Mountain Nardus stricta grasslands as a relic of past farming – the effects of grazing abandonment in relation to elevation and spatial scale

Abstract

The decline of grazing management in mountains has resulted in a dramatic decrease of areas occupied by semi-natural grasslands with Nardus stricta. In order to effectively protect existing fragments, it is important to understand the mechanisms governing the organization of communities with Nardus. The aim of this study was to quantify the relative impact of the time span of abandonment and also of topographic and spatial factors on the species composition of montane and subalpine grasslands. Old and recent phytosociological data from three distinct regions in the northern part of the Carpathians were compared by indirect and direct ordination methods. The majority of the explained variation at the supraregional scale was associated with the joint effect of spatial trends and elevation above sea level. At the intraregional scale, the contribution of land use abandonment was much greater, particularly at low elevations with warmer and drier environmental conditions. The results suggest that the effects of grazing abandonment depend on natural factors such as elevation and climate. Conservation programmes for Nardus grasslands should take into consideration their position along the elevational gradient. In the lower montane zone, management measures should ensure a low nutrient level to restrict the spread of nitrophilous plant species.