[R-sig-ME] lmer/glmer standard error interpretation and visualization

[Colin Wahl]

Hello,
I am in the process of finalizing figures for my thesis on stream
invertebrate distributions among watershed and riparian types. See
below for additional information on the design. I'm having difficulty
including standard errors from the lmer modeling as error bars in the
figures. Here is the table I've created from the lmer output:
estimates of %EPT and St Error are back transformed from logits and
converted from fractions to percents. Estimates are also absolute (not
relative to the intercept).

 Watershed     Effect                  Estimate  St. Error  z score  p value

 Forested      Intercept: F vs. 0       28.23      59.6     -2.346     0.019*
                    Riparian:  F vs. NF   16.017     62.3     -1.436     0.151
 Cultivated    Watershed: C vs. F    1.351     65.3     -5.297    <0.000*
                    Riparian:  F vs. NF    1.555      69.2      1.071    0.284
 Developed   Watershed: D vs. F    0.175      66.8     -7.714    <0.000*
                    Riparian:  F vs. NF    0.292      70.9      1.391     0.164
 Grassland    Watershed: G vs. F    28.94     66.6       0.05      0.960
                    Riparian:  F vs. NF     1.967     70.7     -2.595     0.009*

The st. errors are huge. I initially used standard error calculations
in excel for error bars (stdev(x)/sqrt(n(x))), which look very
reasonable, and are reflective of significant differences.

Does anyone have any advice to offer for visualizing these glmer
results? Should I use the huge model St. Errors? My inclination is
yes, because they are used to calculated significant differences, but
28 + or - 59.6 with a significant p value seems ridiculous.

Thank you,
Colin Wahl
M.S. Candidate
Dept. of Biology
Western Washington University