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EN
The study examined the effect of variation in hydrology on seedling recruitment of shrubs, trees and herbs in peat bogs. The establishment of plants and hydrologic conditions were followed in two peatlands in the Polesie Zachodnie region, Eastern Poland. Meteorological conditions in the study sites ranged from very dry (2006) to very wet (2007) and strongly affected ground water level in the bogs. The emergence of woody species typical for advanced vegetation succession was higher in forest-bog, while the recruitment of typical peat bog plants was higher in open bog. Disturbance in the vegetation positively influencedemergence of typical peat bog species and Betula pubescens, but the effect was only foundin the dry year. Only in Pinus sylvestris did recruitment increase in wet seasons. The results suggested that an increase in the number of woody species in peat bogs may be enhanced during relatively wet seasons and that disturbance in the vegetation cover are not required for seedling recruitment of these plants.
EN
Succession of woody species on bogs is a process limited by high groundwater table. In the case of drainage, this limiting factor becomes suppressed and succession may accelerate. The aim of the study was to assess the development of tree stands on a raised bog influenced by drainage and wild fire and to assess the dynamics of woody species encroachment. The study was conducted in the ‘Brzozowe Bagno koło Czaplinka’ nature reserve in NW Poland, where the originally unforested peat bog was influenced by peat harvesting, drainage and fire over 100 years. The diameter at breast height of tree species and natural regeneration were assessed. Six types of tree stands were distinguished: open bog, bog forest with Pinus sylvestris, early-, mid- and late-successional bog forest with Betula pubescens and pioneer forest with Populus tremula, which occurred in the post-fire sites. After ca 100 years of human activity on an unforested peat bog, dense forest emerged on almost all of the study area. Drainage and wildfire influenced tree stand structure. The course of succession most probably goes from open bog to pine bog forest and early-, mid- and late-successional birch forests. Regeneration of B. pubescens is a crucial phase of woody species succession, because this species creates suitable conditions for growth of late-successional species.
EN
Nitrogen flow through birch stand canopies was studied in the Kampinos National Park (large forested area with inland dunes and wetlands close to Warsaw) during the growing seasons (April-October) of 2005-2006. The amount of nitrogen deposition including main forms like NO[3], NH[4], organic N and the aerosolgaseous fraction of deposition were estimated as well as the influence of birch canopies on this process. Because a method of "artificial foliage" allows to measure an aerosol-gaseous fraction of deposition a gradient of rain collectors equipped with artificial foliage of known surfaces were used. The results were compared with amounts of nitrogen measured in the throughfall of three birch forests. All stands (age 20.50 years) were rather similar, but stand II has smaller LAI (Leaf Area Index = 2.5 m[^2] m[^-2]) than stands II and III (3.8 and 3.9 m[^2] m[-2]). It was found that nitrogen deposition in the Kampinos National Park is rather high - 1.6 kg ha[^-1] month[-1]. Ammoniumnitrogen made almost half of this value, organic nitrogen - over one third, and nitrate-nitrogen constituted the rest. Aerosol-gaseous input significantly made the deposition increased only in the case of nitrate-nitrogen, but deposition of ammonium- and organic nitrogen were similar and independent of catching leaf area. All fractions of nitrogen were effectively taken up during their passing through birch canopies (57% of nitrogen deposition was retained). Generally two thirds of deposited ammonium-nitrogen, more than half of organic N, and one third of nitratenitrogen were taken up by birch canopies. However, uptake efficiency of all N forms was lower for stand with smallest leaf area with no statistically significant retention of organic N.
EN
Nitrogen flow through birch stand canopies was studied in the Kampinos National Park (large forested area with inland dunes and wetlands close to Warsaw) during the growing seasons (April-October) of 2005–2006. The amount of nitrogen deposition including main forms like NO₃, NH₄, organic N and the aerosolgaseous fraction of deposition were estimated as well as the influence of birch canopies on this process. Because a method of “artificial foliage” allows to measure an aerosol-gaseous fraction of deposition a gradient of rain collectors equipped with artificial foliage of known surfaces were used. The results were compared with amounts of nitrogen measured in the throughfall of three birch forests. All stands (age 20–50 years) were rather similar, but stand II has smaller LAI (Leaf Area Index = 2.5 m² m⁻²) than stands II and III (3.8 and 3.9 m² m⁻²). It was found that nitrogen deposition in the Kampinos National Park is rather high – 1.6 kg ha⁻¹ month⁻¹. Ammoniumnitrogen made almost half of this value, organic nitrogen – over one third, and nitrate-nitrogen constituted the rest. Aerosol-gaseous input significantly made the deposition increased only in the case of nitrate-nitrogen, but deposition of ammonium- and organic nitrogen were similar and independent of catching leaf area. All fractions of nitrogen were effectively taken up during their passing through birch canopies (57% of nitrogen deposition was retained). Generally two thirds of deposited ammonium-nitrogen, more than half of organic N, and one third of nitratenitrogen were taken up by birch canopies. However, uptake efficiency of all N forms was lower for stand with smallest leaf area with no statistically significant retention of organic N.
