Fast post-ploughing recovery of traditionally managed semi-natural mountain grasslands in the Romanian Carpathians

Mountain hay meadows are among the most species-rich grassland habitats in Europe, yet many have been historically ploughed and later re-established under traditional management. We examined the legacy effects of past ploughing on plant diversity, vegetation composition, and soil properties in traditionally managed hay meadows in Poienile de sub Munte (Romanian Carpathians), combining vegetation surveys, soil analyses, and farmer interviews across permanent and post-arable meadows representing a chronosequence of up to 65 years since the last cultivation. Ploughing history had no significant effect on vegetation composition or diversity indices, including species richness. Current management practices – particularly mowing frequency and manuring – were the primary drivers of community structure. Species richness remained high immediately after cultivation, declined during the following two decades, then gradually recovered to levels comparable to permanent meadows after about 50 years. Soil organic matter properties represented the most persistent legacy of historical ploughing: permanent meadows showed significantly higher humus content and total nitrogen than post-arable ones, regardless of time elapsed since cultivation. In contrast, no significant elevation of plant-available phosphorus or potassium was detected, likely reflecting the exclusively organic character of historical fertilization. Most interviewed farmers reported functional meadow recovery within five years and reported active traditional restoration practices including hayseed application, legume sowing, and organic fertilization. In traditionally managed mountain grasslands with continuous organic fertilization and proximity to species-rich source communities, ploughing legacy effects on vegetation are weak and transient, while soil organic matter depletion constitutes the most durable consequence of historical cultivation.