Taxonomic Diversity and Selection of Functional Traits in Novel Ecosystems Developing on Coal-Mine Sedimentation Pools

Abstract

Coal-mine sedimentation pools are extrazonal habitats in which the anthropogenic changes of all historic, abiotic, and biotic components, followed by conditions of extreme environmental stress, lead to the formation of novel ecosystems. Our study aims to (i) classify the vegetation on the basis of floristic and ecological criteria, (ii) detect the main environmental gradients responsible for the diversity of vegetation, and (iii) present the selection of species’ functional traits along environmental gradients. A cluster analysis of the floristic data revealed 14 distinct combinations of species. Short- and long-lived ruderals, meadow, xerothermic, and psammophilous species make up the floristic composition of vegetation. A canonical correspondence analysis on the floristic data and average Ellenberg’s indicator values confirmed moisture, soil reaction, and salinity as the main gradients, while fertility and insolation were secondary gradients shaping the diversity of vegetation. A RLQ with a subsequent cluster analysis revealed four groups of species traits selected along environmental gradients. These differed with reference to morphological (canopy height) and physiological traits (specific leaf area, or SLA), as well as persistence (life span), regeneration (reproduction by seeds or vegetative reproduction), and dispersal functional traits. This knowledge can be crucial when planning the restoration of these sites by using spontaneous succession and learning how the various environmental resources can be used to restore or provide new ecosystem services.