# NMDS
spe.nmds<-metaMDS(spe, distance='bray', k=2)
 
### Extraction des résultats
spe.nmds

### Évaluation de la qualité de l'ajustement et construction du diagramme de Shepard
spe.nmds$stress
stressplot(spe.nmds, main='Shepard plot')

# Construction du biplot
windows()
plot(spe.nmds, type="none", main=paste('NMDS/Bray - Stress=', round(spe.nmds$stress, 3)),
     xlab=c("NMDS1"),
     ylab=c("NMDS2"))
points(scores(spe.nmds, display="sites", choices=c(1,2)),
       pch=21, col="black", bg="steelblue", cex=1.2)
text(scores(spe.nmds, display="species", choices=c(1)),
     scores(spe.nmds, display="species", choices=c(2)),
     labels=rownames(scores(spe.nmds, display="species")),
     col="red", cex=0.8)