69 The-Dryopteris-species-in-Wroc³aw- -occurrence-and-distribution 69 The Dryopteris Adans. species in Wroc³aw (SW Poland) occurrence and distribution in urban habitats EWA SZCZÊŒNIAK Institute of Plant Biology, University of Wroc³aw, Kanonia 6/8, PL-50-328 Wroc³aw; e-mail: ewaszcz@biol.uni.wroc.pl ABSTRACT: The species composition, distribution and dynamics of the spontaneous Dryopteris flora were examined in Wroc³aw, a typical large city in Central Europe. In the course of current and previous surveys, four taxa were identified. Dryopteris cristata (L.) A. Gray was not found in the present research, and thus its previous stands were not confirmed; this species is presumed to have become extinct in the city. Dryopteris dilatata (Hoffm.) A. Gray occurs in four localities, all in woodlands: forests and sporadically in abandoned parks; it does not enter typical urban habitats. Dryopteris carthusiana (VIll.) H. P. Fuchs is more common; it was observed in forests, parks and occasionally on scattered sites in the industrial part or in the city centre. These two taxa seem to be urbanophob or moderately urbanophob species. Dryopteris filix-mas (L.) Schott is the most popular species, which occurs in woodlands and typical urban habitats on old walls in all urban zones. It seems to be a neutral taxon in respect of urban habitats. ABSTRAKT: We Wroc³awiu, typowym du ym mieœcie Œrodkowej Europy, przeprowadzone zosta³y badania nad rozmieszczeniem i tendencjami dynamicznymi spontanicznie pojawiaj¹cych siê przedstawicieli rodzaju Dryopteris. W wyniku historycznych i obecnych badañ stwierdzono wystêpowanie czterech gatunków. Dryopteris cristata (L.) A. Gray nie zosta³a potwierdzona i najprawdopodobniej wymar³a na terenie miasta. Dryopteris dilatata (Hoffm.) A. Gray wystêpuje na czterech stanowiskach, wy³¹cznie w zbiorowiskach drzewiastych: lasach i sporadycznie w opuszczonych parkach; nie pojawia siê na typowych siedliskach miejskich. Dryopteris carthusiana (VIll.) H. P. Fuchs jest czêstsza, wystêpuje w lasach i parkach oraz rzadko na rozproszonych stanowiskach w strefie przemys³owej i centrum miasta. Gatunki te s¹ urbanofobne lub umiarkowanie urbanofobne. Dryopteris filixmas (L.) Schott jest najczêstszym gatunkiem, wystêpuje w zbiorowiskach drzewiastych i w siedliskach typowo miejskich na murach we wszystkich strefach miasta. Jej rozmieszczenie wskazuje, e jest to gatunek neutralny w stosunku do siedlisk miejskich. KEY WORDS: ferns, Dryopteris, urban habitat, Wroc³aw, Poland, Szczêœniak E 2009. The Dryopteris Adans. species in Wroc³aw (SW Poland) occurrence and distribution in urban habitats. In: E. Szczêœniak, E. Gola (eds), Genus Dryopteris in Poland. Polish Botanical Society & Institute of Plant Biology, University of Wroc³aw, Wroc³aw, p. 69 80.
