Abstract
The directional element is a local determinant of spatial diversity of flora of a given country, within widely understood geographical elements. In Poland, a country situated in the middle of Europe, most species belong to the transitional element (with no range limit in our country). Besides the transitional element, the directional northern element (with its southern limit in Poland) is present. It can be divided into two distinct groups: species that have their absolute southern range limit in Poland and those that have both southern and northern limits with a significant disjunction in Central Poland. Although they are two different groups, they will be discussed within the combined study. The first one constitutes 1.9% of the directional element, the second one 1.3%. As far as general ranges are concerned, Circumboreal and Eurosiberian species prevail in the first group, with a significant share of the taxa of geographical connective element. European-temperate taxa are the most numerous in the second group. The two above-mentioned groups will also be distinguished by their species belonging to the higher syntaxonomical units. Such a small share of the northern element in the flora of Poland confirms that our country belongs to the Central European Province, where the North-European element is, to a large extent, a relict of the earlier periods of the Holocene.
References
Kornaś J. & Medwecka-Kornaś A. 2002. Geografia roślin, 2 ed., 634 pp. Wyd. Nauk. PWN, Warszawa.
Medwecka-Kornaś A., Kornaś J. & Pawłowski B. 1966. C. Surwey of the Most Important Plant Association in Poland. In: W. Szafer (ed.). The vegetation of Poland, pp. 294-534. Pergamon Press Ltd, Oxford & PWN, Warszawa.
Medwecka-Kornaś A., Kornaś J., Pawłowski B. & Zarzycki K. 1972. Przegląd ważniejszych zespołów roślinnych Polski. In: W. Szafer & K. Zarzycki K. (eds.). Szata roślinna Polski, pp. 279-481. PWN, Warszawa.
Mirek Z., Piękoś-Mirkowa H., Zając A. & Zając M. 2002. Flowering plants and pteridophytes of Poland. A checklist. In: Z. Mirek (ed.). Biodiversity of Poland 1, 442 pp. W. Szafer Institute of Botany, Polish Academy of Sciences, Kraków.
Pawlowska S. 1966. Floristic statistics and elements of the Polish flora. In: W. Szafer (ed.). The vegatation of Poland, pp. 138-241. Pergamon Press Ltd, Oxford & PWN, Warszawa.
Pawlowska S. 1977. Charakterystyka statystyczna i elementy flory Polskiej. In: W. Szafer & K. Zarzycki (eds.). Szata roślinna Polski, I, 3 ed., pp. 129-206. PWN, Warszawa.
Popiela A. 2004. Phytogeographic aspects of the occurrence of forest vascular plant species in Pomerania (north-west Poland). Bot. Jahrb. Syst. 125(2): 97-228.
Szafer W., Kulczyński S. & Pawlowski B. 1953. Rośliny polskie. xxviii+1020 pp. PWN Warszawa.
Zając A. & Zając M. (eds.). 2001. Distribution Atlas of Vascular Plants in Poland. xii+714 pp. Edited by Laboratory of Computer Chorology, Institute of Botany, Jagiellonian University, Cracow.
Zając M. 1996. Mountain Vascular Plants in the Polish Lowlands. Polish Bot. Stud. 11: 1-92.
Zając M. & Zając A. 2000. Phytogeographical and syntaxonomical dependence of species reaching their western and northern limits of distribution in Poland. Fragm. Flor. Geobot. 45(1-2): 413-422.
Zając M. & Zając A. 2001. Zasadność wyróżniania "Działu Północnego" w świetle danych zasięgowych "Atlasu rozmieszczenia roślin naczyniowych w Polsce - ATPOL". Acta Botanica Warmiae et Masuriae 1: 15-24.
Zając M. & Zając A. 2006. Western element in the vascular flora of Poland. Biodiv. Res. Conserv. 1-2: 57-63.
Zając M. & Zając A. 2009. The geographical elements of native flora of Poland. 94 pp. Edited by Laboratory of Computer Chorology, Institute of Botany, Jagiellonian University, Kraków.