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The wild boar is an omnivorous animal, and by foraging (rooting) disturbs the top soil layer. In some regions of Poland and Europe seasonal fluctuations in rooting have been observed. Wild boars not only eat plants, but also strongly modify their habitat. In Białowieża National Park wild boar most frequently visit oak-hornbeam forests on fertile soil. On sites where the forest floor is covered with dense vegetation the germination of seeds is difficult, and wild boar rooting can promote the removal of diaspores from deeper layers of the soil seed bank. Within a 3-year observation on 30 subplots about 10,000 seedlings emerged representing 38 species. Our study revealed that rooted patches are characterised by a very rich and diverse flora of seedlings representing mostly forest species, but their density is low. The dominant species germinating in the disturbed ground vegetation is Urtica dioica, a species forming the persistent soil seed bank. There is a possibility that seedlings of herbaceous plants emerging on permanently rooted patches are of exogenous origin, since the seeds germinating there were in many cases damaged by repeatedly rooting animals and had no chance for further growth and reaching the generative phase. However, the soil seed bank in the rooted area has to be analysed to confirm this theory, that they have exogenous or endogenous origin. Seedling density in a repeatedly rooted oak-hornbeam forest is determined by factors other than those related to rooting. In this context the present study did not demonstrate a negative impact of rooting intensity on seedling emergence.
Long-lived clonal plants provide an optimal place for the natural storage of seeds as a ‘non-soil seed bank’. We tested the hypothesis that the size and species diversity of a non-soil seed bank deposited within the clonal plant Carex cespitosa depends mainly on the plant's size. To verify this hypothesis, an experiment was conducted on an unmown meadow in the Białowieża National Park. The emerging seedlings of different species originating from C. cespitosa tussocks of different size (large and small) were observed under greenhouse conditions for four years. The size of a non-soil seed bank was evaluated based on the number of seedlings. Significant differences in the seedling number were found between large and small sedge tussocks (Mann-Whitney test Z = 3.96, P < 0.001). However, the number of recorded species was independent of tussock size. Both types of tussocks were dominated by meadow, forest and swamp species (in decreasing order). Some of these species are no longer present in the studied area, or their occurrence is limited to small groups at the meadow's edges. A non-soil seed bank within the tussock cores of C. cespitosa may be, similar to a soil seed bank, a tool for studying the changes occurring in plant communities.
Mowing may lead to substantial modification of the spatial structure of phytocenoses and plant populations. An important factor contributing to such modification may be the vicinity of a forest. The aim of this work is to explain how the patterns of the spatial structure of sedge meadows patches change under the influence of annual mowing and how the proximity of a forest affects these changes. The research was conducted in the years 1985-2000 in the south-west part of the Białowieża National Park (NE Poland) Study fields were located in Caricetum acutiformis community, neighbouring ash-alder floodplain forest Fraxino-Alnetum. Three experimental plots and three respective control ones (5 x 5m) were established at the forest boundary (0 m), at a distance of 50 m and 100 m from the forest. Annual mowing conducted for 15 years caused an increase in meadow plants coverage in all mown plots. The spreading of two rush species was also observed - Calamagrostis canescens in patches lying inthe distance of 100 m from the forest edge, and Phragmites australis in the ecotonal zone. The most important changes in a spatial distribution of floristic richness were noticed in mown patches located at the greatest distance from the boundary of the forest. Mowing caused strengthening of the mosaic pattern naturally occurring within patches and changed their structure from "coarsegrained" to "fine-grained" one. Permanent management of sedge meadows caused an increase in a spatial diversity in the first 10 years in all patches, irrespective of their location. After 15 years of management a simplification of the spatial structure occurred. The spatial structure of the clonal species population (Lythrum salicaria, Lysimachia vulgaris) was characterized by relative stability only in the first 5 years of mowing and only in the quadrates located far from the forest. Response of plants of unitary type of growth to management was different - annual mowing caused substantial changes in the distribution of Cirsium palustre individuals in the plots located far from the forest while individuals of Cirsium rivulare in the ecotone remained constantly in their locations. It was found that it can be caused by the presence of clump sedges which may have a greater impact on population structure of that species than mowing.
Content available remote Rekreacyjna wartość Białowieskiego Parku Narodowego
W artykule dokonano wyceny wartości rekreacyjnej Puszczy Białowieskiej. Przeprowadzone szacunki pozwalają stwierdzić, że generuje ona każdego roku strumień korzyści rekreacyjnych w wysokości 11,5 mln zł (2002), co odpowiada całkowitej wartości rekreacyjnej zasobu równej 287 mln zł. Wyceny dokonano za pomocą metody kosztu podroży. Ponad wszelką wątpliwość ukazuje ona ile co najmniej gotowi są poświęcić ludzie, aby odnieść korzyść z zetknięcia się z badanym obiektem. Oszacowane korzyści rekreacyjne dostarczane przez Puszczę Białowieską są 27-krotnie większe od średnich korzyści ekonomicznych generowanych przez Nadleśnictwo Białowieża i blisko 3-krotnie większe od przychodów z tytułu sprzedaży drewna pozyskiwanego na terenie Nadleśnictwa Białowieża w latach 2000-2004.
The Zonal travel cost method (ZTCM) is used to measure the recreational economic benefits from visiting the Białowieża National Park. Zonal TCM involves aggregating visitation data by zones of origin (administrative provinces) and computing the travel cost from the zone to the studied area. Visitors are estimated to have received a total of 11.5 million zł (2002) in net benefits from their recreational experience, above the cost of traveling to the wilderness area, or 105 zł per individual visit. The received values indicate that these benefits are 27 times greater than the profits generated by the Białowieża Forest Division. This signifies that the alternative cost of enlarging the Białowieża National Park onto all of the Białowieża Primeval Forest area is small.
An analysis of the variability of the snow cover was made in 4 different types of Tilio-Carpinetum communities in the Białowieża National Park, transitional area between Central Europe and North-East Europe. Thickness of the snow cover was measured in the period of 25 winter seasons (1963/64-1987/88) on a system permanent study areas. Mean thickness of the snow cover for winter season was from 9,8 to 11,4 cm in the forest communities and 11,7 cm in open area. The snow cover in plant communities occurs from 7 to 14 days more than outside the forest. From the beginning of winter to March thickness of the snow cover is greater in the open than in the forest, while in the rest of winter the snow cover in the forest showing greater thickness. It was found that in each all sub-associations of Tilio-Carpinetum, settlement of the snow cover towards the end of winter and then its melting and exposure of the soil occur on the same sites. The snow cover thickness and its duration are largely dependent on the density of tree crown canopy.
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