[R-sig-eco] Indicator Species in Presence-Absence Data

[Alexandre F. Souza]

Dear all,

I have a large matrix of 680 localities x 6000 species with
presence-absence data divided into 42 ecoregions.  I used the multipatt
function of the indicspecies package to identify indicator species of each
ecoregion.

indic = multipatt(dados3[,2:ncol(dados3)], dados3[,1], func = "IndVal.g",
duleg = TRUE, control = how(nperm = 999))

Results returned many indicator species for some ecoregions but many
ecoregions with zero indicator species. I am in doubt wether the function
options I made are adequate to run the analyses for presence-absence data
since in the tutorial and in the function examples abundance data are used.
I consulted the articles by De Cáceres 2009 and 2010 which mention the
possibility of indicator species for presence-absence data but it does not
become clear to me if they are automatically implemented in the function or
if specific options are needed.

An important information is that the ecoregions were defined through
interpolation of beta dissimilarity metrics (simpson index) and k-means
classification. Is it possible that they are different but do not have
indicator species?

Thanks for any thoughts,

Sincerely,

Alexandre

-- 
Dr. Alexandre F. Souza
Professor Associado
Chefe do Departamento de Ecologia
Universidade Federal do Rio Grande do Norte
CB, Departamento de Ecologia
Campus Universitário - Lagoa Nova
59072-970 - Natal, RN - Brasil
lattes: lattes.cnpq.br/7844758818522706
http://www.esferacientifica.com.br
https://www.youtube.com/user/alexfadigas
http://www.docente.ufrn.br/alexsouza
orcid.org/0000-0001-7468-3631 <http://www.docente.ufrn.br/alexsouza>

	[[alternative HTML version deleted]]