Sphagnum wulfianum Girgens in the Suwałki Landscape Park (NE Poland)

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1 Studia Limnologica et Telmatologica Sphagnum wulfianum Girgens in 4 the Suwałki Landscape 2 (STUD LIM TEL) Park (NE Poland) Sphagnum wulfianum Girgens in the Suwałki Landscape Park (NE Poland) Mariusz Gałka Department of Biogeography and Paleoecology, Adam Mickiewicz University, ul. Dzięgielowa 27, Poznań, gamarga@wp.pl Abstract: The article describes two new sites of one of the rarest occurring sphagnum in Poland Sphagnum wulfianum Girgens, classified as a glacial relict. The newly discovered places of occurrence of Sphagnum wulfianum are located in the NE Poland, within the Suwałki Landscape Park. Sphagnum wulfianum grows on wooded peat bogs overgrown with Picea abies and Pinus sylvestris, with a strongly decomposed surface peat layer. Lack of sites typical of this Sphagnum species in the area in the past allows for making the assumption that it is a newcomer in this area from the borreal zone. Key words: Sphagnum wulfianum Girgens, glacial relicts, peat bog, Suwałki Landscape Park Introduction The Suwałki Region is an interesting area to carry out research on the current and fossil distribution of plants. The fact results from its location in the transitional zone between the deciduous forest and borreal forest zones. It enables the appearance of species typical of both these vegetation zones, and the interpretation of their ranges. Due to this specificity in the geobotanical division of Poland, a separate geobotanical unit was distinguished, namely the Augustów-Suwałki Geobotanical Region (Szafer 1972). The distribution of Sphagnum mosses in the Suwałki Region is known to a largely dissatisfactory degree. The research area covered in papers published so far has usually been insignificant, and data on the occurrence of Sphagnum were often presented only for rare species growing in single locations (Gos K. & Gos L. 1991, Kawecka A. & Karczmarz K. 1993, Pawlikowski 2008). Sphagnum wulfianum is categorized as a subarctic element. On the Northern Hemisphere, it usually occurs in North America. It is also encountered in East Asia on Siberia, in China, and Greenland (Holmen & Lange 1958, Humle 1984). The distribution of this moss in Europe is characterized by a compact locality restricted to Scandinavia (Daniels & Eddy 1990). In other parts of Europe, it belongs to the rarest Sphagnum species. So far, its occurrence has been confirmed in only one location in Romania (Stefureac 1985) and in Poland, where it was found at 14 sites (Sobotka 1975, Karczmarz & Sokołowski 1981, Karczmarz & Kornijów 1981, Herbichowa 2001). Therefore, it was classified as the rarest occurring sphagnum (Ochyra 1992). It is worth noticing that its occurrence in locations mentioned in the literature should be currently confirmed. Methods The discovery of two new locations of Sphagnum wulfianum is directly related to the mapping of peat bogs within the Suwałki Landscape Park (hereinafter also referred to as the SLP). The study on the distribution and types of peat bogs in this area consisted in careful determination of places of occurrence of biogenic sediments in the form of lake peats and gyttja, based on geological probing and measurement of their surface areas by means of a cartographic recorder GPS Tm.

