To cite the cati package:

  Taudiere A. & Violle C. 2015. cati: an R package using functional
  traits to detect and quantify multi-level community assembly
  processes. Ecography.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {cati: an R package using functional traits to detect and quantify multi-level community assembly processes},
    journal = {Ecography},
    year = {2015},
    author = {A. Taudiere and C. Violle},
    volume = {-},
    pages = {-},
    doi = {10.1111/ecog.01433},
  }