70 Ewa-Szczêœniak 70 Introduction The strong anthropopressure in rural and urban environments causes that flora of these habitats is shaped by a specific set of factors. Because of human activity, entirely new habitats arise, each with a specific combination of environmental conditions. A large number of different biotopes, usually sharply separated, results in the great abundance of vascular plants. The flora of these man-made habitats is not the result of long-term evolution but of the rapid spread of plant species in places, from which the original vegetation was stripped (Sukopp 1990). According to classification of Wittig et al. (1985), plants can be divided into groups of urbanophob, neutral and urbanophil plants. Pteridophytes react for urban habitats similarly as other native plants the most of them are urbanophobs, some are neutral, and the smallest group is of the urbanophil taxa. According to Mirek et al. 2002, the genus Dryopteris comprises of eight taxa in Poland. Seven of them have been noted in Lower Silesia and mostly are associated with woodlands and forests. The aim of the present study was to determine which of them occur in the city of Wroc³aw, and how they react to human activity in the main habitat types found in the city. Material and methods The study was based on the author s own research because of the lack of herbarium specimens and a very small number of data published in literature - no detailed studies have been carried out in Wroc³aw on the topic to date. Detailed field studies were performed from 2006 to 2009. The geographical coordinates of each site were determined using GPS and fern distribution was mapped on a 1 1 km grid of the ATPOL system (Zaj¹c 1978); the administrative area of Wroc³aw consists of 352 such squares. In one square, ferns could occur in 1 up to 3 types of habitats. Where it was possible, the new sites were documented by herbarium specimens and sheets were deposited in the Herbarium of the University of Wroc³aw (WRSL). Nomenclature of plant species follows Mirek et al. (2002), plant communities were identified using the classification system proposed by Matuszkiewicz (2008), categorization of urbanophil-urbanophob species accords with Wittig et al. (1985). Study area The present survey was carried out within the administrative city limits of Wroc³aw in the area of 292.8 km 2. The climate is temperate there; the mean
71 The-Dryopteris-species-in-Wroc³aw- -occurrence-and-distribution 71 annual temperature averages 8.5 C (from 1951 to 2000). Annual precipitation is variable, from 407 mm in 1982 to a high of 750 mm in 1986. The growing season lasts 220 days (Dubicka 2006). Elevations range from 107 to 148 m a. s. l. All area is situated in the l¹ska Lowland (SW Poland; Kondracki 2000). The area was originally covered by deciduous forests, primarily belonging to the classes Salicetea purpureae Moor 1958, Alnetea glutinosae Br.-Bl. et R. Tx.1943 and Querco-Fagetea Br.-Bl. et Vlieg. 1937 (alliances AlnoUlmion Br.-Bl. et R. Tx. 1943 and Carpinion Issl. 1931 em. Oberd. 1953). Small areas were also covered by acidophilic oak forests of the class Quercetea robori-petraeae Br.-Bl. et R. Tx. 1931 and pine forests of the class VaccinioPiceetea Br.-Bl. 1939. As a result of the city development, the original forest cover of the study area was destroyed. Original herbaceous flora was limited to communities found throughout the Odra River valley, belonging mostly to the classes Artemisietea vulgaris Lohm., Prsg et R. Tx. in R. Tx. 1950, Phragmitetea R. Tx. et Prsg 1942, Potametea R.Tx. et Prsg 1942, Bidentetea tripartiti R. Tx., Lohm. et Prsg 1950 and Lemnetea R. Tx. 1955. Survived Fig. 1. Urban zones in Wroc³aw: I peripheries, II industrial zone (IIa Le nica, IIb Psie Pole), III historical city centre Ryc. 1. Strefy miejskie we Wroc³awiu: I peryferia, II strefa przemys³owa (IIa Le nica, IIb Psie Pole), III historyczne centrum