2 56 Mariusz Gałka For the purpose of determining the genesis of the peat bog and features of the biogenic sediments on which Sphagnum wulfianum grows, two geological drillings were carried out by means of an Instorf type manual corer. The sediments were described in the field according to the Troels-Smith method (Tobolski 2000). In order to determine whether Sphagnum wulfianum grew in a given location also in the past, two peat cores were sampled from a depth of 0-50 cm. The sediments were sludged under warm stream of water on sieves with 0.25 and 0.5 mm mesh. The identification of macrofossils was carried out by means of a stereoscopic microscope with magnification, and electron microscope with magnification, also used to record images (Fig. 3 a-f). Study site description Two new locations of Sphagnum wulfianum in Poland (I ,2 N, ,53 E; II ,6 N, ,57 E) were discovered in the NE Poland within the Suwałki Landscape Park (Fig. 1). Both places of occurrence of S. wulfianum are currently peat bogs overgrown with mixed forest with the predomination of coniferous trees (Picea abies and Pinus sylvestris). One of the places is located on a peat bog developed at the eastern coast of Lake Jaczno (site I), the second is located on a peat bog to the West of Lake Okrągłe (site II). Note that the latter peat bog is connected with Lake Kojle, and not Lake Okrągłe, by its shape and biogenic sediment coherence. Such a situation was determined during field geological probing. Results Two new locations of Sphagnum wulfianum Girgens, very rare in this part of Europe, were encountered during the field mapping of the distribution of peat bogs and important peat-forming plants. Identification of this Sphagnum does not pose any particular problems. Already in the field, a large, erect, dense moss cap is visible. An additional helpful feature in the case of identification on the moss in the field is the Fig.1. Sites of occurrence of Sphagnum wulfianum Girgens in the Suwałki Landscape Park.

3 Sphagnum wulfianum Girgens in the Suwałki Landscape Park (NE Poland) brown stem. A detailed description of the anatomical features of this Sphagnum species is presented by Daniels & Eddy (1990). The appearance of Sphagnum wulfianum directly at one of the sites is presented in Fig. 2. The accurate identification of this Sphagnum species is, however, ensured by specific diagnostic features of branch and stem leaves. They are presented in Fig. 3. Identifying this moss with the application of a microscope, attention should be paid to the unique shape and distribution of pores on water-bearing cells in branch leaves. A large number of pores, and in particular the number of the rings around the pores (!), Fig 2. Sphagnum wulfianum Girgens at site II. 57 draws attention. Pore rings also occur in the case of Sphagnum warnstorfii (Hölzer 2010), but only in the top part of the branch leaf. In the case of Sphagnum wulfianum, in turn, they occur almost on its entire length. Such specific features of its water-bearing cells certainly make it identifiable also in the fossil form. Note, however, that the world literature does not provide any data on the issue. Difficulties with finding Sphagnum wulfianum in fossil materials may be related to the specificity of locations of its occurrence. It usually grows on overdried and wooded peat bogs, where the newly developed sphagnum moss peat mass is

4 58 Mariusz Gałka Fig. 3. Microscope images of Sphagnum wulfianum Girgens: a-b stem leaves 10, c-d branch leaves 10, e-f clear rings around pores in water-bearing cells on branch leaves, e 20, f 40. subject to almost entire decomposition. It does not exclude, however, the species being a peat-forming species, and in the future, during thorough microscopic analysis, finding any fossil remains of the species. In addition to Sphagnum wulfianum, also other Sphagnum species were found in the area of the entire peat bog: Site I: Sphagnum magellanicum, S. palustre, S. fimbriatum, S. girgensohnii, S. nemorum, S. russowii, S. warnstorfii, S. squarosum, S. teres. Site II: Sphagnum magellanicum, S. palustre, S. girgensohnii, S. nemoreum, S. russowii, S. teres, S. angustifolium. During inventory works, for the purpose of determining the thickness and form of biogenic sediments, two geological drillings were carried out, one at each site. The drillings were performed in the central part of the peat bog (Fig. 1). Description of sediments by means of the TROELS- SMITH method: Site I: 0-15 Sh2, Th+, Tb Tb2, Th1, Sh Th2, Sh Th (Phragm.)3, Sh1

