The study was performed based on an inventory of alien flora in Daugavpils City. During the field studies all the alien species were recorded applying a regular grid consisting of 344 quadrats of 500 m × 500 m. Data of the 84 quadrats that cover all railway lines in the city were analysed to identify relationships between the distribution of alien plants and the location of railway lines. First the obtained data were compared with the first flora inventory in the city, which was conducted from 1975 to 1983. Comparison of data of the previous inventory and those obtained by us showed that the number of the recorded alien taxa along railways differed: 95 and 38 taxa, respectively. Secondly, some factors affecting the distribution of alien species along railway lines were analysed. Obtained results indicate that the highest concentrations of alien plants occurred in areas where railways are crossing or are located close to the adjacent cultivated and abandoned allotments, areas of private houses or cemeteries. Railway management measures such as topsoil disturbance and application of herbicides were found to be important human-induced factors affecting the distribution of annual alien taxa. The results of geospatial and statistical analyses demonstrated that the geographical distribution of alien species in general did not coincide with railway lines. However, the distribution of three species, i.e. Dracocephalum thymiflorum, Erysimum durum, and Lappula squarrosa, was associated only with railway lines, demonstrating the importance of railway infrastructure elements for the expansion of these species.
Bowdler, R., Hanna, S., White, J. & Knight, D. 2007. Paradise Preserved. An Introduction to the Assessment, Evaluation, Conservation and Management of Hisatorical Cemeteries. English Heritage and English Nature, Peterborough.
Buckley, D. S., Crow, T. R., Nauertz, E. A. & Schulz, K. E. 2003. Influence of skid trails and haul roads on understory plant richness and composition in managed forest landscapes in Upper Michigan, USA. Forest Ecology and Management, 175, 509–520.
http://dx.doi.org/10.1016/S0378-1127(02)00185-8
[CSB] Central Statistical Bureau of the Republic of Latvia. 2012. Number of population. http://www.csb.gov.lv/en (accessed 10.12.2012).
Douglas, G. W., Straley, G. B., Meidinger, D. & Pojar, J. (eds). 1998. Illustrated Flora of British Columbia. Vol. 2: Decotyledons (Balsaminaceae through Cuscutaceae). Ministry of Environment, Lands and Parks, Ministry of Forest, British Columbia.
Evarts-Bunders, P., Evarte-Bundere, G., Romanceviča, N., Brutāne, K., Novicka, I. & Nitcis, M. 2012. Rare anthropohytes in the flora of Daugavpils city. Latvian Vegetation, 22, 29–43.
Flory, S. L. & Clay, K. 2006. Invasive shrub distribution varies with distance to roads and stand age in eastern deciduous forests in Indiana, USA. Plant Ecology, 184, 131–141.
http://dx.doi.org/10.1007/s11258-005-9057-4
Flory, S. L. & Clay, K. 2009. Effects of roads and forest successional age on experimental plant invasions. Biological Conservation, 142, 2531–2537.
http://dx.doi.org/10.1016/j.biocon.2009.05.024
Frick, B. 1984. The biology of Canadian weeds. 62. Lappula squarrosa (Retz.) Dumort. Canadian Journal of Plant Science, 64, 375–386.
http://dx.doi.org/10.4141/cjps84-053
Gelbard, J. L. & Harrison, S. 2003. Roadless habitats as refuges for native grasslands: interactions with soil, aspect, and grazing. Ecological Applications, 13, 404–415.
http://dx.doi.org/10.1890/1051-0761(2003)013[0404:RHARFN]2.0.CO;2
Genova, E. 2012. Dracocephalum thymiflorum. http://e-ecodb.bas.bg/rdb/en/vol1/Drathymi.html (accessed 10.05.2012).
Gotelli, J. N. & Ellison, A. M. 2004. A Primer of Ecological Statistics. Sinauer Associates Inc.
Gudžinskas, Z. 2005. Case studies on the alien flora of the vicinity of cemeteries in Lithuania. Acta Universitatis Latviensis: Earth and Environmental Sciences, 685, 21–37.