72 Ewa-Szczêœniak 72 forest species are now entirely confined to parks and secondary woodlands. Nowadays, the anthropogenic vegetation dominates: semi natural, ruderal or even more or less accidental in the most destroyed areas. The structure of the city is not regular. Peripheries (zone I; 254 of 352 squares) and industrial zone (II; 97 squares) intermingled in the result of Wroc³aw rapid development in the 19 th and 20 th centuries, and by merging outlying towns (Leœnica and Psie Pole; Fig. 1) and many villages into the city borders. The clearly distinguishable zone is the densely built-up historical city centre itself, which is confined to the limits of the former city walls (zone III; 1 square). The course of the Odra River, its tributaries and floodplains has also an impact on the structure of the city. Results The Dryopteris species were noted in 66 out of 347 squares. No one location was found in agricultural areas in the zone I, which are generally unfavorable habitats for ferns. According to the historical data and in the course of the current research, four spontaneously occurring taxa of the genus Dryopteris were identified in the area of Wroc³aw. Localities of three of them still exist, but only two species are common in the studied area. Dryopteris cristata (L.) A. Gray probably extinct Crested buckler fern was observed only on wetlands near Rêdzin (NW Wroc³aw; Fiek 1881, Schube 1903; Fig. 2a). The site was not confirmed after 1945 and the species was not found in last years. Its presumable extinction could be an effect of the wetland drainage and the significant drop in a ground water level. Dryopteris dilatata - (Hoffm.) A. Gray very rare Broad buckler fern was observed for the first time in the area of Wroc³aw in 2005. Until now five locations of the species have been noted, four of them in forests (the Osobowicki Forest, the Leœnicki Forest and two in the Pilczycki Forest) and only one stand in a park (the Grabiszyñski Park; Figs 2b and 3). All localities occurring in the zone I, are situated in more or less degraded hornbeam-oak forests of the Galio-Carpinetum Oberd. 1957 association. The entire Wroc³aw population consists of ca. 7 plants. Dryopteris carthusiana (VIll.) H. P. Fuchs common Narrow buckler fern was observed in all distinguished city zones (Fig. 2c). It is common in all forests in the western part of the city, occurs also in parks. Single plants additionally colonize shaded old walls in the city (Figs 3, 4). The
73 The-Dryopteris-species-in-Wroc³aw- -occurrence-and-distribution 73 Fig. 2. Distribution of Dryopteris species in Wroc³aw: A D. cristata, B D. dilatata, C D. carthusiana, D D. filix-mas Ryc. 2. Rozmieszczenie gatunków z rodzaju Dryopteris we Wroc³awiu: A D. cristata, B D. dilatata, C D. carthusiana, D D. filix-mas most numerous populations including up to a few hundred plants occur in forests of the Galio-Carpinetum association and in brushwoods developed on wastelands (zone I). The structure of these populations is not disturbed, spores are vigorous, gametophytes and sporophytes develop properly. Dryopteris filix-mas (L.) Schott common Male fern is the most widely spread Dryopteris species in Wroc³aw (Fig. 2d). It was found in forests, parks, abandoned gardens, on lawns, flowerbeds, sidewalks and old walls. It occurs in the Galio-Carpinetum association, in anthropogenic woodlands and in the wall pioneer communities of the class Asplenietea rupestria Br.-Bl. 1934 in Meier et Br.-Bl. 1934. On old walls, it occurs in various habitat conditions, from shadow and damp places where it grows with Cystopteris fragilis, Gymnocarpium robertianum and mosses, to dry semi shaded communities of Asplenium ruta-muraria, Poa compressa and other drought tolerant species.
74 Ewa-Szczêœniak 74 40 No. of squares (iloœæ kwadratów) 35 30 25 20 15 10 5 0 D. cristata D. dilatata D. carthusiana D. filix-mas -1-2 -3-4 Fig. 3. Occurrence of ferns in different habitats: 1 wetlands, 2 forests and thickets (areas of spontaneous succession), 3 parks and cemeteries, 4 walls Ryc. 3. Obecnoœæ paproci w ró nych siedliskach: 1 tereny podmok³e, 2 lasy i zaroœla (obszary spontanicznej sukcesji), 3 parki i cmentarze, 4 - mury 40 No. of squares (iloœæ kwadratów) 35 30 25 20 15 10 5-1 -2-3 0 D. cristata D. dilatata D. carthusiana D. filix-mas Fig. 4. Occurrence of ferns in urban zones: 1 peripheries, 2 industrial zone, 3 historical city centre Ryc. 4. Obecnoœæ paproci w strefach miejskich: 1 peryferia, 2 strefa przemys³owa, 3 historyczne centrum
75 The-Dryopteris-species-in-Wroc³aw- -occurrence-and-distribution 75 Fig. 5. A group of ferns below a destroyed rain-pipe: Dryopteris filix-mas, Gymnocarpium robertianum and Cystopteris fragilis; a mill Maria, Wroc³aw Ryc. 5. Skupienie paproci poni ej uszkodzonej rynny: Dryopteris filix-mas, Gymnocarpium robertianum i Cystopteris fragilis; m³yn Maria, Wroc³aw In addition, about ten not native species of Dryopteris are cultivated as ornamental plants in Wroc³aw. Spore germination, and gametophyte as well as sporophyte development were tested for the most popular of them: D. erythrosora (Eaton) Kuntze, D. goldiana (Hook. ex Goldie) A.Gray, D. sieboldii (Van Houtte ex Mett.) Kuntze and D. walichiana (Spreng.) Hyl.
