Conjugate occurrence of species as a marker of parcellas at Festuca varia grassland of alpine zone in the Northwest Caucasus

A method for studying mosaicism is proposed. The co-occurrence of species was studied on 5×5 cm quadrats in the Festuca varia grassland of the alpine belt of the Malaya Khatipara Ridge of the Teberda National Park. For each quadrat, the presence of species and the number of their shoots over 5 years were recorded. Conjugate occurrence was studied by analyzing Spearman correlation matrix, occurrence of all species among each other and soil depth. The Festuca varia grassland is a monodominant community with Festuca varia occupying the deepest areas. A small number of species that can grow in its turf are correlated with it: usually one per quadrat. The dominant species had negative correlations with most of the other species. Most species are part of a larger pleiad occupying smaller plots. Among them, 2 parcellas were identified, with negative correlations with each other. The larger parcellus of these breaks up into two groups with a core of joint species. The smaller parcellus consists of 3 species of densely turfed grasses and 2 species that can grow in the turf of Avenella flexuosa . The position of Hieracium lactucella depends on its vitality: when it is low, it is a member of the large pleiad of species, when it is high, it displaces all species except Carex huetiana .