The Influence of Climatic Factors on Clonal Diversity in a Population of Iris pumila

Abstract
An attempt is made to determine whether clonal colour diversity currently existing in a population of Iris pumila was causally related to variation in some climatic factors. It was observed that temporal changes in temperature condition affect the magnitude of clonal diverity in the L. pumila population. A highly significant positive correlation was found between the cohort diversity and the mean spring temperatures at the flowering phase of their sexual progenitors, and a significant negative correlation between cohort diversity and the mean winter temperatures two years before the cohorts were detected. Differential requirements of various life-stages of I. pumila for particular temperature conditions, as well as differential pollen transfer rate at different temperatures might explain these inverse correlations. It is supposed that a combination of fluctuating temperatures giving rise to environmental heterogeneity and a varied attractiveness of diverse colour morphs to pollinators promotes stable coexistence of multiple colour variants in the population of I. pumila.