Hansen, M. J. & Clevenger, A. P. 2005. The influence of disturbance and habitat on the presence of non-native plant species along transport corridors. Biological Conservation, 125, 249–259.
http://dx.doi.org/10.1016/j.biocon.2005.03.024
Hayasaka, D., Akasaka, M., Miyauchi, D., Box, E. O. & Uchida, T. 2012. Qualitative variation in roadside weed vegetation along an urban–rural road gradient. Flora, 207, 126–132.
http://dx.doi.org/10.1016/j.flora.2011.11.005
Houska, J. 2009. Erysimum durum J. Presl et C. Presl. http://botany.cz/cs/erysimum-durum (accessed 10.05.2012).
Kļaviņš, M., Nikodemus, O., Segliņs, V., Melecis, V., Vircavs, M. & Aboliņa, K. 2008. Environmental Science. The Academic Press of the University of Latvia, Rīga.
Kowarik, I. & Von der Lippe, M. 2011. Secondary wind dispersal enhances long-distance dispersal of an invasive species in urban road corridors. NeoBiota, 9, 49–70.
http://dx.doi.org/10.3897/neobiota.9.1469
Laiviņš, M. & Jermacāne, S. 2000. Emergence of certain neophytic plant communities in the vicinity of cemeteries in Latvia. Botanica Lithuanica, 6(2), 143–155.
Mitchell, A. 1999. The ESRI Guide to GIS Analysis: Spatial Measurements and Statistics. Environmental Systems Research Institute, ESRI Press, Redlands, CA, USA.
Niggemann, M., Jetzkowitz, J., Brunzel, S., Wichmann, M. C. & Bialozyt, R. 2009. Distribution patterns of plants explained by human movement behaviour. Ecological Modelling, 220, 1339–1346.
http://dx.doi.org/10.1016/j.ecolmodel.2009.02.018
Nitcis, M., Rutkovska, S. & Evarts-Bunders, P. 2011. Mapping principles of plant records in Daugavpils city. In Abstracts of the 53th International Scientific Conference of Daugavpils University (Oļehnovičs, D., ed.), p. 13. Daugavpils University (in Latvian).
NOBANIS. 2012. (The European Network on Invasive Alien Species) http://www.nobanis.org/Search.asp (accessed 11.10.2012).
Ozinga, W. A., Bekker, R. M., Schaminee, J. H. J. & Van Groenendael, J. M. 2004. Dispersal potential in plant communities depends on environmental conditions. Journal of Ecology, 92, 767–777.
http://dx.doi.org/10.1111/j.0022-0477.2004.00916.x
Penone, C., Machon, N., Julliard, R. & Le Viol, I. 2012. Do railway edges provide functional connectivity for plant communities in an urban context? Biological Conservation, 148, 126–133.
http://dx.doi.org/10.1016/j.biocon.2012.01.041
Pollnac, F., Seipel, T., Repath, C. & Rew, L. J. 2012. Plant invasion at landscape and local scales along roadways in the mountainous region of the Greater Yellowstone Ecosystem. Biological Invasions, 14, 1753–1763.
http://dx.doi.org/10.1007/s10530-012-0188-y
Priedītis, N. 2012. Encyclopedia of Species ‘Nature of Latvia’ http://www.latvijasdaba.lv/augi/ sistematiskais-raditajs/ (accessed 10.10.2012) (in Latvian).
Pyšek, P., Richardson, D. M., Rejmánek, M., Webster, G. L., Williamson, M. & Kirschner, J. 2004. Alien plants in checklists and floras: towards better communication between taxonomists and ecologists. Taxon, 53, 131–143.
http://dx.doi.org/10.2307/4135498
Quinn, G. P. & Keough, M. J. 2006. Experimental Design and Data Analysis for Biologists. Cambridge University Press.
Rasiņš, A. P. 1959. Materials and stories of cultural and weed plants on the territory of the Latvian SSR until the 13th century. In The Vegetation of the Latvian SSR. 2nd ed. Zinatne, Riga (in Russian).
Reid, M. & Thompson, S. 1996. Ecological fieldwork methods. In Essential Environmental Science. Methods and Techniques (Watts, S. & Halliwell, L., eds), pp. 352–390. Routledge.
