Biebrza National Park Research Articles

How to effectively use long-term remotely sensed data to analyze the process of tree and shrub encroachment into open protected wetlands.

Succession caused by agricultural land abandonment is one of the most serious threats to the biodiversity of non-forest ecosystems in Europe. The aim of the study conducted in the Biebrza National Park (NE Poland) was to develop a remote sensing method to analyze the process of tree and shrub encroachment into the open peatland area of the Lower Biebrza Basin of 245 km2. The study covered a period of 50 years, from 1966 to 2015. Tree and shrub coverage was analyzed independently on the basis of airborne imagery acquired in 1966, 1980, 1997, 2006, 2010 and hyperspectral and ALS data from 2015.The method used, which consisted in assigning the area covered by trees and shrubs to permanent reference areas in a grid of squares enabled us to analyze the succession process by integrating various types of airborne data retrieved from various sensors with different geometric, radiometric and spectral resolutions. Owing to this, the process of succession could be characterized on the map by illustrating the spatial distribution of tree and shrub area and the dynamics and directions of their changes in time, and quantitatively by calculating the area of trees and shrubs as well as the dynamics, pace and directions of its change over time. It will be possible to integrate the results of the analysis of archived data with those acquired in the future, which will contribute to even wider use of remote sensing in succession process monitoring. The findings suggest that in the study period the area covered by trees and shrubs increased by 3020 ha, and the open areas decreased from 75.78% of the study area in 1966 to 63.31% in 2015. During the last study period (2010–2015) encroachment of trees and shrubs was inhibited to the rate of 2.7 ha/year as a result of the conservation program being implemented in the Lower Biebrza Basin.

Smouldering fire in a nutrient-limited wetland ecosystem: Long-lasting changes in water and soil chemistry facilitate shrub expansion into a drained burned fen

Wildfires are natural phenomena which regulate functioning and stability of fire-adapted ecosystems. However, their occurrence may impair the functioning of fire-susceptible ecosystems by disturbing nutrient cycling and biodiversity. This work aimed to identify environmental factors shaping post-fire patterns of shrub expansion in a drained, burned peatland. This research was conducted in a fire-susceptible drained rich fen, located in Biebrza National Park (Poland), which was subjected to a large-scale smouldering fire in 2002. In 2014, water and soil chemistry were studied alongside with foliar nitrogen (N), phosphorus (P) and potassium (K) contents of a native shrub (Salix cinerea) in four vegetation types present after the fire. Unburned areas were dominated by herbaceous plants. Willows present were sparse and low, with chloroses and necroses. Their foliar nutrient content indicated strong K limitation. Moderately burned areas were dominated either by willows or nitrophilous plants. Willows in moderately burned areas had high chlorophyll content in leaves and their foliar nutrient content indicated a lack of evident nutrient limitation. In the moderately burned areas, relatively high contents of phosphates (P-PO43−) were recorded in soil and water. In areas with high fire severity, willows were withdrawing and their foliar nutrient content indicated N limitation. Decreased content of P-PO43− and ammonium (N-NH4+) in soil and water was also observed there. Thus, fire-induced changes in fen geochemistry were recorded twelve years after a disturbance which shaped the long-term dynamics of shrub expansion. The fire ceased K limitation in burned areas and increased P availability. Strong K limitation, which is typical in degraded fens, appeared to be critical for keeping unmanaged fen meadows with low shrub cover. The occurrence of strong K limitation in drained fen ecosystems may reduce the need for investment in conservation practices used to restrict shrub expansion (e.g. regular mowing or shrub removal).

