Altitudinal Assessment of Grassland Vegetation Based on Vegetation Indices. Case Study: the Banat Mountains

Abstract

Grasslands are essential agro-pastoral ecosystems in the Banat Mountains, contributing both to maintaining biodiversity and to supporting traditional land use activities. The purpose of this work is to evaluate the altitudinal distribution and vegetation cover of grasslands included in protected areas, by integrating spatial analyses with indicators derived from satellite images. The methodology included three stages: delimitation and quantification of grassland areas on altitudinal levels, identification of grasslands located above 500 m altitude and superimposed on protected natural areas, analysis of the degree of concentration at the area level and evaluation of the vegetation cover based on the NDVI (Normalized Difference Vegetation Index). The results show that an overwhelming proportion of grasslands (over 80% of the total 70,335 ha) are concentrated at altitudes below 700 m, while areas above 1100 m amount to less than 2%, indicating the strong dependence on the conditions of the lower mountain level. The grasslands included in the protected areas and located above 500 m cover 7,834.38 ha and present an uneven distribution between the TAUs, which is confirmed by the high value of the Herfindahl-Hirschman concentration index (HHI=0.80), which suggests a marked degree of polarization of the pastoral resource in only a few territories. The NDVI values, between 0.04 and 0.74 (mean = 0.56), show a generally favorable state of vegetation, almost 60% of the area being characterized by large and very high coverage. The study underlines the need for continuous monitoring of mountain grasslands in order to substantiate effective management measures for pastoral ecosystems in the Banat Mountains.