Nitrogen deposition is generally considered as a main reason for many recent plant expansions, but management changes are often not taken into account. Understanding the effects of agriculture management in the past can be decisive in the explanation of plant expansions at present. In order to understand the spread of <em>Molinia caerulea</em> and <em>Calamagrostis villosa</em> into <em>Nardus stricta</em> dominated subalpine grassland in the Giant Mts. (Krkonoše, Karkonosze), we undertook an experiment to explain farmer decision making and we discussed its effect on grassland succession. We measured mowing productivity, yields, biomass quality and nutrient removal in <em>N. stricta</em>, <em>M. caerulea</em>, and <em>C. villosa</em> dominated swards. With regard to defoliation management performed on the subalpine grasslands for at least 500 years and cancelled after the Second World War, we found the following results and conclusions. 1. Mowing productivity, yield and forage quality were lowest in the <em>N. stricta</em> sward, therefore farmers preferred to harvest <em>C. villosa</em> and <em>M. caerulea</em> stands if they had the possibility to select a sward for mowing. 2. Removal of all nutrients was the lowest in the <em>N. stricta</em> sward. With respect to these facts, the competitive advantage of <em>N. stricta</em> is obvious under long-term scything without fertilization. Consequently, the recent increase of defoliation sensitive species <em>M. caerulea</em> and <em>C. villosa</em> above the timber line must be evaluated with respect to both: termination of agricultural activities and recent nitrogen deposition.