Oak-hornbeam Forests Research Articles

Occurrence of invasive alien plant species in the floodplain forests along the Mura River in Slovenia

Background and purpose: The objectives of our study were to identify invasive alien plant species (IAS) in the main Natura 2000 forest habitat types (FHT) along the Mura River in Slovenia, and to estimate their abundance and cover. The aim of our study was to find out a) What kinds of IAS appear in the research forests? b) What is their frequency and cover percentage? c) Are individual IAS more attached to some FHT than others? d) What is the correlation between the cover of IAS and the tree layer cover?Materials and methods: We analysed the fidelity of invasive plant species to individual FHT. The studied FHTs along the Mura River were following: 91E0* (Alluvial forests with Alnus glutinosa and Fraxinus excelsior), 91F0 (Riparian mixed forests of Quercus robur, Ulmus laevis and Ulmus minor, Fraxinus excelsior or Fraxinus angustifolia, along the great rivers) and 91L0 (Illyrian oak-hornbeam forests). Two forest areas of about 600 ha were studied in total.Results: 16 IAS were recorded in studied FHTs. Some species, like Robinia pseudacacia, Impatiens glandulifera, I. parviflora, Fallopia japonica (incl. F. x bohemica), Erigeron annuus, Ambrosia artemisiifolia, Amorpha fruticosa, Conyza canadensis and Juncus tenuis occur only in one or two FHTs, while some species can be found in all studied FHTs (like Solidago sp.). We have found that the most threatened forests are those with prevailing Salix alba, Alnus glutinosa, Fraxinus angustifolia and Ulmus laevis, tree species, which grow closest to the river and on the wettest sites.Conclusions: The increasing presence of IAS in the study areas seriously affect natural regeneration, stability, and continuity of floodplain FHTs. Therefore, some measures and guidelines for managing of these forests are suggested in this study.

Distribution of Lichen Species of the Genus Lepraria in the Knyszyn Forest (Ne Poland) in Different Forest Plant Communities

Abstract The aim of the study was to evaluate the distribution of lichen species of the genus Lepraria in Knyszyn Forest (NE Poland) to different forest plant communities. Six species of Lepraria [L. eburnea J. R. Laundon, L. elobata Tønsberg, L. incana (L.) Ach., L. jackii Tønsberg, L. lobificans Nyl. and L. vouaxii (Hue) R. C. Harris] recorded from Knyszyn Forest. Lepraria eburnea is a new species for the studied area. The most common species were Lepraria incana and L. lobificans. Among the studied forest communities the richest in species (5 species of Lepraria) were oak-hornbeam forest (Tilio-Carpinetum), and the least species-rich (2 species) were maple-linden slope forest (Aceri-Tilietum), alder carr (Carici elongatae-Alnetum) and spruce forest (Sphagno girgensohnii-Piceetum). The richest lichen diversity in the Knyszyn Forest was found on deciduous trees such as Carpinus betulus L. and Quercus robur L. (4 species), Tilia cordata Mill. (3 spp.), and conifers such as Picea abies (L.) H. Karst. and Pinus sylvestris L. (3 spp.).

Effects of Wild Boar (Sus scrofaL.) Rooting on Seedling Emergence in Białowieża Forest

The wild boar is an omnivorous animal, and by foraging (rooting) disturbs the top soil layer. In some regions of Poland and Europe seasonal fluctuations in rooting have been observed. Wild boars not only eat plants, but also strongly modify their habitat. In Bialowieza National Park wild boar most frequently visit oak-hornbeam forests on fertile soil. On sites where the forest floor is covered with dense vegetation the germination of seeds is difficult, and wild boar rooting can promote the removal of diaspores from deeper layers of the soil seed bank. Within a 3-year observation on 30 subplots about 10,000 seedlings emerged representing 38 species. Our study revealed that rooted patches are characterised by a very rich and diverse flora of seedlings representing mostly forest species, but their density is low. The dominant species germinating in the disturbed ground vegetation is Urtica dioica, a species forming the persistent soil seed bank. There is a possibility that seedlings of herbaceous plants emerging on permanently rooted patches are of exogenous origin, since the seeds germinating there were in many cases damaged by repeatedly rooting animals and had no chance for further growth and reaching the generative phase. However, the soil seed bank in the rooted area has to be analysed to confirm this theory, that they have exogenous or endogenous origin. Seedling density in a repeatedly rooted oak-hornbeam forest is determined by factors other than those related to rooting. In this context the present study did not demonstrate a negative impact of rooting intensity on seedling emergence.

