title: Soil food web changes during spontaneous succession at post mining sites: a possible ecosystem engineering effect on food web organization?
abstract: Parameters characterizing the structure of the decomposer food web, biomass of the soil microflora (bacteria and fungi) and soil micro-, meso- and macrofauna were studied at 14 non-reclaimed 1- 41-year-old post-mining sites near the town of Sokolov (Czech Republic). These observations on the decomposer food webs were compared with knowledge of vegetation and soil microstructure development from previous studies. The amount of carbon entering the food web increased with succession age in a similar way as the total amount of C in food web biomass and the number of functional groups in the food web. Connectance did not show any significant changes with succession age, however. In early stages of the succession, the bacterial channel dominated the food web. Later on, in shrub-dominated stands, the fungal channel took over. Even later, in the forest stage, the bacterial channel prevailed again. The best predictor of fungal bacterial ratio is thickness of fermentation layer. We argue that these changes correspond with changes in topsoil microstructure driven by a combination of plant organic matter input and engineering effects of earthworms. In early stages, soil is alkaline, and a discontinuous litter layer on the soil surface promotes bacterial biomass growth, so the bacterial food web channel can dominate. Litter accumulation on the soil surface supports the development of the fungal channel. In older stages, earthworms arrive, mix litter into the mineral soil and form an organo-mineral topsoil, which is beneficial for bacteria and enhances the bacterial food web channel.
authors.affiliation: Institute of Soil Biology, Biology Centre Academy of Sciences of the Czech Cepublic, České Budějovice, Czech Republic ; Institute for Environmental Studies, Charles University, Prague, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Frouz
authors.forename: Elisa
authors.initials: E
authors.lastname: Thébault
authors.forename: Václav
authors.initials: V
authors.lastname: Pižl
authors.forename: Sina
authors.initials: S
authors.lastname: Adl
authors.forename: Tomáš
authors.initials: T
authors.lastname: Cajthaml
authors.forename: Petr
authors.initials: P
authors.lastname: Baldrián
authors.forename: Ladislav
authors.initials: L
authors.lastname: Háněl
authors.forename: Josef
authors.initials: J
authors.lastname: Starý
authors.forename: Karel
authors.initials: K
authors.lastname: Tajovský
authors.forename: Jan
authors.initials: J
authors.lastname: Materna
authors.forename: Alena
authors.initials: A
authors.lastname: Nováková
authors.forename: Peter C
authors.initials: PC
authors.lastname: de Ruiter
mesh_terms: D018153:Czech Republic; D017753:Ecosystem; D020387:Food Chain; D008906:Mining