Some Ecological Peculiarities of Bulbocodium versicolor (Ker-Gawl.) Spreng. (Colchicaceae, Magnoliophyta) in the Lower Volga Region

Abstract

Abstract—This study presents the results of four years of observations of Bulbocodium versicolor (Ker-Gawl.) Spreng. populations in Saratov and Volgograd oblast. A low ecological plasticity of the species was established. Although the species is confined to steppe phytocenoses that vary in composition and structure, the morphology of specimens was rather conservative, which can be explained by the homogeneity of the vegetation conditions over the studied part of the range during active vegetation and flowering. It was shown that, in the Lower Volga region, B. versicolor is characterized by a reduced stress component of its life strategy and a low index of size plasticity. The species uses a patient strategy. Under stress conditions at the morphological level, plants react by miniaturizing the traits of the generative sphere, i.e., redistributing efforts from developing the generative sphere to maintaining the vegetative sphere. The ecotopic and phytocenotic tolerance of B. versicolor is manifested as the capacity to retain the occupied territory for a long time and to avoid competition by selection of the range. According to the conservation priority index, the majority of B. versicolor populations in the Lower Volga region are in a state close to endangered and their preservation requires immediate action. The main factors limiting the number of species in the region are probably aridization of climate and direct anthropogenic impact, which is reflected in the conversion of wildlands into arable land. There is no obvious negative impact on the species by intensive grazing and collection in bouquets. This may be attributed to the secluded location of the remaining species’ habitats that makes the species practically inaccessible in the period of massive flowering. This is primarily due to the fact that the remaining habitats of the species are relatively far from settlements and that during the period of mass flowering of the species they are virtually inaccessible to an impact from these factors due to the remote location.