Oak Hornbeam Research Articles

Effect of Combined Factors on Moth Communities in Western Hungarian Sessile Oak–Hornbeam Forests

Effect of Combined Factors on Moth Communities in Western Hungarian Sessile Oak–Hornbeam Forests

Phytosociological research into the Illyrian oak–hornbeam forest on the limestone cliffs of Kupa River canyon (Kamanje, West-Central Croatia)

In this paper, we present 14 relevés of oak-hornbeam forest from the limestone cliffs of Kupa River canyon in ­Kamanje, West-Central Croatia. The investigated forest is part of the Natura 2000 ecological network, and it represents one of the rare remnants of climax forest in the area that is not highly influenced by anthropogenic management. Plant ­community composition was recorded using the six-degree Braun-Blanquet scale, and its relation to similar forests studied by other authors was assessed using agglomerative hierarchical clustering. Because of the abundance of limestone rocks and consequently microhabitats, the forest is very species-rich, with a total of 164 vascular species ­recorded, ranging from 42 to 80 species per relevé. The Kamanje forest belongs to the association Epimedio-Carpinetum betuli, with regard to traditional classification to the subassociation staphyletosum, and is rich in species of the Illyrian-­ -­Balkan floral geoelement. However, compared to the forests of the same association from other areas, this forest has some distinct floristic features. Among the trees, Quercus petraea is replaced by Q. robur. The herb layer is abundant with ferns, and geophytes and hemicryptophytes are much more frequent. The most distinct feature of the forest is the high abundance of ferns from the class Asplenietea trichomanis, specifically Asplenium trichomanes and Polypodium vulgare. The cluster analyses separated the Kamanje forest as a unique group in relation to all other traditional ­subassociations. The Kamanje forest could be considered as a fern-rich subass. staphyletosum. However, only after the problems of traditional classification of Epimedio-Carpinetum betuli into subassociations are resolved will the exact floristic context of the studied forest be clearer. </p>

The influence of habitat conditions on abundance and selected individual traits of Arum alpinum in the communities Populetum albae and Tilio cordatae–Carpinetum betuli (Western Carpathians)

Abstract Studies of selected habitat conditions, as well as spatiotemporal variability of the number and selected traits of individuals of the species Arum alpinum were carried out in 2020–2021 in the foothills of the Western Carpathians. The investigations were conducted in permanent patches located in the Golesz nature reserve (Patch I), near the village of Markowce (Patch II), in the Kozigarb nature reserve (Patch III), and near the village of Żółków (Patch IV). Patches I and III were established in a Tilio cordatae–Carpinetum betuli oak–hornbeam forest with undergrowth dominated by low-growth vegetation with narrow leaves, whereas Patches II and IV were established in a Populetum albae riparian forest with undergrowth dominated by broad-leaved species. The most abundant population of A. alpinum was noted in Patch I, but substantial numbers of both vegetative and reproductive individuals were also present in Patches II and IV. The occurrence of temporal variability of individual traits increased from its lowest level in Patch IV, through Patches I and II, to its highest level in Patch III. The significant positive correlation in all populations between length of petioles and blade dimensions, as well as between length of generative stems and infructescence traits confirmed previous findings. Moreover, we showed that A. alpinum was not closely affiliated with a specific forest community. Significant shading and moist nutrient-rich soils are suitable for this species, while dry soils and excessive insolation may limit the flowering and fruiting of individuals.

Seasonal dynamics of herbaceous layer biomass and its contribution to annual net primary production in an oak–hornbeam forest

