Ecological analysis of plant cover of the permanent grassland ecosystem located in the vicinity of Novi Kneževac, Serbia

A total of 205 taxa and stands of 12 plant communities were found to comprise the plant cover of the permanent grassland on the solonetz and solonchakic solonetz soils located in the vicinity of the town of Novi Kneževac (Vojvodina Province, Serbia). The registered taxa included 177 plant species, six subspecies, eight varieties, 13 forms and one lusus. The ecological analysis of the flora involved 191 taxa. That group consisted of 177 species, six subspecies, three varieties and five forms. The three varieties, Aster tripolium L. var. pannonicus ( Jacq.) Beck, Chenopodium rubrum L. subsp. botryoides Sm. var. crassifolium (Hornem) Kov. and Sonchus arvensis L. var. uliginosus (M.B.) Grec. were used for analysis because their higher taxonomic categories were not recorded in the studied flora. The five forms, Aster sedifolius L. f. subsquamosus Soó, Bromus commutatus Schrad. f. violaceus Podp., Mentha aquatica L. f. erromera Top., Poa bulbosa L. f. vivipara Koel. and Scleranthus annus L. f. minimus Schur., were used for the same reason. The ecological analysis encompassed stands of all 12 recorded communities, i.e. ass. Scirpo-Phragmitetum W. Koch 1926, ass. Bolboschoenetum maritimi continentale Soó (1927) 1957, ass. Acorelletum pannonici Soó (1939) 1947, ass. Puccinelletum limosae (Rapcs. 1927) Soó 1930, ass. Pholiuro-Plantaginetum tenuiflorae (Rapcs. 1927) Wendel. 1943, ass. Hordeetum histricis (Soó 1933) Wendel. 1943, ass. Camphorosmetum annuae (Rapcs. 1916) Soó 1933 corr. Soó 1938, ass. Agrostio-Alopecuretum pratensis Soó (1933) 1947, ass. Agrostio-Eleochariti-Alopecuretu geniculati (Magyar1928) Soó (1939) 1947, ass. Artemisio-Festucetum pseudovinae (Magyar 1928) Soó 1945, ass. Achilleo-Festucetum pseudovinae (Magyar 1928) Soó 1945 and ass. Festuco–Andropogonetum ischaemi Vučk. 1985. The ecological analysis of the plant cover indicated that halophytes made 30.37% of the flora of the permanent grassland near the town of Novi Kneževac, and that the stands of the recorded plant communities grew on sites that differed widely in the salt content in the rhizosphere soil layer. On average, these sites were moderately dry (F - 2.72) and moderately basic (R - 3.26), with moderate contents of nitrogen and nitrogen- containing substances (N - 3.07), a medium humus content (H - 2.94) and a moderately favourable aeration (D - 3.99). The plant cover of these sites, typical for meadows, was dominated by thermophilous plants adapted to full light (T - 4.05) but also to some shading (L - 3.84) as well as to the continental climate of the studied location (K - 3.27).