[R-sig-eco] Plot NMDS with size of the points related to abundance

[Barbara Baraibar Padro]

Hello list, 
I am analyzing species composition of weeds in 12 cover crop treatments and a fallow plot. I have been using nmds and got good results and no problems with it (although after some fighting!). My data is a matrix of biomass values sorted by species. Now I'd like to know which of my species are contributing with more biomass to the community in each treatment, that is, I'd like to create a graph such as the one that you get from the option "plot (nmds_model,  type="t", display=c("species")) but instead of getting just the names of the species, I'd like to see dots of different sizes that would refer to the abundance of each of the species, is that possible at all? I know you can do it with CANOCO but wanted to ask if there is a way to do it in R.

I have searched the internet and found something that looks like what I want to do (enclosed to the mail) but haven't found the way to do it. 

I have already done an Indicator Species Analysis with the multipatt function. That gives me information about the species that are related to some treatments but here I'm just looking for the species with more and less biomass in each treatment.

Thank you very much!!
Barbara



-- 
Barbara Baraibar
Post-doctoral scholar - Weed and Applied Plant Ecology
Plant Sciences Department
Penn State University
University Park, Pennsylvania 16802

web-site:http://www.weedecologypsu.com