Relative competitiveness of adventive plant species in herbaceous communities of the Western Caucasus.

摘要

The relative competitiveness of adventive plants in herbaceous communities of the Western Caucasus is analyzed using a simple mathematical model, S_a=N_a (S/N), where N and S are the numbers of vascular plant species on 15-m2 and 0.5-m2 plots, respectively, and N_a and S_a are the numbers of adventive plant species on 15-m2 and 0.5-m2 plots, respectively. The model is based on two assumptions: (1) stochastic character of the processes of species immigration and extinction occurring on the area of plant communities, and (2) ecological equivalence of indigenous and adventive species. If adventive species of a herbaceous community are characterized by a higher or lower competitiveness as compared with indigenous species, then one should expect the actual number of these species on 0.5-m2 plots to be higher or lower as compared with the number calculated using this model. The communities of low-mountain and mid-mountain near-riverbed shoals, forest glades, steppe meadows, annual crop fields, fallow lands, and the herbaceous layer of low-mountain forest communities are chosen as the objects of this study. The results show different competitiveness of adventive plants in different herbaceous communities of the Western Caucasus.Notes Translated from Rossiiskii Zhurnal Biologicheskikh Invasii (2012) No. 2, 2-15 (Ru).Digital Object Identifier http://dx.doi.org/10.1134/S2075111712040029