The role of the herbaceous layer in carbon assimilation and nutrient cycling is still undiscovered and unappreciated. One reason is that simple methods of annual net primary production (ANPP) estimation often underestimate its value, while more accurate methods are too labor-demanding. Moreover, studies on herbaceous layer and litterfall biomass in the same study site are extremely rare and usually conducted during one vegetation season, providing temporally-specific estimates. We hypothesized that (1) the seasonal herb layer biomass dynamics show a two-peak shape and (2) contribution of herbaceous layer biomass production in annual litter production was not more than 5% of tree litterfall. We studied the herb layer and litterfall biomass dynamics in an oak-hornbeam forest in W Poland for three years (January 2013 – October 2015). Samples of the herb layer (ten samples for four sample plots) were collected weekly in March, April and May or every two weeks for the remainder of each year, and litterfall was collected every month. All herb plants were cut at the soil level from circular frames with an area of 0.16 m2. Litterfall was studied with thirty litter traps (height of 15 cm, and catching area of 0.36 m2). We performed Kruskal–Wallis tests with Dunn’s post hoc tests to assess differences in variables among all collection times and linear random effects models to assess variance sources. We observed the highest biomass in 2013 on May 3rd (47.05 g m−2), and the lowest on October 30th in 2015 (4.69 g m−2). The seasonal herb layer biomass dynamic showed a single-peak shape; a very distinct peak occurred in spring and continued in late spring, summer, and early autumn. The spring ephemeralAnemone nemorosahad the highest share of herbaceous layer ANPP with 27% and was responsible for the spring biomass peak every season. The mean contribution of the herb layer biomass in annual litterfall was 9.23%. Our results highlight the underestimation of the herb layer role in biomass production in forest ecosystems in previous studies.

A matter of size and shape: Microclimatic changes induced by experimental gap openings in a sessile oak–hornbeam forest

Forest management integrating nature conservation aspects into timber production focuses increasingly on small-scale interventions. However, the ecological consequences of gap cuttings remain ambiguous in oak-dominated forests. In the Pilis Gap Experiment, we analyze how combinations of different gap shapes (circular and elongated), and gap sizes (150 m2 and 300 m2) affect the microclimate and biota of a mature sessile oak-hornbeam forest in Hungary. We first report the changes in direct and diffuse light, soil moisture, daily air and soil temperatures, and relative air humidity in the experimental cuttings in the vegetation season directly following their implementation. Diffuse light had a central maximum and a concentric pattern. Direct light was distributed along a north-south gradient, with maxima in northern gap parts. Soil moisture was determined by gap shape: it increased significantly in the center of circular gaps, with multiple local maxima in the southern-central parts of large circular gaps. Its pattern was negatively related to direct light, and larger spatial variability was present in circular than in elongated gaps. The daily mean air temperatures at 1.3 m increased in all, especially in large gaps. Soil and ground-level temperatures remained largely unchanged, reflecting on light and soil moisture conditions affecting evaporative cooling. Relative humidity remained unaltered. Even though the opening of experimental gaps changed microclimatic conditions immediately, effect sizes remained moderate. Gap size and gap shape were both important determinants of microclimate responses: gap size markedly affected irradiation increase, gap shape determined soil moisture surplus, while soil and air temperatures, and air humidity depended on both components of the gap design. We conclude that 150–300 m2 sized management-created gaps can essentially maintain forest microclimate while theoretically providing enough light for oak regeneration; and that the manipulation of gap shape and gap size within this range are effective tools of adaptive management.

Classification of European oak–hornbeam forests and related vegetation types

AbstractAimsOak–hornbeam forests and related vegetation types (phytosociological order Carpinetalia betuli) are widespread in temperate western Eurasia. However, their national classification systems are poorly compatible, and a broad‐scale classification based on numerical analyses is lacking. Therefore, we aimed to establish a unified formalized classification system based on a large data set of vegetation plots covering the entire range of these forests.LocationEurope, Anatolia, Caucasus and northern Iran.MethodsWe compiled a data set of 15,817 vegetation plots from the European Vegetation Archive and the Hyrcanian Forest Vegetation Database, using the formal definition of the EUNIS habitat type T1E Carpinus and Quercus mesic deciduous forest. We classified the data set using TWINSPAN. Biogeographically and ecologically similar plot clusters were merged into oak–hornbeam forest types, which were interpreted as alliances. We also developed expert systems for automatically classifying vegetation at the alliance level for both the EuroVegChecklist (EVC) system and the revised classification. In addition, we calculated ordinations to show the major gradients in the species composition of the data set.ResultsWe present a revised classification system of the order Carpinetalia betuli with nine alliances, including basic descriptions of their species composition, distribution, ecology and syntaxonomy. The analyses largely supported the biogeographic concept of classification, analogous to EVC. Compared to EVC, we recognized an additional alliance Physospermo verticillati‐Quercion cerridis (southern Italy) but found no support for the alliances Astrantio‐Carpinion, Erythronio‐Carpinion and Scillo‐Quercion. The greatest difference in species composition was found between the southern and northern‐northeastern Carpinetalia types. Expert systems for the revised classification system (~89% of plots classified) and the EVC system (~72%) are also included.ConclusionsWe provide the first comprehensive overview of alliances of the order Carpinetalia betuli across its whole distribution range. The associated expert systems allow consistent application of the classification of these forests in nature conservation, habitat monitoring, and biodiversity and ecological research.