Fen grassland vegetation under different land uses (Biebrza National Park, Poland)

The majority of European fen grasslands are seminatural and require appropriate management to maintain their high natural value. The research area was located in the middle basin of the Biebrza River Valley, where fen grasslands vegetation was i) grazed by Konik horses, ii) mowed once every 2–4 years, or iii) abandoned for 16 years. The question was as follows: How do different land use types affect the floristic composition and restoration of abandoned fen grasslands? In the examined sites we measured floristic composition and soil physicochemical parameters. The observed changes in the floristic composition resulting from the introduction of the new type of land use were significant and they occurred in a relatively short period of time. With the cessation of mowing for 16 years, the intermittently wet Molinia meadows were replaced by trees and shrubs of alder woodlands (Alnetea glutinosae class), and the plant species diversity significantly decreased. The mowing of the Molinion meadows once every 2–4 years proved to be sufficient to prevent the encroachment of trees, but it was not enough to stop the expansion of Molinia caerulea. In the site grazed with Konik horses for 13 years, the primary fen grassland vegetation (Scheuchzerio-Caricetea nigrae) was replaced by species of low, trampled swards and intermittently wet meadows (Molinio-Arrhenatheretea class). The soils under all of the sites differing in the land use type were classified as Eutric Rheic Hemic Histosols. They were typical peatland soils, slightly acidic to neutral. The results of the soil analyses indicate the high natural states of the studied areas and that their extensive use only slightly affected their physicochemical properties. Greater soil bulk density was noticed under the pasture than under the abandoned and mowed sites, but the extensive grazing of Konik horses caused only a slight increase in volumetric density to 0.19 g cm−3. Our results show that on both the mowed and the grazed sites, the content of soil organic matter and soil organic carbon was higher than that on the abandoned site. In the mowed part as well as in the grazed part, long-lasting monitoring of the effects of the management strategies used on vegetation and soil properties is still needed.

Effect of different land-use on occurrence and morphological traits of Carex buxbaumii (study from Biebrza National Park, Poland)

Carex buxbaumii is rare sedge of moist to wet meadows, marshes and fens. The population trends and detailed habitat requirements of this species remain unknown. In Poland, C. buxbaumii belongs to EN category of IUCN, while is even more endangered in other European countries. The knowledge on this species is limited, but probably it needs active protection for its maintenance. It is also known that plants respond morphologically to changes in the site conditions which may help to determine the ways of effective method of their conservation. Therefore, we examined the frequency and morphology of Carex buxbaumii growing in a sward of fen-grasslands i) abandoned for 15 years, ii) mowed, or iii) grazed by Konik horses. The description of the occurrence and of the morphological reaction to the differentiation in land–use type of C. buxbaumii is presented against the background of changes in vegetation cover that occurred in 2010–2016 in the examined fen-grassland.There was stated that C. buxbaumii grew on peat soils, of high content of organic matter and Ca+2. The type of land-use significantly differentiated both the frequency and morphology of C. buxbaumii. In the mowed site C. buxbaumii grew as an element of the Molinion vegetation and appeared there with 100% frequency. The individuals growing in the mowed site had the longest shoots, the longest inflorescence brackets, and the longest terminal spikes. In the site grazed by Koniks, C. buxbaumii was a component of Scheuchzerio–Caricetea nigrae vegetation, while its frequency of C. buxbaumii was 87%. The shoots there were the shortest, and in general, the morphology was the most differentiated. In the abandoned site C. buxbaumii abundance amounted 46%, and the individuals were smaller than those under the mowing regime but larger than those grazed by Koniks. In that site, the previous vegetation with high proportion of the Molinion and Phragmitetea species was replaced by Alnetea glutionosae vegetation, represented mainly by trees and shrubs. We have shown that the best conditions for the development of the C. buxbaumii population in the examined fen-grasslands are created under an extensive mowing regime.

A Critical Evaluation on the Role of Aerodynamic and Canopy–Surface Conductance Parameterization in SEB and SVAT Models for Simulating Evapotranspiration: A Case Study in the Upper Biebrza National Park Wetland in Poland

