Morphometric and morphological analysis of Populus nigra L. leaves in flooded regions

Abstract

Human activity induced global changes in nature, particularly the flooding regime, which is a stress factor affecting wetland ecosystems. Knowledge of plant strategies of wetland vegetation across a range of flooding gradients is therefore very important. Natural flooding events are increasing as a consequence of constant climate changes. This research was focused on the area of Special Nature Reserve “Gornje Podunavlje” which represents a complex of peculiar marshland, originating from former vast inundated parts of the Danube basin. We have selected samples located on both sides of the embankment in the defended and in the flooded area. The main aim is the assessment of Populus nigra L. riparian tree leaf morphological traits variability (centroid size, shape, developmental instability, specific leaf area and petiole lenght) between two habitats (flooded and not flooded). The geometric morphometry methods were applied to provide visual representation of differences in the leaf shape. We employed leaf composite index indices of fluctuating asymetry as a measure of developmental instability. A statistically ­significant impact of flooding was obtained only for the leaf geometric size and shape, so these traits could be an indicator of flooding as suboptimal environmental conditions.