Biology(investigating an ecosystem)
effects of abiotic factors
most land organism are not found in very dry or very wet areas-reason why-in very dry conditions they become dehydrated. in very wet conditions plant roots are deprived of oxygen.
green plants are not found in areas with low light intensity-reason why-plants need light for photosynthesis
Measuring abiotic factors
measuring...
light
to avoid errors, be careful not to shade the meter and always hold it in the same way when making the reading
a light meter is used
moisture
to avoid errors, make sure you place the moisture meter firmly in the ground and wipe it dry afterwards
a moisture meter is used
can normally be measured using a meter
affect the organisms living in a particular habitat
a physical, non-living factor, such as light, moisture, oxygen, concentration or temperature
identifying organisms
a key must be used
a paired statement key
a branching key
sampling techniques
we cannot collect all the organisms in a habitat, so we must take a sample
using a pitfall trap
however, some may be eaten by other animals which fall in
cup placed in a hole, making sure the top is level with the ground so that the animals fall in
used to take animal samples
using a quadrat
the number of squares containing the plant being studied are counted
thrown randomly on the area being sampled
frame divided into squares
a quadrat is used to take plant samples
Biosphere/ecosystem/habitat
If we want to learn about a particular habitat, we need to carry out an investigatio which involves
measuring the physical conditions
identifying the organisms
collecting the organisms
the place where an organism lives is called a habitat
the biospere can be divided into smaller units called ecosystems
the biosphere is the part of the planet where organisms are found
