Features of Spatial and Temporal Dynamics of Tuberous Orchid Populations

Abstract

Features of the long-term fluctuation dynamics of populations of tuberous orchids (Neottianthe cucullata and Dactylorhiza incarnata) growing under various phytocenotic and climatic conditions are shown as a result of the functioning of a mechanism providing population stability in a heterogeneous habitat. The capability of the population to occupy microsits with favorable conditions determined by the dynamics of climatic factors, the abiotic environment, and interspecific relations has been shown. The irreversible dynamics of tuberous orchid populations determined by demutative and digressive successions in plant communities and influenced by abiotic, biotic, and anthroogenic impacts results not only in the reduction of population magnitude and density, but also in violations in the spatial and ontogenetic structure of the population. A correlation between the population magnitude and climatic factors has been evaluated using a correlation coefficient, the value of which was high for generative plants of forest species (N. cucullata) and for juvenile plants of meadow species (D. incarnata).