НЕКОТОРЫЕ ОСОБЕННОСТИ ЭКОЛОГИИ BULBOCODIUM VERSICOLOR (KER-GAWL.) SPRENG. (COLCHICACEAE, MAGNOLIOPHYTA) В НИЖНЕМ ПОВОЛЖЬЕ

Abstract

The paper presents the results of our four-year observation of Bulbocodium versicolor (Ker-Gawl.) Spreng populations in the Saratov and Volgograd regions. A low ecological plasticity of the species was established. Although the species grows in steppe phytocenoses that vary in composition and structure, the specimens’ morphology was rather conservative, which can be explained by the homogeneity of the species’ vegetation conditions over the territory under study during active vegetation and flowering. It is shown that in the Lower Volga region, B. versicolor is characterized by the reduced stress component of its life strategy and a low index of size plasticity. The species uses a ‘patient’ strategy. Morphologically, plants respond to stress by a diminishment of the reproductive organs and the reproductive-to-vegetative transition. The ecotopic and phytocenotic tolerance of B. versicolor manifests itself in the species’ capacity to retain the occupied territory for a long time and to avoid competition via habitat selection. According to the conservation priority index, the majority of B. versicolor populations in the Lower Volga region are at high risk of becoming endangered and their preservation requires immediate action. The decline in the species’ size in the region is most likely induced by the climate aridization and direct human impact, specifically the transformation of wild lands to croplands. There is no decisive proof that overgrazing and gathering for bouquets have had any significant negative impact on the species. It may be attributed to the secluded location of the remaining species’ habitats that makes the species practically inaccessible in the period of massive flowering.