Rentch, J. S., Fortney, R. H., Stephenson, S. L., Adams, H. S., Grafton, W. N. & Anderson, J. T. 2005. Vegetation–site relationships of roadside plant communities in West Virginia, USA. Journal of Applied Ecology, 42, 129–138.
http://dx.doi.org/10.1111/j.1365-2664.2004.00993.x
Romanceviča, N., Evarts-Bunders, P., Evarte-Bundere, G. & Brutāne, K. 2011. Non-native floral elements in the flora of Daugavpils city. In Abstracts Book of the VII International Scientific Conference of Students and PhD Students (Hamar, I. S., Matiytsiv, N. P., Zaburanniy, N. V. et al., eds), p. 104. Lviv (in Russian).
Royer, F. & Dickinson, R. 1999. Weeds of the Northern U.S. and Canada. The University of Alberta Press.
Rutkovska, S., Pučka, I. & Novicka, I. 2011. Analysis of invasive flora in cemetery territories of
the city of Daugavpils. In Proceedings of the 8th International Scientific and Practical Conference “Environment. Technology. Resources”. (20–22 June, 2011, Rēzekne, Latvia) (Noviks, G., ed.), pp. 344–351. Rēzekne, 2011.
Seiler, A. 2001. Ecological Effects of Roads, A Review. Uppsala.
Smart, S. M., Thompson, K., Marrs, R. H., Le Duc, M. G., Maskell, L. C. & Firbank, L. G. 2006. Biotic homogenization and changes in species diversity across human-modified ecosystems. Proceedings of the Royal Society, 273, 2659–2665.
http://dx.doi.org/10.1098/rspb.2006.3630
Spatial Plan of Daugavpils City for the Period 2006–2018. 2005. 2nd edn. Daugavpils City Council, Daugavpils (in Latvian).
Šulcs, A. A. 1972. Adventive plants as weeds of agricultural lands and ruderal places in Latvia. In Nature Conservation in the Latvian SSR, pp. 79–102. Zinatne, Riga (in Russian).
Šulcs, A. A. 1976. Adventive flora in the territory of the city of Riga railway junctions. Botanicheskij zhurnal, 61(10), 1445–1454 (in Russian).
Šulcs, A. A. 1977. Adventive flora of Riga city. Botanicheskij zhurnal, 62(10), 1513–1523 (in Russian).
Tabaka, L. B., Gavrilova, G. B. & Fatare, I. J. 1985. Flora of Daugavpils City. Flora and Vegetation of Latvian SSR. The Eastern Latvian Geobotanical Area. Zinatne, Riga (in Russian).
Trombulak, S. C. & Frissell, C. A. 2000. Review of ecological effects of roads on terrestrial and aquatic communities. Conservation Biology, 14, 18–30.
http://dx.doi.org/10.1046/j.1523-1739.2000.99084.x
Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A. (eds). 1964–1980. Flora Europaea. Vols 1–5. Cambridge University Press, Cambridge.
Tyser, R. W. & Worley, C. A. 1992. Alien flora in grasslands adjacent to road and trail corridors in Glacier National Park, Montana, USA. Conservation Biology, 6, 253–262.
http://dx.doi.org/10.1046/j.1523-1739.1992.620253.x
Von der Lippe, M. & Kowarik, I. 2007. Long-distance dispersal of plants by vehicles as a driver of plant invasions. Conservation Biology, 21, 986–999.
http://dx.doi.org/10.1111/j.1523-1739.2007.00722.x
Von der Lippe, M. & Kowarik, I. 2008. Do cities export biodiversity? Traffic as dispersal vector across urban–rural gradients. Diversity and Distributions, 14, 18–25.
http://dx.doi.org/10.1111/j.1472-4642.2007.00401.x
Westermann, J., Von der Lippe, M. & Kowarik, I. 2011. Seed traits, landscape and environmental parameters as predictors of species occurrence in fragmented urban railway habitats. Basic and Applied Ecology, 12, 29–37.
http://dx.doi.org/10.1016/j.baae.2010.11.006
Wittig, R. & Becker, U. 2010. The spontaneous flora around street trees in cities – a striking example for the worldwide homogenization of the flora of urban habitats. Flora, 205,
704–709.
http://dx.doi.org/10.1016/j.flora.2009.09.001
http://dx.doi.org/10.1016/j.baae.2005.04.003