How To Find Odonata In The Bia\U0142Owie\U017Ca Forest

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1 MUSEUM AND INSTITUTE OF ZOOLOGY POLISH ACADEMY OF SCIENCES FRAGMENTA FAUNISTICA Fragm.faun. Warszawa, Jörn THEUERKAUF, Sophie ROUYS Habitats of Odonata in the Białowieża Forest and its surroundings (Poland) Abstract: From 1997 to 1999, we found 48 Odonata species in the Białowieża Forest and its surroundings (Poland). We attribute the high number of species in the mainly forested study area to the extensive river network, which is shaped by a mostly natural water regime including many natural pools, and to the abundance of small-scale sandpits bearing water bodies in various stages of succession. The Białowieża Forest is, until now, the northernmost place of a reproduction of Crocothemis erythraea (52 39 N, E). Key words: Białowieża Forest, Crocothemis, damselflies, dragonflies, habitat, Odonata, Poland Authors addresses: Wildlife Biology and Management Unit, Department of Ecosystem and Landscape Management, Munich University of Technical Sciences, Freising, GERMANY; present address: Am Schäperkamp 3, Osterholz-Scharmbeck, GERMANY [email protected] INTRODUCTION The recent articles on Odonata in Northeast Poland are mainly concerned with open landscapes and only few studies included forest habitats (e.g. BERNARD, ŁABĘDZKI 1993, CZACHOROWSKI et al. 1998, JÖDICKE 1999, KALKMAN, DIJKSTRA 2000). Forests may impede the migration of species adapted to open land, so we expected less Odonata species to reproduce in the forest than in agricultural landscape. However, we did not expect a barrier effect in river marshes of the forest as Odonata can migrate by following the river. Rivers flowing through the forest could thus connect agricultural land with some of the larger open habitats of the forest. KALKMAN, DIJKSTRA (2000) recently wrote an annotated species list of Odonata in the area of Białowieża (Poland and Belarus). In our study, we focussed on the habitats used by Odonata in the Białowieża Forest and its surroundings. Our aim was to consider the influence of forest on the distribution of Odonata.

2 34 J. Theuerkauf & S. Rouys STUDY AREA AND METHODS The study area lies in the Polish lowland on the border to Belarus and includes the Polish side of the Białowieża Forest and its surroundings, an area of about 800 km² (Fig. 1). The terrain is relatively flat ( m a.s.l.) and rivers flow slowly. The marsh of the river Narewka and an unused railway lane of about 50 m width connected the open land around the village of Białowieża to the agricultural land around the Białowieża Forest. We searched for Odonata at 99 points in the open area around the village of Białowieża (Narewka river, pools and ponds in and outside the marsh, reservoir in the Białowieża Palace Park), in the whole area of the Białowieża Forest including the N N E Istok 536 Topiło Narew Le ś na Narewka Siemianówka Łutownia Cisówka Guszczewina Hwo ź na Białowieża Railway lane Km Poland E Fig. 1. Map of the studied area: Białowieża Forest (grey), open land (white), rivers (black lines), reservoirs (black surfaces), sandpits with pools or ponds (dots with next village or forest compartment number), state border (dotted line). Białowieża National Park (forest roads, lanes, railway embankments, clearings, reservoir at Topiło, river marshes in the forest, pools and ponds in sandpits) and at the points outside the Białowieża Forest indicated in Fig. 1 (pools and ponds in sandpits at Istok, Guszczewina, Siemianówka and Cisówka, Narew river). Most ponds outside the river marshes were man-made and the majority occurred in sandpits. Pools and ponds in sandpits were of various ages, from newly created to mature with dense vegetation. Rivers are straightened