76 Ewa-Szczêœniak 76 Fig. 6. Dryopteris filix-mas and Cystopteris fragilis in cellar chute; Stawowa Str., Wroc³aw Ryc. 6. Dryopteris filix-mas i Cystopteris fragilis w piwnicznym otworze zsypowym, ul. Stawowa, Wroc³aw All of them germinate and develop properly in cultivation; nevertheless these species do not disperse in Wroc³aw and up to now their spontaneous occurrence has not been noted.
77 The-Dryopteris-species-in-Wroc³aw- -occurrence-and-distribution 77 Discussion Ferns seem to be well adapted to colonize new anthropogenic sites. Their spores are very light and can be carried by the wind for long distances, even thousands of kilometers (Tackenberg et al. 2003). Furthermore, they produce prodigious amounts of spores. On the other hand, pteridophytes arose early in evolution and have a life cycle divided into two distinct free-living generations. Their gametophytes develop properly only in specific and stable micro-climatic conditions, specifically with respect to the high humidity of the habitat. Moreover, spermatocytes require water to be able to migrate in order to close the cycle. Therefore, pteridophytes are sensitive to changes in habitat that are typical of urban environments. In turn, conditions prevailing in man-made habitats seem to be hostile to ferns, reducing the number of germinated spores, properly developed gametophytes and viable sporophytes. There is no pteridophyte species occurring in Poland which distribution is limited to urban habitats or highly correlated with towns (Moraczewski, Sudnik-Wójcikowska 2007). The ability to endure in urban habitats differ between Dryopteris species. For instance, D. cristata is narrowly specialised taxon associated with the Alnetea glutinosae class, which is sensitive to changes of a water level. Its reaction for urban development is rapid and negative. The species is endangered in the Lower Silesia Province (K¹cki et. al. 2003) and vulnerable in Poland (Zarzycki, Szel¹g 2006). Dryopteris dilatata seems to be an urbanophob species which does not enter the urban habitats but still it is able to survive in forests and parks. Sporadic presence of D. cartusiana in the industrial zone (II) and its absence in the urban centre (zone III) suggest that the species is a moderate urbanophob. The most common species in the studied area is D. filix-mas. Its numerous locations on walls in the city centre suggest that this species is tolerant for urban habitats (Figs 3 and 4). Dryopteris filix-mas and D. carthusiana are both woodland species that are not threatened or endangered in the studied area. Dryopteris filixmas is a diagnostic species of the order Fagetalia sylvaticae Paw³. in Paw³., Soko³. et Wall. 1928. Dryopteris carthusiana is more widely distributed than the previous species, and has no diagnostic value. For both species, the Ellenberg ecological indices (Zarzycki et al. 2002) have identical values for the light, moisture, temperature and continentalism, and only slightly differ in the values of soil trophy and acidity. However, distinct differences in both species distribution in the same habitats suggest the discrepancy between ecological preferences indicated by the ecological indices and real tolerance to the environmental conditions. Dryopteris filix-mas tolerates high alkaline substrates that are poor in nutrients. Therefore, this fern species can colonize urban habitats, where is relatively commonly encountered. Its high tolerantion for extreme
