Evaluation of the ecological succession in the gypsum quarry rehabilitation process using the Berger-Parker Index

There is no doubt of the serious impact of mining on the gypsicolous flora, especially the comparatively more restricted endemic taxa. Therefore, rehabilitation should aim particularly at the ecological recovery of the original environments. In this particular matter, the data on the subject of succession, a valuable concept to fully acknowledge the ecological systems, is essential when planning a restoration. In fact, nowadays there is a tendency towards the belief that succession ought and could be integrated within the planning strategy. The aim of this study is to overcome the lack of knowledge on successional stages in gypsum quarry rehabilitation processes in semiarid systems. The restoration strategy was mainly based on subsuperficial organic amendment (MSW compost) and topsoil replacement. The addition of organic amendment serves both physical (structural) enhancement and chemical (nutrient) reinforcement. Topsoil replacement on reclaimed mine lands is vital for improved infiltration, plant rooting media, enhanced nutrient cycling and as potential source of plant propagules to increase plant community diversity. A composition indicator (Berger – Parker index), at community – ecosystem level of organization, is suggested for monitoring gypsum quarry rehabilitation processes. The Berger – Parker index (measure of dominance) has been recommended as one of the most satisfactory diversity measures available. The rate of secondary succession was very fast. The pioneer stage lasted for only 1 year (Halogeton sativus), the tall weed stage 2 years (Moricandia arvensis), and the native perennial grass stage started in the fourth year (Brachypodium distachyon). Following the Berger – Parker index values, the vegetation could be divided into three succession stages, namely monodominant, subdominant and codominant species communities.