ACTA BIOLOGICA CRACOVIENSIA Series Botanica 47/2: 7-13, 2005

Relations between Betula pendula Roth (Betulaceae) Leaf Morphology and Environmental Factors in Five Regions of Croatia

Sanja Kovačić* and Toni Nikolić

University of Zagreb, Faculty of Science, Botanical Department with Botanical Garden, 
Marulićev trg 9, 10000 Zagreb, Croatia

*e-mail: sanja@botanic.hr

Received December 4, 2003; revision accepted March 3, 2005

In this research we used numerical analysis of environmental and morphometric data sets to study the possibility of environmental control of leaf morphology in Betula pendula stands from five regions of Croatia. The correlations were poor between leaf variables and the ecological gradients of the stands, as well as between the ecological, vegetational and biometric characteristics of the two morphologically most similar populations. This being so, we viewed the populations in the historical context. As two morphologically closest B. pendula populations grow in disjoined natural marshland vegetation with different environmental features, their similarity might be found in the genetic background, which should be further investigated. Possibly, at least in these two areas of its Croatian distribution range, B. pendula grows in its primary habitats from preglacial times, and is of older (relict) origin than in the rest of its recent Croatian (secondary) area of distribution, where it recolonized after the Ice Ages. 

Key words: Betula pendula, morphometry, leaf morphology, ecology, clinal variability, Croatia.