Life strategies of plants of meander bars

The article generalizes the data on life strategy of plants in meander bars by the example of the species Limosella aquatica L., Silene tatarica (L.) Pers. and Petasites spurius (Retz.) Rchb., taking into account their life span and centres of environmental impact of a specimen, as well as peculiar features of sustaining a coenopopulation. The annual monocarpic L. aquatica combines its typical ruderal strategy of leaving numerous posterity with vegetative accrescence and iterative branching. The taproot perennial S. tatarica shows a competitor-ruderal strategy: plants entrench themselves and repeatedly territory development the help of root systems, still the coenopopulation (CP) is sustained by means of seed propagation and, possibly, as a kind of support, in a vegetative way, using a bank of dormant buds. Ruderal-competitor strategy of P. spurius is supported by vegetative propagation, development, and entrenchment on the territory by means of clones constantly and regularly renewed. So life of plants belonging to different biomorphs in conditions of meander bars is provided by a full or partial shift to ruderal life strategy.

Flora of fallow lands of the Podlaski Przełom Bugu mesoregion

Studies on flora of fallow lands of the Podlaski Przełom Bugu mesoregion were carried out between 2001 and 2003 in the area of 77 localities, situated in 20 communes. A systematic list of fallow land flora was made and its variation with respect to occurrence frequency, biological spectrum, persistence and belonging to geographic-historical and sociological-ecological groups was analyzed. Flora of fallow lands of the Podlaski Przełom Bugu mesoregion includes 442 species included in 60 families and 241 botanical genera. The most numerous group comprises very rare, rare and quite frequent species. In the floristic composition of the analysed flora, apophytes (72.2%) predominate over anthropophytes (2.8%) as well as perennials (61%) over ephemerals (39%). Considering the biological spectrum of flora, hemicryptophytes (49%) and terophytes (32%) predominate over other life forms. Forest and shrub species (18.5%) as well as meadow (17%) and xerothermic sward plants (17.4%) have the largest share in the flora. The abundant occurrence of segetal (15.8%) and long-lived ruderal communities (8.1%) was also noted. Moreover, the occurrence of 25 species endangered with extinction in fallow land communities of the Południowopodlaska Lowland was noted. They are as follows: <i>Nigella arvensis</i>, <i>Potentilla recta</i>, <i>Platanthera chlorantha</i>, <i>Agrostemma githago</i>, <i>Prunella grandiflora</i>, <i>Populus alba</i>, <i>Silene tatarica</i>, <i>Papaver argemone</i>, <i>Papaver rhoeas</i>, <i>Veronica polita</i>, <i>Hieracium floribundum</i>, <i>Bromus secalinus</i>, <i>Polygonum bistorta</i>, <i>Geum alleppicu</i>, <i>Astragalus arenarius</i>, <i>Centaurium erythraea</i>, <i>Veronica agrestis</i>, <i>Veronica verna</i>, <i>Cirsium rivulare</i>, <i>Allium oleraceum</i>, <i>Hierochlo&#235; odorata</i>, <i>Chenopodium polyspermum</i>, <i>Vinca minor</i>, <i>Dipsacus silvestris</i> and <i>Campanula latifolia</i>.