Rare and endangered species of segetal flora in the Turobin commune

The aim of the study was to make an inventory and describe the localities of interesting species inhabiting the segetal communities of the T urobin commune, which are regarded as endangered in Poland and Europe. The paper presents r sults of a field study conducted in 2011−2013 in crop fields, located on brown soils and ren dzi as. Phytosociological relevés were made with the Braun-Blanquet method at the sites of p hytocoenoses comprising interesting and endangered species. The habitat was assessed with t he use of soil-agricultural maps, and soil pH was measured at the site where the phytosociologica l relevés were taken. In the Turobin commune, 32 interesting species were found; some of them are considered rare and endangered in Poland. In this group, the occurrence of Asperugo procumbens, regarded as an endangered species and included in the red list of vascular plants, is not eworthy.


INTRODUCTION
Literature reports indicate impoverishment of the vascular flora in Europe. In Poland, approximately 30% of vascular species are threatened with extinction [Falińska 1996]. The immediate cause of decreasing species diversity there are continuous changes in the natural environment induced by natural factors and the increasing anthropopressure [Michałowski 2003]. Human activity poses a threat to native flora and natural communities [Harasimowicz and Kostrubiec 2005]. Rural areas in Poland are characterised by unique biological and landscape diversity, which is exceptional in Europe. The major impact on the degree of transformation of the natural richness of agricultural land and rural landscapes is exerted by the increase in the intensity of land management [Dembek and Liro 2001]. Intensification of agriculture leads to a decline in the number of plant species occurring in the agricultural landscape [Kuszewska and Fenyk 2010]. During the last years, environmental scientists signal reduction issue floristic diversity of communi-ties and segetal and have reported the problem of the decreasing floristic diversity of segetal communities and emphasised the need for conservation of the diversity of segetal species and communities to prevent retreat from agrocoenoses [Kornaś 1987, Siciński 2001, Fijałkowski 2003, Trzcińska-Tacik 2003, Stupnicka-Rodzynkiewicz et al. 2004, Trąba and Ziemińska-Smyk 2006. Impoverishment or loss of biodiversity has suggested the necessity of compilation of red lists classifying species according to the category of threat within an entire country or region [Warcholińska 1994, Fijałkowski and Nycz 1998, Trąba and Ziemińska 1998, Zarzycki et al. 2002, Zarzycki and Szeląg 2006. Undoubtedly, local floristic reports play an essential role in identification of currently endangered species. Therefore, the aim of the study was to present habitats of threatened and locally rare species segetal flora.

STUDY MATERIAL AND METHODS
The floristic-phytosociological observations were conducted in 2011−2013, which were carried out in agrocoenoses of the Turobin commune, at the time of the optimal development of the communities. They included an area belonging to 19 villages ( fig. 1). The soil conditions were assessed on the basis of soil-agricultural maps at a scale of 1 : 5000. Moreover, at the observation sites, pH was measured in the top layer of the soil using a colorimetric method with the Hellig plate. Additionally, geographic coordinates were determined with GPS and used for distribution of the species in a 2,5 km ATPOL square grid. The phytosociological relevés were taken with the widely used Braun-Blanquet method. In total, 400 phytosociological relevés and 23 floristic inventories were made. The observations were carried out on brown soils and rendzinas. The occurrence frequencies were presented in an arbitrary scale, assuming that the number of localities was equal to the number of villages. Finally, the analysis of selected species also highlighted a number of lobes of their participation in various localities. A species was regarded extremely rare when noted in 1-2 locations, rare in 2−4 locations, frequent in 5−10 locations, common in 11−15 locations, and extremely common in 16−19 locations. The categories of threat posed to the species were established in accordance with the reports by Warcholińska [1994], Zarzycki and Szeląg [2006], Fijałkowski and Nycz [1998], and Trąba and Ziemińska [1998]. Categories of threat: Ex − extinct and probably extinct species, E − endangered, V − vulnerable, R − rare, I − indefinite status.

