SEGETAL FLORA OF THE WIGRY NATIONAL PARK

Segetal flora of the Wigry National Park (Poland) was studied in the period 2008-2010 within an area occupied by 33 villages. The analysis was based on 195 phytosociological relevés taken in fields of cereal crops, root plants and in stubble fields. The total number of species recorded in agrocenoses was 181 and they represented 36 botanical families. The most numerous families were Asteraceae, Fabaceae and Brasicaceae. The segetal flora of the Wigry National Park included mostly native species of apophytes (53.6%) that predominated over anthropophytes. Among apophytes, meadow apophytes (35 species) and those from waterside habitats (26 species) were noted most often, archaeophytes (74 species) were predominant among anthropophytes, while epecophytes (9 species) and ergasiophytes (1 species) were much less abundant. Among the life forms analysed, therophytes (61.9%) predominated over hemicryptophytes (27.1%) and geophytes (11%). The number of short-lived species in the flora of this Park was much greater (68.5%) than that of perennial ones (31.5%). The flora of the Park included 31 rare species classified in different categories of threat. Among them, Centaurium pulchellum and Centaurium erythraea belong to fully protected species (Dz.U. (Polish Journal of Laws) 2004 No. 168, item 1764).


INTRODUCTION
The process of recession of many species has been observed in Poland for many years (Z a r z y ck i and K a ź m i e r c z a k o w a , 1993).It is also known to relate to a numerous group of segetal weeds (W a r c h o l i ń s k a , 1994a).Within the framework of a general strategy for nature conservation (L i r o , 2002; Programme Document of the Environmental Protection Ministry, 2003), the most valuable components of agrocenoses are also protected.It seems that the protection of segetal weeds can be highly successful in national or landscape parks.Only a few reports have been devoted to the flora of agriculturally used fields within the areas of national parks or their protected zones (T r ą b a and Z i e m i ń s k a , 1998; J ę d r u s zc z a k and O w c z a r c z u k , 2006; S o ł t y s , 2006).In legally protected areas, crop fields are generally small and cultivated using traditional methods.They usually interact with plant communities characteristic of marshy, meadow, sward, forest and shrub habitats, which significantly enriches the flora of agrocenoses and allows conservation of a large group of weeds classified as rare at the regional or national level (K o r n i a k , 1998; W a r c h o l i ń s k a , 1994a).Agrophytocenoses are important components of the landscape of many national parks and occupy from 5% to about 35% of their area (B o m a n o w s k a , 2006; R a t u s z n i a k and S o b i s z , 2006; S o ł t y s , 2006).
As yet, no detailed study on segetal flora in the area of the Wigry National Park (WNP) has been performed, although much attention has been devoted to the plants from natural habitats (Sokołowski, 1996).Segetal vegetation has been studied on a wide scale over the whole region of north-eastern Poland (K o rn i a k , 1992, 1998).
The main aim of the study was to determine the present state of segetal vegetation in the area of the Wigry National Park and its buffer zone.In particular, the study was undertaken to identify segetal flora species segetal flora most valuable for the region and the country, to find the sites of populations of rare and threatened species and to estimate their abundance.

THE STUDY AREA
The Wigry National Park was founded in 1989 in order to protect a valuable complex of lakes and forest ecosystems in the area of the former landscape park.WPN is located in the south-eastern part of the Suwałki administrative unit.The park includes the northern part of the Augustów Primeval Forest, which is the largest compact forest complex in European Lowlands.According to the physiographic division (Kondracki, 2002), the Park's area comprises parts of three mesoregions: Western Suwałki Lake District, Eastern Suwałki Lake District and Augustów Plain.Together with the buffer zone, the Park spreads between 53 o 57 ' and 54 o 10 ' north latitude and 22 o 57 ' and 23 o 15 ' east longitude.
The area of the Park is 15,085.5 ha, of which the greatest part is covered with forests -9,464.5 ha (65.7%), while water occupies 2,907.2ha (19.3%) and agriculturally used land occupies 2 228 ha (14.8%).The area of the buffer zone is 11,283.8ha (D a n o ws k i et al. 2003).As far as morphology is concerned, the Park's terrain is much diversified and it formed as a result of Vistulian glaciation.To the north of Lake Wigry, there are hills of terminal moraines and pressed moraines cut across with many river valleys and lakes, while in the southern part gently rolling sandur plains are predominant.
The Park area lies in the middle part of the Czarna Hańcza River and belongs to the catchment area of the Niemen River, in the range of continental climate.It is the coolest part of Poland; the growing period lasts 175 days and the period with no ground frost is 30 days shorter than in central Poland.Mean annual precipitation is 650 mm.
The soils in the Park area, formed from young glacier sedimentary rocks, are not very diverse.The largest area is covered with brown soils and pararendzinas characterised by a high content of calcium carbonate and skeleton particles, while podsolic soil as well as lessives and silt-peat soils are rare.A considerable part of the area covered by such soils is overgrown with natural vegetation and the soil in arable fields belongs to the poorest agricultural soil complexes.The soils ensuring higher production of the very good rye complex, good wheat complex and cereal-fodder strong complex are found mostly in the central part of the Park, for instance near the villages of Leszczewo, Leszczewek, Magdalenowo, Mikołajewo, Czerwony Folwark, Rosochaty Róg, and Maćkowa Ruda.

MATERIALS AND METHODS
The study on the segetal flora of the Wigry National Park and its agriculturally used buffer zone, whose results are presented in this paper, was conducted in the period 2008-2010.Within the area occupied by 33 villages (see Fig. 1), a series of 195 phytosociological relevés were taken in agrocenoses of cereals and root plants according to the well-known Braun--Blanquet method (P a w ł o w s k i , 1972) as well as a large number of floristic lists were made.

