Ekológia (Bratislava) Vol. 33, No. 3, p. 201–216, 2014 doi:10.2478/eko-2014-0020 CHANGES OF THE ECOLOGICAL CONDITIONS IN THE BÁB FOREST ON THE BASIS OF A BIOINDICATION METHOD IVANA PILKOVÁ Department of Ecology and Environmental, Faculty of Natural Sciences Constantine the Philosopher University in Nitra, Tr. A. Hlinku 1, Nitra, Slovak Republic; e-mail: [email protected] Abstract Pilková I.: Changes of the ecological conditions in the Báb forest on the basis of a bioindication method. Ekológia (Bratislava), Vol. 33, No. 3, p. 201–216, 2014. This work analyses the changes of ecological conditions in the Báb forest on the basis of a bioin- dication method. The comparison is made between the phytocenological records from the years 1968−1969 and 2013 where permanent research plots (PRPs) were established in the forest coppi- ce and on clearcuts. In 2013, the amount of photophilous and thermophilic species increased mainly on the clearcut PRP and the amount of suboceanic taxa on PRP in the forest coppice. Mo- reover, there is also an increase of taxa like nitrogen-rich posts. On the other hand, the share of fre- sh soils indicators and acidophilous species significantly decreased. The change in the ratio of the econumbers of the observed ecofactors between the records from 1968−1969 and 2013 is caused mainly by a diversified management. It is the formation of clearcuts due to which synanthropic, clearcut and invasive species occupy the free space. The given species are mainly thermophilic, photophilous representatives and representatives of nitrogen-rich soils and they have a significant influence on the change in the percentual ratios of the econumbers of the six observed ecofactors. Key words: eco-analysis, Ellenberg’s indicator values, clearcuts, forest cover. Introduction Within the research of the climatic–anthropogenic impact on forest ecosystems, bioindica- tion methods based on ecological demands of the particular plant species were used too often. This method was suggested by Ellenberg (1979, 1992) who defined the ecological demands for most of the plant species with relation to the six most important ecological factors: light, temperature, continentality, moisture, effect of pH and nitrogen (Vladovič et al., 2008). Jurko (1980, 1986) mentions advantages of the bioindication method, such as its simplicity, rapidity, quantifying, clarity and integration of long-term influences on the environment. The study brings the results of the research of the ecological conditions change in the Báb forest within the period of 45 years on the basis of the bioindication method. Administra- tively, the Báb forest area belongs to cadastre of village Veľký Báb, district Nitra and to Nitra Region. It is situated on Nitra loess upland, 19 km from Nitra and 15 km from Sereď. Two reserve areas can be found here – National Nature Reserve Báb forest and the Protected Area Báb Park. 201 Brought to you by | Harvard University Authenticated Download Date | 7/28/15 2:17 PM This forest is remnant of original native forest complexes. Its total area is 66 ha. In the past, it was marked by anthropogenic impacts especially short rotation management. Its sur- roundings were mainly turned into wide-area fields and vineyards (Kubíček, Brechtl, 1970). The Báb forest represents a climax stage of forest succession on loess (Eliáš, 2010). The forest community is included in the unit Carpion betuli (Mayer, 1937) and the association Primulo veris-Carpinetum (Neuhäusl, Neuhäuslová-Novotná, 1964). From 1967 to 1974 there was conducted a synecology research under the International Biological Program (IBP) and the ‘Man and Biosphere’ (MaB) program. Slovakia was chosen, in a global network of study areas IBP, as a representative ecosystem of oak-hornbeam forest in the loess upland. The research presented in this contribution overlies on the phytocenological analysis (phytocenological records) and resultant assignment of Ellenberg’s ecovalues on each of the plant species. One part of the research in the 1960s was also a realisation of 13 phytoceno- logical records in the Báb forest, namely in 1968–1969 (Kubíček, Brechtl, 1970). This research relies on the above mentioned records while comparing the ecological conditions. Present phytocenological records were accomplished in the spring and summer period of 2013 on different habitats on clearcuts and in the forest vegetation. The research was realised on the forest areas no 307, 310, 311, 312 and 314 (labelling according to the forest manage- ment plan in 2004) (Fig. 1). On the areas no 311–312, four clearcuts raised due to a one-time clearcutting in November 2006. The forest area no 314 is integrated in the National nature re- serve of the Báb forest that presents the most indigenous forest community of the Báb forest. The forest coppices, which are located nearby the clearcuts, were thinned due to shelter-wood logging in November 2006 (forest areas no 311 and 312). permanent research field Protected Area of Bábsky