Biodiv. Res. Conserv. 19: 93-102, 2010 BRC www.brc.amu.edu.pl 10.2478/v10119-010-0025-z Grasses in Poland: invincible, but threatened Ludwik Frey Department of Systematics of Vascular Plants, W. Szafer Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 KrakÛw, Poland, e-mail: [email protected] Abstract: The paper presents problems connected with expansiveness and threats of grasses in Poland. Some subjectively selected grass species are given. They have conventionally been divided into two opposite groups: (i) expansive or even invasive grasses, referred to here as Ñinvincibleî, and (ii) grasses that are threatened for a variety of reasons, and deserving protection. Key words: grasses, Poaceae, expansion, invasion, threat, protection, Poland 1. Introduction 2. Invincible grasses Cosmopolitan grasses are among the most impor- Grasses have a characteristic external structure and tant families in the kingdom of flowering plants. In terms show distinctive embryological and physiological features. of the number of species (ca. 10 thousand) they rank Owing to these characteristics they can manifest fourth behind Asteraceae, Fabaceae and Orchidaceae. extraordinary adaptation abilities and are able to live Areas where grasses form the dominating form of vege- under disadvantageous conditions, either natural or tation, e.g. steppes, savannas, prairies or pampas, cover modified by Man. Grasses can grow under considerably nearly one-third of the world landmass. In terms of pro- diverse ecological conditions, from very wet to duction these areas are second only to forests (Clayton extremely dry, and from hot to Arctic cold. They occur & Renvoize 1986; Weiner 1999; Frey 2000). in almost all types of habitats, from sea coasts to high The author of the Latin diagnosis of the family mountains, and from the Equator to the Polar regions Gramineae (called order ñ Genera plantarum 1789) was (Frey 2000). Under favourable conditions, grasses be- A. L. de Jussieu. An alternative name ñ Poaceae ñ was come expansive or even invasive plants. introduced by an American botanist, J. H. Barnhart In Poland it is difficult to find native grass species (Barnh. 1895, Bull. Torrey Bot. Club 22:7). Both these showing evident expansive tendencies. These are not names are deemed legitimate. shown even by those grass species regarded as invasive Against the background of subjectively selected in some other regions, such as Aira caryophyllea in examples of grass species, this paper discusses briefly, Australia, New Zealand, and the Americas, where it on the one hand, issues associated with their expan- colonizes coastal areas upon sea and water bodies, as siveness or even invasiveness and, on the other, well as forests and meadows, Leersia oryzoides that the pressing need to protect them. Poaceae have spreads along river banks and on grasslands of Australia conventionally been divided into two opposite groups: (in Poland, both these species are among those disappea- expansive grasses, that extend their distribution areas ring or classed as endangered species), Ammophila even by means of invasions, referred to here as ìinvin- arenaria that threatens coastal dunes in Australia, New cibleî, and other grasses that are threatened for a vari- Zealand, and North America, Elymus repens ñ a species ety of reasons, some of them even deserving protec- dangerous to farmlands as well as grass communities tion. (prairies, meadowlands) in both of the Americas and in NATURE NATURE CONSERVATIONA © Adam Mickiewicz University in PoznaÒ (Poland), Department of Plant Taxonomy. All rights reserved. 94 Ludwik Frey Grasses in Poland: invincible, but threatened Australia, and Phragmites australis, which colonizes Alopecurus myosuroides is also an expansive grass similar habitats in North America and Australia. Only species, and most recently ñ perhaps even invasive. The several native species, such as Elymus repens or area of its natural range includes the southern and Calamagrostis epigejos, implement the model of ecolo- western regions of Europe. In both Central Europe and gical expansion in Poland (Jackowiak 1999), and display Poland this species is recorded, first of all, in segetal an extraordinary ability to colonize new habitats, often associations. In Poland it spreads chiefly in lowlands on very contaminated soils (Tokarska-Guzik 2007). and in the upland belt, where it reaches the northern Man contributed to the spread of some native species limit of its European range. This grass can adversely of grasses such as Ammophila arenaria and Leymus affect the yield of cereals, especially in places where it arenarius. Their natural distribution is restricted to the occurs in high densities per square metre. It is resistant coastal dune belt. Maps of their distribution in Poland to frost and herbicides, produces great numbers of seeds show, however, many locations further inland (more and is capable of growing new inflorescences after the numerous of L. arenarius, fewer ñ of A. arenaria) that crop is mown (Korniak 2003; Tokarska-Guzik 2007; are not of natural character (Zajπc & Zajπc 2001). As