Body volume in ground beetles (Carabidae) reflects biotope disturbance

Abstract Changes in body size of living organisms can indicate changes in environmental quality. The family Carabidae is frequently used as an indicator of environmental status. We collected ground beetles in 9 Slovakian localities (in the Veporské vrchy Mts and the Juhoslovenská kotlina Basin) of various levels of disturbance, and evaluated the volume of individuals. The lowest average body volumes of individual were found for an intensively grazed pasture (locality 5) and a nitrophilous waterside vegetation (locality 6) (1,298 mm3–4,648 mm3) with predominantly macropterous species. We have confirmed the significantly higher average biovolume value of individual Carabidae in less disturbed habitats: a Picea abies plantation (locality 1), a Carpathian oak-hornbeam forest (locality 4) and a Carpathian turkey oak forest (locality 7) (from 9,837 mm3 to 13,038 mm3), where apterous and brachypterous species dominated.

Формування та ріст рівнинних букових природних насіннєвих деревостанів у свіжій бучині

За матеріалами повидільної бази даних лісовпорядкування проаналізовано формування чистих та мішаних букових деревостанів в умовах свіжої грабової та дубово-грабової бучин. Порівняно з 1996 р. площа рівнинних букових деревостанів збільшилась на 14 тис. га та змінилась структура їх лісового фонду. В умовах свіжого груду найбільші площі букових деревостанів зосередженні у свіжій грабовій (22,5%) та дубово-грабовій (75,7%) бучині. Кількість ділянок мішаних деревостанів більш, ніж у два рази перевищує кількість чистих, але за площею та сумарними запасами чистих і мішаних букових лісостанів відмінність не така суттєва. На запаси чистих деревостанів припадає понад 40% сумарного запасу букових деревостанів.
 До 25-30 років рівнинні букові деревостани переважно характеризуються І класом бонітету, після 30 років інтенсивність їх росту зростає і на віковому проміжку 30-80 років переважають насадження, де бук характеризується Іа та вищими класами бонітету, але пізніше інтенсивність росту чистих і мішаних деревостанів сповільнюється і вони знову характеризуються І класом бонітету. Середній клас бонітету чистих та мішаних деревостанів – Іа,5. Інтенсивне нагромадження запасів в них спостерігається до 80 років, коли досягає 350 м3/га, але їхні запаси є нижчими, ніж у нормальних деревостанах. Суттєво нижчі запаси досліджуваних деревостанів після 80 років, порівняно з нормальними та модальними деревостанами, свідчать про необхідність кваліфікованого підходу до планування та виконання поступових і вибіркових рубок у букових лісостанах.

The first record of a forest land snail <i>Macrogastra plicatula</i>in Central Ukraine (Stylommatophora, Clausiliidae)

Nine specimens of Macrogastra plicatula were collected in the small old-growth oak-hornbeam forest surrounded by the swamps near Myrcha village in Kyiv region. This locality is more than in 300 km to south and south-east from the closest known locations of M. plicatula in north-western Ukraine, Belarus and Russia. Collected shells are described and illustrated. The historical biogeography, habitat preferences and conservation of this species are discussed.

The Illyrian mesic forests of the Villány Mts: phytosociology and conservation importance

AbstractSituated at the interface of Central European and Illyrian vegetation, the mesic forests of southwestern Hungary occupy a special position. Despite their importance in vegetation science and conservation, a comprehensive study of the Illyrian mesic forests of the Villány Mts, the southernmost mountain region in Hungary, has not been provided yet. In this study 60 phytocoenological relevés were prepared in the beech, oak-hornbeam, ravine and scree forests of the Villány Mts. To compare the individual associations, we performed a PCoA-ordination, calculated the per plot species number and the per plot protected species number, computed the percentage constancy values of the protected species, identified significant diagnostic species, and prepared the spectra of the coenological preference groups. We used relative ecological indicator values to assess habitat conditions. The PCoA-ordination, the coenological preference group spectra, and to a certain extent the ecological indicator values suggested that the different mesic forests of the Villány Mts show certain similarities. This is probably due to the fact that beech forests and ravine forests are confined to small and atypical stands by the suboptimal environmental conditions. Nonetheless, the number of diagnostic species and the constancy values of protected plants indicated that significant differences do exist between the four associations, the scree forest being the most distinct. We conclude that oak-hornbeam forests and scree forests of the Villány Mts have a regional conservation importance, while the beech and ravine forests are locally important, enhancing the structural, floristical and habitat diversity of the Villány Mts.

