Relationships between respiration, chemical and microbial properties of afforested mine soils with different soil texture and tree species: Does the time of incubation matter

Respiration is a simple method to describe the overall condition of soils. Most usually, it is suggested CO2 evaluation after 7 days. Our study compared the relationship between soil respiration measured at different periods of times (one and eight weeks and cumulative respiration), as well as basic soil properties and the quantification microbial and fungal communities and their activity. We located our research on three sites with post-mine soils in Poland afforested by pine, birch and oak. Each site had soil derived from different substrate. The samples were taken from the fermentation layer (Oe) and mineral soil layer (A - at 0-5 cm beneath the Oe). In both studied layers basic soil properties such as: pH and C, N contents were analysed while soil texture was determined in A layer only. Microbial respiration was measured after each week of the eighth weeks incubation period. Microbial analyses included determination of ergosterol and phospholipid fatty acid (PLFA) profiles. Microbial respiration was nearly two time higher after the first week than the eighth week in both soil layers. Forest type and soil substrate had an effect on respiration in the Oe layer at both measurement times. Respiration in the A layer measured in the eighth week was affected only by the soil substrate. In the Oe layer, fungal decomposers play a lead role, and their activity was affected both by tree species and soil substrate. In the A layer, however, bacteria activity was predominated and was affected by tree species and substrate composition.