Branch of Institute of Natural and Technical Systems, RF, Sochi, Kurortny Av., 99/18
UDC 551.465 (262.5)
The dynamics of allelopathic activity of the upper 10-cm soil horizon in the forest ecosystems of the humid subtropics of the Sochi Black Sea region was assessed within seven months of the growing season. A series of field experiments in seven forest ecosystems with a monodominant stand included: 1) simulation of recreational loads in the options 1.39, 2.78, 4.17, 6.25, 8.33 people/ha, 2) soil sampling at time intervals, 3) determination of soil volumetric mass and allelopathic activity according to the germination of biotest seeds – radish using standard methods.
Under control conditions, the allelopathic activity of the soil depends on the species composition of the forest stand, varying from April to October in the range of 7.8–71.5%, making up a series according to the degree of activity decrease: Quercus pubescens, Carpinus caucasica, Quercus petrea, Buxus colchica, Fagus orientalis, Castanea sativa, Taxus baccata. In recreationally disturbed ecosystems, depending on the tree species, the value of a one-time recreational load and the time elapsed after the recreational impact, allelopathic effects can manifest both stimulation and inhibition of growth processes. The recovery time of the disturbed allelopathic regime is closely related to the recreational load and characterizes the resistance of the edaphic component to the recreational impact, decreasing in the series: Castanea sativa, Taxus baccata, Buxus colchica, Quercus pubescens, Quercus petrea, Fagus orientalis, Carpinus caucasica. Series were compiled for resistance to the introduction of new species under the canopy of a forest stand in the range of recreational loads of 1.39–8.33 people/ha.