Fallows and meadows: soil physico-chemical properties, vegetation composition, soil microbial communitites structure and functioning in standard conditions and under perturbation: climate change, biocides application.

Descriptive data of six ex-arable fallows and six nearby located wet meadows (Molinio-Arrhenatheretea) with high plant diversity. The study was performed in the years 2008-2010. The aim of this study was to compare two ecosystem types: established (meadow) and early successional (fallow) ecosystems. Meadows, if managed sustainably and systematically over time are relatively little-changing and long-lasting ecosystems with high plant diversity. In contrast, fallows are in the initial stage of secondary succession and have lower plant species richness. The questions asked were: 1) are the soil properties and soil microbial assemblages specific to ecosystem type? 2) are the soil microbial ecommunities in meadows stabler than in fallows? The two grassland types were compared in terms of soil microbial community structure and activity, followed by detailed physico-chemical examination of soils and descrption of plant communities composition. Community biomass and structure were studied with the following methods: substrate-induced respiration (SIR), phospholipid and neutral lipid fatty acid (PLFA and NLFA) analysis, bacteria and algae counts, mycorrhiza root infection frequency and root length. Microbial activity was compared between the two ecosystem types with the use of community physiological profiles on BiologTM Eco plates, growth activity on R2A plates, culturability, soil basal respiration rate, urease, acid and alkaline phoshomonoesterazes activities, cellulose decomposition, nitrogen mineralization rate and potential nitrification. Soil microbial communities from fallows and meadows were also compared for their resistance and resilience toward pesticides: the insecticide teflubenzuron, the bactericide bronopol and the fungicide captan, and to temperature changes. The results were described and discussed in the published papers by D. Chmolowska.