78 Ewa-Szczêœniak 78 habitat conditions was documented during research of Central European railway flora (Wittig 2002). In Wroc³aw, it is found in scattered localities in woodlands and parks, and also in built-up areas, where it often grows in window-wells and in cracks on old masonry walls, especially near damaged rain pipes (Fig. 5) or chutes formerly used to dump coal into cellars (Fig. 6). In urban habitats it grows as a ground fern as well as an epilitic one. Dryopteris carthusiana, on the other hand, is found almost exclusively in woodlands, especially those on wet or moist sites, and occasionally in parks. It can rarely enter industrial and urban built-up areas. Generally, although D. filix-mas populations are not as plentiful as populations of D. carthusiana, male fern is spread in more number of stands. References FIEK E. 1881. Flora von Schlesien preussischen und österreichischen Anteils. J. U. Kern's Ferlag, Breslau, 571 pp. DUBICKA M. 2006. Klimat Wroc³awia. In: CICHOCKI Z. (ed.) Œrodowisko Wroc³awia. Informator 2006. Instytut Ochrony Œrodowiska, Wroc³aw, p. 16-36. K CKI Z., DAJDOK Z., SZCZÊŒNIAK E. 2003. Czerwona lista roœlin naczyniowych Dolnego Œl¹ska. In: K CKI Z. (ed.), Zagro one gatunki flory naczyniowej Dolnego Œl¹ska. Instytut Biologii Roœlin Uniwersytet Wroc³awski, PTPP Pro Natura, Wroc³aw, p. 9-64. KONDRACKI J. 2000. Geografia regionalna Polski. PWN, Warszawa, 441 pp. MATUSZKIEWICZ W. 2008. Przewodnik do oznaczania zbiorowisk roœlinnych Polski. Wydawnictwo Naukowe PWN, 537 pp. MIREK Z., PIÊKOŒ-MIRKOWA H., ZAJ C A., ZAJ C M. 2002. Flowering plants and pteridophytes of Poland a checklist. In: MIREK Z. (ed.), Biodiversity of Poland. 1. W. Szafer Institute of Botany, Polish Academy of Sciences, Kraków, 442 pp. MORACZEWSKI T.R., SUDNIK-WÓJCIKOWSKA B. 2007. Polish urban flora: conclusions drawn from Distribution Atlas of Vascular plants in Poland. Ann. Bot. Fennici 44: 170-180. SCHUBE T. 1903. Verbreitung der Gefäßpflanzen in Schlesien preußischen und österreichischen Anteils. R. Nischowsky, Breslau, 361 pp. SUKOPP H. 1990. Urban ecology and its application in Europe. In: SUKOPP H., HEJNY S. (eds.), Urban Ecology. SPB Academic Publishing, p. 1-23. TACKENBERG O., POSCHLOD P., BONN S. 2003. Assessment of wind dispersal potential in plant species. Ecological Monographs 73: 191-205. WITTIG R., DIESING D., GÖDDE M. 1985. Urbanophob Urbanoneutral Urbanophil. Das Verhalten der Arten gegenüber dem Lebensraum Stadt. Flora 177: 265-282. WITTIG R. 2002. Ferns in a new role as a frequent constituent of railway flora in Central Europe. Flora 197: 341-350.
