Plant communities of the cultivated fields of the Podlaski Przełom Bugu mesoregion. Part 2. Cereal communities

Abstract

Plant communities of the cultivated fields of the Podlaski Prze³om Bugu mesoregion. Part 2. Cereal communities (Otrzymano: 20.12.2004) S u m m a r yPresence of communities without species characteristic for cereal associations was observed in the cultivations of the Podlaski Prze³om Bugu mesoregion. Community Scleranthus annuus and community with species characteristic for alliance Aperion spica-venti were observed in winter cereals. Phytocoenoses similar in floristic composition to root cultivations were noted in spring cereals of the studied area. Plots of communities with participation of species characteristic for alliance Panico-Setarion were observed on loose soils while on more compact and fertile habitats community with species characteristic for Polygono-Chenopodion was noted.

Species diversity of segetal communities in tuber crops and in winter and spring cereals

“…Although it is widely believed that the differences between communities in winter cereals, spring cereals and tuber crops are disappearing [20,24], there is a group of weeds specific to one group of crops, for example winter cereals (Nigella arvensis, Agrostemma githago, Veronica triphyllos and others), which are rarely found in other crops. In turn, communities developing in spring cereals are intermediate between associations characteristic for winter cereals and tuber crops due to a shorter growing season and better thermal and light conditions [25][26][27][28][29][30], which affects the occurrence in these crops of thermophilic species accompanying tuber crops. To sum up, both production intensification and the land use structure negatively influence the biodiversity of segetal communities.…”

Associations and communities of cereal crops of the Łuków Plain. Part III. Intermediate and impoverished communities

“…This process in the study area was reflected in an occurrence of impoverished communities including characteristic species of Aperion spicae-venti and communities with Scleranthus annuus. Such phytocenoses are often found in Poland [14][15][16][17][18][19][20][21].…”

“…Special habitat conditions in spring cereal stands, in particular thermal and light conditions which are much better compared with winter cereal stands, and a shorter growing season result in an establishment in such stands of communities dominated by species characteristic of tuber and root crops [20][21][22]. In spring cereal stands in the Łuków Plain area, it was the community which included species characteristic of Panico-Setarion and the intermediate community Aperion spicae-venti with Polygono-Chenopodion species.…”

“…However, Kozak [29] have classified spring cereal communities as the communities which are the same as those in tuber and root crops, and stressed that they belong to the alliance PanicoSetarion. Skrajna and Skrzyczyńska [21], Rzymowska and Skrzyczyńska [20] and Skrajna et al [30] have demonstrated the same attitude towards spring cereal communities and classified them as belonging to alliances of tuber and root associations of the Polygono-Chenopodietalia order.…”

“…Anthropogenic factors include changes in agrotechnology and fragmentation of fields which makes it easier for weed diaspores spread [4,31]. Intermediate communities in other parts of Poland have been reported for example by: Anioł-Kwiatkowska [15], Wnuk [26], Szmeja [32], Kozak [29], Skrzyczyńska and Marciniuk [17], Rzymowska and Skrzyczyńska [20], Skrajna and Skrzyczyńska [21], Skrajna et al [30].…”