TY - JOUR
T1 - Early decomposer assemblages of soil organisms in litterbags with vetch and rye roots
AU - Georgieva, Slavka
AU - Christensen, Søren
AU - Petersen, Henning
AU - Gjelstrup, Peter
AU - Thorup-Christensen, Kristian
N1 - Keywords: Decomposition; Plant residues; Bacteria; Fungi; Protozoa; Nematodes; Microarthropods; Decomposer assemblages; Resource quality; Intraguild predator–prey interactions; Hairy vetch; Rye
PY - 2005
Y1 - 2005
N2 - The assemblages of microbial (bacteria and fungi), microfaunal (protozoa and nematodes) and mesofaunal (microarthropods) populations were studied in decomposing root residues from hairy vetch (Vicia villosa Roth) and rye (Secale cereale L.) in a litterbag field experiment. Litterbags containing vetch or rye root residues were buried in soil at the same day as either vetch or rye winter catch crops were incorporated into the field soil from which the materials were gathered. The litterbags were sampled after 6 weeks in the field. In vetch, bacterial and fungal biomasses were similar whereas fungi dominated microbial biomass in rye. The biomass of the bacterial consuming fauna dominated by nematodes and microarthropods was similar to the biomass of bacteria in vetch as opposed to in rye where bacterivore biomass was lower than bacterial biomass. This suggests a much higher bacterial production in vetch compared to rye. Furthermore, in vetch dauer larvae of bacteria feeding nematodes prevailed, which is also a sign of high bacterial production followed by food shortage for the bacterivores. Bacterivorous and predatory nematodes with capability of consuming protozoa showed an inverse relationship to flagellated protozoa. This suggests that these nematodes controlled the protozoan biomass constituting a lower fraction of the bacterivore biomass in vetch compared to in rye. Such intraguild predator-prey relationship is therefore indicated for microbivorous organisms among bacterivorous and predatory nematodes (the intraguild predator) protozoa (the intraguild prey) and bacteria (the common prey). The much higher fungal biomass in rye than in vetch litterbags was not reflected in the biomass of the fungal feeders. Due to the generally lower intrinsic rate of increase of the fungivores, as well as of the omnivores and predators, in comparison with the bacterial feeders, they were not able to generate dense populations at this early stage of decomposition.
AB - The assemblages of microbial (bacteria and fungi), microfaunal (protozoa and nematodes) and mesofaunal (microarthropods) populations were studied in decomposing root residues from hairy vetch (Vicia villosa Roth) and rye (Secale cereale L.) in a litterbag field experiment. Litterbags containing vetch or rye root residues were buried in soil at the same day as either vetch or rye winter catch crops were incorporated into the field soil from which the materials were gathered. The litterbags were sampled after 6 weeks in the field. In vetch, bacterial and fungal biomasses were similar whereas fungi dominated microbial biomass in rye. The biomass of the bacterial consuming fauna dominated by nematodes and microarthropods was similar to the biomass of bacteria in vetch as opposed to in rye where bacterivore biomass was lower than bacterial biomass. This suggests a much higher bacterial production in vetch compared to rye. Furthermore, in vetch dauer larvae of bacteria feeding nematodes prevailed, which is also a sign of high bacterial production followed by food shortage for the bacterivores. Bacterivorous and predatory nematodes with capability of consuming protozoa showed an inverse relationship to flagellated protozoa. This suggests that these nematodes controlled the protozoan biomass constituting a lower fraction of the bacterivore biomass in vetch compared to in rye. Such intraguild predator-prey relationship is therefore indicated for microbivorous organisms among bacterivorous and predatory nematodes (the intraguild predator) protozoa (the intraguild prey) and bacteria (the common prey). The much higher fungal biomass in rye than in vetch litterbags was not reflected in the biomass of the fungal feeders. Due to the generally lower intrinsic rate of increase of the fungivores, as well as of the omnivores and predators, in comparison with the bacterial feeders, they were not able to generate dense populations at this early stage of decomposition.
U2 - 10.1016/j.soilbio.2004.11.012
DO - 10.1016/j.soilbio.2004.11.012
M3 - Journal article
SN - 0038-0717
VL - 37
SP - 1145
EP - 1155
JO - Soil Biology & Biochemistry
JF - Soil Biology & Biochemistry
IS - 6
ER -