Botanica Lithuanica , Volume 6, Number 2

2000 m.

This paper continues publication of the conspectus of alien plant species recorded in Lithuania. The Crassulaceae family in Lithuania contains nine alien plant species, the Grossulariaceae family – three species, the Fagaceae family – two species, Saxifragaceae and Violaceae families – two species each, and the Juglandaceae family contains one alien species. Data on the first record, distribution, habitats, level of naturalization, means of immigration, and biology (time of flowering, fructification, and reproduction) of each species are presented. Twelve here described alien species are naturalized and seven are casuals. Distribution of five species is mapped. Two species (Sempervivum ruthenicum and Sempervivum tectorum) are excluded from the list of alien plant species.

Keywords: alien plant species, conspectus, Crassulaceae, Juglandaceae, Fagaceae, Grossulariaceae, Saxifragaceae, Violaceae, distribution, naturalization, reproduction, Lithuania.

Leaf emergence types of some woody species occurring in Quercus cerris var. cerris forests were investigated qualitatively and quantitatively. As a result of this it was found out that tree species belonging to Quercus cerris var. cerris forests have three different leaf emergence types. Mespilus germanica and Acer campestre subsp. campestre have different leaf emergence types as compared with other species’

Keywords: Quercus cerris var. cerris, forests, phenology, leaf emergence types’

Invasion of exotic plant species into natural and semi-natural biotopes and the emergence of neophytic plant communities is a typical feature of the Latvia’s flora over the past decades. The communities dominated by Sedum spurium, S. sexangulare, S. rupestre, and Euphorbia cyparissias establish themselves on dry sandy and gravely substrates as well as on the piles of stones, most commonly next to the cemeteries, on railway embankments, in gravel pits, etc. Neophytic plant communities found in western Latvia are described; the ecology (Ellenberg values) and structure of biological and geographical elements of the communities are analysed. The occurrence of neophytic stonecrop and spurge communities in the Baltics appears to go with the global warming of climate.

Keywords: sedum, Euphorbia, distribution, neophytic plant communities, biota migration.

Phytocoenological relevés of Tilio-Carpinetum betuli corydaletosum cavae communities were recorded in Girukė forest (Meteliai Regional Park, South-West Lithuania) by M. Natkevičaitė-Ivanauskienė and J. Tupčiauskaitė in 1982–1983. Investigations were repeated in 1997 trying to ascertain the dynamical changes of flora composition and structure of these phytocoenoses. Qualitative and quantitative changes of flora composition in these phytocoenoses were imperceptible: dynamic group of permanent species absolutely preiominated, composition and significance of species of syntaxonomic groups almost have not changed. progressive changes of structure were defined: Acer platanoides reached the tree stand, Tilia cordata strengthened in the second layer of tree stand. These changes are the result of dynamical process of regeneration. The phytocoenological evaluation of Tilio-Carpinetum betuli communities is presented, the question of zone vegetation in South-West Lithuania is discussed.

Keywords: forest, vegetation, Tilio-Carpinetum betuli, zonal vegetation dynamics, South-West Lithuania.

The data and investigation results on the diversity of psammophyte communities of the Baltic Sea coast of Lithuania are presented in the paper. The investigated communities represent 2 syntaxonomical classes: Ammophiletea arenariae Br.-Bl. et R. Tx. 1943 ex Westhoff et al. 1946 and Koelerio-Corynephoretea Klika in Klika et Nov?k l94l. The first one includes psammophyte communities of various development stages that inhabit sites of extreme climatic conditions accompanying poor soils. These sites are located on white dunes and on the bottom of their slopes. The Ammophiletea arenariae Br.-Bl. et R. Tx. 1943 ex Westhoff et al. 1946 class is represented by one association’ The differences in site ecological conditions of these communities are reflected by segregation into four subassociations. The Koelerio-corynephoretea Klika in Klika et Nov?k 1941 class includes communities of grey dunes and psammophyte grasslands. These communities are sensitive to the amount of light, thus can poorly compete with other plant communities. On the Baltic Sea coast of Lithuania the Koelerio-Corynephoretea Klika in Klika et Nov?k l94l is represented by 3 associations belonging to 3 alliances and 1 order’ one of these associations (Carici arenaria-Airetum praecocis Westh. et al. 1962) is rare in Lithuania and is included in the Red List of plant communities’ One new subassociation of Carici arenaria-Airetum praecocis subas. centaureatosurn littoralls is described in this paper.

Keywords: syntaxonomy, plant communities’ white dunes’ grey dunes’ Baltic Sea coast, Lithuania.

Investigations on lichens and allied fungi in Vie5vile Strict Nature Reserve (Lithuania) are presented in the paper. In total 170 species were registered, nine of them being new to Litht::ania: Arthonia leucopellaea ,A. vinosa, Biatora chtysantha, B. helvola, Gyalideopsis anastomosans, Micarea cinerea, M. peliocarpa, Vezdaea leprosa, Vouauxiomyces santessonii. Two species of the present Red Data Book of Lithuania and ten species proposed for the new edition of the Book were registered during this study.

Keywords: lichens, lichenicolous fungi, strict nature reserves, Lithuania.

Fruit trees such as peaches and plums with the dark-red and almost black leaves absorb the light energy at the average level of 9.9 % across the visible spectrum of light. Therefore, using the red-leafed plants we can expect greater yield and higher economical effect compared to the green-leafed plants. This effect is illustrated with the peach cultivar ‘Negus’ newly selected by the author. It is concluded that the described method of selection is highly promising.

Keywords: Persica, Prunus, selection, red-leafed plants, antocyanins, photosynthesis.

Cardamine flexuosa – a new species for the flora of Lithuania – is described on the basis of specimens collected in 1997 in Žemaitija National Park (Plungė district) and Dambrava forest (Kaišiadorys district). Earlier report on the occurrence of this species in Punios šilas Nature Reserve is based on a misidentified specimen. Characteristics of C. flexuosa habitats and notes on the changes of species abundance in the course of three years are described. Distribution map of C. flexuosa is presented.

Keywords: Cardamine flexuosa, Brassicaceae, distribution, Lithuania.