4.4 Populations and Sampling Techniques Vocabulary

ecosystems

the living organisms and the environment with which they interact

habitat

the natural environment where an organism lives

niche

the role of a species within ecosystem

species

a group of similar organisms that can interbreed naturally to produce fertile offsprings

population

all of the individuals of a species that live in the same place and time

biotic factors

the living parts of an ecosystem, which includes the organisms and their effects on each other

disease

an illness characterized by a recognizable set of signs and symptoms

intra-specifc competition

competition between individuals of the same species (for example, for food or a mate)

inter-specific competition

competition between members of different species (for example, predator-prey)

mark-release-recapture

a method to estimate the population size of mobile species

lincoln index

a mathematical equation that can use the mark-release-recapture data to estimate the population size

frame quadrat

a plastic or metal square that sets a standard unit of area for study of the distribution of marine organisms

transect

a rope or tape marked at regular intervals that sets standard distances for study of the distribution of marine organisms

line transect

a sampling method involving counting of species that touch the transect

continuous sampling

samples are taken along the whole length of the transect

systematic sampling

samples are taken at fixed intervals along the transect

belt transect

a sampling method involving

counting of species in frame quadrats placed adjacent to the transect

random sampling

samples are taken at random places within the sample site

ethical method

evaluates and chooses ways to protect the natural habitat under investigation

safe method

Identifies potential hazards and then reducing their risk of occurring

kite graph

A graph of the distribution and abundance of organisms in the littoral zone that allows zonation patterns to be easily seen.

richness

the number of species in a community

evenness

a measure of the relative abundance of the different species making up the richness of an area

Simpson's Diversity Index

a biodiversity measure that accounts for both species of richness and evenness

Null Hypothesis (H0)

there is no correlation between the two sets of variables

hypothesis

an explanation of an observation that can be tested through experimentation

scatter graph

when two sets of variables are plotted to indicate if there is a relationship between them

Spearman's rank correlation

a mathematical tool used to find out if there is a correlation between two sets of variables, when they are not normally distributed

critical values of rs

indicate when the calculated spearman's rank is sufficient to suggest a correlation between the two sets of variables

alternative hypothesis

there is a significant correlation between two sets of variables