Scientific publications

A significant amount of scientific papers devoted to the problem of soils’ genesis under forest cuttings in conditions of the middle taiga zone is published. However, they do not contain enough information on the soils formed on bedrocks. In this regard, the aim of the work was to study the process of such soils’ transformation resulting from pine stands’ clear-cutting in Karelia. The undercuts of 3- and 9-year-old cuttings of pine forests were the objects of the study. The sample area undisturbed by cuttings of pine stands located in blueberry forest was used as a controlling area. It was established that in the initial stages of natural reforestation the emergence of deciduous tree species resulted in the change of the soil’s morphological structure and its chemical characteristics. With age, deforestation provides gradual increase of the forest floor capacity due to the enlarged amounts of deciduous litter entering the soil’s surface. In the process of soil recovery its acidity decreases, the content of total nitrogen increases, narrowing the ratio C/N, and an intensive organic matter mineralization occurs. An active organic litter transformation on the 3-year old cuttings results in the development of an OA horizon, and in 9 years it leads to the formation of the humus horizon. After a prolonged period of rest following the anthropogenic impact reserves of the organic matter in the upper organogenic horizon increase. The reserves also become more ample in the 30 cm layer of the rooting zone (8 and 43 t/ha in 3-year-old and 9-year-old clear cuts, respectively). However, in the first years after logging, they remain 2-3 times lower in comparison with the controlled area. The obtained data can be used to predict essencial characteristics of the soil upon clear-cut operations.