[R-sig-ME] modeling the effect of grass height on insect biomass

[Thierry Onkelinx]

Dear Joaquin

Your model seems reasonable, assuming that you measure the pitfalls only
once.

Best regards,

ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and
Forest
team Biometrie & Kwaliteitszorg / team Biometrics & Quality Assurance
Kliniekstraat 25
1070 Anderlecht
Belgium

To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to say
what the experiment died of. ~ Sir Ronald Aylmer Fisher
The plural of anecdote is not data. ~ Roger Brinner
The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of data.
~ John Tukey

2015-10-05 13:22 GMT+02:00 Joaquín Aldabe <joaquin.aldabe op gmail.com>:

> Dear all, I want to see the effect of grass height on insect biomass in a
> farm close to a coastal lagoon in Uruguay. For that I chose 5 pairs of
> fields. Each pair consist on a field with tall grass and the other with
> short grass. Each pair of fields are close to each other, in order to
> reduce the effect of soil type and other confounding variables. In each
> field I installed 6 pitfall traps, separated 100 m each. I collected
> insects for 30 days.
>
> Is the following modeling approach correct?: I called Site to each field
> pair (as they are geographically separated)
>
> model=lme(insect biomass~grass height + (1|Site\Field), data)
>
> Alternatively I thought of doing paired t-test..
>
> Thankyou very much for your help.
>
> Joaquín.
>
> --
> *Joaquín Aldabe*
>
> *Grupo Biodiversidad, Ambiente y Sociedad*
> Centro Universitario de la Región Este, Universidad de la República
> Ruta 15 (y Ruta 9), Km 28.500, Departamento de Rocha
>
> *Departamento de Conservación*
> Aves Uruguay
> BirdLife International
> Canelones 1164, Montevideo
>
> https://sites.google.com/site/joaquin.aldabe
> <https://sites.google.com/site/perfilprofesionaljoaquinaldabe>
>
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