EN
Succession of woody species on bogs is a process limited by high groundwater table. In the case of drainage, this limiting factor becomes suppressed and succession may accelerate. The aim of the study was to assess the development of tree stands on a raised bog influenced by drainage and wild fire and to assess the dynamics of woody species encroachment. The study was conducted in the ‘Brzozowe Bagno koło Czaplinka’ nature reserve in NW Poland, where the originally unforested peat bog was influenced by peat harvesting, drainage and fire over 100 years. The diameter at breast height of tree species and natural regeneration were assessed. Six types of tree stands were distinguished: open bog, bog forest with Pinus sylvestris, early-, mid- and late-successional bog forest with Betula pubescens and pioneer forest with Populus tremula, which occurred in the post-fire sites. After ca 100 years of human activity on an unforested peat bog, dense forest emerged on almost all of the study area. Drainage and wildfire influenced tree stand structure. The course of succession most probably goes from open bog to pine bog forest and early-, mid- and late-successional birch forests. Regeneration of B. pubescens is a crucial phase of woody species succession, because this species creates suitable conditions for growth of late-successional species.
EN
The study of foliage was carried out in two different forest ecosystems: Vaccinio uliginosi- Betuletum pubescentis and Empetro nigri-Pinetum in the Slovinski National Park in the period of 2002-2005. The largest volume of nitrogen and phosphorus in the litter of coniferous needles was found in early summer at the moment of maximum growth. An average concentration of nitrogen in examined needles was between 1.296% and 1.358% N in Vaccinio uliginosi-Betuletum pubescentis and from 1.010% to 1.118% N in Empetro nigri-Pinetum. The decrease of biogenes concentration in plant tissues was observed in the autumn months as a result of lower demand and recession of biogenes connected with storage of valuable elements in the fatter parts of the trees. In the fall season, a gradual recession of nutrients from the litter of coniferous needles was observed. In Vaccinio uliginosi-Betuletum pubescentis insignificant quantity of nitrogen recesses (average 5.6%) from the new and one year old litter of coniferous needles, including 47.2% N-NH4 and 78.6% N-NO3 and about 21.8% P, including 11.7% P-PO4. In Empetro nigri-Pinetum more intensive recession of biogenes was found from the litter of coniferous needles of common pine than in Vaccinio uliginosi-Betuletum pubescentis. On average 11.5% T-N is translocated, including 41.4% N-NH4 and 23.8% N-NO3 as well as 22.3% P, including 11.8% P-PO4.
PL
Badania listowia prowadzono w dwóch rożnych ekosystemach leśnych: Vaccinio uliginosi- Betuletum pubescentis i Empetro nigri-Pinetum w Słowińskim Parku Narodowym w latach 2002-2005. Największe ilości azotu i fosforu w igliwiu stwierdzono wczesnym latem w czasie maksymalnego wzrostu. Średnia koncentracja azotu w badanym igliwiu mieściła się w przedziale od 1,296% do 1,358% N w Vaccinio uliginosi-Betuletum pubescentis oraz od 1,010% do 1,118% N w Empetro nigri-Pinetum. Obniżenie koncentracji biogenow w tkankach roślinnych obserwowano w miesiącach jesiennych jako wynik mniejszego zapotrzebowania na nie oraz wycofywania biogenów związanych z magazynowaniem cennych pierwiastków w grubszych częściach drzew. W okresie jesiennym zaobserwowano rownież stopniowe wycofywanie nutrientów z igliwia. W Vaccinio uliginosi-Betuletum pubescentis wycofywane są nieznaczne ilości azotu (średnio 5,6%) z igliwia nowego i jednorocznego, w tym 47,2% N-NH4 i 78,6% N-NO3 oraz około 21,8% P, w tym 11,7% P-PO4. W Empetro nigri- Pinetum stwierdzono silniejsze wycofywanie biogenów z igliwia sosny zwyczajnej niż w Vaccinio uliginosi-Betuletum pubescentis. Średnio retranslokacji ulega 11,5% T-N, w tym 41,4% N-NH4 i 23,8% N-NO3 oraz 22,3% P, w tym 11,8% P-PO4.
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