Qualitative Sampling Different Types of Qualitative rosenbed/FRWS3700/Lec-09 qualitative...1 Qualitative vs. Quantitative Sampling What is the difference between: Quantitative and Qualitative Sampling?? • Qualitative Sampling: Observational evaluation of some

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    Qualitative vs. Quantitative Sampling

    What is the difference between: Quantitative and Qualitative


    Qualitative Sampling:Observational evaluation of some


    Quantitative Sampling:The measure or count of some


    Qualitative Sampling Observational, not direct measurement. Observer makes evaluation on condition

    or quantity. Often much quicker than quantitative

    sampling. Can be timely for making quick

    management decisions. May be more subject to observer bias than

    quantitative sampling. May be difficult to verify.

    Different Types of Qualitative Sampling

    Presence or absence of species or trait

    Site-condition evaluation Rough estimates of population size or

    attribute Photo interpretation

    Presence or Absence

    Plant survival after fire

    Rare plants

    Evaluate Spread of Disease

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    Evaluation of Site Condition

    Poor grazing quality

    High fire potential

    Assess Population




    Qualitative Data: Use of Photos

    Photo Documentation Photo Plots Photo Points Remote Sensing aircraft, satellite

    All can trigger or guide management actions

    Photo Documentation of Treatment Effects

    Photo Documentation

    of Invasive Weed


    Edge encroachment

    Dispersed encroachment

    Photo Plot

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    Photo PointsMarch, 2002

    April, 2002

    May, 2002

    Aug, 2002

    Sep, 2002

    Remote Sensing from Aircraft

    Normal photo image Spectral Images e.g., infra-red band Digital Pixel Size: Often 10 cm to 30 m

    Remote Sensing

    from Aircraft



    Ant colonies (relative density)

    Community boundaries

    Remote Sensing

    from Aircraft


    Juniper stand (density, tree dimameter)


    Satellite Remote Imaging

    Normal Image Photo Multi-spectral bands Pixel Resolution: 0.25

    km - 10 km

    Remote Sensing from Satellite

    Fires in southeast USA

    Volcanic Ash, Kodiak Is.

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    Remote Sensing from Satellite

    Dust storm in Afghanistan

    First snow, Lake Baikal

    Satellite Processed Images

    Gross Primary Production (gross photosynthesis)

    Determine at least one qualitative and one quantitative sampling method for each objective

    1. Determine whether a specific toxic substance is leaking from an old tank into the Logan River.

    2. Determine age structure of a pronghorn herd in central Wyoming.

    3. Determine whether canvasback ducks are migrating through Cache Valley, Utah.

    4. Determine whether ATV users have been driving off trail in Swan Flat.

    5. Determine whether West Nile virus has reached Utah.6. Determine forage availability for sheep on a winter

    allotment.7. Determine whether common dandelion has invaded

    your lawn.8. Determine whether volcanic ash from Kodiak Island

    volcano is reaching the Anchorage, Alaska airport.


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