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Cryptogamic diversity is a reliable indicator of the state of forest ecosystems. In this study we analysed the variations in both bryophyte species richness overall and number of hemerophobic bryophyte species in Central European managed forests over a 20-year time span, based on data collected in 132 plots scattered across Poland. We tested differences in species richness among five temporal replicates, as well as among site types grouped based on elevation a.s.l., dominant tree species and stand age. The analyses revealed no significant trend in species richness across years. Meanwhile, species richness significantly increased along with elevation a.s.l., especially in broadleaved forests. No significant difference in species number between spruce and pine dominated stands emerged for mature stands, while there was a strong difference for young stands, with spruce forest hosting a much higher number of species. Species richness exhibited a slight, but not significant, increase over time in broadleaved forests, no significant variations in pine dominated stands and significant fluctuations in spruce dominated stands, yet without a significant trend. Out of the tested drivers, dominant tree species exhibited the strongest impact on species community composition. Number of hemerophobic and strongly hemerophobic species did not undergo significant variations across years either. The lack of bryophyte diversity trends highlighted in this study suggests Central European managed forests are in an equilibrium sate, maintained by the opposing effects of climate changes, on one side and of more sustainable forest management and pollutant deposition decline, from the other.

W dniach 15–17 marca 2022 r. w Instytucie Badawczym Leśnictwa odbyła się XII Sesja Zimowej Szkoły Leśnej, której tematem był „Wpływ zmian klimatu na środowisko leśne”. Spośród licznych propozycji, o wyborze powyższego tematu przesądziło obserwowane od wielu lat systematyczne pogorszanie się stanu zdrowotnego drzewostanów na skutek synergicznego oddziaływania wielu czynników abiotycznych i biotycznych w warunkach zmian klimatu. Współorganizatorem Sesji była Dyrekcja Generalna Lasów Państwowych. Merytoryczne aspekty XII Sesji zostały przygotowane i opracowane przez Radę Programową Zimowej Szkoły Leśnej w składzie: dr hab. Krzysztof Stereńczak, prof. IBL (przewodniczący), prof. dr hab. Bogdan Brzeziecki, mgr inż. Michał Graczyk, prof. dr hab. Andrzej Grzywacz, prof. dr hab. Andrzej Jagodziński, prof. dr hab. Janusz Olejnik, mgr inż. Jan Tabor, mgr inż. Krzysztof Rostek, prof. dr hab. Iwona Skrzecz, dr inż. Klaudia Ziemblińska. Rada Programowa określiła nie tylko zakres problematyki XII Sesji, ale także propozycje tematyczne referatów zamawianych oraz ich autorów. W trakcie trzech dni obrad prelegenci przedstawili 33 referaty. Referaty wygłosili również zaproszeni goście zagraniczni reprezentujący: Uniwersytet w Helsinkach, Czeski Uniwersytet Przyrodniczy w Pradze, Instytut Badań nad Zmianami Globalnymi (Czechy), Uniwersytet Wspólnoty Wirginii, Łotewski Państwowy Instytut Badawczy Leśnictwa oraz Integrated Carbon Observation System. W XII Sesji, która odbyła się w wersji online, wzięło udział niemal 200 osób reprezentujących m.in.: Ministerstwo Klimatu i Środowiska, jednostki organizacyjne Lasów Państwowych, ośrodki uniwersyteckie i instytuty badawcze. Liczne grono stanowili również przedstawiciele ośrodków naukowych oraz polskich uczelni leśnych.