5 Sphagnum wulfianum Girgens in the Suwałki Landscape Park (NE Poland) Th2, Sh Th1, Tl1, Sh Ld1, Lc3, Dh+, Dg Lc2, Ld1, Gmin Gmin4 Site II: 0-28 Tb(Sph.)1, Sh2, Th Th1, Sh Th2, Sh Th3, Sh1, seeds of Menyanthes trifoliata Tb(Bryal.)2, Th1, Sh Th2, Sh2, Tl Tb(Bryal.)2, Th1, Sh Th2, Sh2, layer with charcoals Tb(Bryal.)1, Th2, Sh Tb(Bryal.)3, Th Th2, Sh2, Tb Tb(Bryal.)3, Th1 epidermises of Eriophorum vaginatum Th2, Tb(Sph.)1,Ld Tb(Sph.)3,Th Th2, Sh Sh3, Gmin1, Th Gmin3, Gmaj1 During analyses of plant macrofossils concerning two cores with the top layer peat sediments with a length of 50 cm, sampled from the place of current occurrence of Sphagnum wulfianum, no fossil remains of the species in the form of leaves were found. It should be emphasized that the frequency of other macrofossils was very low. It resulted mainly from the degree of decomposition of the sediment. The following were found, however: needles of Picea abies, a seed of Rubus sp., fruit of Potentilla sp., fruit of Carex sp. Discussion Similarly as in cases presented in the literature, within the Suwałki Landscape Park, Sphagnum wulfianum grows on strongly decomposed peat ground, at shaded sites, in a spruce forest. Within the peat bog where it was found, also other Sphagnum species occur. The largest area is occupied by Sphagnum teres, Sphagnum palustre, and Sphagnum girgensohnii. In view of the total lack of this species in fossil material, its status as a glacial relict should be reconsidered. It cannot be assumed that it is not present in bionic sediments of this part of Europe, but the fact that its occurrence has not been observed so far is worth attention. The situation in this case is not as clear as in the case of the location of Betula nana on the Linie peat bog. There, the palaeobotanical analysis evidenced the continuous occurrence of Betula nana in the location throughout thousands of years (Noryśkiewicz 2005). It is worth noticing that the discussed Sphagnum wulfianum grows in the SLP within peat bogs which could not constitute its habitat in the past. In one of the cases, the peat bog is limnogenic with Sphagnum mosses appearing not long ago, as evidenced by the macrofossil analysis of the top layers of sediments. In the second case, the peat bog is of paludification origin, and its profile is dominated mainly by herbaceous peat, moss peat, and herbaceous-moss peat. During geological drilling at this site, a layer with fossil Sphagnum was found, but its thickness amounted to as little as 53 cm, and constitutes an interlayer between the layers of herbaceous peat and moss-herbaceous peat. The distribution and form of sediments suggest that in the locations described, Sphagnum wulfianum had no possibility of continuous development throughout thousands of years. Therefore, it should be considered whether it is a newcomer in this area evidencing the proceeding borrealization of the area. Analogical doubts concerning the status of a relict in other areas have already occurred in the literature. Tobolski et al. (1997) questioned the status of Rubus chamaemorus as a glacial relict at the Baltic Sea coast, and Milecka (2005) questioned such a status in the case of Lobelia dortmanna and Isoëtes lacustris in the Bory Tucholskie forest. The time of appearance of these species in the mentioned areas was determined either by the appearance of habitats favorable for them, or change in climatic-edaphic conditions, reflecting the course of glacial-interglacial cycles (Iversen 1964, Tobolski 1976, Dzięciołowski & Tobolski 1982). It is also worth emphasizing that the species appeared lately in the Pomorze Region (Herbichowa 2001), which can be explained by its slow spreading in northern Poland. The influence of the borreal climate in the Suwałki Region favors migration of plants classified as glacial relicts to these areas. Gradual borrealization of the area, forced by climate change (understood as a process lasting hundreds of years) also results in withdrawal of plants with atlantic features from the area, e.g. Juncus subnodulosus (Gałka 2009).

