Native carbon mineralization of an acid organic soil after use of the chloroform-fumigation method to estimate microbial biomass  <B>Native carbon mineralization of an acid organic soil after use of the chloroform-fumigation method to estimate microbial biomass</B><P></B><B>M.M. Couteaux(l), R. Henkinet(l), P. Pitta(l), P. Bottner(2)</B>, <B>G. Billes(2), L. Palka(l), and G. Vannier(l)</B><I><P> (l )CNRS/UA 689, Museum National d'Histoire Naturelle, Laboratoire d'Ecologie Generale, 4, avenue du Petit Chateau, F-91800 Brunoy, France<BR> (2) CNRS/CEPE, B.P. 5051, F-34033 Montpellier Cedex, France</I><B><P> Summary. </B>Two experiments were carried out on a dysmoder humus sampled from a depth of 2- 5 cm from a mixed hardwood forest. In acid soil, the chloroform fumigation-incubation method failed to estimate the microbial biomass, not because bacterial growth was inhibited after fumigation but because a labile C source was taken up which differed from the killed biomass C.<B><P> Key words: </B>Biomass - Chloroform fumigation-incubation technique - Acid organic soil - Carbon mineralization<P> Biol Fertil Soils (1989) 8:172- 177<P>