Park and National Wildlife Bábsky forest forest covers Fig. 1. The area of interest in the Báb forest (Source: ILE SAS, branch Nitra). The aim of the given contribution is the evaluation of long-term changes of the environ- ment by means of designating attributes of plants and the evaluation of plant species which take part in this change. The long-term changes of the environment are expressed in the 202 Brought to you by | Harvard University Authenticated Download Date | 7/28/15 2:17 PM comparison of the econumber ratio (%) of the particular ecofactors counted from the phyto- cenological records from the years 1968−1969 and 2013. In the case of the comparison of the records ‘1968−1969’ (hereinafter older records) and 2013 – clearcut, forest coppice (hereinaf- ter new records) we can presume significant climatic–anthropogenic influences on the given forest ecosystem. A significant change is expected mainly in the case of comparing the older records with the records from the clearcut permanent plots. Methodology In the observed area of the Báb forest, there were 32 areas in the size of 20×20 m (Fig. 2) measured and permanently marked in May and June 2011. The permanent plots are established only in the plateau part of the Báb forest. The given permanent research plots (PRP) are divided into two groups. 22 34 19 23 41 10 35 20 24 13 21 11 36 14 7 28 15 8 12 29 9 4 30 37 38 1 40 5 2 6 39 3 Fig. 2. The area of interest Báb forest with marked permanent plots (Source: ILE SAS, branch Nitra). The first group is formed by 20 areas established in the forest coppice – PRP no 13, 14, 15, 19, 20, 21, 22, 23, 24, 28, 29, 30, 34, 35, 36, 37, 38, 39, 40 and 41. Nine PRP (no 13, 14, 15, 19, 20, 21, 22, 23 and 24) are situated in the National nature reserve of the Báb forest. These are anthropically little influenced forest communities which have more or less indigenous structure of the upper tree, shrub and herb layer. These permanent plots are organised in three transects where each of the transects includes three areas. The remaining 11 forest areas are situated in the forest coppice where logging is expected in the future. Each transect consists of three measured and permanently marked permanent research plots. The second group is formed by 12 areas (no 1–12) established on the four clearcuts. On each of the clearcuts there are three areas placed in the line transect. New phytocenological records were made in the spring and summer period of 2013. The entries were accom- plished according to standard phytocenological methods (Moravec, 1994). The older records were used from the work (Kubíček, Brechtl, 1970). The 10-item ordinal scale by Zlatník used in the above mentioned work was trans- formed to a 9-item ordinal scale (Westhoff, Van der Maarel, 1978): 203 Brought to you by | Harvard University Authenticated Download Date | 7/28/15 2:17 PM 1 – 1 or 2 individuals, 2 – more individuals, abundance less than 1 %, 3 – abundance 1–5% small number of individuals, 4 – abundance 1–5%, many individuals, 5 – abundance 5–12.5%, 6 – abundance 12.5–25%, 7 – abundance 25–50%, 8 – abundance 50–75%, 9 – abundance more than 75%. The new as well as older phytocenological records were afterwards inserted into the database Turboveg (Hen- nekens, Schaminee, 2001). In the database to each of the plant species in the phytocenological record designating numbers (econumbers) of the six ecological factors ‘light, temperature, continentality, moisture, effect of pH and nitrogen’ were assigned (Ellenberg, 1992). For each ecological factor, percentage ratios of the abundance of the designating numbers were counted, i.e. ratios of the total abundance of species with the same designating value. The change of the environmental conditions is expressed in differences, i.e. differences in the average values of ratios of the econumbers abundance in time t² and t¹. Results From the observed ecofactor ‘light’ while evaluating the older ‘1968−1969’ phytocenologi- cal records the biggest percentage ratio is reached by the econumber 4 and 5 (Table 1). The given econumbers represent plants between shade and half shade and plants of half shade. In the older records, these species represent them: Acer platanoides, Campanula trachelium, Carex pilosa, Carpinus betulus, Cerasus avium, Geum urbanum, Hedera helix, Lathyrus ver- nus, Melica nutans, Milium effusum, Mycelis muralis, Sanicula europaea, Scrophularia nodosa, Sorbus torminalis, Tilia platyphyllos, Viola mirabilis, V. reichenbachiana (econumber 4), Acer campestre, Alliaria petiolata, Bromus benekenii, Convallaria majalis, Euonymus verrucosus, Geranium robertianum, Chaerophyllum temulum, Lamium maculatum, Lathyrus niger, Lith- ospermum purpurocaeruleum, Melittis melissophyllum, Poa nemoralis, Pulmonaria officinalis, Robinia pseudoacacia, Ulmus minor, Viola odorata (econumber 5). T a b l e 1. Significance of changes in percentage coverage of Ellenberg indicator values (econumbers) for factor „light“ (according to Ellenberg, 1992).