RESULTS
In 2011−2013, in 19 localities, the occurrence of 32 species of vascular plant taxa classified as rare or endangered. The location of the village is given in figure 1 below, the list of species with characteristic positions.  (FE 7921). The species is very common in the study area. It was highly abundant in some habitats, in quantity: 1, 2, 3. It was noted on brown soils in the pH range from 4 to 8 in Tokary, Zagroble, Elizówka, śurawie, Gródki Drugie, Nowa Wieś, Huta Turobińska, Czernięcin Poduchowny, Przedmieście Szczebrzeszyńskie, Wólka Czernięcińska, Olszanka, Zabłocie, śurawie, Tarnawa Mała, Kol. śabno, Gaj Czernięciński, Czernięcin Główny, Guzówka Kolonia, on rendzinas with a pH of 4.5 in Elizówka and 7.5 in śabno. Species recorded in spring barley and winter, with winter and spring wheat, rye, oats, buckwheat, mustard dirt, spring oilseed rape and winter, spring mix, corn, tabacco, sugar beet, potatoes and raspberries. Category of threat: I -according to Warcholińska [1994] ). This very common species was dispersed over the entire area of the commune. In some localities, high density was noted, in quantity: +, 1, 2, 3. The species performed on brown soils in the range of pH 4 to 8 in Olszanka, Tokary, Nowa Wieś, Czernięcin Poduchowny, Zabłocie, Czernięcin Główny, Wólka Czernięcińska, Tarnawa Mała, śurawie, Gaj Czernięciński, Gródki Drugie, Zagroble and on rendzinas in the range of pH od 4 to 7,5 in śabno, Guzówka Kolonia, Turobin, Kol. śabno, Elizówka. The weed infested spring barley and winter barley, spring and winter wheat, mixture of barley and oats spring oilseed rape, winter oilseed rape, sugar beet, potatoes, raspberries, black currant, poppy seed, parsley, oats, rye, triticale and long-term plantation of red clover. Category of threat: I − according to Warcholińska [1994] The species was a very common species across the entire area of the commune. It occurred quite abundantly in agricultural crop fields, in quantity: +, 1, 2, 3. Species recorded on brown soils in the pH range from 4.5 to 8 in Huta Turobińska, Czernięcin Główny, Przedmieście Szczebrzeszyńskie, Tarnawa Mała, Kol. śabno, Nowa Wieś, Gaj Czernięciński, Olszanka, Tokary, śurawie, Zagroble, Zabłociu and rendzinas in the pH range of 5 to 6.5 in Czernięcin Poduchowny, śabno, Elizówka, Turobin. Species appeared in winter and spring wheat, triticale, spring barley and winter rye, spring mix, rye, corn, buckwheat, spring oilseed rape and winter rye, wild mustard, sugar beet, long-term plantation red clover, black currants and raspberries. Category of threat: V -according to Warcholińska [1994] (FE 7931). A great number of specimens of the rare species in agricultural crop fields, in quantity: 1, 2. Performed on brown soil with a pH of 6 in Gaj Czernięciński, of pH 7.5 in Gródki Drugie, at pH 7 in śabno and on rendzinas in Turobin of pH 5 and of pH 4 in Kol. śabno. The weed infested growing parsley, raspberry, poppy seeds, oats and tobacco. Category of threat: Iaccording to Warcholińska [1994], I -Trąba and Ziemińska [1998].
10. Allium vineale L.: Gaj Czernięciński (FE 7933), Kol. śabno (FE 7912), Elizówka (FE 7900), Turobin (EE 7911). The species was noted in 6 specimens, in quantity: +, 1. Species located on brown soil with a pH of 6 in the village of Gaj Czernięciński, on rendzina at pH 7 and brown soil with a pH of 7 and 7.5 in Elizówka, on rendzina with a pH of 6 in Kol. śabno and of pH 7 in Turobin. Rarely performed in the cultivation of vegetables, sugar beet, spring mix, triticale, winter wheat, spring barley. Category of threat: I − according to Trąba and Ziemińska [1998].