International audience; A central challenge of today's ecological research is predicting how ecosystems will develop under future global change. Accurate predictions are complicated by (a) simultaneous effects of different drivers, such as climate change, nitrogen deposition and management changes; and (b) legacy effects from previous land use. We tested whether herb layer biodiversity (i.e. richness, Shannon diversity and evenness) and functional (i.e. herb cover, specific leaf area [SLA] and plant height) responses to environmental change drivers depended on land-use history. We used resurvey data from 192 plots across nineteen European temperate forest regions, with large spatial variability in environmental change factors. We tested for interactions between land-use history, distinguishing ancient and recent (i.e. post-agricultural) forests and four drivers: temperature, nitrogen deposition, and aridity at the regional scale and light dynamics at the plot-scale. Land-use history significantly modulated global change effects on the functional signature of the herb layer (i.e. cover, SLA and plant height). Light availability was the main environmental driver of change interacting with land-use history. We found greater herb cover and plant height decreases and SLA increases with decreasing light availability in ancient than in recent forests. Furthermore, we found greater decreases in herb cover with increased nitrogen deposition in ancient forests, whereas warming had the strongest decreasing effect on the herb cover in recent forests. Interactive effects between land-use history and global change on biodiversity were not found, but species evenness increased more in ancient than in recent forests. Synthesis. Our results demonstrate that land-use history should not be overlooked when predicting forest herb layer responses to global change. Moreover, we found that herb layer composition in semi-natural deciduous forests is mainly controlled by local canopy characteristics, regulating light levels at the forest floor, and much less by environmental changes at the regional scale (here: warming, nitrogen deposition and aridity). The observed disconnect between biodiversity and functional herb layer responses to environmental changes demonstrates the importance of assessing both types of responses to increase our understanding of the possible impact of global change on the herb layer.

The aim of this study was to test the sensitivity of epiphytic and epixylic bryophytes and lichens as indicators of forest naturalness, by comparing their diversity patterns with forest structural, compositional and historical features associated with different management/protection regimes and protection time spans. The study was carried out in the Bialowieza Forest (Poland). Out of 1370 pre-existing inventory plots established all across the Polish part of the Bialowieza Forest, we randomly selected 10 plots for each of the 18 plot aggregation groups resulting from the combination of 3 management/protection regimes and 6 habitat types, for an overall number of 180 plots. At each of them, we carried out bryophyte and lichen sampling on four substrates (coarse woody debris – CWD, standing dead trees, stumps, living trees). The management/protection regimes exemplifying the gradient of forest naturalness were: the 100 years-old Bialowieza National Park (BNP), a set of more recently established nature reserves and managed forests. We tested differences in mean species richness values among management/protection regimes, protection time spans, habitat types and stand age classes by analysis of variance and calculated coefficients of correlation with 45 selected structural and compositional features of forest stands. Differences in species composition of epiphytic and epixilic bryophytes and lichens among management/protection regimes were tested by ordination methods. Lastly, we compared frequency of red-listed species and primeval forest relics among management/protection regimes. Species richness of lichens was significantly correlated with the degree of forest naturalness assessed by structural and historical features along the naturalness gradient, with the highest number of species recorded in BNP and the lower in managed stands, while bryophyte number did not exhibit a clear dependence on the management regimes. Relic species of primeval forests and red-listed species occurred with significantly higher frequency in protected areas than in managed forests for both lichens and bryophytes, with the highest frequency observed in BNP for lichens and in nature reserves for bryophytes. Volume of deadwood, particularly of CWD in advanced decays stage, species richness of undergrowth vascular plants, tree layer diversity, shrub cover and herb layer cover exhibited the strongest correlation with cryptogam species richness and cover on the various substrates. Response to light availability strongly differenciated bryophyte and lichens optimal niches. The results of this study clearly show that cryptogams, and lichens in particular, are indeed reliable ecological indicators of forest status, since they sensibly intercepted the environmental changes observable along the tested naturalness gradient.

Raised bogs dominated by the vegetation association Ledo-Sphagnetum magellanici Sukopp 1959 em. Neuhausl 1969 are a valuable and ecologically important plant community that occurs in Central Europe. They develop in impervious depressions with precipitation as the only water source, and are particularly sensitive to drainage, climate change, eutrophication and overgrowing by trees and shrubs. The high pressure of threat justifies taking protective measures. This research focused on the effects of the removal of birch from two bogs, which were dominated by two birch species (Betula pubescens, B. pendula) and also included stands of Scots pine (Pinus sylvestris); the bogs are located in northeastern Poland and showed signs of drying. The trees were removed in early spring 2008. To capture the response to tree cutting, vegetation monitoring was performed for 7 years. The results were compared to pre-cutting environmental conditions (precipitation, temperature, air transpiration). At the first site, which was drained at the beginning of the twentieth century, the ground water level initially decreased; then, from 2010 onwards, the level stabilised and exhibited a negative correlation with the average annual air temperature. While the second site exhibited no significant differences in the ground water table, a correlation with the average annual rainfall was found. At both sites, there was an increase in the coverage of species appropriate for raised bogs, Oxycocco-Sphagnatea Br.-Bl. et R. Tx. 1943, whereas only the second site had significant coverage of these species. These actions improved the habitat conditions and initiated the process of raised bog restoration at that site because Oxycocco-Sphagnatea species cover and frequency increased.