Evapotranspiration (ET) estimation through the surface energy balance (SEB) and soil-vegetation-atmosphere-transfer (SVAT) models are uncertain due to the empirical parameterizations of the aerodynamic and canopy-substrate conductances (gA and gS) for heat and water vapor transfers. This study critically assessed the impact of conductance parameterizations on ET simulation using three structurally different SEB and SVAT models for an ecologically important North-Eastern European wetland, Upper Biebrza National Park (UBNP) in two consecutive years 2015 and 2016. A pronounced ET underestimation (mean bias −0.48 to −0.68 mm day−1) in SEBS (Surface Energy Balance System) was associated with an overestimation of gA due to uncertain parameterization of momentum roughness length and bare soil’s excess resistance to heat transfer (kB−1) under low vegetation cover. The systematic ET overestimation (0.65–0.80 mm day−1) in SCOPE (Soil Canopy Observation, Photochemistry and Energy fluxes) was attributed to the overestimation of both the conductances. Conductance parameterizations in SEBS and SCOPE appeared to be very sensitive to the general ecohydrological conditions, with a tendency of overestimating gA (gS) under humid (arid) conditions. Low ET bias in the analytical STIC (Surface Temperature Initiated Closure) model as compared to SEBS/SCOPE indicated the critical need for calibration-free conductance parameterizations for improved ET estimation.

The fish poaching problem in the Biebrza National Park

Abstract This article discusses the issue of poaching in Biebrza National Park. This is one of the important but often overlooked factors influencing the species composition and abundance of fish in the Biebrza River and its tributaries. This article analyzes the documentation of the Biebrza National Park Guard in the Osowiec-Twierdza from 2007 to 2016. The obtained results show that the scale of the described phenomenon is serious and its methods of combating are not effective. It is also a serious shortcoming in the absence of mandatory analysis of fish found in poaching tools, which prevents proper estimation of losses both in economic and environmental terms.

INVESTMENTS ON PROTECTED AREAS ON THE EXAMPLE OF BIEBRZA NATIONAL PARK

The study discusses the issue of assessment of investment projects planned in environmentally valuable areas. The study area was Biebrza National Park. The source of data was the available literature on the subject, as well as information contained in the Chronicles of Biebrza National Park of year 2015 and 2016. An interview with the park authorities was also conducted. Analyses were developed and conclusions were drawn with regard to investments in the park area. The types of investment projects implemented were specified, as well as the share of these projects in communes located within the park area in relation to the number of inhabitants. It was found that investment projects implemented in the areas protected as a part of the national park were investments in farm buildings, animal houses and – most of all – residential buildings.

Seasonal and daily variability of CO2 emissions from the Czerwone Bagno peat bog in Biebrza National Park (Poland)

The article describes the results of field studies carried out in the period from April 2013 to May 2014. The study concerned the assessment of the magnitude of CO 2 emissions from marsh soils in the area of Czerwone Bagno (Red Swamp), which is a part of the largest complex of marsh in Poland. The authors used the closed chamber method to measure seasonal variability of net ecosystem CO 2 emission and drew attention to the impact of environmental factors (air temperature, air pressure and soil moisture) on it. The highest values of average daily CO 2 emission (over 630 mg(CO2)×m –2 ×h –1 ) were recorded in late spring and summer. Lowest values were obtained in late autumn and winter (in the range of 178-212 mg(CO2)×m –2 ×h –1 ). The need for monitoring of wetlands in temperate latitudes is stressed due to the progressive process of wetlands drying which enables the release of large quantities of greenhouse gases – CO 2 , CH 4 – into the atmosphere.

Seed dispersal in six species of terrestrial orchids in Biebrza National Park (NE Poland)

Knowledge about seed dispersal is required to explain problems in ecology, phylogeography, and conservation biology. Even though seed dispersal is a fundamental mechanism to understand problems at different levels of biological organization (individual, population, species, landscape), it remains one of the least recognized processes. Similar to other groups of plants, very little is known regarding patterns and distances of seed dispersal in orchids. Orchid seeds are generally assumed to be widely dispersed by wind because of their small size and low weight. Between 2006 and 2008, we conducted a field study of the distances at which orchid seeds are dispersed, and determined factors affecting dispersal. Investigations included 13 populations of six terrestrial orchid species – <em>Cypripedium calceolus</em>, <em>Cephalanthera rubra</em>, <em>Epipactis helleborine</em>, <em>Goodyera repens</em>, <em>Neottia ovata</em>, and <em>Platanthera bifolia</em>. To evaluate seed dispersal in orchid populations, 8.5-cm Petri dishes (traps) with self-adhesive paper were placed along transects, starting from a group of fruiting plants, which were considered to be the dispersal source. Seeds of the investigated orchid species were dispersed over relatively short distances. There were statistically significant negative correlations between seed density and distance from the fruiting plants. Seeds of species with taller fruiting shoots were dispersed farther than those with shorter ones (<em>R</em> = 0.68, <em>p</em> < 0.05). We discuss the causes and consequences of the dispersal patterns of orchid seeds.

