Sirbu C. et al. INVASIVE NEOPHYTES IN NATURAL GRASSLANDS OF ROMANIA SÎRBU Culiţă **, VÎNTU V.*, SAMUIL C.*, STAVARACHE M.* * University of Agricultural Sciences and Veterinary Medicine, Iaşi * Corresponding author e-mail: [email protected]; [email protected] Abstract In this paper, we have drawn up a list of neophytes which invade the primary and secondary grasslands of economic interest from Romania (pastures and hayfields), based on our own field works (2008-2016) and the literature. The list includes a number of 33 invasive neophytes, most of them native in North America and Asia. The harmful character of these species was discussed, related to their effect on the biodiversity and economical quality of the invaded grasslands. A large variation in the number of invasive neophytes in the analyzed grasslands have been registered, depending of the grassland type. The grasslands with the highest number of invasive neophytes were those from the orders Potentillo-Polygonetalia and Arrhenatheretalia, which are usually stronger disturbed by anthropogenic or natural factors. The less disturbed grasslands (from the orders Nardetalia and Caricetalia curvulae) were either invaded by a low number of neophytes or entirely free of neophytes. Keywords: alien plants, biodiversity, natural grasslands, neophytes, plant invasion. INTRODUCTION Alien plants in a given area archaeophytes (introduced before are those spontaneous and sub- 1500) (PYŠEK et al. 2002). spontaneous plants, native in other Most plants introduced by geographic regions, whose presence man into a new area fail to survive in that area is due to accidental or too long in the new home if they intentional introduction, as a result of (those deliberately introduced) are human activity (RICHARDSON et not under the direct human care. al. 2000). The invasion of alien They can flourish and even plants is globally recognized, as one reproduce occasionally in the new of the greatest threats to natural area, but cannot form long term self- biodiversity, economy and human sustaining populations. If anyone health (VITOUSEK et al. 1997; had the opportunity to register them, PIMENTEL et al. 2000; MCNEELY they only increase the list of casual 2001; HULME 2007). alien plants (sensu RICHARDSON Conventionally, in the et al. 2000). botanical literature, alien plants are However, a small fraction of these classified as neophytes (introduced immigrants, ca. 0.1%, according to after the year 1500), and some estimates Romanian Journal of Grassland and Forage Crops (2016)13 57 Sirbu C. et al. (WILLIAMSON and FITTER 1996) (2011a), the number of alien species benefiting by the absence of recorded in Romania amounts to competitors, by certain climatic 671, of which 593 neophytes conditions similar to those of their (88,4%). Among them, over 100 homelands, or by other favorable species may be considered invasive. circumstances, after a longer or Given their high ability to spread in shorter stage of naturalization (a nature, these species have a real or phase in which they gain the ability potential capacity to cause negative to reproduce themselves consistently impact on natural biodiversity, in the place of introduction, without economy as well as on human health human intervention), can become (SÎRBU and OPREA 2011a). invasive, i.e. able to spread to a The invasion of neophytes considerable distance from the especially affects habitats strongly parent populations, conquering an determined or influenced by man, increasingly large area. Some of the such as anthropogenic woodlands, invasive alien plants, which have a ruderal habitats, arable lands or demonstrated negative impact on trampled areas, as we have shown for natural ecosystems, were designated eastern Romania (Moldavia) in the literature as transformers (SÎRBU et al. 2012). However, some (RICHARDSON et al. 2000). species can invade natural habitats, Research conducted in the too, and in this study, we aimed to last decades have shown a make a general assessment of the continuous enrichment of the presence of the invasive neophytes in neophyte flora of Romania. the permanent grasslands from According to SÎRBU and OPREA Romania. MATERIAL AND METHOD Data were collected both by invasive neophytes from the primary own field research carried out on or secondary grasslands of economic alien plants (2008-2016) and by interest from Romania (pastures and studying of an extensive floristic and hayfields), which are dominated by phytosociological literature (for a perrenial herbs, belonging to the complete list of references, see following classes and orders of COLDEA 1997, 2012; SÎRBU and vegetation (brief characterization, OPREA 2011a; CHIFU 2014). The according to COLDEA 1997, 2012): invasive neophytes of the flora of - Class Festuco-Brometea Br.