Partitioning variance with VarPart - permutation test on difference between fractions

Tue, Feb 3, 2009 8:06 AM

Hi there!

I am analyzing a dataset on hoverflies along an altitudinal gradient and
I managed to partition the variance explained among four predictor
variable sets (CLIMATE, RESOURCES, STRUCTURE, and SPACE) in R with
varpart and tested the significance of the (testable) fractions by
single (partial) RDAs.

However, how can I test whether two fractions differ significantly from
each other in R with the permutation test proposed in the Ecology paper
by Peres-Neto et al. 2006?

I know there is an executable program in the appendix of that paper, but
I would like to continue my analysis in R. Does anybody know of an
available R command or R code to test whether two fractions differ?

Best wishes from windy Berlin (+2 degrees, no snow),

Frank

Prof. Dr. Frank Dziock
Animal Ecologist and Head of Department (Juniorprofessor)

Department of Biodiversity Dynamics
Technische Universitaet Berlin
Sekr. AB 1
Rothenburgstr. 12
D - 12165 Berlin
Germany

Tel: 030 ? 314 71368

Secretary Gisela Falk
gisela.falk at tu-berlin.de
Tel: 030 - 314 71350
Fax: 030 ? 314 71355

http://www.biodiv.tu-berlin.de/