Environmental factors influencing the distribution of agricultural terraces: Case study of Horný Tisovník, Slovakia

Abstract The cadastral district of Horný Tisovník represents a traditionally managed Carpathian mountain agricultural landscape with extensive terraces. It was historically governed by two counties with different feudal economic systems - agricultural and industrial. This paper aims to enrich traditional methods in environmental history. We applied geospatial statistics and multivariate data analysis for the assessment of environmental factors influencing the distribution of agricultural terraces. Using linear models, the hypothesis was tested that the terrace distribution is functionally related to selected factors (affiliation to the historic counties; average altitude and slope; distance from water, buildings and settlements; units of natural potential vegetation; and current land use). Significantly greater amounts of terraces were located in the agricultural county compared to the industrial county. A principal component analysis showed the coincidence between the current agricultural land use and higher concentrations of terraces occurring in lower altitudes, closer to settlements and buildings, and within the unit of Carpathian oak-hornbeam forests. These findings regarding the most significant factors influencing the distribution of terraces are used in proposals for incentives to improve the management of the traditional agricultural landscape.

Specific Vicariance of Two Primeval Lowland Forest Lichen Indicators

To date, the lichens Chrysothrix candelaris and Varicellaria hemisphaerica have been classified as accurate primeval lowland forest indicators. Both inhabit particularly valuable remnants of oak-hornbeam forests in Europe, but tend toward a specific kind of vicariance on a local scale. The present study was undertaken to determine habitat factors responsible for this phenomenon and verify the indicative and conservation value of these lichens. The main spatial and climatic parameters that, along with forest structure, potentially affect their distribution patterns and abundance were analysed in four complexes with typical oak-hornbeam stands in NE Poland. Fifty plots of 400 m2 each were chosen for detailed examination of stand structure and epiphytic lichens directly associated with the indicators. The study showed that the localities of the two species barely overlap within the same forest community in a relatively small geographical area. The occurrence of Chrysothrix candelaris depends basically only on microhabitat space provided by old oaks and its role as an indicator of the ecological continuity of habitat is limited. Varicellaria hemisphaerica is not tree specific but a sufficiently high moisture of habitat is essential for the species and it requires forests with high proportion of deciduous trees in a wide landscape scale. Local landscape-level habitat continuity is more important for this species than the current age of forest stand. Regardless of the indicative value, localities of both lichens within oak-hornbeam forests deserve the special protection status since they form unique assemblages of exclusive epiphytes, including those with high conservation value.

Floristic differentiation between mid-seral communities of abandonedcharcoal kilns in the forests of the Gargano Promontory (south Italy)

We searched for patterns in species composition and richness of mid-seral communities developed on abandoned charcoal hearths that might be induced by differences in succession progress and forest context. One phytosociological releve was performed on each of the 22 charcoal platforms located in beech (Anemono apenninae-Fagetum) and oak-hornbeam forests (Doronico-Carpinetum). The ratio of forest understorey to non-forest species richness (F/nF) at plot level was used as a proxy for the succession progress. There was a sharp differentiation of plant communities due to their floristic resemblance with the understory vegetation of the forest type in which they were integrated. Nevertheless, these mid-seral communities still contained a number of nitrophilous weeds that were remnants of the preceding pioneer assemblages. A subgroup of communities (integrated in the beech forest) that lacked the non-forest species mentioned above (high F/nF ratio) could be ascribed to a more advanced seral stage. Species richness on charcoal platforms was not related to forest type, but that might be the consequence of the small sample size. Instead, the number of species decreased steadily with increasing F/nF ratio, which is consistent with the predictions emerging from the paradigm of ecological succession. The forest context accounted for most of the observed floristic dissimilarity between these mid-seral communities. Differences in succession progress seem to be traceable through the number of species, which declines towards more mature stages. The observed communities shared probably the same type of pioneer plant assemblage (Alliario-Chaerophylletum temuli) in the preceding seral stage.

