Abiotic Sampling Flashcards
Measuring Abiotic Factors
Organisms all have requirements for life that mean they are suited to their habitats. This is known as adaptations. These environmental factors that affect an organisms ability to live in an area are known as abiotic factors.
Biological Oxygen Demand
The amount of polluting material in a body of water can be determined by the biological oxygen demand. BOD is a measure of the amount of oxygen required to breakdown organic matter from water in the process of decomposition by aerobic bacteria.
Biological Oxygen Demand 2.
The more oxygen that is used, the greater the bacterial activity, and therefore the greater the pollution. A high BOD results in less oxygen being available for aquatic organisms such as fish and invertebrates, which will die or shift away from the polluted area.
Transect Lines
Transects are a from of systematic sampling that involves a line being laid out across a site. they can be used to assess how abundance and distribution of organisms is affected by changes in abiotic factors across a habitat.
Transect Lines 2.
Transect Lines can be used to investigate increasing distances from a field margin. Or measuring abundance of species along the water edge on a rocky shore.
Line Transects
Line Transects are longer lines, often 100m long or more, created by laying a measuring tape or string line across the environment you wish to sample. At regular distances along the tape, e.g. 1m, record the identity of the organisms that touch the line.
Belt Transects
Belt Transects are similar, except two lines are laid out in parallel to form a belt across the ecosystem. Any plant located within the belt is counted.
Quadrats
Quadrats can be placed at regular intervals, along the line and the abundance or percentage over of each species within each quadrat can be recorded.
Kite Diagrams
A kite diagram can show the number of animals against distance along a transect. We use the width of the bar from the midline to see how many individuals are present.
