| Popis: |
Tetínské skály Nature Reserve is one of the major sites for the presence of protected species, which are Dianthus gratianopolitanus, Saxifraga rosacea subsp. Sponhemica and Saxifraga paniculata. My goal was a field survey and data collection about the incidence of these species on the surfaces of rock walls, followed by identification of key environmental factors and description of their impact on the species. Such survey has not been conduncted so far. I used mainly multivariate analysis, PCA and RDA and One-way ANOVA to determine the interrelationships. The analysis results showed significant differences in species abundances influenced by different combinations of environmental factors. The factors with significant influence include cardinal direction. The highest proportion of species abundances showed areas of eastern orientation. Another important factor was shading from vegetation, which proved to have strong negative impact on abundace, especially for species S.rosacea subsp. sponhemica and D. gratianopolitanus. These two variables indicate a preference for sunny areas. Other factors with a significant influence on the occurrence of species are also a presence of soil surface rock wall and a presence of gardens in the area over the rock wall, which greatly increased the proportion of... |
