Online Trick

library(vegan)

### data on 35 species of Oribatid mites
### data description at: http://cc.oulu.fi/~jarioksa/softhelp/vegan/html/mite.html
data(mite)

### ...and environmental variables
data(mite.env)

### the factor which you wish to use for labeling the displayed sites
### in the ordination diagramm:
fac<-mite.env$Topo
sol<-metaMDS(mite)

windows(9,5)
par(mfrow=c(1,2))

### graph with "spider":
plot(sol,type="n")
points(sol, display = "sites", cex=0.65, select=which(fac=="Hummock"),
       pch = 21,col="black", bg="black")
points(sol, display = "sites", cex=0.65, select=which(fac=="Blanket"),
       pch = 21,col="black", bg="white")
ordihull(sol,group=fac,show.groups="Hummock")
ordihull(sol,group=fac,show.groups="Blanket",lty=3)
orditorp(sol, dis = "sp", pcex=0,air=0.85,col="grey35",cex=0.8 ,font=3)

### graph with "hull":
plot(sol,type="n")
points(sol, display = "sites", cex=0.65, select=which(fac=="Hummock"),
       pch = 21,col="black", bg="black")
points(sol, display = "sites", cex=0.65, select=which(fac=="Blanket"),
       pch = 21,col="black", bg="white")
ordispider(sol,group=fac,show.groups="Hummock")
ordispider(sol,group=fac,show.groups="Blanket",lty=3)
orditorp(sol, dis = "sp", pcex=0,air=0.85,col="grey35",cex=0.8 ,font=3)