Measuring Abiotic Components of Ecosystems (DP IB Environmental Systems & Societies (ESS))

 Light-meter

Quick and easy to use, non-invasive, accurate and precise measurement if direction and angle of use is consistent over repeats

Can only measure at a single point, doesn't measure spectral quality or light direction, affected by shading, cloud cover and atmospheric conditions

 Thermometer

Simple and easy to use, highly accurate if using an electronic thermometer (temperature probe), which can measure temperature of air, water and varying soil depths

Can only measure at a single point, doesn't measure temperature fluctuations over time (unless used alongside a datalogger)

 Anemometer

Quick and easy to use, non-invasive, accurate and precise measurement if direction and angle of use is consistent over repeats

Gusty conditions can lead to large variations in data

 Oxygen-meter

Can measure changes over time if used alongside a datalogger

Can be expensive and require calibration, can be affected by temperature and salinity, or contaminated by oxygen in air if correct procedure not followed

 Flow-meter

Provides accurate measurements and can be attached to a datalogger

Water flow can fluctuate greatly due to rainfall or ice melt, can be affected by turbulence or eddies

 Secchi disc

More accurate if used in shady areas of water

Sun glare and reflections reduce visibility of disc, measurements are subjective, alternative more sophisticated optical equipment (e.g. nephelometer or turbidimeter

 pH meter or pH probe

Soil pH can also be measured (using a soil test kit)

Requires calibration, affected by surrounding environment

 Evaporate water  or soil moisture probe

Fairly inexpensive (although requires use of an oven)

Time consuming, organic soil content may be burned off during heating, reducing soil weight and giving inaccurate readings