Microalgae community structure analysis based on 18S rDNA amplification from DNA extracted directly from soil as a potential soil bioindicator A. Bérard, U. Dorigo, J.F. Humbert and F. Martin-LaurentAgron. Sustain. Dev., 25 2 (2005) 285-291DOI: https://doi.org/10.1051/agro:2005004