The effect of reforestation on microbial activity in post-agrogenic soils in European part of Russia

Microbial activity in post-agrogenic sod-podzolics, grey and dark-grey forest soils was studied. The soils represented consequent stages of reforestation on agricultural lands across the forest site types. The stages of post-agrogenic soil succession included arable, abandoned lands of various ages, and forest coenoses. We measured organic carbon (Corg), total nitrogen (N), pH, water holding capacity (WHC), basal respiration (Vbasal), microbial carbon (Cmic) and indicators of functioning of microbial communities: metabolic quotient (qCO2), Cmic/Corg ratio; basal respiration rate (Vbasal/Corg) in samples from 0–10 cm and 10–20 cm of soils. We have found that conversion of an arable soil to grassland or woodland resulted in accumulation of organic carbon in 0–10 cm layer, and consequently to rise of soil respiration, and pool of microbial carbon. On the other hand acidity grew significantly in the 10–20 cm layer owing to podzolisation in the forest, which decreased Vbasal and Cmic concentration. Microbial indicators (Vbasal and Cmic) and other soil properties (Corg, N, WHC) had the highest correlations at every stage of post-agrogenic succession. The dynamics of changes of all soil properties during post-agrogenic development was controlled by the following (in order of relevance): forest domain/soil type > age of abandoned field ≈ depth in ploughed layer. © 2018, Izdatel'stvo Nauka. All rights reserved.