V. Baldy et Mo. Gessner, TOWARDS A BUDGET OF LEAF-LITTER DECOMPOSITION IN A FIRST-ORDER WOODLAND STREAM, Comptes rendus de l'Academie des sciences. Serie 3, Sciences de la vie, 320(9), 1997, pp. 747-758
To construct a budget of carbon transformations occurring during leaf
decomposition, alder leaves were placed in a woodland stream, later re
trieved at weekly intervals, and rates of fungal and bacterial product
ion, microbial respiration, and release of dissolved organic matter (D
OM) and fine particulate organic matter (FPOM) were determined during
short laboratory incubations. Carbon dioxide was the major decompositi
on product, explaining 17% of the microbially mediated leaf mass loss.
DOM and FPOM were also important products (5 and 3% of total mass los
s, respectively), whereas carbon flow to microbial biomass was low (2%
). Fungal biomass in leaves always exceeded bacterial biomass (95-99%
of total microbial biomass), but production of bacteria and fungi was
similar, indicating that both types of microorganisms need to be consi
dered when examining leaf decomposition in streams. Comparison of leaf
mass loss in coarse and fine mesh bags revealed, in addition, that th
e shredder, Gammarus pulex, had a major impact on leaf decomposition i
n this study.