Assessing biodiversity in arable farmland by means of indicators: an overview Christian Bockstaller, Françoise Lasserre-Joulin, Sophie Slezack-Deschaumes, Séverine Piutti, Jean Villerd, Bernard Amiaud and Sylvain Plantureux OCL, 18 3 (2011) 137-144 Published online: 15 May 2011 DOI: 10.1051/ocl.2011.0381