S2 Fig. Observed and expected soil microbial
biomass N amended by litter mixtures at 14, 42, 84 and 182 days of incubation. Data are means ± SE, with n=4. MP+AS: mixture of Mongolian pine + A.scoparia; MP+SV: mixture of Mongolian pine + S. viridis; MP+PC:
mixture of Mongolian pine + P. communis; AS+SV: mixture of A.scoparia
+ S. viridis; AS+PC: mixture of A.scoparia + P.
communis; SV+PC: mixture of S. viridis + P. communis;
MP+AS+SV: mixture of Mongolian pine, A.scoparia and S.
viridis; MP+AS+PC: mixture of Mongolian pine, A.scoparia and
P. communis; MP+SV+PC: mixture of Mongolian pine, S. viridis and P.
communis; AS+SV+PC: mixture of A.scoparia, S. viridis and
P. communis; MP+AS+SV+PC: mixture of Mongolian pine, A.scoparia,
S. viridis and P. communis. Expected soil microbial biomass N amended by mixtures was calculated
from the values amended by monocultures (S2 Fig a) at 14, 42, 84 and 182 days of incubation according to Eq.
(1).