Chapter 18 Introduction to ecology

the biosphere

consist of all of earth organisms, plus the physical spaces we all inhabit

- includes inorganic chemicals like water, our nitrogen rich atmosphere, and more

- is crucial to our survival and well being because of humans depend on the biosphere for food and raw materials

ecology

the scientific study of interactions between organisms and their environment

- biotic factors: other living organisms

- abiotic factors: non-living

ecosystem

the system of interacting abiotic and biotic factors

weather

short-term atmospheric conditions in a limited geographic area

climate

the prevailing weather of a region over relatively long periods of time (30 yrs or more)

- determined by incoming solar radiation, global movements of air and water, and major features of earth surface

- strongly influences organisms more than any other feature of their environment

climate change

a large scale and long term alteration in earths climate

- includes global warming, change in rainfall patterns, increased frequency of violent storms

- largely caused by humans

hydrologic cycle

the circulation of water from the land to the sky and back again

- happens most substantially near the equator

- warm, moist, air rises, but as it rises, it begins to cool

- heat causes it to expand, making it less dense and lighter than unheated air

- cool air cannot hold as much water

- much of the moisture from a cooling air mass falls out as rain

where glacier meets sea

loses ice in 1 of 2 ways:

- an iceberg breaks off and melts in the ocean

- water melts the ice sheet from underneath

global warming

a significant increase in the average surface temp of earth over decades or more

- 1 type of climate change among many

- temp is determined by angle at which sunlight strikes the planet

greenhouse gases

- carbon dioxide (CO2), water vapor (H2O), methane (CH4), and nitrous oxide (N2O)

- absorb heat that radiates from earths surface and prevent it from escaping to space

- let sunlight in and trap heat (greenhouse effect)

carbon

in CO2 form gas, most abundant element, composes backbone of every large biomolecule, acquired by consuming photosynthetic bacteria, algae, and plants

- fossil fuels: petroleum, coal, natural gas

photosynthesis

plants, algae, and some bacteria remove CO2 from the atmosphere

respiration

organisms release CO2

combustion

the burning of carbon-rich materials, living or not: pants, fossil fuels

decompostion

releases carbon into the surrounding environment

carbon sink

a natural or artificial reservoir that absorbs more carbon than it releases

carbon source

a reservoir that releases more carbon than it absorbs

sustainable

an action or process that can be continued indefinitely without causing serious damage to the environment

ecological footprint

The area of biologically productive land and water that an individual or a population requires to produce the resources it consumes and to absorb the waste it produces expressed in:

- GHA

- earth equivalents: the number of plants earth needed to provide our required resources and absorb the waste we produce