Weeds of ruderal habitats of Gatchina (Leningrad Region)

Weeds can grow both on segetal and ruderal habitats, including outside the agroecosystems of farms. Therefore, it is necessary to study their distribution not only in the fields. The purpose of the study is to identify the species composition of weeds and its features in the ruderal habitats of Gatchina (Leningrad Region). Ruderal habitats were monitored, 78 species of weeds from 62 genera and 21 families were identified. Perennial species prevailed in life expectancy. The taxonomic structure of the species composition has been established. Five families prevailing in terms of the number of species and genera are identified. Calculation of occurrence and assessment of its constancy by classes were carried out. The occurrence of the V class of constancy has 7 species, IV class - 10 species, III class - 8 species, II class - 11 species, I class - 42 species. Groups of 25 dominant and 11 concomitant species were identified. The relationship between species compositions of weeds of ruderal habitats of Gatchina and fields of the Leningrad Region was revealed - 55.56 % of weeds dominating in the fields of the region with different occurrence were registered in ruderal habitats.