Botanica Lithuanica , Volume 6, Number 3

2000 m.

This paper continues publication of the conspectus of alien plant species recorded in Lithuania The Azollaceae family in Lithuania contains one alien species, the Pinaceae f’amily – 8 species, and the Srlicaceae family – 6 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 three are casuals. Four species (Abies alba, Salix alba, Salix acutifolia, and Salix fragilis) are excluded from the list of alien plant species.

Keywords: alien plant species, conspectus, Azollaceae, Pinaceae, Salicaceae distribution, naturalization, reproduction, Lithuania.

Results of the investigations of Hypericum perforatum habitats are presented. The stands where H. perforatum is the most abundant belong to the Agropyrtialia repentis communities. H. perforatum from these habitats could be used for the exploitation or raw material. The second group of habitats comprises the communities of the Trifolio-Geranietea sanguinei and Festuco-Brometea classes, Molinietalia and Festuco-Sedetalia ord,ers, and Cynosurion cristati association. The habitats differ by the content of soil nutrient (N, P, K, humus) and acidity. On the basis of cluster analysis, the similarity of habitats basing on soil chemistry was defined. H. perforatum demonstrates a significant ecological plasticity.

Keywords: Hypericum perforatum, habitats, anthropogenic communities, cluster analysis.

The research data on biological productivity and state of the perennial naturalised sown meadow (11 and 12 years old) communities on different parts of the hill slope are presented in the paper. The results were obtained in Sėliškės Experimental Field Station (Utena region) in 1998 and 1999.

Keywords: naturalised meadow, communities, biological productivity, hilly relief, Lithuania.

Aiming to ascertain species diversity of macrophytes in the lakes of urbanised landscape, in 1998 the inventory of species in 15 lakes of Vilnius city was carried out. Species diversity of macrophytes, dominating communities, and overgrowth type of each lake are presented.

Keywords: lake macrophytes, communities, species, urbanistic landscape, Vilnius city.

Phytotoxicity tests were performed on the following higher plants: great duckweed (Spirodela polyrhiza (L) Schleid.), garden cress (Lepidium sativum L.), and spiderwort (Tradescantia). Toxic and genotoxic effects of water and foam of the Ignalina NPP heated water canal that are characterised by high concentration of various contaminates, including heavy metals, were investigated applying the model mixtures prepared basing on the concentrations of heavy metals found in the water of heated canal in 1996. It was established that the stamen-hair system of spiderwort was the most sensitive to model and natural mixtures of heavy metals. The great duckweed was less sensitive to the impact of mixtures of heavy metals, and garden cress was the least sensitive of the tested plants. Investigation of the phytotoxicity of model and natural mixtures of heavy metals showed that spiderwort, great duckweed, and garden cress are sufficiently sensitive and useful as a complex of test-organisms. This complex indicates the level of the phytotoxicity of the investigated water samples, and moreover, it allows to clarify the physiological a1d genetic aspects of the effects induced by heavy metals.

Keywords: phytotoxicity, heavy metals, Tradescantia, Spirodela polyrhiza, Lepidium sativum.

The paper deals with historical and new data about a highly specialised ectoparasitic fungi on insects of the order Laboulbeniales from Lithuania. Sixteen species parasitising Coleoptera, including fungi species reported earlier, are described and their illustrations are presented. Taxonomical position of some of these species is discussed. Nine species were collected for the first time and are described as new for Lithuania: Laboulbenia argutoris C?péde et Picard, L. calathi Majewski, L. ophoni Thaxter, L. pedicellata Thaxter, L. phiilonthi Thaxter, L. murmanica Huld?n, L. thaxteri C?péde et Picard, Aphanandro-myces audisioi W. Rossi, Botryandromyces heteroceri (Maire) I. Tavares et Majewski. Data on Laboulbeniales distribution, their hosts, and ecological data on the recorded species is presented.

Keywords: fungi, Ascomycotina, Laboulbeniales, distribution, ecology, insects, Lithuania.

The paper presents the data of investigations carried out in 1995–1999 on the selected strains of micromycetes and other organisms and their application in accelerating the utilisation processes of different materials. The aim of investigation was to isolate microorganisms from natural environmental substrata contaminated with various pollutants, to identify them, to determine their destructive properties, and to establish the most favorable conditions for destructive processes of organic materials. Regulation of the activity of microorganisms, the application of the micromycetes selected basing on the specific criteria, and suggestions concerning optimum conditions for their functioning may accelerate the utilisation of organic and other materials, and thus to obtain useful products.

Keywords: microorganisms, fungi, waste materials, degradation, utilisation.

30 species of the genus Diplodia, 12 of Microdiplodia, and 6 of Sphaeropsis are briefly described. The figures of conidia are presented. 29 species are reported as new to the mycoflora of Lithuania.

Keywords: Coelomycetes, Diplodia, Microdiplodia, Sphaeropsis, teleomorph, host plants, distribution. Lithuania.