ICP-Forests relies on a representative pan-European network based on a 16 × 16 km grid-net covering around 6,000 plots. Dead wood volumes for 3,243 plots, related to 19 European Countries, are presented in this data paper as a result of harmonised sampling procedure, and under compliance with FAIR Data Principles. Dataset access is at . Associated metadata are available at .

Marshy pine forests have a relatively broad range of distribution across Europe but are very scattered. The typical Vaccinio uliginosi-Pinetum association is mainly restricted to nature reserves, because bog forests have been drained in many unmanaged sites where they naturally occur. Changes in the vegetation of natural forest associations in protected areas of NE Poland were studied with respect to environmental changes and ongoing autogenic successional processes in Vaccinio uliginosi-Pinetum associated plant communities. Changes in the species composition of natural communities after ca. 40 years were monitored on 14 releves in nature reserves. Most plots (nine) were located in the Bialowieza National Park with the rest in nature reserves in the Augustow and Knyszyn forests. The re-sampling of phytosociological releves was done by the same method originally used by Braun-Blanquet. The groundwater table and depth of organic layer were measured close to each releve edge. The collection of vegetation data for the two periods (old - new releves) included such parameters as: species richness, cover of layers, ecological indicator values, number of occurrences and cover coefficients of species and particular taxonomical groups. The analysis of vegetation changes in natural communities of marshy pine forest indicated that four more species were present than in the past. The largest changes in species richness occurred in the moss and herbaceous flora. The mean number of trees, shrubs and herbaceous species per plot increased significantly. Notable changes in the vertical structure of forest communities were visible. There was also an increase of ca. 20% in the secondary layer of tree canopy cover and a concomitant decrease in the moss layer. The depth of the soil organic layer reached 150 cm. The groundwater table exhibited large seasonal fluctuations in height between spring (mean of 24.3 cm) and summer (mean of 86 cm). There were changes in all the measured parameters describing the species composition of the Vaccinio uliginosi-Pinetum association. Tree species Picea abies, Betula spp. and Quercus robur, all increased in abundance over the period between sampling and re-sampling, either through increased presence in the lowest layer of stands in new releves or, in the case of Quercus robur, previously unreported occurence in the shrub layer. Many species characteristic of bog communities disappeared or significantly decreased in abundance, whereas some species typical of mineral soils became more common. The vegetation in repeatedly sampled plots became more chacteristic of wet sites than the initial bog sites over the 40 year period between sampling.

The habitat of ash-alder swamp forest, was studied in a phytosociological context. A census of changes in the species composition of natural communities was performed 40 years after the original survey had been carried out in 31 releves located in natural forests. The study sites were localized in Augustow and Bialowieza nature reserves.Re-sampling of releves followed the same Braun-Blanquet assumptions as previously. The chemical characteristics from nine soil cores were also analysed, and the peat thickness and ground water table level were measured close to every vegetation sample. Phytosociological surveys were conducted in both spring and summer. Comparative analysis of vegetation data from the two periods (old - new releves) was performed for selected variables: species richness, layers cover, ecological indicator values, number of occurrences and cover coefficients of species and syntaxonomical groups.The analysis of changes in the natural communities of vegetation occurring on ash-alder swamp forest habitat over the last 40 years indicated that decreasing humidity has caused the succession of ash-alder swamp forest to moist variants of oak-lime-hornbeam forest. An increase in cover of the understorey layer (and parallel decrease in cover of the moss layer) was evident in every sample. The species richness increased significantly over time, but this was mainly caused by the increasing number of species in the herbal flora. The species richness increasing significantly, but it was mainly caused by increasing of species number in herbal flora.

