Potential indicators of soil quality in temperate forest ecosystems: a case study in the Basque Country Nahia Gartzia-Bengoetxea, Ander González-Arias, Ellen Kandeler and Inazio Martínez de AranoAnn. For. Sci., 66 3 (2009) 303DOI: https://doi.org/10.1051/forest/2009008