Non-native predator control increases the nesting success of birds: American mink preying on wader nests

The ongoing decline of breeding wader populations in Europe has been mostly explained by habitat changes and the increasing impact of native predators, but the influence of non-native invasive predators has been neglected. A seven year study of the nesting success of the northern lapwing, common redshank and black-tailed godwit was carried out in Biebrza National Park in north-eastern Poland, alongside the American mink control programme, which was undertaken with low and high intensities of mink control. Indices of mink density, based on the percentage of floating rafts with mink tracks and the number of mink trapped per 100 trap-nights, declined with the increasing number of mink removed in consecutive years. In our model, the mink control and water level covariates explained most of the variation in daily nest survival rates. A decline in mink density led to increases in daily survival rates of nests and to the overall nesting success of all three wader species. Lower water levels led to a decrease in the overall daily survival rate (DSR) but this covariate affected DSR differently throughout the breeding season. These results demonstrate that predation by an introduced species, alongside low water levels during the nesting period, can limit the nesting success of multiple wader species, and that American mink should be considered as a key predator affecting ground-nesting wetland bird populations. Conservation plans for many wader species declining in numbers should include local reductions in mink populations in order to increase nesting success. Thus, intensive continuous mink control is recommended for important nesting refuges, utilising adaptive management to ensure control efforts remain sufficiently high.

Pollinator limitation affects low reproductive success in populations of nectarless orchid in the Biebrza National Park

The deficiency of pollinators is indicated as the main factor limiting fruit set in orchids. Nectariferous species are more successful in setting fruits than nectarless species. In the present study, we tested whether pollinator limitation lowers reproductive success in populations of <em>Cypripedium calceolus</em> on environmental islands in the Biebrza National Park, NE Poland. Moreover, we analyzed how population size and structure affect pollination success. Our observations and results of experiments document the low level of fruiting in populations of nectarless <em>C. calceolus</em> (9.2% on average) and strong pollen limitation. Generally, we noted a positive relationship between pollination success and all parameters of population size (measured by both occupied area and number of clumps or shoots) and parameters measuring floral display (number of flowers in population, number of flowers in clumps, spatial structure of flowering shoots). We suggest that information about factors influencing the reproductive success of this endangered species may be useful for planning appropriate conservation actions.

Long-term fire effects of the drained open fen on organic soils

AbstractFire has considerable impact on vegetation and organic soils properties. As we observed that the differences between vegetation of burnt and unburnt areas on the rich fen are visible 11 years after the fire, we assumed that the post-fire changes are long lasting, yet limited exclusively to the burnt areas. In order to check this hypothesis we studied spatial differentiation of physical and chemical properties of soils, and productivity capacities of burnt and unburnt areas in the fen in Biebrza National Park. We took soil samples from the neighboring burnt and unburnt areas, from the depth of 0–30 cm and 30–50 cm. We analyzed 21 parameters of the soils including: pH, ash content, moisture, bulk density, exchangeable K, Na, Ca, available P, N-NH4+, N-NO3−, total N, C, K, Na, Ca, Mg, Fe, P; and calculated C:N, C:P ratios. Surface layer of the burnt soils differed significantly from the unburnt soils in respect of 17 out of 21 parameters. The most pronounced difference was observed for available phosphorous (on average 6 times higher for the burnt soils). The differences in the deeper layer were mostly insignificant. The burnt areas were also characterized by twofold higher plant productivity than recorded for the unburnt areas. The influence of fire on peaty soils was long lasting but mostly limited to the surface layer of the soils. In the case of particular soil features, the post-fire differences were modified by advanced muck formation (moorshing) processes in the unburnt areas. Since the fire led to long lasting increase of fertility, the recovery of fen vegetation is unlikely.

