A study of lignin degradation in leaf and needle litter using 13C-labelled tetramethylammonium hydroxide (TMAH) thermochemolysis: Comparison with CuO oxidation and van Soest methods

► Using the 13C-TMAH method, we studied lignin decay in field-exposed leaves & needles. ► Phenol yield and acid/aldehyde ratio indicated wood rot decay vs. time. ► Build up of demethylated lignin from brown rot decay was not found. ► The results were compared with those from other methods applied previously. ► The long assumed lignin preservation was not found using the CuO & 13C-TMAH methods.