14. Aspegugo procumbens L.: Zabłocie (GE 7023), Przedmieście Szczebrzeszyńskie (EE 7911), Gródki Drugie (FE 7931). The species occurred as single in 5 specimens in several localities, in quantity: r. Species recorded on brown soils with a pH of 5.5 in the village Gródki Drugie, with a pH of 6, 6.5 and 7 in the Przedmieście Szczebrzeszyńskie and a pH of 7 in the Zabłocie. It is rare in the study area, although in some locations it was noted in plantations of raspberry, sugar beet, winter and spring wheat as well as in long-term red clover plantations. Category of threat: V − according to Warcholińska [1994], E - Zarzycki and Szeląg [2006], V − Fijałkowski and Nycz [1998].
17. Adonis aestivalis L.: śabno (FE 7912), Zabłocie (GE 7023). Three localities of the species were recorded in two villages. The species occurred as single specimens in quantity: r. The species rendzina performed at pH 6.5 and 7.5 in the village śabno and brown soil with a pH of 7 in the village of Zabłocie. The species inhabited canopies of winter wheat, spring oilseed rape and maize. Category of threat: V − according to Warcholińska [1994] 19. Melampyrum arvense L.: Elizówka (FE 7901), śabno (FE 7912). Single specimens of the species were noted in winter wheat canopies, in quantity: r. The species located on rendzina with at pH of 7.5 in śabno, and in brown soil at pH of 7 in Elizówka. Category of threat: V -according to Warcholińska [1994], V -Trąba and Ziemińska [1998], I - Fijałkowski and Nycz [1998].
22. Aphanes arvensis L.: Olszanka (FE 7920). Lokalized two specimens of single the species, in quantity: r. Species performed on brown soil with a pH of 6.5 and 7. Were found the occurred of the species in winter wheat and spring barley. Category of threat: I − according to Trąba and Ziemińska [1998].
25. Centaurium pulchellum L.: Tarnawa Mała (FE 7910). One locality of some specimens of the species, in quantity: +. Was found on a brown soils with a pH of 6.5 in spring barley canopy. Category of threat: R − according to Warcholińska [1994], R -Fijałkowski and Nycz [1998].
26. Cerinthe minor L.: śabno (FE 7912). Three localities of the taxon were reported from this village. The species occurred as single specimens, in quantity: r. Was found on rendzina with a pH of 6.5. Was noted in a winter wheat canopy. Category of threat: Raccording to Warcholińska [1994], R - Trąba and Ziemińska [1998], R -Fijałkowski and Nycz [1998].
31. Veronica agrestis L.: śabno (FE 7912). A small number of specimens in quantity: 1, were noted in spring barley. The species located in rendzina of pH 6. Category of threat: I -according to Trąba and Ziemińska [1998].
32. Veronica opaca L.: śabno (FE 7912). Several specimens of the species in quantity: 1, were noted in a plantation of spring cereal mixture. The species located on brown soil of pH Category of threat: V -according to Warcholińska [1994], V -Fijałkowski and Nycz [1998].
Three of the presented species are described in the Red List of Vascular Plants [Zarzycki and Szeląg 2006]. There is include Asperugo procumbens, which have been categorized as extinct species. In turn, Adonis aestivalis and Bromus secalinus are regarded as endangered species. Moreover, five species are included in the Red List of Segetal Plants [Warcholińska 1994] in the rare species category. These are Centaurium pulchellum, Cerinthe minor, Chaenorhinum minus, Peplis portula, and Thlaspi perfoliatum.