in some places but flood in spring so that natural pools are frequent in the river marsh. On the Narewka river, there are also sandbanks, especially in the open area north of the Białowieża Forest. Although parts of the forest were drained, there is still a high percentage of wet forests, which are flooded in spring. Our study spanned from 1997 to 1999 during the flight period of Odonata (May- September). On average once per week (64 days), we caught, identified and released Odonata if we were sure of our identification. We collected exuviae and dead imagines and documented important species with photos when we could not find exuviae or a dead imago. We considered reproduction as confirmed when we found larvae, exuviae or fresh imagines of a species. When we observed copulations or ovipositions of a species, we assumed that this species developed in the given habitat. We included observations from C. Bleidorn, O. Pollmeier, and C. Venne (Department of Biology, University of Bielefeld, Germany, personal communication, 1998) and from X. Jutz

3 Odonata in the Białowieża Forest 35 (Report of birds, vascular-plants and dragonflies in an area near the village Narew, Northeast-Poland, unpublished report, PTOP, 1999). RESULTS From 1997 to 1999, we found 48 species of Odonata in the study area (Table I). Thirty-five species occurred in the open area around the village of Białowieża, 41 species in the open land around the forest and another 41 species inside the forest. Twenty species occurred in 4 sandpits in the forest and 34 species in 4 sandpits outside the forest. We found 24 species in river marshes outside the forest, 26 species in marshes in the forest and 29 species in marshes around the village of Białowieża. Several males of Crocothemis erythraea (BRULLÉ) emerged from pools in a sandpit near the forest border (forest compartment 536, see Fig. 1) at the beginning of September We also found a female of Sympetrum meridionale (SÉLYS) in a large swampy clearing near the forest border (north of the sandpit in forest compartment 242). It is unclear whether this species was indigenous to the Białowieża Forest or had migrated there in the warm year of Four of the species found in the study area are considered as rare for Poland in a proposal of the Red List of Polish Odonata (ŁABĘDZKI et al. 1999): Ophiogomphus cecilia (FOURCROY) occurred only in the area outside the Białowieża Forest along the Narew and Narewka river where trampling by cows opened the riverside vegetation and left sandbanks free of vegetation. We found Leucorrhinia dubia (VANDER LINDEN) in two places (forest compartment 396 and Siemianówka). Both sites were old sandpits with a well-established water vegetation and shallow water covered by Sphagnum mosses. Leucorrhinia albifrons (BURMEISTER) also occurred in two places (reservoir at Topiło and sandpit near Cisówka). We only found Leucorrhinia caudalis (CHARPENTIER) in a very shallow part of a fish pond in a sandpit near Cisówka. This part of the pond was not in use and was well covered with vegetation. DISCUSSION The number of species in the area around the Białowieża village was lower than in the open land around the forest. This is probably not a result of the forest acting as a barrier but of the lack of sandpits with water bodies around the village of Białowieża, as almost all species missing in Białowieża occurred outside the forest in sandpits (see Table I). We attribute the high number of species inside the forest to the high variety of habitats in the forest. River marshes were even richer in species inside the forest than outside. This may be a result of the land use. Fields and meadows outside the Białowieża Forest reach up to the riverbanks thus reducing the extent of the river marshes. Besides, fields are drained, which affects the water regime by causing the disappearance of temporary and permanent pools form the river marsh. Pools are still abundant in marshes of the forest and around the village of Białowieża. However, Ophiogomphus cecilia seem to profit from the situation outside the Białowieża Forest, where poaching of riverbanks by cows probably improves the chances of this species