Puccinia passerinii (Pucciniales) on Thesium ebracteatum in the Biebrza National Park – new data on its distribution in Central Europe

This work provides a morphological description of a parasitic fungus <em>Puccinia passerinii</em> Schroet. discovered in the Biebrza National Park on bractless toadflax <em>Thesium ebracteatum</em> Hayne, a host plant listed in Appendix II of the Habitat Directive and strictly protected in Poland. <em>Puccinia passerinii</em> was recorded in 1916 within the borders of current-day Poland, however, owing to a lack of herbarial materials it was not included into the checklist of Polish microscopic fungi. This work is the first report, after 100 years, on the appearance of this species in Poland, which enlarges the list of microfungi in this country and particularly in the Biebrza National Park. Moreover, a common parasite of rust fungi – <em>Sphaerellopsis filum</em> (Biv.) B. Sutton is reported for the first time on <em>P. passerinii</em>.

Urban – Wetland contrast in turbulent exchange of methane

Continuous eddy-covariance measurements of turbulent methane exchange between the ground and the atmosphere were carried out during the period from July 2013 to September 2015. The measurement sites were located in areas characterized by different types of use: the city (Łódź, central Poland) and the wetlands of Biebrza National Park (northeastern Poland). Regardless of the type of surface, such long-term, continuous measurements of the turbulent fluxes of methane are rare. Our aim was to investigate the temporal variability of the turbulent methane exchange in the surface–atmosphere system, while considering the impact of land use. Because cities are a huge source of atmospheric carbon dioxide, we compared the intensity of methane emissions from the city as compared to the wetland, which is considered to be the most intense natural source atmospheric methane. In both cases, the results show a clear prevalence of positive as compared with negative fluxes. This shows that both areas are net sources of methane to the troposphere. The measurements also demonstrated the existence of a clear annual cycle of turbulent methane flux in the centre of the city (average values in winter ranged from ∼40 to 60 nmol m−2·s−1 and were significantly greater than values measured in summer) as well as in the wetlands, where maximum values were observed during the warm part of the year (approximately 80 nmol m−2·s−1 or more). The different times of maximum CH4 flux (FCH4) occurrence resulted from the differentiation of processes that determine methane emissions: in the city these are anthropogenic emissions (strongest in winter); in the wetland, natural processes dominate. The diurnal variability of FCH4 was faintly detectable, except for the cold half of the year in the city and the warm half of the year in the wetland. The studied area of the centre of Łódź, in turn, is also characterized by a weekly cycle of methane exchange: the values measured on working days were higher by 6.6% (winter) to 5.6% (summer) than those observed on weekends. Differences in the annual exchange of methane in 2014 were insignificant: the centre of Łódź emitted 17.4 g m−2 net, while the wetland emitted about 18.7 g m−2 net. The results of the measurements performed during the period from January to September 2015, however, suggest that a very dry summer, drying of the soil and, consequently, a reduced water level in the fen significantly reduced the ability of the wetland to emit methane. This pattern was not observed in the city.

Methane and carbon dioxide fluxes of a temperate mire in Central Europe

Observational data on greenhouse gases exchange between ecosystems and the atmosphere are crucial in understanding the global climate mechanisms. Among different methods of estimation of this exchange, the eddy-covariance (EC) technique provides a direct measure of the net flux density across the atmosphere-ecosystem interface. Still, such data are highly scarce for Central European wetlands. In this work, we present the results of two years (2013–2014) of continuous open-path EC measurements of methane (CH4) and carbon dioxide (CO2) fluxes at the wetlands of the Biebrza National Park in northeastern Poland – one of the biggest coherent lowland wetland area in Central Europe. The measurement site (53°35′30.8″N, 22°53′32.4″E) was located near the Kopytkówka river in a fen peatland, whose soils are slightly decomposed due to dehydration. The mean annual sum of CH4 release equaled 29±4gCH4m−2yr−1 in wetter year 2013 and 20±1gCH4m−2yr−1 in drier year 2014. The mean annual uptake of CO2 reached 980±150gCO2m−2yr−1 and 560±130gCO2m−2yr−1 in 2013 and 2014, respectively. Both fluxes show a clear annual pattern with maximum CH4 release in June and July (at a level of 130nmolm−2s−1) and maximum CO2 uptake in June (at a level of 4.2μmolm−2s−1). The considerable C–CO2 uptake in comparison to C–CH4 emissions suggests that the Biebrza river wetlands are a significant carbon sink, but the net contribution of the Biebrza mires to the climate forcing is unclear because of different metrics which can be used to specify the relative weights of CO2 and CH4.