Ландшафтна структура природного заповідника “Медобори”

Tovtry is a complex of fossil reef Miocene buildings that creates one of the most picturesque scenery of the surrounding plains of Podillya region. Tovtry zone consists of main ridge (the late Baden barrier reef), isolated Tovtry hills (the late Baden bioherms, located east of the ridge), isolated tovtry (the early Sarmat bioherms, located west of the main ridge), the territories of the former channels, lagoons and passes between certain reef masses, the part of which is occupied with the modern rivers. These geological and geomorphological elements are the basis of the definition of Podillian Tovtry landscapes areas, and their combination is the basis of the individual landscapes. The great contribution to the study of Tovtry landscapes was made by K. Herenchuk (1949, 1979, 1980), who identified the main types of localities and individual landscapes. In addition to his distinguished achievements, the researches done by M. Chyzhov (1963), T. Kovalyshyn and I. Kaplun (1998), P. Shtoyko (2000), K. Moskalyuk (2011) and others could be mentioned. In Tovtry there are four landscapes: Mylno, Zbarazh, Medobory (Krasna) and Tovtry (Kamianets-Podilskyi). Natural Reserve “Medobory” (9 516.7 hectares) is located in the central part of Tovtry, mainly in Medobory landscape. The landscape map of nature reserve, covering the surrounding area, at a scale of 1: 25,000 has been done. Six landscaped areas and more than 70 kinds of tracts have been identified. The largest area is the area of elongated summit plains of main Tovtry ridge rocky hills, covered by beech hornbeam-oak forests on humus-carbonate soils. The territory with the buried reef formations, overlained by loess-like loams, with hornbeam-oak forests on humus-carbonate soils in combination with grey forest soils occupies large area. The area of grouped and isolated side tovtry, covered by rock and meadow-steppe vegetation, shrubs on humus-carbonate soils are fragmentary represented in the natural reserve. Outside the territory of natural reserve, there are areas of the extensive plains with chernozems. They were covered by meadow vegetation in the past and now they are the agricultural lands. Some areas of the reserve are covered by wavy interfluves of Husiatyn and Lanivtsi landscape, which are typical for stratal-tiered landscapes of Podillya. Wavy watersheds, composed of thick strata of loess loam, are mainly covered by hornbeam forests in place of oak on grey forest soils and podzolic chernozem. Along Zbruch and Gnyla the area of narrow river valleys with wide floodplains and low terraces fragments are very common. Floodplain is covered by grass-forb meadows, with alder and osier bed centres on meadow and meadow soils. The regional and local features of the landscape structure of the reserve have been defined. Enough representation of the main types of Tovtry areas, their altitude differentiation (landscape layering) and monolithic areas of Tovtry main ridge are the most important. Key words: Podillian Tovtry, main ridge, side tovtry hills, nature reserve “Medobory”, area of landscape.

Invasive Impatiens parviflora has negative impact on native vegetation in oak-hornbeam forests

Impatiens parviflora (Balsaminaceae) is one of the most widespread invasive plant species in Central Europe. Nevertheless, both mechanisms and consequences of its invasion are still poorly understood. In this study we attempt to understand the impact of this species on native vegetation.The impact of I. parviflora on native vegetation was studied using removal experiment on permanent plots in oak-hornbeam forests in central Bohemia, Czech Republic. Nine pairs of plots were established in invaded vegetation, one plot in each pair stayed invaded and the other served as removal plot and all I. parviflora individuals were repeatedly removed from the plot. Species composition in 4 subsequent years was recorded in the plots. Species response to I. parviflora removal was correlated to plant traits to reveal trait characteristics of species suppressed by the invasion.Significant increase in both numbers and cover of native species was observed in removal plots in comparison with invaded plots during the experiment, with the greatest change in first two years after invader removal. Species composition also significantly differed between invaded and removal plots. Species with high affinity to removal plots, i.e. species that are most restricted by I. parviflora invasion, were mostly species with small releasing height and early start of flowering.Our results indicate that I. parviflora has negative impact on native vegetation but that the vegetation can recover within few years after the invader removal. Due to its extensive distribution and high turnover, removal of the species from larger plots is, however, not realistic in practice.

How Biotic Differentiation of Human Impacted Nutrient Poor Deciduous Forests Can Affect the Preservation Status of Mountain Forest Vegetation

