Environmental Systems 3
Biotic
abiotic
the living organisms in an ecosystem
nonliving, physical features of the environment, including air, water, sunlight, soil,
temperature, and climate
trophic level
each step in a food chain or food web
producer
an organism that makes its own food. e.g. grass
consumer
organisms that cannot make their own food and eat other organisms to obtain energy
and matter.
decomposer
an organism that breaks down and obtains energy from dead organic matter. example:
crustaceans
herbivore
Consumer that eats only producers. primary consumer. e.g. zebra
carnivore
flesh-eating animal, organism that obtains energy by eating animals. secondary
consumer. e.g. lion
pyramid of
representation of the number of individual organisms in each trophic level of an
numbers
ecosystem
pyramid of
illustrates total biomass at each successive trophic level
biomass
pyramid of
contains the flow of energy through each trophic level. It shows the energy being
productivity
generated and available as food to the next trophic level during a fixed period of time.
bioaccumulation
the increase in concentration of a substance(s) in an organism or a part of that organism
bio-magnification
the increase in concentration of a substance in a food chain
species
a group of organisms that interbreed and produce fertile offspring.
population
a group of organisms of the same species living in the same area at the same time
habitat
the environment in which a species normally lives
niche
where and how a species lives. This includes all the information about what defines a
species.
community
ecosystem
a group of populations living and interacting with each other in a common habitat.
a community of interdependent organisms (the biotic component) and the physical
environment (the abiotic component) they inhabit.
intraspecific
competition within a species.
competition
interspecific
The competition between different species.
competition
predation
the occurrence of one animal/plant eating another. e.g. snowshoe hare and lynx.
parasitism
the relationship where the parasite benefits at the expense of the host from which it
derives food. e.g. ticks and tapeworms
mutualism
a symbiotic relationship in which both species benefit. e.g. coral reefs and lichens.
the Lincoln index
a method of estimating animal population size by collecting a sample from the population,
marking them in some way, releasing them back into the wild, then resampling some time
later and counting how many marked individuals you find the second capture. Also known
as 'capture-mark-release-recapture' technique. The formula used in calculating
population size is N = n1 x n2 / m
quadrats
a method of estimating animal population size by limiting the sampling area of nonmobile organisms. Sizes vary from 0.25m square-1m square and are optimal for the
particular organisms.
stratified random
taking results from two different ha, a process or selecting individuals from a population in
sampling
such a way that the subgroups in the population are represented in the sample, the
population is divided into subpopulations and random samples are taken of each stratum.
transect
A line along which one reads and records the object of study (elevation, animal/insect
life, plants)
systematic
A method of sampling in which you determine randomly where you want to start selecting
sampling
in the sampling frame and then follow a rule to select every xth unit from the sampling
frame list.
continuous
A method of sampling in which every organism along a transect is recorded
sampling
percentage
the percentage of the area within the quadrat covered by one species.
frequency
biomass
the mass of organic material in organisms or ecosystems, usually per unit area.
diversity
the number of different species and the relative numbers of individuals of each species.
The Simpson's
a way of calculating diversity. D = N(N-1) / sum of n(n-1). N = total number of organisms
diversity index
of all species found. n = number of individuals of a particular species.
biome
a collection of ecosystems sharing similar climatic conditions.
rainforest
a particular biome with constant high temperatures and high rainfall throughout the year.
they lie in a band around the equator within the tropics of Cancer and Capricorn and
accumulate high light levels. Their position enables high levels of photosynthesis and
high rates of NPP. A very high biodiversity