Table of Contents
1.2 Biology/Ecology of Slaters
1.3 Aims of the project, Hypothesis/Null Hypothesis
2.3 Apparatus Construction
2.4 Experiment Method
2.5 Control Experiment Method
2.6 Control of Variables
3.2 Control Experiment
3.3 Statistical analysis, Chi square
4.1 Discussion of the Experiment results
4.2 Discussion of the Control Experiment Results
4.3 Discussion of the Statistical Analysis
4.4 Critique of methodology
5.1 Summary Results and Explanations for them
5.2 Summary Statistical analysis and Explanations for them
Porcellio Scaber is the scientific name for the slater studied. Another more commonly known name for the Porcellio Scaber is ‘Woodlice.’ Slaters are named due to their tendency to chew the wood out from just under the bark of trees and also where they are commonly found. The Slater belongs to the biological class Crustacea. Slaters are found in damp, cool and often humid conditions. They are most easily found in spring and autumn when the temperature range does not reach the extremes that it does in summer and winter in New Zealand. The most common areas to find slaters are on compost heaps or under shelter such as bark and boards left in shaded, moist conditions or wood piles. They may also be found in deep, damp, leaf and soil litter under the shelter of bushes and trees.
1.2 Biology/Ecology of Slaters
Slaters begin to desiccate if they don’t have sufficient water to keep themselves moist, therefore the places they are usually found are cool, damp places as stated above. Slaters show negative phototaxis (the orientation and movement of an organism away from the source of a light stimulus) therefore they move out of bright light. Areas with brighter light conditions are usually drier, so by staying out of bright light slaters are minimising desiccation. High summer temperatures (up to 32 degrees celsius) cause the woodlice to retreat deeper into shelter making them more difficult to locate. The cooler winter temperatures (down to -5 degrees celsius) also cause them to retreat further into shelter. Most slaters are between 1-1.5cm in length. They are mainly omnivorous scavengers, feeding on a variety of decaying vegetation, tree bark, rotting wood etc. Slaters may also graze on fungi associated with decay, or consume dead insects or larger animal carcasses.
Many animals such as small mammals, birds, centipedes and ground beetles will eat slaters if given the opportunity which is yet another reason slaters prefer to remain protected under shelter.
For this experiment a significant number of slaters were collected from the base of damp, dark and moist woodpiles. The slaters were often found clumped together under the bark, or between the split wood pieces and the moist ground surface. The approximate temperature in the area the slaters were found at the time of collection was 22 degrees celsius, on a cloudy day. The outside air temperature was 24 degrees celsius.
Living in woodpiles, compost heaps and bushes provide good conditions for slaters as these often have a low light intensity, high humidity and cooler temperatures. This study was designed to investigate which substrate the slaters prefer to live in.
Slaters often clump together to maintain moisture levels.
1.3 Aims of the Project
To determine which substrate slaters prefer to live in.
If given the choice of 5 different substrates; wood, bark, dry soil, compost, and leaves the slaters will exhibit a preference for wood.
If given the choice of 5 different substrates; wood, bark, dry soil, compost and leaves the slaters will show no...