, northeastern Asia, and western and central Europe. Dominated by tall deciduous trees. Well-defined seasons include a distinct winter. Logged extensively, only scattered remnants of original temperate forests remain.

Boreal Forests or Taiga

represent the largest terrestrial biome. Dominated by needleleaf, coniferous trees. Found in the cold climates of Eurasia and North America: two-thirds in Siberia with the rest in Scandinavia, Alaska, and Canada. Seasons are divided into short, moist, and moderately warm summers and long, cold, and dry winters. Extensive logging may soon cause their disappearance.

Temperate Shrub Lands

occurs along the coast of Southern California and the Mediterranean region. Characterized by areas of Chaparral-miniature woodlands dominated by dense stands of shrubs.

Savannas

grassland with scattered individual trees. Cover almost half the surface of Africa and large areas of Australia, South America, and India. Warm or hot climates where the annual rainfall is 20-50 inches per year. The rainfall is concentrated in six or eight months of the year, followed by a long period of drought when fires can occur.

Temperate Grasslands

dominated by grasses, trees and large shrubs are absent. Temperatures vary more from summer to winter, and the amount of rainfall is less than in savannas. Temperate grasslands have hot summers and cold winters. Occur in South Africa, Hungary, Argentina, the steppes of the former Soviet Union, and the plains and prairies of central North America.

Deserts

covers about one fifth of the Earth's surface and occur where rainfall is less than 50 cm/year. Soils may have abundant nutrients, need only water to become productive, and have little or no organic matter. Common disturbances include occasional fires or cold weather, and sudden, infrequent, but intense rains that cause flooding.

Tundra

treeless plains that are the coldest of all the biomes. Occur in the arctic and Antarctica. Dominated by lichens, mosses, sedges, and dwarfed shrubs Characterized by extremely cold climate, permanently frozen ground (permafrost) low biotic diversity, simple vegetation structure, limitation of drainage, short season of growth and reproduction.

Wetlands

areas of standing water that support aquatic plants including marshes, swamps, and bogs. Reduce flooding. Species diversity is very high.

Fresh Water

defined as having a low salt concentration (less than 1%). Plants and animals are adjusted to the low salt content and would not be able to survive in areas of high salt concentration (i.e., ocean). There are different types of regions: ponds and lakes, streams and rivers, and estuaries.

Oceans

the largest of all the ecosystems. Regions are separated into separate zones: intertidal, pelagic, abyssal, and benthic.

Safe Drinking Water Act

set maximum contaminant levels for pollutants that may have adverse effects on human health.

Clean Water Act

Aim: to make all US waterways safe for fishing and swimming. set maximum permissible amounts of water pollutants that can be discharged into waterways. Require the repairment of damaged wetlands.

Clean Air Act

NAAQS for 6 criteria pollutants. Set emission standards for mobile and stationary sources, and limits release of air pollutants. Multiple amendments, most influential modern env. law

Montreal Protocol

global agreement to phase out of ozone depleting substances.

Endangered Species Act

identifies threatened and endangered species in the US, and puts their protection ahead of economic considerations.

Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)

regulates the use and effectiveness of pesticides

Herbicide

a toxic chemical that kills plants

Insecticide

a toxic chemical that kills insects

Rodenticide

a toxic chemical that kills rodents

Fungicide

a toxic chemical that kills fungi

Niche

organism's role in the ecosystem of which it lives

Invasive Species

introduced into an ecosystem and out-compete native species

NO2, SO2, Pb, PM (2.5 and 10), O3, CO

6 criteria air pollutants

Top 4 indoor air pollutants in DEVELOPED countries

Tobacco smoke, Formaldehyde, Radon Gas, Fine and Ultrafine Particulate Matter

saltwater intrusion

an infiltration of salt water in an area where groundwater pressure has been reduced from extensive drilling of wells

rock cycle

A series of processes on the surface and inside Earth that slowly changes rocks from one kind to another

Erosion

Processes by which rock, sand, and soil are broken down and carried away (i.e. weathering, glaciation)

soil conservation

a method to maintain the fertility of the soil by protecting the soil from erosion and nutrient loss

edge effect

different environmental conditions that occur along the boundaries of an ecosystem. May observe higher biodiversity