Communities with Ambrosia artemisiifolia L. in the Kursk Region

The purpose of this study is to characterize plant communities with Ambrosia artemisiifolia in the Kursk Region. The work is based on 32 relevés made by the author in the city of Kursk and few district centers­ of the Kursk Region in 2009–2018. Some information about natural conditions of the Kursk Region is given in Table 1. Classification is carried out according to Braun-Blanquet approach. The data were treated by IBIS 7.2 software package (Zverev, 2007). The names of the higher syntaxa follow to «Vegetation of Europe…» (Mucina et al., 2016). Synoptic tables include only species with a constancy above I. Ecological conditions (soil moisture, richness in mineral nitrogen, light) were assessed with the use of average values by H. Ellenberg et al. (1992) ecological scales while hemerobiality with use of average values by N. G. Ilminskikh (1993) ecological scale and processed by IBIS software (Zverev, 2007).

4 associations of 3 classes of vegetation were revealed.

Ass. Ambrosietum artemisiifoliae Viţălariu 1973 (alliance Atriplicion Passarge 1978, order Sisymbrietalia sophiae J. Tx. ex Görs 1966, class Sisymbrietea Gutte et Hilbig 1975). Table 2, relevés 1–12. Diagnostic species are Ambrosia artemisiifolia, Amaranthus retroflexus, Lactuca serriola, dominant one is Ambrosia artemisiifolia. Species of the class Sisymbrietea prevail in association coenoflora. Total cover is 60–80 %. Often there is a moss layer with total cover 1–60 %. 58 species are registered in association (the number of species per relevé is 6–27). Phytocoenoses are formed in xerothermic conditions on the gravelly substrate of railway embankments. Among syntaxa of the alliance Atriplicion within our region (Table 3), this association is the closest to ass. Kochietum densiflorae Gutte et Klotz 1985, which is also formed on railway embankments. Communities of both associations are characterized by the least moist habitats and the highest level of hemerobiality (Fig. 2). Area of ass. Ambrosietum artemisiifoliae extends fr om south-eastern Europe to the South Urals. The variation of the floristic composition in different regions (Table 4) is determined by specific conditions of community habitats.

Ass. Melilotetum albo–officinalis Sissingh 1950 var. Ambrosia artemisiifolia (alliance Dauco-Melilotion Görs ex Rostański et Gutte 1971, order Onopordetalia acanthii Br.-Bl. et Tx. ex Klika et Hadač 1944, class Artemisietea vulgaris Lohmeyer et al. in Tx. ex von Rochow 1951). Table 2, relevés 13–18. Diagnostic species of association are Melilotus officinalis, M. albus (which determine the physiognomy of communities); these of variant are Ambrosia artemisiifolia, Lotus corniculatus, Oenothera rubricaulis, Xanthium albinum. The grass layer usually is not close (30–55 %). 48 species are registered in syntaxon (the number of species per relevé is 18–28). The phytocoenoses are common on railway embankments and nearby sites. They are formed under strong anthropogenic impact and are at the earlier stage in succession series compare to the var. typica of this association (Arepieva, 2015, 2017), that’s why species of classes Sisymbrietea and Digitario sanguinalis–Eragrostietea minorisare more common there.

Ass. Odontito–Ambrosietum artemisiifoliae  Jarolímek et al. 1997 (alliance Dauco-Melilotion, order Onopordetalia  acanthii, class Artemisietea  vulgaris). Table 2, relevés 19–24; Fig. 3. Diagnostic species are Ambrosia artemisiifolia, Lolium perenne; dominant one is A. artemisiifolia. Species from classes Artemisietea vulgaris and Molinio-Arrhenatheretea (with small cover) accompany it. Total cover is 50–100 %. Sometimes there is a moss layer with small total cover. 59 species are registered in association (the number of species per relevé is 13–29). Communities are formed on construction sites and wastelands with strogly damaged and undeveloped plant cover. Association has the highest level of hemerobiality since periodic damages contribute to the formation of its phytocoenoses. Among syntaxa of the alliance Dauco-Melilotion within our region, this association is similar to ass. Artemisio–Oenotheretum rubricaulis Passarge 1977 in species composition (Table 5) and habitats (Fig. 4), and to ass. Ambrosietum artemisiifoliae in species composition (the Jaccard index is equal to 29.5 %). The similarity is in the dominance of Ambrosia artemisiifolia, as well as in the high constancy of some species. Part of species of initial successional stages is less represented in it (Tables 2, 6). Although species of classes Artemisietea vulgaris and Molinio-Arrhenatheretea are common in its communities, the prevalence of biennials and perennials is positioning it into class Artemisietea vulgaris.

Ass. Ambrosio artemisiifoliae–Bidentetum frondosae ass. nov. hoc loco (alliance Bidention tripartitae Nordhagen ex Klika et Hadač 1944, order Bidentetalia Br.-Bl. et Tx. ex Klika et Hadač 1944, class Bidentetea Tx. et al. ex von Rochow 1951). Table 2, relevés 25–32; Fig. 5,6; nomenclature type (holotypus hoc loco) — relevé 28 (author’s number — 1107); coordinates: 51.68447° N, 35.27555° E, 30.07.2016, Kursk Region, Lgov, wasteland on the right bank of the river Seym near the bridge on Karl Marx street. Author — L. A. Arepieva. Diagnostic species and dominants are Ambrosia artemisiifolia and Bidens frondosa. Total cover is 50–100 %. 73 species are registered in association (the number of species per relevé is 9–28). Both xeromesophyte species of initial successional stages (Atriplex tatarica, Bromus mollis, Sonchus arvensis) and species of wetland habitats (Bidens frondosa, Echino­chloa crusgalli, Persicaria lapathifolia, Agrostis stolonifera) are represented in coenoflora. Communities are formed in coastal ecotopes with variable moisture regimes. Phytocoenoses of derivate сommunity are more common on wetter and eutrophic soils and substrates (Fig. 7), that’s why there are more hygro- and nitrophilous species. Among syntaxa of the class Bidentetea within our region, this association is similar to derivate сommunity Bidens frondosa [Bidentetea] in species composition (Table 8). It has the highest level of hemerobiality that’s why species of the class Sisymbrieteaare common there (Table 9).

Communities with Ambrosia artemisiifolia and hygrophilous species are described in Serbia (Jarić et al., 2011) wh ere subass. Chenopodio–Ambrosietum artemisiifoliae bidentetosum Jarić et al. 2011 was recorded in abandoned fields. It is differentiated by biennials and perennials from classes Artemisietea vulgaris and Molinio-Arrhenatheretea and others (Table 10). The features of communities with Ambrosia artemisiifolia identified in this work are important for the development strategies to combat this dangerous plant.