6 60 Mariusz Gałka Acknowledgments I am grateful to Mr. Bronisław Wojtuń from Wrocław and Mr. Adam Hölzer from Karlsruhe. As my hosts in scientific internship programs they enabled me to begin scientific work on the distribution and ecology of present-day and fossil Sphagnum mosses. The research work was carried out in the scope of the research project N N (Peat bogs and fossil lakes of the Suwałki Landscape Park a source of palaeoecological knowledge) financed from the resources of the Ministry of Science and Higher Education (head Mariusz Gałka). References Daniels R.E, Eddy A Handbook of European Sphagna. Institute of Terrestrial Ecology. Natural Environment Research Council. London: HMSO. Dzięciołowski A., Tobolski K Czwartorzędowe cykle klimatyczno-ekologiczne a ewolucja gleb. Roczniki Gleboznawcze. 33(1/2): Gałka M A Juncus subnodulosus SCHRANK fossil site in Holocene biogenic sediments of Lake Kojle, Studia Limnologica et Telmatologica 3/2: Gos K., Gos L Interesujące torfowowisko przejściowe koło Blaskowizny w Suwalskim Parku Krajobrazowym. Zesz. Nauk. Uniw. Gdańsk. Biologia 9: Herbichowa M New locality of Sphagnum wulfianum Girgens in Poland. Biological Bulletin of Poznan 38: 214. Holmen H., Lange B Sphagnum wulfianum and Sphagnum centrale. Their morphology and occurrence in Greenland. Bot. Tidsskr. 54: Hölzer A Die Torfmoose Südwestdeutschlands und der Nachbargebiete. Versandbuchhandlung Andreas Kleinsteuber. Humle L A new find of Sphagnum wulfianum Girgens in Greenland. Lindbergia 9: Iversen J Plant indicators of climats, soil and other factors during the Quaternary. Report of the VIth international Congress on Quaternary. Warsaw. 2: Kawecka A., Karczmarz K Występowania rzadkich i wyróżniających mszaków w zbiorowiskach roślinnych Suwalskiego Parku Krajobrazowego. Parki Nar. Rez. Przyrody. 12(1): Karczmarz K, Sokołowski A.W Bryophyte flora of Northeastern Poland. Annales Universitatis Mariae Curie-Sklodowska. Sectio C. Biologia 36: Karczmarz K., Kornijów A Distribution of some rare Bryophytes in Poland. Lindbergia, 7: Milecka K Historia jezior lobeliowych zachodniej części Borów Tucholskich na tle postglacjalnego rozwoju szaty leśnej, Wyd. Nauk. UAM, Poznań. Noryśkiewicz A. M Preliminary results of study on vegetation history in the Linje Mire region using pollen analysis. Monogr. Bot. 94: Ochyra R Czerwona lista mchów zagrożonych w Polsce [Red list of threatend mosses in Poland]. In: Lista roślin zagrożonych w Polsce (wyd. 2) (K. Zarzycki, W. Wojewoda, Z. Heinrich, eds.) pp Inst. Botaniki im. W. Szafera PAN. Kraków. Pawlikowski P Nowe stanowiska zagrożonych gatunków torfowiskowych roślin naczyniowych i mchów w Suwalskim Parku Krajobrazowym i jego otulinie. Fragm. Flor. Geobot. Polonica 15(1): Sobotka D Rozmieszczenie Sphagnum wulfianum Girgens. w Polsce Distrbution of Sphagnum wulfianum Girgens. in Poland. Fragm. Flor. Geobot. 21: Stefureac T.I Relicts in the flora of Romania, 1. Revue Roumaine de Biologie Serie de Biologie Vegetale 3: Szafer W Szata roślinna Polski niżowej. W: Szafer W. i Zarzycki K. (red.) Szata roślinna Polski. T. II PWN Warszawa. Tobolski K Przemiany klimatyczno-ekologiczne w okresie czwartorzędu a problem zmian we florze. Phytocoenosis. 5(3): Tobolski K Przewodnik do oznaczania torfów i osadów jeziornych, Wydawnictwo Naukowe PWN, Warszawa. Tobolski K., Mocek A., Dzięciołowski W Gleby Słowińskiego Parku Narodowego w świetle historii roślinności i podłoża, Wyd. Homini, Bydgoszcz Poznań.