Among the characteristics of a plant population, a particular value is vested in those remaining invariant in different ecological conditions and random environmental fluctuations. These features can be interpreted within the metapopulation concept (here, the metapopulation means a set of relatively isolated local populations). The genus Alchemilla L. consists of more than 1000 taxa, about 300 of which have been described in Europe. Because of the large variation, the genus has been an object of widespread scientific interest since the last century. The structural indices approach was used in the taxonomy of 23 microspecies of Alchemilla L. (occurring in the Estonian flora) to overcome the problem of statistical incorrectness caused by testing the objectivity of taxa applying the same variables as those used to define them. The questions should be answered are the following. How distinct are microspecies according to the metric and count variables? How do the structural indices distinguish microspecies? What are the most stable proportions between characteristic variables? Which characteristics are most informative in microspecies distinction?
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2. Sepp, S., Nahtman, T., Möls, T, Paal, J. (2000). Study of the multivariate structure of the Estonian Alchemilla L. (Rosaceae) microspecies: an example of the structural indices approach. Proc. Estonian Acad. Sci. Biol. Ecol., 49, 289-301.
3. Pihu, S., Hõimra, J., Köster,E. , Pärtel, M. (2009). Environmentally Dependent Morphological Variability in Seven Apomictic Microspecies from Alchemilla L. (Rosaceae). Folia Geobotanica, 44, 159-176.