In the absence of a pronounced anthropogenic impact, allelopathic tension in forest ecosystems of the main formations of the Sochi Black Sea region and its influence on the saturation of phytocenoses with an adventive plant group are analyzed. The studies were carried out in 38 forest ecosystems of 7 formations at 13 stationary sites in the foothill zone. The absence of anthropogenic load was determined by the average bulk soil mass and the class of atmospheric air pollution. The аllelopathy environment of individual trees was assessed according to the activity of the forest floor of 21 tree species recorded in the analyzed forest communities. The tension of biotopes in ecosystems was assessed with the joint growth of 1 to 5 tree species in the main canopy. The activity of water-soluble colins was determined by biotesting of water extracts from forest litter according to A.M. Grodzinsky. The activity of the solutions was assessed by the index of allelopathic activity. It is shown that the magnitude of the contribution of the influence of phytocenosis to the allelopathic background of the biotope depends on the species-specific features of the stand and the manifestation of a synergistic or antagonistic effect of аllelopathy related to the level of species completeness of communities. An increase in species completeness to 0,4-0,6 is accompanied by an increase in the synergistic effect, a decrease in the intensity of the аllelopathic background and saturation with adventive species, with their proportion increasing by 11,9-21,5%. An increase in the species completeness by more than 0, 6 is statistically reliably accompanied by a decrease in the synergistic effect and a transition to antagonism, with an increase in allelopathic tension in the community, increasing the proportion of native species, reducing the number of free niches for adventive species and the level of vulnerability of communities to their introduction and distribution.
Allelopathic tension of biotopes in forest ecosystems of wet subtropics
