Rich new data on Nehalennia speciosa in Poland, collected or published after the first Polish synthesis (Bernard, 1998), have mostly been presented only on a synthetic level so far (Bernard 2004; Bernard & Wildermuth 2005a, 2005b). Hence, many populations and habitats have not been described in detail or even have not been published at all. Therefore, the aim of the current article is to complete the list of Polish localities and to present basic data on them according to the state of knowledge for the end of 2007. A synthetic assessment of the conservation status and habitat selection of N. speciosa in Poland is also included. 65 localities of N. speciosa have been discovered in Poland so far, including 31 ones presented in the first synthesis (Bernard 1998). Some corrections and completions to several of these ‘old’ localities are added. The consistent numbering of localities, begun in that paper, is remained and continued. 34 localities discovered or published since 1998 (Nos. 32–65) are presented in detail. For each locality the following data are given: its name and situation, information that the locality has been published (P) or unpublished (U), sources of data (the authors’ own data (RB – R. Bernard, PB – P. Buczyński), publications, unpublished data of other persons), a brief description of a habitat, dates of records, NS – the size of N. speciosa population (the number of imagines in a day of visit if not described in another way; os. – individuals), records of: L – larvae, Ex – exuviae, T – teneral individuals, BR – breeding behaviour). The increase in number of known localities is mostly the result of intensified odonatological exploration during the last ten years. However, a colonization of new sites is also possible on a small scale as Brzeziczno Lake (No. 56, colonized after 1997) shows. 38 local populations recorded since 1990 are treated current, although one of them (No. 51) is already extinct. Considering insufficiently explored areas in the North and East, ca 50 current localities are expected. The current distribution of N. speciosa in Poland is almost confined to the North above 53ºN (rich in primary habitats) and the local far East (fig. 1). Unexpectedly, the species has recently been rediscovered in the Upper Silesia in the South (two very small strongly isolated populations, Nos. 64, 65) were it had been assumed extinct for a long time (Miszta, Dolný 2007). The distribution is highly scattered with several more densely inhabited islands of the range (Fig. 1). Many Polish local populations are large, at least 8 of them (Nos. 39, 37, 35, 34, 41, 54, 56, 47) exceeded 1.000 imagines per visit. At the locality 39 even 8-10 thousand individuals in the peak of flight season and a very high average density 10–12 individuals/ m2 were recorded. However, the maximum density (60 individuals/m2) was once observed at Golce (No. 34). The percentage of small, it seems vanishing populations (e.g. No. 58, 60, 62, 64, 65) is the highest in the southern part of current distribution, i.e. in southern, mideastern and southeastern Poland. Summing up, the conservation status of N. speciosa in Poland, though significantly decreased, is still much better than in many other areas of Europe apart from its mideastern parts and Bavarian Prealpine Region (Bernard, Wildermuth 2005a). N. speciosa is a stenotopic species in Poland (see details in Bernard, Wildermuth 2005a). It inhabits: mainly (1) small primary water bodies (mostly < 1 ha) bounded with Sphagnum bogs, additionally (2) Sphagnum bogs and fens without larger open water bodies, but at least temporarily flooded, and (3) secondary excavation pools, mostly peat excavations, exceptionally old clay pits overgrown with Carex (No. 26 in Bernard 1998). Localities are frequently situated in postglacial or inter-dune depressions and are surrounded by forest, mostly pine, exceptionally deciduous. Larvae and imagines use: (I) narrow zone of floating and flooded vegetation mats bordering the open water of lakes and pools, and (II) at least temporarily flooded parts of Sphagnum bogs and fens, most frequently in their small depressions (Germ. ‘Schlenken’). The former habitats (I) predominate in Poland, the latter ones (II) are represented at 5 localities and marginally at several other sites. N. speciosa is related to specific vegetation with its texture as the crucial factor (Bernard 1998; Bernard, Wildermuth 2005a). In the emergent vegetation above the water surface and adjacent Sphagnum mats, Carex limosa and C. lasiocarpa are by far the most important components. When they occur together at the locality, a preference of N. speciosa for C. limosa stands or for those combined with C. lasiocarpa was noticed. Carex rostrata is prevailing in the habitats only at six localities in E Poland (3–4 of them are secondary habitats). Other vascular plants only exceptionally constitute the main component: Rhynchospora alba (locality No. 43, but with Carex limosa), Equisetum fluviatile (No. 50, generally for the first time in N. speciosa) and Molinia caerulea (partly No. 63, not in water!). At several localities, Scheuchzeria palustris and Agrostis canina play an important but not a leading role. The ‘lawn-like’ texture of vegetation is mainly formed by the narrowleaved Carex species. A mosaic of loose and dense formations, with a predominance of fairly dense ones, constitute the best conditions. Due to regular additives – Menyanthes trifoliata, Lysimachia thyrsiflora, Peucedanum palustre, Potentilla palustris – the vegetation appears less dense. The submerged vegetation is mainly composed by: (a) flooded parts of helophytes, both live and dead, (b) edge parts of Sphagnum mats, (c) floating Sphagnum and other mosses, mainly Warnstorfia fluitans, (d) Utricularia minor or intermedia. With the exception of ‘a’ all other components are optional, but mosses are regular and Utricularia frequent. However, at a part of Broduszurki locality (No. 63), only ‘soup’ of W. fluitans occurs in water, while Molinia caerulea above directly adjacent land. Though in contact, habitats of larvae and imagines are generally separated in space there (Bernard, Daraż 2008). The water of the larval habitat is: (a) shallow, up to 30(40) cm, (b) frequently slightly brownish-yellowish, (c) fast warming up and warm, (d) rather acid, pH 3,3–6,9, mostly 4–5,5, (e) poor in electrolytes, conductivity low 20-90 μS/cm, mostly <50 μS/ cm, exceptionally above 150 (up to 378 μS/ cm), (f) poor in nutrients, dystrophic though described also as oligotrophic, rarely mesotrophic. In some habitats (type II), the water can temporarily disappear from the vegetation surface as a result of long term precipitation deficits. The larvae may probably survive this situation hidden in soaked mats of Sphagnum and other mosses. Considering the regress, N. speciosa has been classified into the category EN in the Polish red list (Bernard et al. 2002). Eight local populations in Poland are protected in nature reserves and three in national parks. Additionally, buffer zones in the range of up to 100 m around localities with N. speciosa, proposed by one of us (RB), were legally implemented in Poland in 2004 by the Ministry of Environment, so far in theory only. The authors propose to cover nine most valuable localities (not protected at all so far) with this conservation measure.
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