WETLAND MAPPING WITH SAR/QUAD-POL DATA ACQUIRED DURING TANDEM-X SCIENCE PHASE

The aim of this study was to exploit fully polarimetric SAR data acquired during TanDEM-X – Science Phase (2014/2015) over herbaceous wetlands of the Biebrza National Park (BbNP) in North-Eastern Poland for mapping seasonally flooded grasslands and permanent natural vegetation associations. The main goal of this work was to estimate the advantage of fully polarimetric radar images (QuadPol) versus alternative polarization (AltPol) modes. The methodology consisted in processing of several data subsets through polarimetric decompositions of complex quad-pol datasets, classification of multitemporal backscattering images, complementing backscattering images with Shannon Entropy, exploitation of interferometric coherence from tandem operations. In each case the multidimensional stack of images has been classified using ISODATA unsupervised clustering algorithm. With 6 QUAD-POL TSX/TDX acquisitions it was possible to distinguish correctly 5 thematic classes related to their water regime: permanent water bodies, temporarily flooded areas, wet grasslands, dry grasslands and common reed. This last category was possible to distinguish from deciduous forest only with Yamaguchi 4 component decomposition. The interferometric coherence calculated for tandem pairs turned out not so efficient as expected for this wetland mapping.

WETLAND MAPPING WITH SAR/QUAD-POL DATA ACQUIRED DURING TANDEM-X SCIENCE PHASE

Abstract. The aim of this study was to exploit fully polarimetric SAR data acquired during TanDEM-X – Science Phase (2014/2015) over herbaceous wetlands of the Biebrza National Park (BbNP) in North-Eastern Poland for mapping seasonally flooded grasslands and permanent natural vegetation associations. The main goal of this work was to estimate the advantage of fully polarimetric radar images (QuadPol) versus alternative polarization (AltPol) modes. The methodology consisted in processing of several data subsets through polarimetric decompositions of complex quad-pol datasets, classification of multitemporal backscattering images, complementing backscattering images with Shannon Entropy, exploitation of interferometric coherence from tandem operations. In each case the multidimensional stack of images has been classified using ISODATA unsupervised clustering algorithm. With 6 QUAD-POL TSX/TDX acquisitions it was possible to distinguish correctly 5 thematic classes related to their water regime: permanent water bodies, temporarily flooded areas, wet grasslands, dry grasslands and common reed. This last category was possible to distinguish from deciduous forest only with Yamaguchi 4 component decomposition. The interferometric coherence calculated for tandem pairs turned out not so efficient as expected for this wetland mapping.

Do moose redistribute nutrients in low-productive fen systems?

The reduction of human use in many grassland systems across Europe has led to bush encroachment and a loss of biodiversity. Low intensity grazing systems by livestock has often been used as a cost-effective management tool to counteract this process. However, not all semi-natural grasslands are suitable for this due to large distance from human settlements or adverse environmental conditions. In this study we address the question whether natural wild large ungulates can be a useful management tool as well. In nutrient-limited systems, large herbivores can affect vegetation dynamics by redistribution of nutrients next to their direct effects on the vegetation. They can preferentially forage plant species and deposit their pellets at other locations leading to nutrient redistribution. We studied whether moose (Alces alces) in the Biebrza National Park (Poland), plays a role in nitrogen dynamics. Microscopic analyses of faeces showed that 57% of the diet consisted of Salix cinerea, which was preferentially foraged upon indicated by a positive Jacobs’ selectivity index. Pellet density was significantly higher in patches of S. cinerea compared to the surrounding vegetation. Based on the chemical composition of moose pellets and the pellet density, we calculated that moose-derived N (faeces and urine) leads to a relevant N-input in willow patches compared to other sources of N in the system. We show that moose do not redistribute nitrogen between different vegetation types but instead speed up the local recycling of nitrogen in patches dominated by willows during the growing season. As a consequence, nutrients become quicker available here than in other parts of the system. We hypothesize that enhanced N-availability in willow patches may off-set the growth reduction caused by moose browsing on willows, which fits to the observed continuous expansion of willows in the study area despite high density of moose. This suggests that moose likely stimulate the growth of willow rather than the often supposed suppression of this woody species. In these systems, more labour-intensive management (f.e. mowing) is required to counteract bush encroachment.