A significant loss of biodiversity resulting from human activity has caused biotic homogenisation to become the dominant process shaping forest communities. In this paper, we present a rare case of biotic differentiation in European temperate deciduous forest herb layer vegetation. The process is occurring in nutrient poor oak-hornbeam forests in mountain areas (Polish Eastern Carpathians, Central Europe) where non-timber use was converted into conventional forest management practice. This change contributed to increases in the nitrogen content and pH reaction of the soil that, contrary to predominant beliefs on the negative impact of habitat eutrophication on diversity, did not result in a decrease in the latter. We discuss possible reasons for this phenomenon that indicate the important role of tree stand composition (an increasing admixture of beech worsening the trophic properties of the soil). The second issue considered involves the effect of the changes in herb species composition of oak-hornbeam forest on its distinctiveness from the beech forest predominating in the Polish Eastern Carpathians. Unfortunately, despite the increase in the species compositional dissimilarity of oak-hornbeam forest, a reduction in their distinctiveness in relation to the herb species composition of beech forest was found. Such a phenomenon is an effect of the major fragmentation of oak-hornbeam forests, a spread of beech forest-type species, and forest management that gives preference to beech trees. Consequently, it can be expected that changes occurring in oak-hornbeam forest vegetation will contribute to a decrease in the forest vegetation variability at the regional scale.

Impact of the Former Vineyard Land Use on the Productivity of Secondary Forest Herb Layer in the Little Carpathians (SW Slovakia)

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.

The Assessment of the Effectiveness of Applying Natural Regeneration of Pedunculate Oak (Quercus Robural L.) at Reforestation in Solid Blockhouse in the Conditions of Fresh Hornbeam Oak Forests In Podillya

Проаналізовано особливості природного поновлення дуба звичайного у Подільському регіоні. Досліджено сучасний стан та динаміку використання природного поновлення за лісовідновлення. Виявлено зниження рівня насіннєношення та частки використання природного поновлення у загальному обсязі лісовідновлення із роками. Протягом 2013-2015 рр. проведено збір даних щодо наявного природного поновлення дуба звичайного на суцільних зрубах в умовах Поділля, встановлено можливість успішного лісопоновлення дуба звичайного на суцільних зрубах після проведення рубок головного користування у насіннєві роки.

Characterization of total ecosystem-scale biogenic VOC exchange at a Mediterranean oak–hornbeam forest

Abstract. Recently, the number and amount of biogenically emitted volatile organic compounds (VOCs) has been discussed in great detail. Depending on the ecosystem, the published number varies between a dozen and several hundred compounds. We present ecosystem exchange fluxes from a mixed oak–hornbeam forest in the Po Valley, Italy. The fluxes were measured by a proton transfer reaction-time-of-flight (PTR-ToF) mass spectrometer and calculated using the eddy covariance (EC) method. Detectable fluxes were observed for up to 29 compounds, dominated by isoprene, which comprised over 60 % of the total upward flux (on a molar basis). The daily average of the total VOC upward flux was 10.4 nmol m−2 s−1. Methanol had the highest concentration and accounted for the largest downward flux. Methanol seemed to be deposited to dew, as the downward flux happened in the early morning, right after the calculated surface temperature came closest to the calculated dew point temperature.We estimated that up to 30 % of the upward flux of methyl vinyl ketone (MVK) and methacrolein (MACR) originated from atmospheric oxidation of isoprene. A comparison between two methods for the flux detection (manual and automated) was made. Their respective advantages and disadvantages were discussed and the differences in their results shown. Both provide comparable results.

Physiological plasticity of main tree species of lowland hornbeamoak forest as a results of forest gap regeneration

Specific leaf area (SLA) of English oak (Quercus robur L.) and hornbeam (Carpinus betulus L.) as members of Querco robori-Carpinetum were investigated in two different habitat in terms of gap forest management: in the gap and in the inert forest. The artificial opening process of the forest resulted in more light for growing saplings and need for acclimatization. Photosynthesis is one of the most important ways for plant life and plant production basically influenced by altered light condition resulted in opening process. Efficient photosynthesis is important for plant life, plant production, but species-dependent plasticity of photosynthesis makes one species more tolerant, than others. The specific leaf area is acceptable parameters for characterising plant production, dry matter content and leaf structure. The dry matter content based on known leaf area is higher in oak both sun and shade leaves, than hornbeam. The different place of leaves in the canopy of trees did not influence the values of SLA.

