Agrology (Nov 2022)
Ecological evaluation of the adventitious fraction of dendroflora and analysis of the biodiversity of the flora of the Tunelna Balka Tract (Dnipro, Ukraine)
Abstract
The paper presents the study of the state of seed self-regeneration of woody plants of the Tunelna Balka Tract in the conditions of the city of Dnipro, Ukraine. Three sites with different levels of recreational load (strong, moderate and absent) were studied. The following floristic methods of research were applied – elucidation of the taxonomic composition and selection of the adventitious fraction of dendroflora, methods of species richness assessment (according to the Menkhinik index and Margalef index), determination of floristic commonality (according to the Jacquard index) and floristic homogeneity (according to the Koch index of biotic dispersion), methods of ecological analysis (by biomorphs and ecomorphs), physical, physicochemical, chemical methods of soil analysis, statistical methods of data processing (descriptive statistics and correlation analysis). We determined that in the Tunelna Balka Tract, cultured stands are capable of forming a sufficient amount of viable young plants of autochthonous and introduced (adventurous) species, the ratio of which is 47.4% to 52.6%. The number of young woody advent plants in the areas according to the level of recreational load was distributed as follows: with no load – 38.8% of the number of self-regenerating trees, with moderate – 29.0%, with strong – 69.1%. The Margalef and Menkhinik species richness indices of self-regenerating tree species for the site under heavy recreational load was the lowest compared with the sites subject to no and moderate recreational loads. Evaluation of the qualitative commonality of the species composition of the experimental sites with self-regenerating tree species showed the presence of a trend towards maintaining the diversity of the flora of the sites, which is achieved precisely due to the different level of recreational load. The calculated Koch index of biotic dispersion (26.1%) indicates a sufficiently low level of floristic homogenization in the studied territory of the tract. The correlation coefficient between the number of introduced and self-regenerating autochthonous tree species for the site under no recreational load turned out to be insignificant and weak (0.27), for sites with a moderate and strong level of recreational load – significant and strong (0.96 and 0.91, respectively). Therefore, the studied areas have a low degree of floristic homogeneity, which is confirmed by the low index of floristic commonality. We determined that the species richness of the self-regenerating dendroflora of the studied territory depends on the level of recreational load, and its strong level determines the low species richness. We should emphasize the need to analyze and predict the possible remote consequences of the introduction of alien species in the composition of the dendroflora.
