Popiela et al. (2015) Acta Botanica Gallica

Popiela A., Łysko A., Molnár V.A., Kącki Z., Lukács B. A.(2015): Elatine triandra Schkuhr (Elatinaceae) in Europe, with special emphasis on the central part of thecontinent. – Acta Botanica Gallica – Botany Letters 162 DOI:10.1080/12538078

Abstract

Elatine trianda Schkuhr is the most widespread species within the genus Elatine L.; it can be found in all continents, except Antarctica, but the majority of the locations have been recorded in Europe. The study is based on an extensive dataset of literature, herbaria and web data, which spans the period 1828–2012. The range of the species in Europe is disjunctive; it covers the southern and western parts of the Central European Plain and the northern shores of the Baltic Sea, it can also be found along some river valleys. In Central Europe many localities especially isolated ones in northern part of the range are historical now. According to the dataset we determined that E. triandra can be observed between May and October. We also found a remarkable historical decrease of observation time. We found that species observation has a near significant shift since 1828 that correlates to changes in environmental variables. Depending on the environmental conditions individuals of the taxon could develop in two forms: terrestrial and aquatic. The aquatic form is characterized by twice longer stems and internodes, and also almost twice longer lamina and petiola. E. triandra seeds show consistent characteristics both in terms of forms and populations. Our studies show that the best diagnostic feature, in addition to the construction of flowers, are size, shape and surface structure of seeds. In Central Europe E. triandra occurs exlusively in communities classified to the Isoëto-Nano-Juncetea, however the number of species characteristic for the class and lower syntax in patches decreases from north to south of the continent.

Keywords

chorology, ephemerophyte, Isoëto-Nano-Juncetea, phytogeography, vegetation, morphology, maps, phenology

Popiela et al. (2013) Acta Botanica Croatica

Popiela A., Lysko A., Molnár V. A. (2013): Recent distribution of the Euro-Siberian-sub-Mediterranean species Elatine alsinastrum L. (Elatinaceae). – Acta Botanica Croatica 72(2) DOI: 10.2478/v10184-012-0022-8


Abstract
The general distribution of the endangered Euro-Siberian sub-Mediterranean species Elatine alsinastrum L. is provided using literature, web-sources and herbaria dataset. The distribution pattern shows some regularities: occurrence of locations along river valleys, formation of concentrated site clusters in some lowlands, wide distances between locations or site clusters or single locations between their clusters. The distribution patterns in central Europe seem to be rather well related to the history of the human migration in Europe at least since the Late Holocene. The scattered locations on the eastern part of the distribution area are likely to be a consequence of missing information, rather than to the fragmentation of its distribution.


Keywords
Elatine alsinastrum, ephemerophyte, distribution

Takács A. et al. (2013) Preslia

Takács A., Schmotzer A., Jakab G., Deli T., Mesterházy A., Király G., Lukács B. A., Balázs B., Perić R., Eliáš P. jun., Sramkó G., Tökölyi J. & Molnár V. A. (2013): Key environmental variables affecting the distribution of Elatine hungarica in the Pannonian Basin. – Preslia 85: 193–207.


Abstract
Elatine hungarica Moesz is a small wetland ephemerophyte that occurs and is classified as extinct, data deficient or a very rare and endangered taxon in most countries in eastern and central Europe. Based on literature and herbarium data, supplemented by 160 field records collected between 1998 and 2011, we present the currently known distribution of this species in the Pannonian Basin, which mostly but not exclusively includes Hungary. Within the Pannonian Basin this species is distributed throughout Hungary, with sporadic occurrences in Romania, Serbia and Slovakia. The temporal distribution of floristic records is very uneven. This species was recorded only in 27 years during the last 213 years (1798–2011). When examining presence/absence data for most of the 20th century, we found a significant correlation between the number of records of this species in a given year and two key, but not independent, environmental variables: rainfall and the extent of the area inundated in the same year. In the more intensively documented period between 1998 and 2010, there is only a significant correlation between the numbers of records of this species and the extent of flooding, which is because there is a delay in the effect of an increase in rainfall. The peak occurrence of records in the 1940s and 1950s is associated with extensive rice production in Hungary. Today, most records are for agricultural fields that are subject to flooding and becoming temporary wetlands. The comparison of recent and past distributions of E. hungarica reveals a consistent and marked regional difference; whereas this species is not rare along the Tisza river and its tributaries, it is markedly scattered in similar habitats near the Danube.


Keywords
ephemerophyte, flooding, Hungary, inland water, Isoëto-Nanojuncetea, Elatinaceae, mapping, rainfall, rice weeds, Romania, Serbia, Slovakia, temporary ponds