barplots

Hello,

I have somewhat of a weird data set and am attempting to create a barplot
with it.

I have 8 columns with different variables and their percentages. I have 1
column with representations of 4 different treatments the variables undergo.
I also have 1 column with year the data was recorded. I want to create a bar
plot that plots all 8 variables grouped by treatment and year.

I've tried creating subsets of each of the variables, no luck.

My variables are arranged similar to this:

Vascular.plants Solid.rock Gravel.and.cobbles
             72.5        1.0                  5
            67.5        2.0                  6
             67.5        2.5                  9
             59.0        2.0                 25