Changes to Species Diversity of Vegetation Communities During Restorative Successions in Different Types of Forests

In this work, we study changes in species diversity of vegetation communities during restorative successions at logging sites in different types of forests, using the South Ural region as an example. Data from 180 geobotanical relevés of logging sites and secondary forests of different ages of the four main types of the South Ural region forest communities (cool-temperate dark-coniferous, nemoral broad-leaved, hemiboreal light-coniferous and boreal light-coniferous forests) were analyzed. Trends in changes to species diversity manifest themselves in different ways during each stage of the ‘native forest – logging – secondary forest' succession sequence. In broad-leaved and cool-temperate dark-coniferous forests, changes in species diversityfollow the parabolic trajectory during restorative successions at clear-cutting sites; in other words, the diversity initially increases and then decreases during the progress of the succession. This is caused by the introduction of invasive synanthropic species during the early stages of the succession. The level of species diversity at clear-cutting sites in hemiboreal light-coniferous forests barely changes due to the rapid expansion of reed grass, which prevents the invasion of synanthropic species in the logging areas. Keywords: species diversity, restorative succession, logging, secondary forests, synanthropic specie