The European temperate forest zone has great importance, in terms of maintaining the habitats of not only forests but also anthropogenous grasslands, which were formed as a result of habitat reconstruction. These habitats have great importance, by means of nature conservation, landscape use, economy, and forest and grassland use. The mosaic-like habitat complexes that consist of these grasslands and forest patches help to increase biodiversity and supply the habitat for forest game. In this survey, changes in the vegetation of the temperate forests (Fagetum) of the Mátra Mountains of Hungary were investigated after reconstruction. In 2012, shrub cutting was carried out in the area of Parádóhuta, and then three different management methods (abandoning, mowing, and grazing) were utilized. Our goals were the following: to perform a vegetation survey of the sample areas (i); surveying the natural regeneration of the grassland and analyzing its biodiversity, nature conservation, and economical value (ii); and analyzing the vegetation in terms of nature conservation and valuing its life form spectrum, economy values, and livestock-feeding ability (iii). According to our results, systematic mowing and a less-intensive grazing had a significantly positive effect on biodiversity and the coverage of species, thus increasing the naturalness of the studied grassland habitats, while wild game were able to act as ecological engineers.