Comparison of vascular plants in herb layers of ecotones in urban and non-urban forests in Brzesko city (Polish Carpathian foreland)

Abstract Nowadays, human influence is more noticeable in urban and non-urban ecosystems, which, in turn, leads to the transformation of valuable natural resources. This article presents a study on the diversity of species composition of the vascular herb layer species of ecotones in selected urban forests of the city of Brzesko and in forests outside the city. All forests represented the association of oak–hornbeam plant. The results showed that there are inconsistent and consistent vascular plant species with the Tilio-Carpinetum habitat in urban and non-urban forests. Plant species were significantly (c2 test, p < 0.05) found more frequently in the herb layer of non-urban forests than in urban forests. This proves, among other things, that the influence of anthropogenic activity is more on these objects than in forests outside the city.

Nectaronous and pollonous plants in forest plantations of the Middle Forest-Steppe of Prydniprovia

To provide the beekeeping industry with honey lands it is important to have a significant variety of natural and cultivated raw materials in a particular region. In this regard, promising honey products are artificial and natural forest plantations, which are widespread in the Middle Forest-Steppe of Prydniprovia, due to the significant participation of a wide range of honey plants. We primarily analyzed the participation of nectar- and pollen-bearing plants from the list of tree and shrub species of forest plantations in this area. For this purpose, forest management materials were used, the total area of forest plantations in this area is 251341.3 ha, of which 245209.7 ha (97.56%) are nectar- and pollen-bearing plants. Thus, Robinia pseudoacacia (26406.0 ha, 10.51%) and Tilia cordata (1868.8 ha, 0.74%) are the main raw material species of the forest-forming species, which includes 54 species of woody and shrubby honey plants. They provide the main productive honey harvest from natural honey plants. In addition, other species were found in the plantations (Pinus sylvestris (116592.9 ha, 46.39%), Quercus robur (60049.7 ha, 23.89%), Fraxinus excelsior (7835.5 ha, 3.12%) etc.), which can be sources of medical collection of small amounts of nectar and pollen. Forest plantations with available species of woody, shrubby and herbaceous plant species are valuable as raw materials for beekeeping. As a result of the analysis of the raw material value of forest lands by forest types in the ecological conditions of the Middle Forest-Steppe of Prydniprovia, out of 62 forest types distributed in the study area, 8 most valuable lands were identified. These include fresh hornbeam (32871.8 ha, 13.08%) and maple-linden oak wood (15144.4 ha, 6.03%), hornbeam oak wood (9034.3 ha, 3.71%), dry maple linden (12810.9 ha, 5.10%) and hornbeam (3585.2 ha, 1.43%) oak wood, fresh (2056.4 ha, 0.82%) and moist (1410.4 ha, 0.56%) linden-oak-pine sugrud, moist maple-linden oak wood (714.8 ha, 0.28%). This block of tree and shrub species of forest ecosystems does not take into account the phytodiversity of field protective forest strips of this area, but this complex of species is a promising source of nectar and pollen.

