These last years, in Romania, the management of semi-natural grasslands has become more and more deficient, while most of them were abandoned. Raising animals on private farms has become a rare practice, which led to a decrease of the grazing pressure on semi-natural grassland. Abandonment of the grassland surfaces represent a great problem among entire Europe, prevalent in the higher areas, one of the reasons being and the decrease of the number of animals those determining the dynamics of vegetation and biodiversity. Also, there were appeared deep changed in the quality and productivity of the vegetation cover. Knowing the dynamics of vegetation on pastures has become important in ecology, since pastures are one of the most important sources of food for both wild and domestic animals. The goal of the paper is to point out the effects of under-exploitation on biodiversity on some semi-natural grassland in Banat. The study took place in Western Romania in the hills of Surduc which are situated at the bottom of the Poiana Rusca Mountains, east from the Bega – Luncani River and north from the terraces of the Bega River. We have studied three semi-natural grasslands which we observed for five years (2005-2009). The floristic composition was determined with the help of the double meter (linear) method, and biodiversity was determined with the Shannon-Weaver index and the results were processed on the ground of the botanical sampling. The statistical method used was the analysis of the correlations among different parameters of the vegetation. As a conclusion, we can say that the dynamics of vegetation has a well-defined trend and that the biodiversity index has suffered changes year after year. That is why our goal to continue this study is to notify the specialist regarding implementation of some rehabilitation measurements for the biodiversity of these half natural pasture.

grasslands; biodiversity index; management

Presentation: oral