Thirty years of vegetation dynamics in the Rospuda fen (NE Poland)

Little is known about the vegetation dynamics of fens, and especially of hydrologically undisturbed examples. We described the vegetation of an undisturbed mesotrophic rich fen (percolation mire) in 2006–2008 and 2016 and compared our results with vegetation records from the 1980s to identify any longer-term changes. Eight vegetation types were distinguished. On the whole, the vegetation of the mire has remained very stable throughout the last 30 years. However, detailed comparisons of permanent plots recorded twice in the last ten years indicated an expansion of shrubs in patches of Sphagnum - small sedge vegetation. There were also several less prominent changes in the abundance of particular species in other mire vegetation types: (1) an increase of sedges, reeds and Calliergonella cuspidata at the expense of rich-fen moss species in communities of brown moss - small sedge; (2) a change in composition of the moss layer in pine - birch fen woodland; (3) an increase of reedbed species and reduced Alnus glutinosa abundance in flooded riparian alder woodland; and (4) a decline of wetland herbs and mosses in alder spring fen woodland at the edges of the valley

New data on the distribution and habitat conditions of stoneworts (characeae) in Poland (2010–2012) including protected areas and lands involved in agri-environmental programmes

W artykule przedstawiono wyniki badań rozmieszczenia ramienic, prowadzonych w różnych regionach kraju w latach 2010–2012. Szczegółowo przedstawiono warunki siedliskowe 52 stanowisk, na których występowało 15 gatunków z rodzajów: Chara (12), Nitella (2) i Nitellopsis (1). W analizowanej grupie stanowisk najczęściej notowano Chara vulgaris, Ch. contraria, Ch. globularis i Ch. virgata. W trakcie badań odnaleziono liczne stanowiska gatunków zagrożonych wymarciem w Polsce, takich jak: Ch. aspera, Ch. filiformis, Ch. hispida, Ch. intermedia, Ch. polyacantha, Ch. rudis i Nitella mucronata. Gatunkiem uznawanym za zanikły w kraju jest odnaleziona Ch. connivens. Ramienice zasiedlały głównie wody płytkie i bardzo płytkie (młaki, torfowiska, potorfia, przybrzeżne strefy akwenów), choć w niektórych rozległych zalanych piaskowniach i kamieniołomach występowały także na znacznych głębokościach (do 8,7 m). Ramienice występowały także na obszarach monitorowanych użytków rolnych, objętych programem rolnośrodowiskowym (Chara vulgaris, Ch. globularis, Ch. virgata, Ch. tomentosa, Ch. hispida). W takich miejscach najczęściej występowała Ch. vulgaris var. longibracteata. Na uwagę zasługuje stwierdzenie zdecydowanej większości stanowisk ramienic poza jeziorami polodowcowymi, w Polsce uznawanymi za ich główne siedlisko. Większość danych z Wyżyny Śląsko-Krakowskiej z lat 2010–2012 omówiono w osobnych pracach, niemniej wykorzystano je w zestawieniach, analizach i wnioskach niniejszej pracy, obejmujących łącznie 22 gatunki na 108 stanowiskach (230 notowań).The paper is a compilation of stonewort records made during the field surveys in various regions of Poland in the years 2010–2012. We present in detail habitat conditions of 52 sites with 15 charophytes representing 3 genera: Chara (12 species), Nitella (2) and Nitellopsis (1). Among them, there are some of the rarest Polish charophytes like Chara connivens considered extinct in Poland and endangered species like: Ch. aspera, Ch. filiformis, Ch. hispida, Ch. intermedia, Ch. polyacantha, Ch. rudis and Nitella mucronata. Chara vulgaris, Ch. contraria, Ch. globularis and Ch. virgata have been the most frequently found species. Numerous records of charophytes outside glacial lakes (in Poland commonly regarded as the main habitat of stoneworts) are particularly noteworthy. Stoneworts were recorded mostly in shallow and very shallow waters. However, in some deep sand- and stone pits they occurred to a depth of 8.7 m. Surprisingly, charophytes were also found in rural landscape areas included in agri-environment schemes (Ch. vulgaris, Ch. globularis, Ch. hispida, Ch. tomentosa, Ch. virgata). The most often recorded species in such habitats was Chara vulgaris var. longibracteata. Chara vulgaris was also the most frequently recorded species in all types of habitats, confirming its wide ecological amplitude and distribution. Most data of Silesia-Cracow Upland of 2010–2012 were published in detail separately, however, we used them in summaries, analysis and conclusions, which cover a total of 22 species in 108 sites (230 records)