Adatok a Duna Komárom-Esztergom és Fejér megyei szakaszainak flórájához

A cikk elsősorban a Duna árterének vízi és iszapnövényzetével foglalkozik. Az adatok többnyire a 2019-es, tartósan alacsony vízállás mellett végzett felmérések eredményeit tükrözik. A Komárom-Esztergom megyei szakasz iszapnövényzete viszonylag jól kutatottnak számít, míg a Fejér megyei korábban alig volt ismert. A vizinövények közül a Gönyű és Neszmély közötti szakaszról korábban ismert, egyébként is ritka Hippuris vulgaris és Hydrocharis morsus-ranae nem került elő. Megjelent viszont több veszélyes özönnövény, így a Salvinia molesta, Myriophyllum aquaticum, Limnobium laevigatum, valamint a Crassula helmsii, melynek ez az első hazai adata. Hosszú évtizedek után ismét előkerült a Vallisneria spiralis, jelen van az Elodea canadensis, illetve egyre elterjedtebb az Elodea nuttallii és az Azolla taxonok. Az iszapnövényzetben új fajként jelent meg, sőt meglehetősen elterjedt lett a Lindernia procumbens és az adventív Lindernia dubia. Özönnövények közül megjelent a Cyperus esculentus, az Euphorbia maculata és az Eleusine indica. A korábban ismerthez képest jóval elterjedtebb lett a Veronica catenata és a Schoenoplectus triqueter, valamint nagyobb állományai vannak a Cyperus glomeratus-nak. A nyílt kavicsos felszínek érdekes növénye a több lelőhelyen is megtalált Polygonum graminifolium, melynek egészen a közelmúltig nem voltak aktuális hazai adatai.

Accumulation of heavy metals in aquatic vegetation of the Barguzin River

This study is devoted to the analysis of the distribution of heavy metals in the aquatic system of the Barguzin River. This is one of the largest rivers of the Baikal lake system. The element composition of the aerial scion of Potamogeton pectinatus L. (syn. Stukenia pectinata (L.) Borner), Potamogeton perfoliatus L., Hippuris vulgaris L. and Nymphoides peltata (S.G. Gmelin) O. Kuntze of the Barguzin River is studied in this research. One of the main results of the study is the establishment of the following sequence of the accumulation of metals in aquatic plants: Mn > Fe > Сu (Zn) > Сr > Ni > Сo > Pb > Cd > Hg. Hippuris vulgaris L. contains the highest concentration of the studied metals. Thus, this research provides one of the important steps for the development of regional environmental standards and environmental risk assessments.

РАРИТЕТНІ ВИДИ РОСЛИН У ФЛОРИСТИЧНОМУ СКЛАДІ БАЗАЛЬТОВИХ КАР’ЄРІВ ВОЛИНСЬКОГО ПОЛІССЯ

Industrial deposits of basalt are located in the northwestern part of Rivne region and confined to Rivne tectonic fault and Volyn trap cover. Close deposits of basalt to the surface is observed in the basin of the Goryn River (on the gap between the village of Zlazne and Basaltove (the tract of Janov Dolyna), the neighborhood of Berestovets, Velykyi Mydsk (near the village of Mutvytzia), near the village of Rudnya) in Kostopil district, also in the Styr River basin (the neighborhood of Polytzi and Ivanchi (Rafalivskyy Quarry) in Volodymyrets district). Materials from field floristic research conducted over 2017-2018 were used for analysis. The research included areas of existing and produced basalt quarries, as well as an adjacent area of direct influence of 10-50 m width. Species of flora were included in the structure of the rare phytocomponent, listed in the third edition of the Red Book of Ukraine (2009) and also species that are subject to protection at the regional level. All identified rare species of flora were analyzed by category of rarity within the entire territory of Rivne region (4 categories of species were identified: very rare, rare, limited distribution, endangered). According to the results of the research, 4 species of flora from the Red Book of Ukraine (2009) and 18 species are under Rivne region protection. Among the Red List species, stable populations form Epipactis helleborine and Utricularia minor. Dactylorhiza incarnata and Atocion lithuanicum are represented by isolated generative individuals in the studied territory. By category of rarity, limited distribution and endangered species are presented. The rarest species, Primula elatior was found, there are 4 rare species (Gagea pratensis, Aquilegia vulgaris, Rosa mediata, Melittis sarmatica). 9 species are endangered, most of them are typical for reserves: Batrachium circinatum and Hippuris vulgaris. 4 species belong to the group of limited distribution. Phytososological interest in Rivne region is the findings of such species as Pyrola media, Scabiosa columbiana and Chamaenerion dodonaei. The gradual regeneration of natural vegetation after the termination of direct anthropic influence helps to distribute rare phytocomponents. Most of the rare species have a limited distribution, a small number and are often spread in the areas with a lower cenotic competition.

Development of a subarctic peatland linked to slope dynamics at Lac Wiyâshâkimî (Nunavik, Canada)

A palaeoecological study of a subarctic minerotrophic peatland was undertaken to reconstruct the formation of the site as an archive of slope geomorphological processes. The study peatland is located about 400 m from Caribou slope (unofficial name) on Lepage Island, Lac Wiyâshâkimî, Nunavik (northern Québec, Canada). The site is close to the lakeshore and receives runoff directly from Caribou slope and its catchment. Gravity processes have been active on Caribou slope since the deglaciation of the region at approximately 6000 cal. yr BP. These processes may be differentiated in terms of Holocene stages of intensity. The objective of our study was to detect evidence of gravity processes in the peatland and to note their frequency since its establishment using loss-on-ignition testing, macrofossil analysis and radiocarbon dating. Our results indicate that peat began to accumulate over the sandy-gravelly sediments at around 4900 cal. yr BP. Larix Laricina, Carex aquatilis and Carex rostrata were present at this time until 4660 cal. yr BP, at which point these taxa were replaced by aquatic taxa such as Hippuris vulgaris and Daphnia (aquatic invertebrates). The percentage of mineral sediments (sand) remained high during this period, which could be linked to slope activity. After 4660 cal. yr BP, sandy sediments diminished while episodes of aquatic conditions and sand inflow occurred on at least three occasions (at 4660, 3905 and 3130 cal. yr BP). The increase in water flow and the introduction of more medium to fine sand into the peatland could be linked to slope movements and the long-distance runout of debris flow that we observed in the field. Given these factors, conditions at the study site remained wet from the earliest phases until the present. Unlike the subarctic permafrost peatlands in northern Québec, permafrost did not become established at the study site.