79 The-Dryopteris-species-in-Wroc³aw- -occurrence-and-distribution 79 ZAJ C A. 1978. Atlas of distribution of vascular plants in Poland. Taxon 27(5-6): 481-484. ZARZYCKI K., TRZCIÑSKA-TACIK H., RÓ AÑSKI W., SZEL G Z., WO EK J., KORZENIAK U. 2002. Ecological indicator values of vascular plants of Poland. W. Szafer Institute of Botany, Polish Academy of Science, Kraków, 183 pp. ZARZYCKI K., SZEL G Z. 2006. Red list of the vascular plants in Poland. In: MIREK Z., ZARZYCKI K., WOJEWODA W., SZEL G Z. (eds.), Red list of plant and fungi in Poland. W. Szafer Institute of Botany, Polish Academy of Sciences, Kraków, p. 9-20. Gatunki z rodzaju Dryopteris Adans. we Wroc³awiu (Polska po³udniowo-zachodnia) wystêpowanie i rozmieszczenie w œrodowisku miejskim. Obiektem badañ by³y gatunki z rodzaju Dryopteris, bêd¹ce spontanicznym sk³adnikiem flory Wroc³awia. Wroc³aw jest po³o ony na Nizinie Œl¹skiej, w strefie ³agodnego klimatu. Pierwotnie obszar ten pokrywa³y lasy liœciaste oraz w nieznacznym stopniu bory sosnowe i mieszane. W wyniku szybkiego rozwoju miasta naturalna okrywa roœlinna zosta³a zniszczona. Wch³oniêcie satelickich miasteczek (Leœnica i Psie Pole) oraz wsi, a tak e obecnoœæ Odry i jej dop³ywów wraz z terenami wodonoœnymi powoduj¹, e uk³ad stref w przypadku jest Wroc³awia nieregularny (Ryc. 1). W granicach administracyjnych miasta odnotowano 4 rodzime gatunki z rodzaju Dryopteris: Dryopteris cristata wymar³a; podawana by³a z podmok³ych terenów na Rêdzinie (Fiek 1881; Schube 1903; Ryc. 2A), po wojnie nieobserwowana i w trakcie badañ niepotwierdzona. Jako wyspecjalizowany gatunek, zwi¹zany z klas¹ Alnetea glutinosae, jest wra liwa na zmiany warunków siedliskowych. Powodem zaniku stanowiska by³a najprawdopodobniej melioracja terenu i obni enie poziomu wód gruntowych. Gatunek urbanofobny. Dryopteris dilatata bardzo rzadka; odnaleziona na terenie Wroc³awia w roku 2005, obecnie znana z 5 stanowisk (4 w mniej lub bardziej zdegradowanych zbiorowiskach gr¹dowych Galio-Carpinetum, 1 w zapuszczonym parku; Ryc. 2B). Populacja sk³ada siê z ok. 7 roœlin. Gatunek urbanofobny. Dryopteris carthusiana czêsta; obecna we wszystkich strefach (Ryc. 2C), choæ zdecydowan¹ wiêkszoœæ wyst¹pieñ notowano w lasach, zaroœlach (powi¹zanych z Galio-Carpinetum) i parkach (Ryc. 3). Pojedyncze okazy pojawiaj¹ siê na murach (Ryc. 4). Gatunek umiarkowanie urbanofobny.
80 Ewa-Szczêœniak 80 Dryopteris filix-mas czêsta; obecna we wszystkich strefach (Ryc. 2D), najliczniejsze populacje obserwowano w lasach gr¹dowych na obrze ach miasta, lecz najwiêksza liczba stanowisk zwi¹zana jest ze stref¹ miejsko-przemys³ow¹ (Ryc. 4). Gatunek wchodzi na mury, zarówno wilgotne i zacienione, jak i pó³cieniste i suche (Ryc. 3). Gatunek urbanoneutralny. Ponadto w hodowli jako roœliny ozdobne uprawia siê oko³o 10 gatunków obcych przedstawicieli rodzaju Dryopteris. Dla 4 najczêstszych (D. erythrosora, D. goldiana, D. sieboldii i D. walichiana) sprawdzono ywotnoœæ zarodników. W uprawie kie³kowanie przebiega³o dobrze, gametofity rozwija³y siê poprawnie, zachodzi³o zap³odnienie i licznie pojawia³y siê sporofity. Jednak mimo wysokiej ywotnoœci spor gatunki te nie pojawiaj¹ siê spontanicznie na terenie Wroc³awia.