Greetings to all,
I have presence/absence data for species in plots in different years. My
matrices looks like that:
YEAR1
sp1 sp2 sp3 sp4
1 1 1 0 1
2 1 1 1 1
3 1 1 0 1
4 1 1 0 1
5 1 1 0 1
YEAR2
sp1 sp2 sp3 sp4
1 0 1 0 1
2 1 1 1 1
3 0 1 0 0
4 1 0 1 1
5 1 1 0 1
I tried 'distance' in {ecodist}, 'vegdist' in {vegan},
'jaccard' in {prabclus}, 'clujaccard' in {fpc} and others. The
thing is that I don't understand the comparisons its method does, and
consequently the outcome of the calculations. My final aim is to test for
compositional disimilarity, doing a Mantel correlation Analysis, based on
Jaccard similarities for matrices of species presences/absences between plots
within a year and between years within plots.
thanks
---
Dr. Alexandros Galanidis
Biodiversity Conservation Laboratory
Department of Environment
University of the Aegean
GR-811 00, Mytilene, Lesbos, Greece
Tel. +30 22510 36215
Fax. +30 22510 36296
Email: agal at env.aegean.gr