ANALYSİS AND ASSESSMENT BASED ON THE GIS PROGRAM OF ANTHROPOGENİC LOAD İN SOME LANDSCAPE COMPLEXES OF THE LENGEBİZ RİDGE

Purpose. GIS program-based analysis and evaluation of anthropogenic load in some landscape complexes of the Lengebiz ridge. Methodology. The study was carried out in three stages: cameral preparatory, field laboratory, and final. At the final stage, a landscape map of the area at a scale of 1:100,000 was compiled. The boundaries of landscapes and contours of anthropogenic origin within them were calculated based on the GIS program. Conclusion. Within the object of study, the following types of landscape are identified: low-mountain forests; low-mountain forest shrubs (arid-sparsely wooded and shrub complexes); low-mountain steppes; xerophytic dry steppes of upland plains; low-mountain semi-deserts; dry steppes of accumulative plains; river-valley landscapes. The low-mountain forest landscape is represented by a mixture of oak and hornbeam oak. Among anthropogenic factors, settlements, communication routes, as well as agricultural land, especially arable land, have a significant impact on landscape complexes. the total area allocated for settlements, roads, etc., structures is 76.19 hectares, or 0.83% of the area of this landscape type. However, depending on individual types of landscapes, this indicator is 0.56% -1.09%. And the total area of agricultural land on the territory of the studied object is 2102.9 hectares, which is 22.96% of the landscape type area. Depending on individual landscapes, this indicator increases from 13.21% to 31.96%. Due to the great interest in arable land, their share in landscapes ranges from 0.31% to 3.04%, and hayfields and pastures - from 11.29% to 27.24%. 442.05 or 8.99% of the territory of this type of landscape is located on slopes with a slope of more than 400. 1871 thousand hectares or 38.05% of the area were subjected to anthropogenic load. However, this indicator has different values depending on the type of landscape: 23,63%-65,92 %. The total area occupied by settlements, roads, communication lines and man-made structures of the district was 100.5 hectares or 2.04%. The total area of agricultural land (arable land, hayfields, pastures) within this landscape amounted to 1771.3 hectares (36.01%) were subjected to anthropogenic influence. Scientific novelty. For the first time, based on the GIS program, the anthropogenic load in some landscape complexes of the Lengebiz range of Azerbaijan was analyzed and evaluated.

Peculiarities of taxonomic and ecological structure of forest toxocene of Collembola of Eastern Pоdillya

We have made a comparative analysis of the taxonomic and ecological structure of forest taxa of the collemboles of Eastern Podillya. 71 species of collemboles belonging to 40 genera and 15 families were found in the study area. It was found that the structure of dominance, spectra of life forms and biotope groups of the studied taxocenes have their own specifics due to local edaphic conditions, as well as the origin of forest phytocenoses. The ratio of life forms and biotope groups, as well as the structure of the dominance of taxonomies of Collemboles, can be considered as an indicator of the ecological regime of forest edaphotopes of Eastern Podillya. It is established that in different forest phytocenoses of Eastern Podillya, and two different types of Collemboles taxocenes were formed: 1) prefabricated type – in semi-natural hornbeam oak and 2) specialized type – in artificially created forest phytocenoses, where more than 40% of the number have meadow-steppe species.

Unequivocal Differences in Predation Pressure on Large Carabid Beetles between Forestry Treatments

Carabid beetles (Coleoptera: Carabidae) are considered as one of the most cardinal invertebrate predatory groups in many ecosystems, including forests. Previous studies revealed that the predation pressure provided by carabids significantly regulates the ecological network of invertebrates. Nevertheless, there is no direct estimation of the predation risk on carabids, which can be an important proxy for the phenomenon called ecological trap. In our study, we aimed to explore the predation pressure on carabids using 3D-printed decoys installed in two types of forestry treatments, preparation cuts and clear cuts, and control plots in a Hungarian oak–hornbeam forest. We estimated the seasonal, diurnal and treatment-specific aspects of the predation pressure on carabids. Our results reveal a significantly higher predation risk on carabids in both forestry treatments than in the control. Moreover, it was also higher in the nighttime than daytime. Contrarily, no effects of season and microhabitat features were found. Based on these clues we assume that habitats modified by forestry practices may act as an ecological trap for carabids. Our findings contribute to a better understanding of how ecological interactions between species may change in a modified forest environment.

Soil Microbial Functional Diversity under the Single-Season Influence of Traditional Forest Management in a Sessile Oak Forest of Central Europe

This one-year study focuses on the responses of a soil environment to the implementation of traditional forest management practices in oak–hornbeam stands with the following treatments: cut (C), cut + litter raking (CR), cut + grazing (CG), cut + litter raking + grazing (CRG) and control (Ctrl). The cut was conducted in 2018 through extremely heavy thinning. In autumn of 2017 and 2018, we sampled the soils, focusing on microbial functional diversity (FD) assessments using BIOLOG EcoplateTM. After one season, the FD was the highest in the Ctrl stand and the lowest in the CRG stand. Furthermore, we detected significant seasonal differences in soil reaction, nitrate nitrogen content, phosphatase activity and microbial biomass among the treatments. In particular, the Ctrl stand was defined via FD indices and biochemical and biological soil properties that contrasted mainly with those of the CRG stand defined by the content of mineral nitrogen forms. The soil properties did not differ substantially in the remaining treatments. Of the 31 carbon sources defining FD, 6 were treatment-specific (putrescine, L-arginine, L-serine, L-threonine, D-cellobiose and glycogen), while the remaining carbon sources mainly displayed either uniform high or low activity across the treatments.

