Although several studies provide a broad overview of vegetation changes in the Carpathian Basin during the Holocene, stand-scale vegetation changes are lesser known because of the rarity of suitable sampling sites. In this study we investigated the sediment of a small closed-canopy site (Nagy-forrás forest hollow, 685 m a.s.l., 0.1 ha), located in the Mátra Mountains, on the north facing slope of Kékes (1014 m a.s.l.). We carried out detailed pollen, conifer stomata and plant macrofossil analyses, as well as radiocarbon dating to examine Late Glacial and Holocene dynamics of vegetation development. The site dates back to ca. 15,500 cal yr BP, when open boreal forests and wet tundra-like habitats occurred around the hollow. Closed forest cover developed around 14,600 cal yr BP, when a boreal European larch-Swiss stone pine ( Larix decidua-Pinus cembra) forest surrounded the hollow. This vegetation type remained stable up to 7700 cal yr BP. We observed a hiatus between 7700 and 2710 cal yr BP, followed by a beech ( Fagus sylvatica) dominated mixed temperate deciduous forest. Our results confirmed that the area was covered by a primary forest, as human influence was visible only from 175 cal yr BP. The relatively long lasting persistence of Pinus cembra in the Holocene at relatively low altitude was documented, which has never been found in Holocene sediments in the Pre-Carpathians before. We hypothesize that the north facing slope acted as a cold-stage refugium in the Early Holocene and could play the same role for the present-day beech forest that is threatened by recent climate change.

<p>Over the last 10 years several alpine lakes were studied from the Southern Carpathian Mountains (SCM) using paleoecological, geochemical and stable isotope techniques. The aim of these studies were to obtain quantitative climate reconstructions for the alpine region for the Late Glacial (LG) and Holocene, reconstruct tree and timberline changes and examine how rapid climate change events manifested in this region, what are the regions characteristics. Absolute chronologies were also supported here for the first time with tephra chronology in the Early Holocene. In addition, environmental DNA studies were used to explore what molecular techniques can add to a more exact and often species level reconstruction of past floristic compositions. This talk will summarize these researches and use multivariate statistics to examine leads and lags in ecosystem response at multiple sites (Retezat, Pareng, Fogaras, Ciomadul Mts). These analyses first of all demonstrate that the amplitude of warming was attenuated in the SCM at the GS-2/GI-1 transition relative to NW Europe (~2,8-3 <sup>o</sup>C), summer temperatures increased abruptly already at 16.2 ka cal BP in direct response to the weakening polar circulation and the tripartite GS-1 had weak summer temperature decrease (<1 <sup>o</sup>C), but winter cooling was strong. Regarding the order of ecosystem changes, lead and lag analysis revealed <50 yr lag in vegetation response, 0-100 lag in aquatic floristic response and ~100-150 yr lag in aquatic faunal response to external forcing. Environmental DNA studies showed that despite the method is capable to better capture grass (Poaceae) floristic diversity and replicates woody specie composition obtained by plant macrofossil data, it fails to provide higher resolution for the herbaceous flora around the studied lakes that feature was explained partly by the incompleteness of reference DNA sequences for the trnL region and the DNA preservation characteristics of alpine lakes. Using these pioneer studies, several promising research directions were identified for this region: modelling of projected tree and timberline changes in combination with reconstructed data, using eDNA techniques to decipher alpine farming histories in the mountains and its impact on late Holocene tree and timberline change, reconstruction the accelerating speed of ecosystem change over the last 100 yr. in alpine lakes and calling attention for the irreversibility of these changes, demonstrating tipping points. These will be discussed in the presentation.</p>