4 36 J. Theuerkauf & S. Rouys by providing some areas free of vegetation. We could not find Ophiogomphus cecilia in the river marshes inside the forest, maybe because the densities of wild ungulates maintained relatively low by human hunters did not allow such a poaching effect. The forest seems to be an important hunting habitat for Odonata and even to offer some species suitable places to reproduce. Some species, for example Sympetrum vulatum (LINNÉ), S. flaveolum (LINNÉ) or S. sanguineum (MÜLLER), were very abundant in the forest. We believe that the three above-mentioned species as well as Leucorrhinia rubicunda develop in the forest as large areas of the forest are flooded in spring and many pools persist throughout the year. Table I. Odonata species found in the open area around the village of Białowieża, in the Białowieża Forest and outside the Białowieża Forest between 1997 and reproduction possible but only imagines found; reproduction likely (copulations or ovipositions); reproduction confirmed (larvae, exuviae or fresh imagines); A found by C. Bleidorn, O. Pollmeier and C. Venne; B found by X. Jutz; C proof specimen or photo in authors collection; 1 fish ponds and pools outside the Narewka river marsh; 2 reservoir in the Białowieża Palace Park; 3 river and natural pools in the Narewka river marsh; 4 reservoir in Topiło; 5 open marsh of the Narewka, Łutownia, Hwoźna and Leśna river in the forest; 6 roads, lanes, railway embankments and clearings in the forest; 7 sandpit pools and ponds in forest compartments 181, 242, 396 and 536; 8 sandpit pools and ponds at Istok, Guszcewina, Cisówka and Siemianówka; 9 Narew river marsh. Years Observed flight period (day/month) Białowieża (open area) Ponds 1 Reservoir 2 Marsh 3 Reservoir 4 Białowieża Forest Marsh 5 Forest 6 Sandpits 7 Outside Sandpits 8 Marsh 9,B Calopteryx virgo (LINNÉ, 1758) /5-24/8 Calopteryx splendens (HARRIS, 1782) /5-4/9 Lestes viridis (VANDER LINDEN, 1825) + B 20/6 Lestes virens (CHARPENTIER, 1825) /6-8/9 Lestes sponsa (HANSEMANN, 1823) /6-7/9 Lestes dryas KIRBY, /6-14/8 Platycnemis pennipes (PALLAS, 1771) /5-31/8 Sympecma paedisca (BRAUER, 1877) + + A 29/7-28/5 Pyrrhosoma nymphula (SULZER, 1776) C + + B 16/5-13/7 Erythromma najas (HANSEMANN, 1823) C /5-30/7 Erythromma viridulum (CHARPENTIER, 1840) /5-31/7 Coenagrion hastulatum (CHARPENTIER, 1825) /5-10/7 Coenagrion lunulatum (CHARPENTIER, 1840) + A + 29/5-1/6 Coenagrion puella (LINNÉ, 1758) /5-31/7 Coenagrion pulchellum (VANDER LINDEN, 1825) C /5-30/7 Enallagma cyathigerum (CHARPENTIER, 1840) C /6-30/8 Ischnura pumilio (CHARPENTIER, 1825) + A 1/6-11/7

5 Odonata in the Białowieża Forest 37 Table I.cont Ischnura elegans (VANDER LINDEN, 1820) /5-12/8 Aeshna juncea (LINNÉ, 1758) C /6-7/9 Aeshna mixta LATREILLE, B 27/7-5/9 Aeshna cyanea (MÜLLER, 1764) C /7-21/9 Aeshna viridis EVERSMANN, B 8/7-1/8 Aeshna grandis (LINNÉ, 1758) C /6-4/9 Aeshna isosceles (MÜLLER, 1767) + B 20/6 Anax imperator LEACH, 1815 C + A + 1/6-30/7 Brachytron pratense (MÜLLER, 1764) C + 23/5-13/6 Gomphus flavipes (CHARPENTIER, 1825) C + B 30/6-30/7 Gomphus vulgatissimus (LINNÉ, 1758) /5-13/7 Ophiogomphus cecilia (FOURCROY, 1785) + 16/6-4/9 Cordulia aenea (LINNÉ, 1758) C /5-18/7 Somatochlora metallica (VANDER LINDEN, 1825) C /5-31/8 Somatochlora flavomaculata (VANDER LINDEN, 1825) C /6-15/8 Epitheca bimaculata (CHARPENTIER, 