RESULTS
The segetal flora of the Wigry National Park was found to comprise 181 species of vascular plants representing 125 genera and 36 botanic families.The majority (62%) of the flora represent 7 most abundant families of which the most richly represented were: Asteraceae (24 species and 20 genera), Fabaceae (19 species and 6 genera) and Brasicaceae (16 species and 15 genera).Over half of the species identified was found to be very rare or rare (102-56%).These were mostly the species coming from the neighbouring forest and meadow or ruderal communities, such as: Pimpinella saxifraga, Rumex acetosa, Stellaria graminea, Lathyrus pratensis, Torilis japonica.As far the conservation status is concerned, endangered species (Rc) such as: Centaurium erythraea, Centaurium pulchellum and those on the national red lists of vulnerable species: Lathyrus tuberosus, Geranium dissectum, Centunculus minimus and others, were also rarely found.Typical weeds accompanying field crops, which are eurytopic taxa such as: Matricaria maritima subsp.inodora, Centaurea cyanus, Echinochloa crus-galli, Polygonum aviculare, were frequently encountered.Troublesome field weeds represented by 21 species and accounting for 11.6% of the segetal flora of the Park, such as: Chenopodium album, Polygonum lapathifolium subsp.lapathifolium, Fallopia convolvulus, Stellaria media, Viola arvensis, Cirsium arvense, Elymus repens and others were also frequent.
Analysis of the proportions of geographical--historical groups in the segetal flora of the Park revealed the predominance of native species and apophytes (96 species making up 53.6% of the flora) over anthropophytes (Fig. 2).Species diversity of the apophytes reflects the habitat conditions of the area studied.The dominant species are apophytes of meadow habitats (35 species) and waterside habitats (26 species).The proportion of apophytes originating from forest and shrub habitats is also significant -16 species.The other apophytes found were characteristic of xerothermic grassland (11 species) and psammophylous grassland (9 species) (Fig. 3).Common apophytes are, e.g., Equisetum arvense, Polygonum lapathifolium subsp.lapathifolium, Arenaria serpyllifolia, whereas Herniaria glabra, Arabidopsis thaliana, Gypsophila muralis and others are met much less frequently.
Among anthrophytes, the most numerous group is that of archaeophytes (74 species), including troublesome weeds such as Viola arvensis, Anthemis arvensis, Cirsium arvense, as well as all protected, rare and threatened species in the country, such as: Agrostemma githago, Papaver argemone, Neslia paniculata, Centunculus minimus.The percentage of kenophytes is low (5.5% of the flora); they are mainly represented by epecophytes (9 species) of which Oxalis fontana, Veronica persica, Conyza canadensis and Galinsoga parviflora are the most frequently noted and which locally can be a threat to field crops.Ergasiophygophytes are represented only by Fagopyrum tataricum which is very rare in the Park area.
The flora of the Park's phytoagrocenoses includes 31 valuable species representing the conservation status of endangered, rare and legally protected species.On the basis of the red list of segetal species threatened in our country (W a r c h o l i ń s k a , 1994; Z a r z y c k i and S z e l ą g , 2006), 30 species representing four categories of conservation status were identified: E

DISCUSSION
The segetal flora of the Wigry National Park accounts for 51% of the flora of agrocenoses of north--eastern Poland (K o r n i a k , 1992).Taking into account the small area occupied by agrocenoses in the Park and its buffer zone, it can be considered to be rather rich.The richness is mostly a consequence of the specific character of agriculture in the area (arable fields are usually small and tilled in a traditional way) and the diverse mosaic landscape of the Park related to diverse ecological potential of the field habitats.Such a specific form of agricultural land use is assumed by the National Strategy of Protection and Moderate Use of Biological Diversity as one of the measures aimed at conservation of the diversity of agrophytocenoses.
The main threat to segetal weeds in the protected area is cessation of agricultural use of the fields in this area.2006).An interesting feature is the presence of a large group of species of different conservation status.The species from this group represent 44.3% of total species with conservation status in the region (K o rn i a k , 1998).This group of species includes those from the national red list (W a r c h o l i ń s k a 1994a; Z a r z y c k i and S z e l ą g , 2006) and fully protected species (the Decree of the Environmental Protection Minister of July 28 th , 2004).
The problem of impoverishment of segetal communities has been discussed in many papers and it concerns the flora of both protected areas (K o rc z y ń s k i , 2006; R z y m o w s k a and S k r a j n a , 2006; S o k o ł o w s k i , 1989; S o ł t y s , 2006) and typical agriculturally used land (F i j a ł k o w s k i and N y c z , 1998; K o r n i a k , 1992; S i c i ń s k i , 2003; W a r c h o l i ń s k a , 1994b).In view of the above and given the results of our study, it seems highly recommendable to monitor the segetal flora, in particular the rare species, in the area of the Wigry National Park in order to grasp the dynamics of changes in its structure and to conserve the species diversity of agrocenoses.

Fig. 4 .
Fig. 4. Proportions of different biological forms in the segetal flora in the area of the Wigry National Park.
Changes in land use lead to changes in the species composition of the segetal flora and to restriction or disappearance of entire communities (B o m an o w s k a , 2006; S o ł t y s , 2006).The analysis of the segetal flora of the Wigry National Park shows that the contribution of geographically-historical groups, life forms and the persistence of species are similar to those in the majority of local segetal floras of protected areas (B o m a n o ws k a , 2006; G o ł d y n et al. 2002; H o ł d y ń s k i and K o r n i a k , 1994; R a t u s z n i a k and S o b i s z , 2006; S o ł t y s , 2006; Z i e m i ń s k a -S m y k ,
Fig. 2. Proportions of geographical-historical groups in the segetal flora in the area of the Wigry National Park.Origin of apophytes in the segetal flora in the area of the Wigry National Park.