This paper presents the result of researches on the segetal flora of the Bolimów Nature Park. The segetal flora of this area comprises 282 taxons of vascular plants. Apophytes (171 taxons) and therophytes (170 taxons) constitute the most numerous group. There are 54 taxons on the list threatened segetal plants.
In Poland, like in other parts of Central Europe, dry grasslands significantly contribute to the biodiversity of both fauna and flora. Anthropogenic pressure impair many species of xerothermic habitats, and several populations face an increased risk of extinction. The goal of the study was to define factors that may affect the size of wild populations of Anemone sylvestris L., a protected species in Poland, with both a short- and long-term perspective, and to examine the influence of vegetation changes on the density, the abundance of flowering and male function (pollen production, pollen viability), as well as seed set. In situ observations were performed in 2005-2006 and 2011-2012 in three populations located on the Lublin Upland, SE Poland. The reduction in population density and A. sylvestris blooming was exacerbated by the expansion of the shrubs, but not by Brachypodium pinnatum. Male characteristics of A. sylvestris, i.e. pollen amount per multi-staminate flowers or pollen viability appeared to decrease under pressure of shrub competition. Populations with limitation of male function had impaired degree of seed set. Various consequences for the functioning of populations within a metapopulation system can be expected due to substantial qualitative and quantitative disorders in pollen traits. It is crucial that successful recovery programs for A. sylvestris primary should aim to conserve and manage the habitat.
Chrysanthemum segetum is a rare species in Poland, which is within the easternmost extent of its range. The species is an anthrophyte that is not native to Poland. The aim of the present study was to determine the the present-day distribution of the species on the basis of field investigation, revised herbarium materials, review of the literature, and both published and unpublished data. Altogether, the species was found at 281 sites in 92 ATPOL squares in Western Pomerania.
Along a 4.8 km long stretch of the ecological corridor of the lêza river, 175 patches dominated by Helianthus tuberosus s.l. were found. Among them, about two-thirds are not bigger than 4 m2, but many of the other patches cover areas of several hundred square meters to about 1300 m2. The effect of the H. tuberosus stands on the vegetation of anthropogenic habitats was studied at two sites: one post-agricultural and one post-industrial. At both sites, a system of transects with study plots was laid out. The transects began outside of the H. tuberosus stands (stage A) and penetrated their inside comprising three distinguished stages (B to D) of increasingly higher and denser thickets of sunflower. No significant differences between habitats were found. At both sites, there was a strong decrease in the number and biomass of co-occurring species only in the older stages (C and D) of thicket development, but not at the edges (B), where short H. tuberosus individuals strongly compete with other species.