Some suggestions to avoid
mistakes and to make it easier to get accurate data...
- As a suggestion for the 1/2 x
1/2 m2
plots in which centipede tests need to be conducted (see Procedure), PVC pipe constructed in squares works
very well to lay down on the ground and dig within.
- Always wear gloves when dealing
with centipedes, they can bite.
- Make sure each centipede is not counted multiple
times, this can be avoided by putting dirt in a bucket as it is taken out of
the ground.
- Make sure centipedes are being counted and not
millipedes, as they can look similar. (Millipedes have a more rounded body and
legs tucked under their body as well as two pairs of legs per body segment,
not one.)
http://www.enchantedlearning.com/subjects/invertebrates/arthropod/Centipede.shtml |
http://www.enchantedlearning.com/subjects/invertebrates/arthropod/Millipede.shtml |
- If you find that your p-values as a result of
T-testing are high, a Densiometer can be used to corroborate your data
- To create: take a tube of diameter, 4 cm and
length 7.5 cm. Attach 2 strings to cross perpendicularly over the top and on
the other end attach an 18 cm piece of string with a metal nut hanging from it
(shown below)
- look up through the densiometer making sure the
metal nut is below the intersection of the perpendicular strings, and
calculate the percentage of the circle in which the canopy cover is seen
- holding the densiometer at waist level look down
into it, making sure the metal nut is directly below the intersection point of
the 2 strings, calculate the percentage of the circle in which ground cover is
seen
- Use the 4 divided sections to estimate the
percent covered by plants
- This can help to determine whether plant density
is a determining factor in centipede populations
- Make sure if a densiometer is made that the
string with the metal nut is secured very tightly, ours fell off
Densiometer Before |
Densiometer
After |
|
|
Home
|
Introduction |
Procedure |
Results & Analysis |
Troubleshooting
Pictures|
Contact Information |
References |
Acknowledgements