Coexistence of ancient forest species as an indicator of high species richness

Continuity of forest habitats is evaluated by using the indicator value of plants considered as ancient forest species or closed forest species. This is a subjectively defined group, which includes species that prefer old-growth forests. Until now, the fidelity between ancient forest species and its relation to species richness has not been assessed. Analyses were performed using resources of the Polish Vegetation Database, from which we selected relevés containing at least one species from the group of ancient forest species. Subsequently, we examined whether these species demonstrate a tendency to coexist. We established these relations using the phi coefficient of fidelity. We have distinguished eleven groups of coexisting ancient forest species (CAFS groups). Fairly common taxa in the data set constituted the majority of species forming these groups (frequency of >10%). Only one CAFS group found in the dataset was strongly localised geographically. The other groups did not demonstrate specific patterns of distribution and were recorded in relevés throughout the country. The average species richness of forests, in which at least one CAFS group was present, was significantly higher than the average in the forests, where there were no groups of CAFS found. These forests also differed significantly in the total number of ancient forest species and the number of closed forest species. We found that the coexistence of ancient forest species was an indicator of forest communities characterized by a high diversity. In all types of forests identified in the data set, at least one group of coexisting ancient forest species was identified. However, the occurrence of the CAFS groups was not equally frequent in all types of forests. CAFS groups occurred most often in the oak-hornbeam forests, species-rich beech forests and ravine forests, which are zonal types of vegetation. On the other hand, the CAFS groups were rarely found in bog Scots pine woodlands, acidophilous spruce forests, alder carrs and willow-poplar forests of lowland rivers, and these are mostly azonal vegetation types with a limited range.CAFS groups can be used as a trans-regional indicators of forests with a high diversity of species, however, their usefulness may be limited in relation to forests found in oligotrophic habitats or azonal forest systems.

A Harkány-Nagynyárádi-sík zárt lösztölgyesei (Pulmonario mollis-Quercetum roboris Kevey 2008)

The study deal with the phytosociological charac-teristics of oak forests growing on the loess-covered hills on the Harkány-Nagynyárád plain, where the author found rep-resentative stands of a recently described community, the closed pedunculate oak forest on loess (Pulmonario mollis-Quercetum roboris). This community occupies xero-mesic habitats between the more xeric habitat of the open steppe woodland (Aceri tatarici-Quercetum roboris) and the mesic habitats of the closed oak-hornbeam forest (Corydali cavae-Carpinetum). In terms of its ecological role, this community is the ecological equivalent of the closed pedunculate oak forest on calcareous sand (Convallario-Quercetum roboris). In the closed pedunculate oak forest, character species of dry grasslands (Festuco-Brometea, Festucetalia valesia-cae, Festucion rupicolae, etc.) play a subordinate role as opposed to the open steppe woodland, in which these spe-cies are prevalent. Unlike the open steppe woodland, the community harbors a number of mesic species (Querco-Fagetea, Fagetalia, Carpinenion) in the understorey, owing to the xero-mesic character of its habitat. It is separated from the often adjoining stands of closed oak-hornbeam forest, which grows at the bottom of the valleys, by the oc-currence of species characteristic of dry oak woods (Quer-cetea pubescentis-petraeae, Quercetalia cerridis, Aceri tatarici-Quercion), and the absence of several mesic spe-cies (Querco-Fagetea, Fagetalia, Carpinenion) typical in the oak-hornbeam forest. This community is thus classified as a member of the Polygonato latifolio-Quercenion roboris Kevey 2008 suballiance.

Ancient and recent (post-agricultural) forest communities as indicators of environmental conditions in north-eastern Poland (Masuria and Kurpie region)

The paper analyses three forest types belonging to the following associations: (1) fresh pine forest (Peucedano-Pinetum), (2) mixed pine forest (Querco roboris-Pinetum) and (3) oak-hornbeam forest (Tilio cordatae-Carpinetum betuli). They are located in north-eastern Poland. We compared the indicator value of three sets of data: (1) phytosociological relevés representing ancient forests (each type/association), (2) phytosociological relevés representing the youngest recent forests with the shortest regeneration period (each type/association) and (3) the ‘abstract pattern’ (representing the core of a specific type of plant community with a characteristic combination of species and clearly representing a separate type of ecosystem/association). Three sets of data together with their indicator values/numbers: light intensity (L), soil moisture (F), soil reaction (R), and nitrogen supply (N) according to the Ellenberg scale, constituted the basic material for comparative indicator analysis. The percentage shares of ecological groups of species have been calculated as well as the average indicator values for each of these within a data set. The results obtained show that the ‘abstract pattern’ can be treated as a good measure for the evaluation of ancient forest habitat conditions; it is clearly visible in the mean L and F indicator values of the Peucedano-Pinetum and Querco-Pinetum associations, and also in the N of Peucedano-Pinetum and R of Querco-Pinetum, which are closer to ancient forest than to recent forest. In all cases, we found ecological differences between the ancient and recent forests based on their indicator values. Statistically significant differences of the mean L indicator values between ancient forest and recent forest have been found in three types of forest community.