DISCUSSION
In recent years, conservation of biodiversity has been more frequently considered at the regional level, and documentation of flora extinction and threat on a local scale has become increasingly necessary [Piękoś-Mirkowa 2003]. The phenomenon of flora impoverishment induced by anthropopressure has long been observed in Poland and across Europe [Májeková and Zeliberková 2005, Stehlik et al. 2007, Storkey et al. 2011, Skrzyczyńska and Ługowska 2006. Increased intensification of agriculture and elimination of marginal habitats contribute to extinction of species that are characterised by narrow ecological amplitude or are associated with old agriculture [Davies et al. 2000, Henle et al. 2004, Koh et al. 2004]. This process can be observed in Europe, e.g. in Switzerland, where comparison of the current lists of rare and endangered plant species with lists compiled ten years ago reveals substantial losses ranging from 21% to 38% [Stehlik et al. 2007]. Due to the intensification of agriculture and related changes in the way tillage, fertilization and plant protection major changes occur in the flora segetal [Májeková andZeliberková 2005, Lososová andSimonová 2008]. Extensive and ecological farming promotes conservation of endangered and rare species [Storkey et al. 2011]. In ecologically managed farms, the biodiversity of weed communities in agricultural crops is by several tens of percent higher [Frieben and Köpke 1995, Frieben 1998, Hyvönen et al. 2003, Bengtsson et al. 2005]. Application of chemical fertilisers has a negative impact on the species composition in segetal communities [Májeková andZeliberková 2005, Lososová andSimonová 2008]. Increased use of fertilisers eliminates large numbers of oligotrophic species in meadows [Schippers andJoenje 2002, Myklestad andSaetersdal 2004], and application of herbicides reduces the number of weeds in fields [Stehlik et al. 2007]. Changes in the number of ruderal weed species reflect the gradual loss of typical rural habitats caused by the increasing nutrient supply [Lososová and Simonová 2008]. Over the last decades, intensified farming has led to extinction of species inhabiting old culture landscapes [Chamberlain andFuller 2000, Maes andVan Dyck 2001]. This can be illustrated by the example of Asperugo procumbens which according to the Red List of Vascular Plants is an endangered species in Poland [Zarzycki and Szeląg 2006]. The group of vulnerable plants comprises species whose presence is related to seed material purity; these are typical speirochores associated mainly with extensive farming. Agrostemma githago is a representative taxon regarded as an endangered species in Poland [Warcholińska 1994] and reported as a rare species in the Czech Republic [Fijałkowski andNycz 1998, Lososová andSimonová 2008]. Similarly, Bromus secalinus, which has a status of an endangered species in the country and region, is a typical speirochore [Warcholińska 1994, Fijałkowski and Nycz 1998, Zając et al. 2009, Zarzycki and Szeląg 2006. Currently, the species is reported from agricultural fields in eastern Poland [Kapeluszny andHaliniarz 2010, Rzymowska andSkrajna 2011]. In the area of the analysed commune, Bromus secalinus is a very common species. The group of endangered species comprises those associated with extreme, e.g. calcareous, habitats [Stehlik et al. 2007], for instance Adonis aestivalis and Fumaria vaillantii, which have been assigned the threatened with extinction category in the country [Warcholińska 1994]. Melampyrum arvense has also been included in the group of threatened taxa [Warcholińska 1994, Trąba and Ziemińska 1998, Jackowiak et al. 2007]. Also in the study area, a small number of specimens of the species occur in two localities only. Lathyrus tuberosus and Consolida regalis appeared to be common in the agricultural crop fields and roadsides of the Turobin commune area. Both species occur quite frequently in agricultural crops in some regions of the country as well Rzymowska 2001, Skrzyczyńska andŁugowska 2006]. In contrast, according to Zarzycki and Szeląg [2006] and Zając et al. [2009], Lathyrus tuberosus is an endangered species in the country. According to Stehlik et al. [2007], even common species are threatened with extinction or they significantly reduce habitat richness. These authors report an extinction index for forest species, such as Campanula rapunculoides or Melampyrum pratense, and agrophytes, e.g. Papaver rhoeas or Vicia tetrasperma [Stehlik et al. 2007]. As reported by Warcholińska [1998], approximately 100 species of field weeds are threatened with extinction in Poland and one in four species is threatened with extinction. Therefore, the necessity of conservation of weed biodiversity in traditional agriculture fields is being increasingly underlined. By signing the Convention on Biological Diversity, Poland acknowledged the obligation to preserve the country's natural wealth for future generations [Siciński 2001]. Conservation of species diversity of segetal weeds is necessary for economic, natural, aesthetic, and cultural reasons so that future generations will inherit Poland with all the richness and beauty of nature [Trzcińska-Tacik 2003]. CONCLUSIONS