Characteristics Of Natural Oak Forests Of In Se "Khmilnytske Lisove Hospodarstvo" And Implementation Of Measures For Their Regeneration

As a consequence of the intensive economic use of oak forests in the region, the share of stands of natural origin is significantly reduced, which requires an in-depth study of their condition, productivity, and natural restoration processes. The purpose of this study is to investigate the state, structure, and reforestation processes of oak forests for their further natural reproduction. Generally accepted methods in forestry and comparative ecology were used to compare the dynamics and condition of the studied stands with the reference ones. The paper presents the findings of the study of the productivity and state of natural forests within the state enterprise “Khmilnytske lisove hospodarstvo”. It was found out that natural oak stands are represented by 7 forest types, mainly in fresh hornbeam oak forest (area – 471 hectares). According to the results obtained, it was found that natural oak stands of vegetative origin predominate within the studied enterprise (528.6 ha). They are mainly represented by forests of the 11th age class (188.0 ha). High-bonitat oak forests of the 1st quality class predominate. Mature and over-mature stands have slightly lower productivity (2nd quality class, stand density of 0.6-0.7). The largest total reserve is characterised by stands of the 11th age class. The maximum average reserves are typical for stands of the 9th age class (290 m3 /ha). The greatest share of oak in stand composition (9-10 units) was found in stands of 9-10 age classes. The study shows that the natural renewal of oak is concentrated mainly in fresh sudubrava (fresh hornbeam sudubrava) in plantings in the presence of Scots pine and common oak. The density of natural renewal is 1-3 thousand units/ha. The practical value of the study is conditioned by the possibility of introducing the basic principles of forestry aimed at growing stable high-yield stands of common oak through more complete utilisation of natural renewal

Ecological and typological assessment of forest vegetation of the Middle Dnieper (Forest-steppe of Ukraine)

The paper shows the importance of a detailed study of various aspects of modern phytodiversity as an essential element of preservation of natural ecotypes for building national ecological network in the system of pan-European network. To do this, it is necessary to explore various aspects of natural and spontaneously formed vegetation. Based on the ecological specifics of the Middle Dnieper (Forest-Steppe of Ukraine), a detailed analysis of natural and artificially formed forests on the Dnipro cliffs, in ravine-beam systems and on the Dnipro floodplain is required. Peculiarities of forest vegetation conditions, distribution of tree species and ecological conditions of their growth are given. According to forest management data, the area covered with forest vegetation is 251341.3 hectares. The distribution of forest areas by edatopes is as follows: trophotopes — subors (78083.2 hectares, 31.07%), sugruds (77232.6 hectares, 30.73%), oak wood (72520.6 hectares, 28.85%) and pine forests (23504.9 hectares, 9.35%); hygrotopes — fresh conditions (183792.4 hectares, 73.13%), dry (34938.5 hectares, 13.90%), damp (19038.7 hectares, 7.57%), moist (11401.1 hectares, 4.54%), wet (1896.0 hectares, 0.75%) and very dry conditions (274.6 hectares, 0.11%). There are 62 types of forests areas covered with forest vegetation, which are dominated by fresh oak-pine forest (68319.9 hectares, 27.18%) and hornbeam oak wood (32871.8 hectares, 13.08%), a slightly smaller area occupied by fresh pine forest (17568.3 hectares, 6.99%), hornbeam-oak-pine sugrud (16952.2 hectares, 6.74%), maple-linden forest (15144.4 hectares, 6.03%) hornbeam-pine (13775.4 hectares, 5.48%) and hornbeam (9334.3 hectares, 3.71%) sudibrovas and dry maple-linden forest (12810.9 hectares, 5.10%). The composition of forest-forming species is quite diverse and is represented by 71 species of woody and shrubby plants. The main forest-forming species are Pinus sylvestris (116592.9 hectares, 46.39%) and Quercus robur (60049.7 hectares, 23.89%). Robinia pseudoacacia (26406.0 hectares, 10.51%), Alnus glutinosa (11391.7 hectares, 4.53%) and Fraxinus excelsior (7835.5 hectares, 3.12%) have slightly smaller areas, all other species occupy small areas. Identifying all the diversity of forest habitats will provide an opportunity to plan the conservation, reproduction and protection of phytodiversity, including species of sozophytes from different conservation lists, as well as to balance the provision of ecosystem services by tree plantations of the Middle Dnieper.