The vegetation of 107 study plots has been described twice, first in the 1960s and 1970s and then again in 1998 and 2003-2005, on the basis of phytosociological releves produced using the Braun-Blanquet method. In addition, soil studies were carried out in 2005 on the basis of soil-core sampling for chemical analysis. The research took in all of the natural types of forest wetlands to be met with in the study area. Phytosociological releves in the two repeat sets were obtained in line with the Braun-Blanquet method, while successional changes were analysed using DCA, on the basis of weighted average values for the species indicator values, analyses of the layer cover of phytocoenoses, number of species, and frequencies and cover of herb-layer vegetation. The analysis of vegetation in the two research periods shows that wetland habitat in the Bialowieza forest has been subject to successional processes conditioned by changes in the environment, i.e. desiccation through a lowering of the water table, and climatic changes inter alia entailing an increase in air temperature at the same time as amounts of precipitation have been falling. The reduced humidity of soils is leading to an accelerated process of peat decay, and hence to increased fertility and acidity of the soils. Changes in habitat conditions are bringing about major changes in both the floristic composition of the herb layer and the structure of the phytocoenoses in marshland and riparian forest habitats.

A regeneration process of oak–lime–hornbeam community (Tilio-Carpinetum typicum Tracz., 1962), developing after a clear cutting followed by a plantation of Scots pine stand (Pinus sylvestris L.), is analysed. A study material comes from managed and strictly protected (The Bialowieza National Park) part of the Bialowieza forest. A series of managed Scots pine stands, comprising developmental phases from thicket to old-growth, is compared with an analogical series of managed pedunculate oak stands – Quercus robur L. (in case of managed stands considered to be in a harmony with a target tree species composition for a given site type), as well as with a series of natural (strictly protected since ca. 80 years) stands, occurring in the Bialowieza National Park. The three experimental variants, occurring in similar site conditions, are compared with regard to the vegetation and stand structure, as well as to the chemical properties of two uppermost soil layers. Analysis of vegetation includes, i.a., calculation of a species richness, a share of species typical for Scots pine and oak–lime–hornbeam forest, ecological indicator values, as well as an analysis of overall floristic similarity by means of DCA ordination method. Soil conditions are studied by analysis of, i.a. pH in KCl and base saturation. It is concluded that the development of Scots pine stands on the site of oak–lime–hornbeam community, under conditions of the Bialowieza forest, has not brought about neither a persistent site degradation nor degeneration of the community. Some differences between pine and oak managed stands occurring on the site of oak–lime–hornbeam forest in the vegetation and chemical properties of the topsoil are generally confined to the comparatively short time period; from thicket to high polewood stages. The acidifying influence of pine needle litter on the site and ground layer vegetation is balanced, or even overridden, by processes associated with the regeneration of the phytocoenosis, first of all by the influence (shading and litter fall) of a rapidly developing hornbeam (Carpinus betulus L.) layer. Intensive regeneration processes of natural oak–lime–hornbeam community, supported by site eutrophication, caused by the input of air-borne chemicals and climate warming, lead to the growing discrepancy between Scots pine stands and site conditions. The results obtained suggest that the restoration of more natural conditions in the replacement Scots pine stands can be achieved, in a greater extent than previously assumed, by a means of spontaneous regeneration processes.

The response of an ash-alder swamp forest to water damming was studied in the Łutownia stream running in Bialowieza Forest. The Łutownia stream with artificial dam existing from 2001 for small water retention purposes was the test object. The first observation of vegetation was done in 2004, when small retention construction started to influence surrounding forest, but beavers had not built their dam yet. After one year of experiments (2005) the beaver dam was constructed close to man-made dam and its influence was most significant for further studies. So, the first observation refers to the status of ash-alder swamp forest before beaver damming. Water table level was measured from the beginning of 2004. The main goal of presented studies was to determine changes of terrestrial vegetation and its habitat after increasing of the water level in the stream. One square metre plots in a frame 5 x 5m were localized in a transect close to the stream upstream and downstream artificial dam. Within 104 such plots ground vegetation (growing up to 0.5 m above ground) was described using Braun-Blanquet scale of abundance. The vegetation studies were conducted twice in 2004 and repeated in 2007. The list of species and their abundance were determined twice: in spring and in summer. Changes of species richness and coverage by species characteristic for floodplain and swamp forest site were evaluated. Ecological indices of soil moisture and fertility determined as the means weighed by percent cover by plant species were calculated for two periods of observation. Calculated indicator values showed that water retention increased the number of swamp forest species by 8 times, but the area of swamp habitat increased 16 times compared with 2004. The mean number of species per sample plot was the same before and after water damming by beavers. The plant association (ash-alder riparian forest) changed its floristic composition to swampier variant. Obtained results showed real impact of beavers’ activity on ground vegetation and its habitat in ashalder swamp forest. Observed increased number of swamp species close to the beaver dam is positive from ecological point of view. Presented results indicate also, that species richness is strongly controlled by beaver damming. The population dynamics of beavers could also potentially affect species richness by altering the age distribution of beaver dams and abandoned ponds across the river valley landscape. Generally, this point of view could have adverse social effects because beavers’ activity brings losses to forestry and agriculture. Therefore, we should try to find a balance between economy and wildlife management. Monitoring of the beaver sites should be continued to evaluate ecological consequences and to find best solution of these problems. DOI: 10.2478/v10025-010-0032-7 Unauthenticated Download Date | 6/13/16 9:14 AM 250 J. CZEREPKO et al.

