Statistical Analysis


Seeing as I have to write a thesis on all of this sort of stuff, I'd say its not a very good chance that this is going to be updated in the immediate future.
These statistics are preliminary descriptive statistics from the 2003 field season pilot study sticky trapping.

Contents:

Animal trap design and collection information is at the Animals page.

Descriptive Statistics- ANOVA

The following tables compare upper vs. lower branches, live vs. dead branches, and trunk vs. branch trap placements. For each comparison the average, or mean, number of animals collected from 32 traps in 4 trees (or number of beetle species) is presented. Because there were 2 categories in each comparison, the averages are based on samples of 16 traps. Remember, they only represent 4 trees!

The grey column labeled S.D. is Standard Deviation, an indicator measure of how much variation from the mean there is in the data. A high S.D. means the variability in the data is high, and a comparisons between two averages are harder to place confidence in. The red boxes below indicate a statistically significant difference in the comparison indicated. For example, there were statistically more beetle species found in the upper canopy samples than the lower canopy samples.

Descriptive Statistics: Branch placement vs Trap collection (.HTML web ouput) (.XLS Excel)

Descriptive statistics comparing upper and lower branches live and dead branches, and trunk and branch placements are shown above. Significant (p<0.05) differences as detected by one-way ANOVA are highlighted in red.

3220 animals were collected. 89% of all animals collected were flies. The data on abundances for “all arthropods” are therefore confounded with Dipteran abundance.

Beetle morphospecies richness was found to be significantly higher in upper branches than lower branches. 111 beetle individuals (20 morphospecies in 15 families) were collected. Throscidae: Aulonothroscus sp. beetles were the most widespread and abundant non-Dipterans detected.

Dipteran abundances were found to be significantly higher on the branches than on the tree trunks, while both spiders and Hemipterans were found to be significantly more abundant on the trunk.

Variables


 Variables from sticky trapping available for animal analysis:(.HTML web page) (.XLS Excel)

Trap Placements


 Sticky Trap placement data (.HTML web page) (.XLS Excel)

Statistics Software SPSS Output


 Trap Placement vs. Trap Collection ANOVA testing output (.HTML web ouput) (.SPO SPSS Output)


You must have faith!