Secondary Serpentine Forests of Poland as a Refuge for Vascular Flora

The aim of present study was to determine the role of secondary, serpentine forests in Poland in the protection of rare vascular plant species. On the basis of 95 phytosociological relevés collected between 2009 and 2020, we identified the main types of serpentine forest communities and assessed their diversity indices. Ordination methods were used to determine the relationship between the degree of transformation of forest communities (reflected by the occurrence of alien and nitrophilic species) and the presence of endangered species in their undergrowth including the environmental background. We distinguished four types of communities: thermophilic and mesophilic pine plantations (both secondary in origin) as well as thermophilous oak forest and acidophilous oak–hornbeam forest (semi-natural and close to natural in character, respectively). Rare and endangered species were unevenly distributed and concentrated in oak forest (16 species) and thermophilic pine plantation (nine species). The endangered species mainly preferred sites at higher altitudes and with higher slope inclination, light availability, and soil reaction. We did not confirm that the presence of alien or nitrophilic species negatively influenced the ability of studied forests to preserve rare plants. As secondary forests can still harbor endangered species, they should fulfil complementary functions in the nature protection system.

Environmental implications of past socioeconomic events in Greater Poland during the last 1200 years. Synthesis of paleoecological and historical data

We explored the past environmental history inferred from a fen located in northwestern Poland, in a historically important location. Pollen, plant macrofossils, micro- and macrocharcoal particles, and non-pollen palynomorphs were analyzed continuously in a 1-cm resolution, supplemented with archeological data and historical written sources. The last 1200-year environmental history of the fen was supported with accelerator mass spectrometry (AMS) radiocarbon (14C) dating (19 dates per 172 cm of the profile) and validated by 59 210 Pb dates. Our research showed that primeval oak–hornbeam forests near the Kazanie mire disappeared gradually, starting from 1035 ± 20 cal. yr CE, due to the economic development of the newly formed Polish (Piast) statehood. The pollen data revealed no shortage of oak timber during the 11th century, as recorded by previous studies in the area between Poznań and Gniezno. The Czech invasion in 1039 CE, which was associated with mass depopulation and domestic crisis, seemed to be manifested by the increase of pioneer Betula taking advantage of weaker human impact. Substantial land-use changes started with the further development of Polish statehood between the 15th and the 16th century CE, as reflected by cultivated land, ruderal, and meadow and pasture pollen indicators, as well as the rise of microcharcoal influx. The economy of Poland was disrupted by a noticeable socioeconomic collapse in the 17th century CE, which caused depopulation (by approximately 67.5%) and a decline in arable land (by 35%). Paleoecological data reflect this socio-environmental crisis with a decrease in all anthropogenic indicators, rapid forest regeneration, and secondary succession of pine on the abandoned land. According to palynological data, rapid landscape transformation due to agricultural reforms and industrialization commenced in the 19th century CE and was associated with the expansion of pastures, meadows, and arable lands. The following rapid decrease of cultivated land pollen indicators in 1940 ± 10 cal. yr CE is linked with the economic collapse after World War II and/or the implementation of new crops which produce less pollen.

Carabus Population Response to Drought in Lowland Oak Hornbeam Forest

Forest management practices and droughts affect the assemblages of carabid species, and these are the most important factors in terms of influencing short- and long-term population changes. During 2017 and 2018, the occurrences and seasonal dynamics of five carabid species (Carabus coriaceus, C. ulrichii, C. violaceus, C. nemoralis and C. scheidleri) in four oak hornbeam forest stands were evaluated using the method of pitfall trapping. The climate water balance values were cumulatively calculated here as cumulative water balance in monthly steps. The cumulative water balance was used to identify the onset and duration of drought. The number of Carabus species individuals was more than three times higher in 2018 than in 2017. Spring activity was influenced by temperature. The extremely warm April in 2018 accelerated spring population dynamics; however, low night temperatures in April in 2017 slowed the spring activity of nocturnal species. Drought negatively influenced population abundance, and the effect of a drought is likely to be expressed with a two-year delay. In our investigation, a drought in 2015 started in May and lasted eight months; however, the drought was not recorded in 2016, and 2016 was evaluated as a humid year. The meteorological conditions in the year influenced seasonal activity patterns and the timings of peaks of abundance for both spring breeding and autumn breeding Carabus species.

