Botanica Lithuanica, Volume 5, Number 4

1999 m.

Growth and development of eight cultivars, two varieties, and 18 morphotypes of lingonberry (Vaccinium vitis-idaea L.) were studied in the field collection at the Institute of Botany in 1993–1997. The soil type made the most visible impact on growth and fruiting comparing with other factors conditioning growth. Plants cultivated on an acid peat soil exhibited better development than those cultivated on a sandy loam soil. Simultaneously some genetically caused growth difference were observed in different loganberry accession grown under identical condiction. All cultivars produced two harvests – summer and autumn, while among, the morphotypes only six produced a secondary (autumn) harvest.

Keywords: lingonberry, cultivar, morphotype, accession, field collection, cultivation, growth, fruiting.

This paper continued publication of the conspectus of alien plant species recorded in Lithuania. The Amaranthaceae family in Lithuania contains 9 alien plant species, the Polyginaceae family – 13 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. Nine here described alien plant species are naturalized and 13 are casuals. Distribution of seven species is mapped. Three species (Amaranthus caudatus, Aconogonon alpinum, and Rumex palustris) are excluded from the list of alien plant species.

Keywords: alien plant species, conspectus, Amaranthaceae, Polyginaceae, distribution, naturalization, reproduction, Lithuania.

Data on dynamics of biological productivity (aboveground ant underground phytomass (t/ha dry-weight substance of the 1st harvest) of natural and cultural grassland in hilly agrolandscape ecosystems, i.e. slopes, cultivated low type peat-bogs between hills, and river slopes was presented. Biological productivity of grasslands makes 28–51, of cultural 22–36 t/ha. The stability of grasslands productivity depends on of the composition of species, fertility of the soil, and particularly on water regime. The development of aboveground ant underground parts of plants in the studied phytocenoses plays a more or less important anti-erosive role. Cultural grasslands (28 years or order) provide a reserve for natural vegetative renewal through a process of re-naturalization and stabilization of agrolandscape ecosystems.

Keywords: natural grasslands, cultural grasslands, productivity, ecosystems, Lithuania.

Process of 14CO2 assimilation and organic matter transformation in the community of planctonic organisms (chain algae–bacteria) in the littoral zone of mezotrophic Lake Gulbinas (group of lakes Žalieji ežerai in Vilnius district) were investigated in summer of 1998. It was estimated that in the beginning of summer, when the representatives of Bacillariophyceae and Chrysophyceae classes dominated by their abundance and biomass, the excretion of organic carbon from algae was more intensive comparing with late summer when Chrysophyceae and Chlorophyceae algae dominated by their abundance, and Bacillariophyceae class algae – by their biomass. In the beginning of summer the cenoses of bacteria utilised ten times more than organic carbon for their biomass synthesis than bacteria in late summer. Major amount of assimilated organic carbon (90 %) was used by heterotrophic bacteria as a source of energy irrespective of the investigation period.

Keywords: planktonic algae, bacteria, 14CO2 assimilation, organic carbon excretion, trophic relation, freshwater ecosystem.

The speed of radial colonial growth of seven fungi strains (96-1, 98-1 – Septoria convolvuli Desm., 97-1 – Mycovellosiella convolvuli (Tracy et Earle) U. Braun, 97-2, 98-2 – S. polygonorum Desm., 98-3 – Ramularia inaquale (Preuss) U. Braun and 98-4 – Ascochyta chenopodii (P. Karst) Died.) on different solid media (malt extract agar (MEA), potato dextrose agar (PDA), Czapes dox agar (CDA), and natural agar (NA) and the influence of microelements on growth of fungal biomass in liquid media were investigated. Pathogenic fungi, growing and sporulating on artificial media, after the investigation on their specialization and effect on host plants could be used for the mycoherbicidic weed biocontrol. The project was financially supported by the Lithuanian State Science and Studies Foundation.

Keywords: phytotrophic fungi, intensivy of growth, fungal biomass.

Twenty species of lichens and seven species of lichenicolous fungi are reported ass new to Lithuania: Abrothallus bertianus, Acrocordia cavata, Arthonia didyma, Biatora ocelliformis, Cladonia norvegica, Corticifraga peltigerae, Fellhanera vezdae, Fuscidea arboricola, Haematomma ochroleucum, Hypocenomyce sorophora, Lecania suavis, Lepraria jackii, Licenochora obscuroides, Lichenoconium pyxidatae, L. usneae, Pertusaria pupillaris, Phaeophyscia chloantha, P. endophoeniceae, Porina chlorotica, Psilolechia clavulifera, Pyrenula laevigata, Sarcosagium campestre, Stenocybe pullatula, Tremella cladoniae, T. phaeophysciae, Verrucaria bryoctona, Vezdaea aestivalis.

Keywords: lichens, lichenicolous fungi, Lithuania.

Seven lichens species from Lithuanian are presented: six species are new for the country: Anaptychia runcinata, Arthonia byssacea, Bacidia fraxinea, Lepraria eburnea, Leproloma vouauxii, and Pachyphiale fagicola. One species – Peltigera horizontalis is re-found after more than 60 years in Lithuania.

Keywords: lichens, Lithuania.

For a long time only one locality of Isopyrum thalictroides in Lithuania was known (Kamša Botanical-Zoological Reserve, Kaunas district). In 1998 the species was found near Lyduvėnai, Raseiniai district. Distribution and habitat conditions of Isopyrum thalictroides are presented.

Keywords: Isopyrum thalictroides, distribution, habitat conditions, new locality, Lithuania.

Life and scientific activity of the famous Lithuanian botanist Algirdas Lekavičius (1921–1999) is described. His work in fields of floristics, phytogeography, applied botany, and protection of botanical diversity are analysed. List of publications by A. Lekavičius is presented.

Keywords: Lekavičius, botany, floristics, biography, biobliography, Lithuania.