Dajdok & SzczÍúniak 2009). both species are important as anti-erosion grasses, they Avena strigosa originated from the Mediterranean have been introduced (particularly L. arenarius) on region. Presumably, the Iberian Peninsula was the centre inland sites either as sand stabilizers or decorative plants. of its origin and differentiation. As late as in the second For example, information on cultivation of L. arenarius half of the 20th century it was found as a grain cultivar on a location situated far inland, in the Lublin area near or weed in many European countries, for example in Kock was reported as early as 1829 (Waga 1847; Poland, and particularly in its southern and central parts. Korniak & Urbisz 2007). After its cultivation had been discontinued, it seemed The other type of expansion in the meaning applied to head into complete disappearance from the area of by Jackowiak (1999), i.e. chorological (territorial) Poland (Frey 1991a, 1991b). In recent years, however, expansion, which consists in a species penetrating out- this grass has embarked on a new period of expansion, side its natural distribution area, is shown chiefly by especially in the north-eastern part of the country. It is archaeophytes. The species which may be included in all the more interesting, because the data on its occur- this group are e.g. Apera spica-venti and Avena strigosa, rence in this region have been lacking until recently. grasses which reach their optimum in segetal habitats The species grows chiefly in segetal habitats, and rarely (in Bohemia, A. spica-venti is regarded as an invasive in ruderal ones (Frey 1991a; Korniak 1997; Korniak & species ñ Pyöek et al. 2002), Avena fatua, Echinochloa Urbisz 2007). crus-galli, Hordeum murinum, Setaria viridis and In Poland the truly expansive grasses are those of Alopecurus myosuroides. alien origin, largely kenophytes. They constitute a size- In recent times, three of the aforementioned species able percentage of Polish flora and their share has grown have evidently been increasing the number of their in recent decades. Hence, the first preliminary list of locations in Poland. kenophytes (Kornaú 1968) included only 4 grass species, Hordeum murinum occurs in Europe, from Spain to and according to Zajπc et al. (1998) among the 251 the Ukraine; its northern limit extends through the British species representing new arrivals in the flora of Poland Isles, the Jutland Peninsula to the southern tip of the 13 were grasses. Scandinavian Peninsula (Mizianty 2006). In Poland a The status of some species of grasses in the Polish typical subspecies (subsp. murinum) is found. This flora has also changed. In the list of ephemerophytes archaeophyte, naturalised in our flora, has distinctly low compiled by RostaÒski & Sowa (1986-1987), which habitat requirements. It grows in synanthropic locations, contains 662 species, 92 species were grasses, 5 of devoid of natural vegetation (rubble heaps, embankments, which are species now regarded as fully or locally walls) and it is regarded as a pioneer species. Its distri- naturalised plants. bution area extends mainly as a result of human activity. As far back as 25 years ago, Bromus carinatus and Until recently, it has been recorded throughout Poland, Eragrostis albensis were listed as ephemerophytes, except for the north-eastern part (Zajπc & Zajπc 2001), while now they are regarded as kenophytes, that are where its spread has been very rapid nowadays. presently extending their secondary ranges. Nonetheless, as of now, it still occurs there much less Bromus carinatus occurs naturally in the western frequently than in the other areas of Poland (Mizianty part of North America and in the south reaches of the 2006). This taxon owns its expansiveness, particularly Andes in Colombia. In Europe, the first locations were in urban situations, to rapid ripening and self-pollina- found at the beginning of the 20th century in Sweden, tion, as well as the production of huge numbers of seeds Belgium, the Netherlands, and Germany (Sutkowska with awns having hooked hairs, facilitating their trans- & PasierbiÒski 2009). In Poland it was first recorded in port by humans and animals (Bieniek 2010). the Wielkopolska region in 1911 (Tokarska-Guzik Biodiv. Res. Conserv. 19: 93-102, 2010 95 2005). Under the criteria proposed by some authors (e.g. Polish Lowlands (Kuüniewski 1996; Tokarska-Guzik Pyöek et al. 2004) it could be regarded as an invasive 2005; Korniak & Urbisz 2007). As these accidental species. This grass was first introduced into Poland as introductions were of an ephemeral nature, they were a cultivated plant in the first half of the 20th century, not noted. The first official records (from the Pomeranian under the name of Bromus unioloides Humb. & Kunth. and Silesian provinces) date back to the second half of From cultivation this grass spread onto anthropogenic the 19th century. It is interesting to note that until the habitats, and particularly ruderal ones. Outside urbanized year 1960 the species was not recorded in Central areas it is increasingly often recorded in semi-natural Poland.