1825) C + A + 21/5-17/6 Libellula quadrimaculata LINNÉ, 1758 C /5-30/7 Libellula depressa LINNÉ, /5-29/7 Orthetrum cancellatum (LINNÉ, 1758) /5-31/7 Crocothemis erythraea (BRULLÉ, 1832) C + 1/9-4/9 Sympetrum vulgatum (LINNÉ, 1758) /7-21/9 Sympetrum meridionale (SÉLYS, 1841) C + 9/8 Sympetrum flaveolum (LINNÉ, 1758) /6-8/9 Sympetrum sanguineum (MÜLLER, 1764) /6-21/9 Sympetrum danae (SULZER, 1776) C /7-21/9 Sympetrum pedemontanum (ALLIONI, 1766) C /7-28/8 Leucorrhinia caudalis (CHARPENTIER, 1840) C + 13/6 Leucorrhinia albifrons (BURMEISTER, 1839) C + A + 4/6-13/6 Leucorrhinia dubia (VANDER LINDEN, 1825) C + 22/5-8/6 Leucorrhinia rubicunda (LINNÉ, 1758) + + B 16/5-29/5 Leucorrhinia pectoralis (CHARPENTIER, 1825) C + 22/5-13/6 Sandpits, which are recognised as an important secondary habitats for dragonflies (e.g. WILDERMUTH, KREBS 1983, BUCZYŃSKI 1999), carried in our study area the highest numbers of species (39 species). In the study area, sandpits are non-intensively exploited, leading to a mosaic of new and shallow to mature and vegetated water bodies. This mosaic probably explains the high number of Odonata species that we found in only 8 sandpits. All five European Leucorrhinia species occurred in sandpits. These species are usually associated with peat bogs (ASKEW 1988) or as L. dubia even depend on the occurrence of Sphagnum (MIELEWCZYK 1969, BUCZYŃSKI 1998, BUCZYŃSKI, STANIEC 1998). The high number of acidophilous species may be explained by the inflow of water from the forest, which is rich in humus acids and cannot be buffered by the poor sandy soil (P. Buczyński, personal communication). Single individuals of Crocothemis erythraea were previously found in southern and western Poland (BERNARD, SAMOLĄG 2000). The closest populations of this species to

6 38 J. Theuerkauf & S. Rouys our study area are however in the south of Slovakia (ASKEW 1988). We found Crocothemis erythraea emerging at the beginning of September. It seems that despite the long hot summer, the larvae took long to develop under the relatively colder climate in our study area. Sympetrum meridionale is also known to migrate regularly into Southeast Poland (BUCZYŃSKI 1999). We found the thermophilous species Crocothemis erythraea and Sympetrum meridionale within 1 km of the forest s outer edges but not outside the forest. This may be surprising as the forest s canopy could reduce ground insulation and therefore the warmth of the water bodies. However, the clearings where these two species occurred were large and the forest may have provided shelter from wind thus causing water bodies in clearings to become warmer than those outside the forest. Warmth was probably not the reason why the number of species in sandpits in the forest was lower than in sandpits outside the Białowieża Forest. Vegetation and the state of succession also have an important effect on the species richness of sandpits (BUCZYŃSKI 1999). The sandpit pools and ponds we investigated, whether in the forest or outside, ranged from newly created to mature, which may explain the species richness of the sandpits. The only ponds in which we found introduced fish were in the sandpit of forest compartment 536 and in the sandpit near Cisówka, which were the species-richest sandpits in the forest (14 species) and outside the forest (21 species) respectively. It is therefore unlikely that the presence of fish in ponds had an important negative effect on species richness in our study area. We conclude that forests alter the colonisation chances of species living in clearings either by impeding migration or by shaping the habitat but that forests are no barrier to river marshes species. Furthermore, water flow tends to be less regulated in the forest than in agricultural land, and fields do not impinge on the river marshes in the forest. In combination with CZACHOROWSKI et al. s (1998) statement that natural pools in river marshes play an important role in the biodiversity of Odonata, we suggest that open habitats may therefore be of better quality in than out of the forest. ACKNOWLEDGEMENTS We thank B. Jaroszewicz (Białowieża National Park) for providing us with information for this study, C. Bleidorn, O. Pollmeier, C. Venne, and X. Jutz for making their data available, A. B. Becker, P.