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2.2 Measuring Abiotic Components

+Investigation

Must Choose 2 of the following factors to study

Investigate how these factors vary between ecosystems, or different areas over time, distance, or depth

+Three Major Ecosystem Types

Marine – oceans, salt water

Freshwater – rivers, lakes and streams

Terrestrial – land

+Temperature

Temperature - Every organism has an optimal temperature range in which it thrives.

How to measure- Use a Thermometer (Vernier)

Temperature

+Salinity

Salinity (saltiness) - marine organisms tolerate a variety of salt concentration levels in the water

How to measure: Electrical conductivity can also indicate the amount of dissolved ions in solution – can use Vernier conductivity probe.

Conductivity

+pH – Acidity

0- 14 scale (0= Strong Acid, 14 = Strong Base) The pH of saltwater is higher (8.2)than freshwater (7.5).

How to measure- Vernier pH probe

pH

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Dissolved oxygen -the amount of oxygen available determines which organisms can survive in a particular location.

DO levels fall with increased temperature and organic compounds from either sewage, agriculture, or industry

DO can range from 0-18 mg/L, but most healthy ecosystems have a DO level of 5-6 mg/L

How to measure – Use Vernier probe to measure DO by stirring the probe in a water sample

Dissolved Oxygen Probe

Dissolved Oxygen

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The rate at which water moves through a specified area in a given amount of time.

How to measure- Time how long a partially-submerged object takes to travel a certain distance

Flow Velocity

+Turbidity

A cloudy condition in water due to suspended silt or organic matter.

How to measure- Use a Secchi disk and record the length at which it is no longer visible (pictured Below)

+Temperature Depends on insolation (incoming sunlight), wind &

ventilation, latitude, color and texture of the surface

Temperature

+Light Intensity

Influences photosynthesis rates as well as body temperature of ectotherms (cold-blooded animals)

Light intensity varies with weather conditions, season, time of day, and surrounding terrain & vegetation cover

How to measure - light meters / sensor

Light Sensor

+Wind Speed

Wind speed –wind carries sediment and acts as a desiccating (drying) force in ecosystems, increasing evaporation and transpiration rates

How to measure - Anemometer: spinning cups on a permanent or hand-held post. The number of revolutions per time period can be converted to a wind velocity

Anemometer