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  • Author: Jozef Kollár x
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Andrej Palaj and Jozef Kollár

Abstract

This paper examines changes in alpine vegetation over 50 years in the Western Tatras part of the Western Carpathians Mountains in Slovakia. We focus on the following most widespread vegetation types: subalpine to subnival grasslands (alliance Juncion trifidi Krajina 1933), snowbed vegetation (alliance Festucion picturatae Krajina 1933) and dwarf-shrub vegetation (alliances Loiseleurio-Vaccinion Br.-Bl. in Br.-Bl. et Jenny 1926 and Vaccinion myrtilli Krajina 1933). The historical 1971–1977 sampling dataset was re-sampled in 2016–2017 and our research is based on a comparison of 40 pairs of these relevés. Herein, we studied (i) changes in species frequencies; (ii) changes in phytodiversity and site conditions using estimates of Ellenberg’s eco-indices and (iii) comparison of historical and current relevés over time using the nonmetric multidimensional scaling gradient analysis (NMDS) ordination method. The frequency curves reveal differences; especially in the most frequent species at 37.5−80%, which reach higher values in the current data. The higher 7.5−25% value of medium-frequent species in the historical relevés indicates progressive homogenisation of the examined vegetation. In addition, the Shannon-Wiener index of individual vegetation types revealed no significant differences in diversity or average number of species. The historical relevés included 75 species while 74 were confirmed in the current data. Statistically significant differences were determined in light factor for all three vegetation groups. This was due to the retreat of some light-demanding species. While NMDS indicated changes in Festucion and Vaccinion relevés over time, the Juncion group relevés did not follow this trend, thus confirming their high stability. The observed changes between current and historical data are attributed to changes in climate and altered land use with the cessation of grazing.

Open access

Lukáš Zima, Jozef Kollár and Ivana Vykouková

Abstract

The Little Carpathians Mountains include a vineyard region with long tradition that dates back up to the Roman Empire period (and according to some opinions, even earlier). In the late 19th century, it was strongly impacted by the phylloxera epidemic, and the vineyard area has significantly reduced here. Large areas of the former vineyards are covered by forests, which mostly have formed spontaneously, but some of them were also planted. This contribution is focused on the impact of the former vineyard land use on the productivity (aboveground, belowground, and total biomass) of such forest herb layer. Research included also the forests, which occupy rocky mounds formed by rock gathering and their placement on the vineyard borders. There were sampled by following four stands, mostly differed by tree composition, origin, age, and succession stage: (i) up to 100 years old spontaneously formed thermophilous acidophilous oak forest on the former vineyard on the granite substrate, (ii) up to 100 years old spontaneously formed oak-dominated forest on the rocky (granite) mounds (borders between the former vineyards formed by rock gathering), (iii) 40–60 years old planted ash stands on the gneiss bedrock, and (iv) 40–60 years old planted ash-dominated stands on the rocky (gneiss) mounds. According to our results, the former land use modified original relief, where the former vineyards have modified soil profile and new relief forms rocky mounds were created. These mounds with no or just shallow soils are usually much less covered by vegetation, thus production of herb layer biomass is lower here than in the adjacent former vineyards. Moreover, rocky mounds show a higher ratio of synanthropic species and apophytes than the adjacent former vineyards, and same as for ratio of therophytes. The younger the stands on the former vineyards, the higher is the ratio of synanthropic species, apophytes, and therophytes. On the other hand, when estimating the production quantity, the values of herb layer production on the former vineyards are similar to those in natural oak-hornbeam forests found in the Little Carpathians Mts. and the adjacent regions, except for the rocky mounds covered by old oak forests, which are less productive. In other words, the former vineyard land use affects the herb layer production quality rather than quantity.

Open access

Jana Vojtková, Peter Minarič and Jozef Kollár

Abstract

This paper is focused on phytocoenological characteristics and production analysis of herbaceous layer biomass of the softwood floodplain forests (Salici-Populetum (R. Tx. 1931) Meijer Drees 1936 association) and their phytocoenological characteristics. The sampling site was located in the young stands, which were formed after the Gabčíkovo Waterwork construction in 1992. Redirection of the major ratio of flow into the supply channel has caused essential decrease of water level in the old Danube riverbed. As a result of this, new bare sites have appeared having character of pioneer habitat. In the process of primary succession, new softwood floodplain forests have formed here within a few years. These stands are the subject of the study presented in this paper. We estimated herb layer biomass using indirect sampling modified for non-repeated field measurements (Kubíček, Brechtl, 1970). Total biomass of herbaceous layer was estimated to be 5577 kg ha−1, the aboveground biomass was 4065 kg ha−1 while the belowground biomass was 1512 kg ha−1. The results were compared with the data of Kubíček et al. (2009) and Kollár et al. (2010). Some attention was also paid to their phytocoenologic characteristics. Considering this, it seems that they represent full-value softwood floodplain forest of the Salici-Populetum association despite a bit higher occurrence of some synanthropic species. Such statement is supported by comparison with the data of Jurko (1958) and Šomšák (2003).