AICE Environmental Management - Sampling Techniques

Quadrats - Description of technique

square plots, either open frame or with grid and points, normally laid on ground and sections used, by random or systematic sampling

Quadrats - benefits

easy to use; inexpensive

Quadrats - limitations

hard work in the field that is physically demanding; prone to study error; disturbs habitats

Quadrats - when to select and use as suitable technique

studying plants, slow moving animals, or moving animals with small range (insects)

Quadrats - example of technique in use

distribution patterns, estimations of %cover, abundance, and frequency

Pitfall traps - description of technique

collection of fauna using hidden deep bucket (comparable size) they can't get out of due to smooth walls and covered to keep predators out

Pitfall traps - benefits

simple; cheap; typically doesnt kill; can collect multiple samples; safe to operate

Pitfall traps - limitations

length of time to wait; location; tricky to report-not standardized possibility of death/injury

Pitfall traps - when to select and use as suitable technique

low rainfall or covered areas

Pitfall traps - example of technique in use

estimate relative abundance, daily activity, and biodiversity using Simpson's index

Sweep nets - description of technique

collection of insects/invertebrates from long grass, brush, crops

Sweep nets - benefits

simple; fast/no set-up time; collect dispersed species; low cost

Sweep nets - limitatons

delicate/can be damaged; need other tooled also; limited locations; skills required; labor intensive

Sweep nets - when to select and use as suitable technique

monitor throughout flowering harvest or tall grasses

beating trays - description of technique

stretched cloth under tree, shake tree, invertebrates fall from foliage then examined and returned

beating trays - benefits

can collect quickly; inexpensive

beating trays - limitations

difficult to count fast enough; repeated several times around a plant; disruptive/traumatic; needs other tools too; only insects that fall easy

beating trays - when to select and use as suitable technique

when insects prefer living/eating from small tree or bush; when collecting small insects, beetles, ect.

beating trays - example of technique in use

estimate relative abundance and daily activity, and biodiversity using Simpson's index

kick sampling - description of technique

net placed in direction of flow of stream or river with opening facing upstream. scientist kicks substrate in front of net for a period of time and dislodged organisms are carried into net for counting and analysis

kick sampling - benefits

easy; inexpensive; can collect multiple samples

kick sampling - limitations

disruptive; labor intensive; disturbs habitats

kick sampling - when to select and use as suitable technique

at bed of stream or river

kick sampling - example of technique in use

overall heath, abundance, frequency

light trays - definition of technique

light used at night to entice nocturnal insects into trap

light trays - benefits

nocturnal collection; easy

light trays - limitations

less production when cold/wet/windy, or near other bright artificial light; limited to nocturnal insects; length of time to wait

light trays - when to select and use as suitable technique

at night for nocturnal species where non competing with ambient light

light trays - example of technique in use

moths, crickets, beetles; monitor for disease such as mosquitos or sand flies

capture-mark-capture - description of technique

sample of population is collected and tagged or otherwise marked then released. samples collected repeatedly and marked are counted

capture-mark-capture - benefits

any time of day; collect dispersed species

capture-mark-capture - limitations

time consuming; need tools; labor intensive; disruptive/traumatic; spatial distribution can change

capture-mark-capture - when to select and use as suitable technique

when animals are limited in range, fish in lake, land locked area

capture-mark-capture - example of technique in use

estimate population size using Lincoln Index