environmental science

molecule

two or more same element atoms bonded together

compound

two or more different kind of atoms bonded together

lithosphere

earths crust

hydrosphere

all water, liquid and solid forms

atmosphere

thin layer of gases separating the earth from outer space

the six key elements that characterize living things

carbon, hydrogen, oxygen, nitrogen, phosphorous, sulfur

three major gases in atmosphere

oxygen, nitrogen, carbon dioxide

hydrosphere is comprised of these two elements

hydrogen, oxygen

mineral

any hard crystalline, inorganic material of a given chemical composition

organic

chemical compounds making up tissues of living organisms

inorganic

non-carbon based molecules or compounds

natural organic compounds

compounds making up living organisms

synthetic organic compounds

human made compounds containing carbon

forms of energy

heat, light, electricity, movement

energy

the ability to move matter

kinetic energy

energy in action or motion

potential energy

energy in storage

chemical energy

potential energy contained in fuels

calorie

unit of measure for energy; amount of heat required to raise the temperature 1 gram of water 1 degree celsius

law of conservation of energy; first law of thermodynamics

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

second law of thermodynamics

in any energy conversion, some energy is always lost

entropy

measure of the degree of disorder in a system

anaerobic

oxygen free

initial source of energy

sunlight

biochemical cycles

circular pathways that involve biological, geological, and chemical processes

the major difference between carbon cycle and phosphorous cycle

no matter where CO2 is released, it will mix in and maintain its concentration in the atmosphere, phosphorous however does not have a gas phase, so it is recycled only if the wastes containing it are deposited in the ecosystem from which it came

how is the nitrogen cycle like the carbon and phosphorous cycle?

it has a gas phase, and it acts as a limiting factor

how is nitrogen cycle unique?

bacteria in soils, water and sediments perform most of the steps of the cycle

what is the main resevoir of nitrogen

air

denitrifications

a microbial process that occurs in soils and sediments depleted of oxygen

nitrogen cascade

sequential impacts of Nr as it moves through the environemtal systems, creating problems as it goes

equilibrium

when death and birth rates of a popluation are generally equal over a long period of time

exponential increase

when a species population grows under ideal conditions (population continually doubles)

population explosion

when a population increases rapidly all at once, and then inevitably crashes (J curve)

biotic potential

the ability of a potential to increase, number of offspring of that species under ideal conditions

recruitment

survival through the early growth stages to become part of the breeding poulation

two reproductive strategies

1. produce massive numbers of young and then leave survival to the whims of nature 2. have low reproductive rate, but care for and protect the young until they can compete for resources with adult members of population

life history

strategies for for reproduction and survival that enables the species to be successful in a niche and ecosystem

environmental resistence

all of the biotic and abiotic factors that may limit a populations incres

replacement level

when reproduction is just enough to replace the adults (equilibrium)

carrying capacity

the maximum population of a species that a given habitat can support the habitat being degraded over a long period of time (sustainability)

dynamic balance

additions and subtraction fluctuate around a median (S curve)

population density

the number of individuals per unit area

density dependent

as population density increases, environmental resistance becomes more intense.

density independent

the effect is independent of the population density

critical number

a certain minimal population base that a population depends on for survival and recovery

threatened species

species populations that are decreasing rapidly

endangered

when a population reaches what scientists believe to be its critical number

keystone species

a species with a crucial role in maintaining ecosystem abiotic structure

interspecific competition

when species niches overlap and create competition

intraspecific competition

when a resource is scarce and species compete within their own population

riparian woodlands

when trees grow only along waterways

epiphytes

air plants (moss)

four factors that ensure a species will survive new conditions

1. geographical distribution 2. specialization to given habitat or food supply 3. genetic variations within the gene pool of species 4.reproductive rate relative to the rate of change

reproductive isolation

when one species separates into different populations that don't interbreed

how are new species formed

gradual modifications of existing species

ecological or natural succession

phenomenon of transition from one biotic community to another

facillation

when earlier occupants create conditions that are more favorable to new occupants, and are replaced by them

climax ecosystem

dynamic balance between between all of the species and the environment

primary succession

when an area has not been occupied previously, and the process of initial invasion occurs

secondary succession

when an area has been cleared by fire or humans and left alone, plants and animals from surroundings may gradual reinvade

fire climax ecosystems

ecosystems that depend on the recurrence of fire to maintain their existence

resilience

an ecosystem that maintains in normal functioning, its integrity, even with disturbance

instrumental value

when a species or organism existence or use benefits another entity

intrinsic value

an organism or species that has value for its own sake; its not useful to us but still has value

genetic bank

natural biota

ecotourism

tourist visit places in order to observe wild species or unique ecological sites