-M. A. Dettinger-Klemm, R. Reyes, U. Richter, and A. Wanner for their help in the field, and P. Buczyński for literature and useful comments on earlier versions of this article. REFERENCES ASKEW R. R The dragonflies of Europe. Harley Books, Essex, 291 pp. BERNARD R., ŁABĘDZKI A Występowanie Sympetrum pedemontanum (Allioni, 1766) (Odonata, Libellulidae) na niżu polskim - The occurrence of Sympetrum pedemontanum (Allioni, 1766) (Odonata, Libellulidae) in Polish lowlands. Wiad. Entomol., 12: [In Polish with English summary]. BERNARD R., SAMOLĄG J An interesting record of Crocothemis erythraea (Brullé) in midwestern Poland (Anisoptera: Libellulidae). Notul. Odonatol., 5:

7 Odonata in the Białowieża Forest 39 BUCZYŃSKI P Ważki (Odonata) rezerwatu Torfowisko przy Jeziorze Czarnym i okolic (Pojezierze Łęczyńsko-Włodawskie) - Dragonflies (Odonata) of the Peatbog at Czarne Lake nature reserve and environs (Łęczna-Włodawa Lake District). Parki Nar. i Rez. Przyr., 17: [In Polish with English summary]. BUCZYŃSKI P Dragonflies (Odonata) of sand-pits in south-eastern Poland. Acta Hydrobiol. (Kraków), 41: BUCZYŃSKI P., STANIEC B Waloryzacja godnego ochrony torfowiska Krugłe Bagno (Pojezierze Łęczyńsko-Włodawskie) w oparciu o wybrane elementy jego fauny - Environmental evaluation of the conservation worth Krugłe Bagno peatbog (the Łęczyńsko-Włodawskie Lake District) based on the selected elements of its fauna. Salamandra, 2: [In Polish with English summary]. CZACHOROWSKI S., BUCZYŃSKI P., ALEXANDROVITCH O., STRYJECKI R., KURZĄTKOWSKA A Materiały do znajomości owadów i pajęczaków rezerwatu Las Warmiński (Pojezierze Olsztyńskie) - Material required for knowledge of insects and arachnids of the Warmiński Forest nature reserve (The Olsztyn Lake District). Parki Nar. i Rez. Przyr., 17: [In Polish with English summary]. JÖDICKE R Libellenbeobachtungen in Podlasie, Nordost-Polen. Libellula, 18: KALKMAN V. J., DIJKSTRA K.-D. B The dragonflies of the Białowieża area, Poland and Belarus (Odonata). Opusc. Zool. Flumin., 185: ŁABĘDZKI A., BUCZYŃSKI P., TOŃCZYK G Zagrożenia i ochrona ważek (Odonata) w Polsce [Threats and protection of dragonflies (Odonata) in Poland]. In: BUCHHOLZ L., NOWACKI J. (eds), Konferencja naukowa Ochrona owadów w Polsce u progu integracji z Unią Europejską. Kraków, września 1999, pp , Polskie Towarzystwo Entomologiczne, Poznań, 43 pp. MIELEWCZYK S Larwy ważek (Odonata) niektórych torfowisk sfagnowych Polski - Odonatenlarven einiger Sphagnum-Moore Polens. Polskie Pismo Ent., 39: [In Polish with German summary]. WILDERMUTH H., KREBS A Sekundäre Kleingewässer als Libellenbiotope. Vierteljahresbericht der Naturforschenden Gesellschaft Zürich, 128: [Tytuł: Występowanie ważek (Odonata) w Puszczy Białowieskiej i jej okolicach] STRESZCZENIE W trakcie badań prowadzonych w latach w Puszczy Białowieskiej wykazano 48 gatunków ważek (Odonata). Tak wysoką liczbę gatunków ważek autorzy tłumaczą sprzyjającymi warunkami związanymi z naturalnym reżimem wodnym obszaru leśnego, gdyż teren ten obfituje w liczne cieki, bajora i oczka wodne w różnym stadium sukcesji, powstałe na terenie byłych piaskarni. Puszcza Białowieska jest, dotychczas, najbardziej wysuniętym na północ miejcem reprodukcji gatunku Crocothemis erythraea (52 39 N, E).