НОВЫЕ МЕСТОНАХОЖДЕНИЯ РЕДКИХ И ОХРАНЯЕМЫХ ВИДОВ СОСУДИСТЫХ РАСТЕНИЙ В ЛЕНИНГРАДСКОЙ ОБЛАСТИ И САНКТ-ПЕТЕРБУРГЕ, "Ботанический журнал"

Приведены новые сведения о местонахождениях 31 редкого вида сосудистых растений, обнаруженных автором на территории Ленинградской обл. и Санкт-Петербурга в 2002-2017 гг. Большинство видов является редкими для Северо-Запада России, из них 5 (Alisma wahlenbergii, Dacty- lorhiza baltica, Isoites echinospora, Littorella uniflora, Myrica gale) занесены в Красную книгу Российской Федерации, 25 - в Красную книгу Ленинградской области и 3 вида (Alisma wahlenbergii, Caulinia tenuissima, Isoetes echinospora) - в Красную книгу Санкт-Петербурга. Cochlearia danica, Crambe maritima, Crepis czerepanovii, Lemna turionifera известны на Северо-Западе России из единичных местонахождений. Особого внимания заслуживают новые находки редких в регионе видов - Euphorbia palustris, Myosotis ramosissima, Ruppia brachypus, Viola persicifolia. Кроме того, для охраняемых видов Littorella uniflora и Luzula campestris подтверждены местонахождения, ранее известные только по старым указаниям. Приведены данные о распространении видов, численности и динамике их локальных популяций. Большая часть находок сделана в границах существующих и проектируемых особо охраняемых природных территорий (ООПТ) Ленинградской обл. и Санкт- Петербурга.

Littorella Uniflora (L.) Ascherson: A Review

Littorella uniflora (L.) Ascherson, a member of Plantaginaceae family, belongs to a group of isoetids - small, slow-growing, evergreen aquatic plants. They are characterized by strong and stiff basal leaves and a large amount of root biomass. Oligotrophic and mesotrophic freshwaters are typical habitats for this plant. L. uniflora is a boreal subatlantic European species. It is spread over whole western and northern Europe including the United Kingdom and Ireland. Austria, Czech Republic, and Poland lie on the southeast border of L. uniflora distribution. In the Czech Republic, as well as in the Netherlands or Ireland, the number of suitable habitats is rapidly decreasing. Therefore it is important to understand the needs of this macrophyte in order to propose quality rescue management to restore its population. This paper gives brief information about biology and ecological adaptations of L. uniflora. It also focuses on threats, distribution, and management at some of its current localities in the Czech Republic.

Iridoid glucosides in Littorella uniflora (L.) Ascherson

In <em>Littorella uniflora</em> two iridoid glucosides already known from the <em>Plantaginaceae</em> family are present: aucuboside and catalpol. The present and an earlier study of sugars and sucrose alcohols indicate a biochemical relationships of <em>Littorella</em> to <em>Plantago</em>.

Biomass allocation to anchoring structures in the aquatic macrophytes from the subcontinental and Atlantic climates in Europe

Biomass allocation to anchoring structures in 10 species of aquatic macrophytes in two types of the cool and humid temperate climate in Europe, subcontionental (NW Poland) and Atlantic (W France), was examined. The study focused on the weight of anchoring organs in <em>Chara delicatula</em> Ag., <em>Ch. fragilis</em> Desv., <em>Juncus bulbosus</em> L., <em>Littorella uniflora</em> (L.) Asch., <em>Luronium natans</em> (L.) Raf., <em>Potamogeton pectinatus</em> L., <em>P. perfoliatus </em>L., <em>P. natans</em> L. and <em>Ranunculus fluitans</em> (Lam.) Wimm., as well as submerged structures in <em>Hydrocharis morsus-ranae</em> L. The plants were collected from 10 geographically distant lakes and 2 rivers with a current velocity of 0.3-0.5 m s^-1. It was assumed that biomass allocation to anchoring structures in rooting macrophytes depends on the time that mechanical forces, which can remove the plants from the occupied area, exert their effect. It was found that, in the Atlantic and subcontinental climates, the ratio between the biomass of underground (or submerged) and above-ground structures (U/A index), calculated for the ramets of <em>Chara fragilis</em>, <em>Hydrocharis morsus-ranae</em> and <em>Ranunculus fluitans</em>, has similar values (p&gt;0.05). Nevertheless, among seven species of <em>Cormophyta</em>, which were anchored in the lake or pond littoral, six (<em>Juncus bulbosus</em>, <em>Littorella uniflora</em>, <em>Luronium natans</em>, <em>Potamogeton pectinatus</em>, <em>P. perfoliatus</em> and <em>P. natans</em>) had higher values of the U/A index in the Atlantic climate than in the subcontinental type (p &lt; 0.05). This can be explained by the lack of ice cover and, consequently, a longer time of wave action than in the subcontinental climate.

Habitat differentiation of the Myriophyllum altemiflorum and Littorella uniflora phytocoenoses in Poland

The present study showed the ecological differentiation of phytocoenoses dominated either by <em>Myriophyllum alterniflorum</em> or by <em>Littorella uniflora</em>, which in Poland are classified within the Myriophylletum alterniflori or Myriophyllo-Littorelletum association. The properties which best differentiated the waters of the above types of phytocoenoses were calcium and factors associated with the carbonate complex (pH, electrolytic conductivity, total and carbonate hardness), and pH in the case of substrates. The most distinct differences in the habitats were found between the phytocoenoses dominated by <em>L. uniflora </em>from the Pomeranian <em>Lobelia </em>lakes and those dominated by <em>M. alterniflorum </em>from the Łęczna-Włodawa Lake District, in which other species from the Littorelletea uniflorae class were absent. The <em>L. uniflora </em>phytocoenoses are associated with soft waters poor in Ca²⁺ and with the lowest values of pH, electrolytic conductivity, dissolved organic matter (COD-KMnO₄) and dissolved SiO₂. The substrates they inhabit are mineral and more acidic. By contrast, the values of the above-mentioned properties are considerably higher in the case of the phytocoenoses from the Łęczna-Włodawa Lake District. The habitats of the <em>M. alterniflorum </em>phytocoenoses from the Pomeranian <em>Lobelia </em>lakes occupy an intermediate position and are more similar to those of <em>M. alterniflorum </em>from the Łęczna-Włodawa Lake District. The results obtained in this study suggest that the phytocoenoses of <em>L. uniflora </em>and <em>M. alterniflorum </em>should not be included in the same association. Further studies are, therefore, necessary to resolve this problem. The comparative analysis of the present ecological findings and data obtained from other regions of Europe show that in Poland the phytocoenoses dominated either by <em>L. uniflora </em>or by <em>M. alterniflorum</em>, in which the contribution of Littorelletea uniflorae species is appreciable, are clearly associated with soft waters and their habitats are representative of the Littorelletea uniflorae class. The massive development of the phytocoenoses with both <em>L. uniflora </em>and <em>M. alterniflorum </em>in the <em>Lobelia </em>lakes is not always indicative of the increase in water hardness and euthrophication of waters typical of the communities of the Littorelletea uniflorae class. The <em>M. alterniflorum </em>dominated phytocoenoses without other Littorelletea species could be good indicators of the above processes taking place in such water ecosystems.