Gastrointestinal parasites of the Polish primitive horses from the Biebrza National Park

Summary Thirty-one Polish primitive horses (Equus caballus) from three herds (two from the reserve and onefrom the stable) were dewormed with ivermectin+praziquantel and examined for the gastrointestinalparasite fauna. A total of 21.231 parasites were collected from the faeces at 24, 36 and 48 hoursposttreatment. There were 35 nematode species, one cestode and one botfl y larva. Strongyloideswesteri infection was confirmed pretreatment by faecal sample examination and no threadwormspecimens were found after deworming. Large and small strongyle prevalence was 90 % – 100 % and represented by 31 species. Among a total of 25 cyathostome species recovered (from 19 to 24in each group), five species (C. catinatum, C. minutus, C. longibursatus, C. nassatus and C. ashworthi)had a prevalence of 100 % in three groups of horses. Meanwhile 14 species were 100 % prevalent in one herd. A total of six large strongyle species were found in adult horses. Oxyuris equiwas recorded in 60 – 100 % of the horses while Parascaris equorum was detected in 100 % of foalsand 16.7 % – 30 % of adult mares. Habronema muscae was found in 30 % of the horses from onefree-ranging herd. Tapeworms (Anoplocephala perfoliata) were found in 90 % of the horses from onefree-ranging group, whereas botfl y larvae (Gasterophilus intestinalis) were found in 50 – 80 % of allsurveyed horses. The present results are compared with earlier studies of Polish primitive wild horsesfrom similar reserves in Poland. A total of 36 gastrointestinal parasite species were recorded fromwild and stabled horses from the Biebrza National Park. This is in comparison with 35 such speciesin free-ranging and stabled horses from the Roztocze National Park and with 28 such species offree-ranginghorses from the Popielno forest reserve. Among parasites recovered, the highly prevalent S. vulgaris, tapeworms and botfl y larvae pose aserious risk of serious abdominal disorders in horses.

Preliminary studies of fungi in the Biebrza National Park. Part IV. Macromycetes – new data and the synthesis

The paper presents the last part of the results of the short-term inventory of fungi species in the Biebrza National Park and synthesises all the data gathered during two surveys, including the information published by other authors. The main body of research is focused on a survey of macrofungi identified with morphology-based methods. In case of some specimens molecular technics have been applied. In total 346 macrofungal taxa (21 belonging to ascomycetes and 325 to basidiomycetes) were found during the survey, including 186 species unobserved during the previous inventory in 2012. As a result of previous and ongoing studies, the current number of macrofungi recorded from the Biebrza National Park reached 508 species. Among them eight taxa are newly reported for Poland (<em>Conocybe velutipes</em> var. <em>nitrophila</em>, <em>Entoloma caeruleum</em>, <em>E. plebejoides</em>, <em>Inocybe rennyi</em>, <em>I. vulpinella</em>, <em>Pholiota pityrodes</em>, <em>Pholiotina utricystidiata</em>, and <em>Tomentella pilosa</em>). The next seven species (<em>Bovista paludosa</em>, <em>Fistulina hepatica</em>, <em>Ganoderma lucidum</em>, <em>Geastrum schmidelii</em>, <em>Inonotus obliquus</em>, <em>Tulostoma kotlabae</em>, and <em>Xerocomus parasiticus</em>) are protected by law and 95 species belong to red-listed species. The results of two intensive, but relatively short-term survey clearly indicate the Biebrza National Park as a hot spot of macrofungi and suggest the need to undertake extended and regular inventories also in other Polish national parks.