Dear Francois,

You are right, I forgot to mention some important things. To answer your questions:

I want to measure 1 to 2 traits (I haven't decided yet), and the traits will be continuous as seed size. I have a dataset of 50 species that could be suitable for my site, but only with average values obtained from other trait data bases.

Any suggestions will be appreciated!

Take a look at the work of Owen Petched, he developed several well designed indices of Functional Diversity (based on traits) and also compared indices

Hi Florencia,

R packages are the best tool to deal with FD. try downloading the FD package (that includes the vegan package) and you will find a lot of tools in there. you can also choose the dist function or, if you have also categorical variables the gowdis.

Let me suggest you to use more than two traits as some could be very easy to find or measure yourself. the traits you use really depend on what your hypothesis is and you will get different distances of FD indices by using different traits. Some traits could be:

max height, seed mass, wood density (but I'm guessing you are not working with trees),

max photosynthesis, specific leaf area, nitrogen per mass (for these last three you might want to check this article "The worlwide leaf economics spectrum".

The FD package also tolerates missing values, but sometimes you can fill the missing values. for example you could fill them using the value of phylogenetically near species living in the same environment.

Good luck