[R] Save a group of matrix

[Alfonso Pérez Rodríguez]

Hello, I'm creating a loop to work with vegan, to get a species abundance curve. Here I send the script I've created and also an excel file to prove what it can do.
Well, I have a database with 20 years, and each year we have sampled 19 stratum, and in each estratum we have carry out some sumpling. Then, with the script that I've sent I've got to calculate the species abundance curve for each stratum but only for one year. I want to be able to do this for the 20 years sampled but separately, obtaining one independent matrix for each year, but I don't know how to do, I sure it's very simple but I've not encountered the way to do it.

If someone can help me I would be very grateful, thank you


Alfonso Pérez Rodríguez
Instituto de Investigaciones Marinas
C/ Eduardo Cabello nº 6 
C.P. 36208 Vigo (España)
Tlf.- 986231930 Extensión 241
e-mail: fonsilei en iim.csic.es