Analysis of factors affecting the regeneration of major forest-forming species in the pine forests of the southern Moscow region

We carried out a quantitative analysis of the dependence of the vitality and species composition of tree undergrowth in pine forests of the southern Moscow region on a complex of biotic, abiotic, and edaphic factors. The paired sampling plots were established (consisting of sub-plots with and without undergrowth). The stand characteristics, the dominating species of the ground layer vegetation were determined, and the light intensity, the thickness and moisture of forest floor, the concentration of carbon and nitrogen in forest floor and mineral soil were measured on each of sub-plots. We used the principal component analysis, a pairwise comparison of environmental factors on sub-plots with and without undergrowth, as well as multiple multivariate correlation analysis for data processing. The results of the study showed that the main factors affecting natural regeneration are soil characteristics and light regime, while the influence of the forest ground vegetation on tree regeneration was not identified.