Forests and agricultural lands cover over 26 million ha in Poland (83.6% of the land, including inland water). The area of forests is 9.1 million ha, including 7.1 million ha managed by the State Forests National Forest Holding and 1.7 million ha owned by private owners, out of which 1.1 million ha are the agricultural farms. The scale and the way of land management by the Public Treasury enable the independent running, without a system support from funds devoted to the development of rural areas. The aim of this paper is to present the characteristics of the Polish forest-timber sector and its contribution to the development of the rural areas, as a complement to agriculture, including forests of all forms of ownerships and the scope of three most important groups of functions - production, environmental and social.

International audience; Species richness is a key variable in measuring diversity of ecological communities. It is crucial to get reliable estimates for the number of plant species in space (mapping) and - even more important in the context of monitoring - over time. Therefore, knowledge on error rates related to recordings of species numbers should be considered in such inventories. The performance of observers in four field tests to capture species numbers carried out in forest ecosystems in central and southern Europe were compared. Observer-related species accumulation (rarefaction) curves and derived efficiency curves were analysed, resulting in mean error rates of 29.7% and 39.4% over series of plots sized 4m(2) and 100m(2) respectively. As a new approach individual rarefaction and efficiency curves reveal site-specific and spatially differentiated capabilities of observers to register plant species. Since expertise and individual searching strategies are difficult to parametrise, reasons for variation in error rates remain largely unknown. However, statistical modelling with site- and scale-specific mean error rates gave an overview on important influential factors like location, scale, spatial integration, and their interactions. Our results underline the importance to incorporate specific training and inter-comparison measures in monitoring programs and critical perception of results on temporal changes of species richness.

The analyses of 4 permanent study plots located in the Białowieża forest (NE Poland, at 52º43´ N, 23º50´ E) were carried out 4 times, first time in 1973 or 1974 and next in 1985, 1998, 2008. The paper presents the results of a long–term study on natural forest dynamics in two forest communities: raised-bog pine forest of the association Ledo-Sphagnetum magellanici Sukopp 1959 em. Neuhäusl 1969 and transitional bogs represented by the boreal spruce forest Sphagno girgensohnii-Piceetum Polak. 1962. On each measurement date the DBH of all trees were recognized. At the same time, stems of shrub species as well as tree species with the height lower than 1.3 m were counted within the experimental areas. During the study period the structure of stands changed significantly. The major change observed on raised bog sites was an increase in numbers of Betula spp., Picea abies (L.) H. Karst. and Quercus robur L. After 34th-year of observations the boreal spruce forest stand partly passed the terminal phase and regenerated. New species occurred in the stands, especially in their lower layer, are typical for oak-lime-hornbeam forest, such as e.g. Carpinus betulus L., Q. robur, Acer platanoides L. Rapid development of Corylus avellana L. was also observed. During last decades, the decrease in the number of Pinus sylvestris L. trees has been observed. The results of analyses of stand data in four research periods show that the wetland habitat of the Białowieża forest has been a subject to the processes of succession conditioned by environmental changes such as desiccation through lowering of the water table as well as climatic changes entailing inter alia an increase of the air temperature and a decrease of precipitation.