-Bl. et Romania have been selected R. Tx. ex Klika et Hadač 1944: ord. according to Anastasiu & Negrean Festucetalia valesiacae Br.-Bl. et R. (2009); SÎRBU and OPREA (2011a) Tx. ex Br.-Bl. 1949 (continental, and SÎRBU et al. (2012). steppic grasslands, more or less We have inventoried the xerophilous); ord. Brometalia erecti Romanian Journal of Grassland and Forage Crops (2016)13 58 Sirbu C. et al. Br.-Bl. 1936 (subatlantic grasslands, - Class Festuco-Puccinellietea Soó more or less thermophlous and 1968: ord. Puccinellietalia Soó 1968 meso-xerophilous, on calcareous (Eurasian thermo-continental substrates); ord. Stipio vegetation of saline meadows); ord. pulcherrimae-Festucetalia pallentis Scorzonero-Juncetalia gerardii Pop 1968 (sub-continental Vicherek 1973 (continental moist xerophilous grasslands, on halophytic meadows of south-east, rendzinas, in hilly and mountainous central and eastern Europe); floors); - Class Trifolio-Geranietea - Class Koelerio-Corynephoretea sanguinei Th. Müller 1961: ord. Klika in Klika et Novák 1941: ord. Origanetalia vulgaris Th. Müller Festucetalia vaginatae Soó 1957 1961 (secondary grasslands in (continental xerophilous grasslands contact with ± thermophilous and on sandy soils); xero-mesophilous forests, on plains - Class Molinio-Arrhenatheretea R. and hills); Tx. 1937: ord. Molinietalia - Class Calluno-Ulicetea Br.-Bl. et caeruleae W. Koch 1926 (pasture R. Tx. ex Klika et Hadač 1944: ord. and meadows on alluvial, moist or Nardetalia Oberd. 1949 (secondary peaty soils); ord. Arrhenatheretalia mountainous and subalpine R. Tx. 1931 (pasture and meadows mesophilous and acidophilous on well-drained and fertile soils); grasslands); ord. Potentillo-Polygonetalia R. Tx. - Class Juncetea trifidi Klika et 1947 (meso-higrophilous, Hadač 1944: ord. Caricetalia mesotrophic grasslands on alluvial curvulae Br.-Bl. 1926 (primary soils, tolerant halophilous, in alpine and subalpine acidophilous intensively grazed habitats); grasslands). RESULTS AND DISCUSSIONS Neophytes invasive in the canadensis (L.) Cronq., Cuscuta natural grasslands from Romania. campestris Yunck., Cytisus A total number fo 33 invasive scoparius (L.) Link., Elaeagnus neophytes have been recorded in angustifolia L., Erigeron annuus (L.) various types of natural grasslands Pers. (ssp. annuus & strigosus from Romania (Tab. 1), i.e. (in an (Muhl. ex Willd.) Wagenitz), alphabetical order; Fig. 1 and 2): Helianthus tuberosus L., Juncus Ailanthus altissima (Mill.) Swingle, tenuis Willd., Lycium barbarum L., Ambrosia artemisiifolia L., Amorpha Medicago sativa L., M. × varia fruticosa L., Armoracia rusticana Martyn, Oxalis stricta L., Paspalum P.Gaertn., B.Mey. et Scherb., paspalodes (Michx.) Scribn., Picris Asclepias syriaca L., Chamomilla echioides L., Reynoutria japonica suaveolens (Pursh) Rydb., Conyza Houtt., R. × bohemica Chrtek & Romanian Journal of Grassland and Forage Crops (2016)13 59 Sirbu C. et al. Chrtková, Robinia pseudacacia L., G.L. Nesom, S. lanceolatum (Willd.) Rudbeckia laciniata L., Sisyrinchium G.L. Nesom, Trigonella caerulea montanum Greene, Solidago (L.) Ser., Xanthium orientale L. canadensis L., Solidago gigantea subsp. italicum (Moretti) Greuter, Aiton, Sorghum halepense (L.) Pers., Xanthium spinosum L., Zingeria Symphyotrichum ciliatum (Ledeb.) pisidica (Boiss.) Tutin. Fig. 1. Neophytes invasive in grasslands (1): a-Ailanthus altissima (Măluşteni, Vaslui county), b-Amorpha fruticosa (Holboca, Iaşi county), c-Cytisus scoparius (South of Moineşti, Bacău county), d-Erigeron annuus (Dobrovăţ, Iaşi county), e-Elaeagnus angustifolia (Crăieşti, Galaţi county), f-Helianthus tuberosus (Ibăneşti, Mureş county). Romanian Journal of Grassland and Forage Crops (2016)13 60 Sirbu C. et al. Among the invasive proportions. The other species are neophytes from grasslands, the most therophytes (30%), phanerophytes numerous belong to the families (18%) or hemi-therophytes (3%). Asteraceae (40%) and Fabaceae With few exceptions (e.g. (18%). Other 11 families are Medicago sativa, M. × varia), the represented only by 1-3 species. herbaceous perennial neophytes, as The majority of the invasive well as the ligneous ones neophytes from grasslands are native (phanerophytes), have a great in North America (52%) and Asia capacity for competition and (21%). The other ones originate from vegetative propagation, by stolons, the Mediterranean region, South rhizomes, root suckers. In addition, America, tropical regions, or from most of the annual neophytes (e.g. the Central, South and South-East Conyza canadensis, Erigeron Europe. Two taxa resulted in Europe annuus, Ambrosia artemisiifolia by intrageneric hybridization, having etc.) are very prolific, producing a one or both parental species of exotic large number of seeds (HOLM et