Hoverfly (Diptera: Syrphidae) assemblage of an oak-hornbeam in the Merlino Wood Natural Reserve and implications for its conservation.

Merlino Wood is a typical oak–hornbeam forest in the Po Plain hydrographic region. It is one of the few remaining lowland forests in Northern Italy and is a Regional Natural Reserve and a Site of Community Interest (code IT1160010). This is the first survey on hoverflies in the study area and they act as bioindicators to assess habitat conservation. Sampling was performed with three Malaise traps and an entomological net. A total of 61 species of Syrphidae were recorded between March and October 2019. Three of the species observed are considered to be under threat in Europe, three species have been recorded for the first time in Piedmont and Heringia latitarsis (Egger, 1865) has been recorded for the first time in Northern Italy. The Syrph the Net analysis has been used to assess habitat conservation. It shows good preservation of xylosaprophagous species, while the conservation conditions of other larval trophic categories are poor.

Prevailing forest types in the river catchments within the Left-Bank Forest-Steppe zone, Ukraine

Abstract The aim of the study was to determine the distribution of prevailing forest types within the catchment areas of the biggest rivers in the north-east of Ukraine. During the allocation of the catchment areas of the studied rivers, the MapInfo Professional 12.5 program and the vector map of Ukraine were used. The research covered the forest area (more than 502,000 ha) of the state forest enterprises managed by the State Forest Resources Agency of Ukraine. The studied area located on the tributaries of the Sula, Psel, Vorskla and Siversky Donets rivers within the Poltava, Kharkiv, Sumy, Chernihiv, Kyiv and Cherkasy administrative regions of Ukraine. The analysis of the forest fund was carried out based on the electronic subcompartment database of the Ukrderzhlisproekt Production Association, using the application software and geoinformation technologies. It was revealed that a large variety of forest types in the tributaries of the Sula, Psel, Vorskla and Siversky Donets rivers as well as the prevalence of fresh fertile maple-lime oak and fresh fairly infertile oak-pine forest types (in 75 tributaries of Psel, Vorskla and Siversky Donets rivers) and fresh fertile maple-lime oak and fresh fertile hornbeam oak forest types (in 20 tributaries of the Sula River) are due to the relief, hydrological and soil-climatic conditions of the studied area, as well as anthropogenic factor. Assuming homogeneous natural conditions, an insignificant number of forest types are formed (up to five). For a large variety of natural conditions, there are at least six forest types that should be taken into account during forest management, along with the characteristics of the catchment areas of tributaries. The analysed data on the total number of forest types in the catchments of rivers would be appropriate to use in the future when creating a single list of forest types for the Left-Bank Forest-Steppe zone of Ukraine. The prevalence of certain forest types within the catchment areas of tributaries of the Sula, Psel, Vorskla and Siversky Donets rivers directly depends on the soil and climatic conditions, geomorphological structure, relief and anthropogenic influence in the forests. The results should be used in forest management activities to preserve and restore the species diversity of forests within the river catchments.

Трансформация лесов на юго-восточной части Большого Кавказа

Three experimental plots of beech–hornbeam–oak mixed forests of the southeastern part of the Greater Caucasus were examined. Biometric and phytocenological observations were carried out, species composition and fullness of forests, growth, diameter and height of trees. The report of the forestry department of the southeastern part of the Greater Caucasus is analyzed. The transformation of hornbeam forests in the southeastern part of the Greater Caucasus occurred as a result of the destruction of beech forests and restoration of forestry. Over the past 50–60, and in some places in the southeastern part of the Greater Caucasus for 100 years, on the site of cut down valuable beech forests, hornbeam, hornbeam–linden and hornbeam–oak forests have formed. The physiological and environmental parameters of the hornbeam and other trees and shrubs allow them to successfully grow in place of logged beech forests and fill artificially formed bared spaces. The transformation of dominant plants by artificial or natural means in accordance with the laws of biogeocenology, in turn, contributes to a change in the whole structure and appearance of the environment.