Nitzschia austriaca Hustedt: a characteristic diatom of Hungarian inland saline waters including a morphological comparison with the type material

A detailed scanning electron microscopic investigation was carried out to clarify the taxonomic status of a small sigmoid Nitzschia species, a potential indicator of Central European soda waters. We found this taxon to be one of the dominant epiphytic diatoms collected from sodic bomb crater ponds at Apaj (Hungary). The large population allowed for a morphometric comparison based on frustule ultrastructure with the type material of the most similar species, Nitzschia austriaca Hustedt that was originally described from a soda pan in the region. The results clearly demonstrated an overlap between the Apaj population and the type material of N. austriaca (based on NMDS analysis), therefore we argue that they represent the same taxon. An emended diagnosis of N. austriaca is given. Total suspended solids and total phosphorous proved to be the most important factors predicting the occurrence of the species, with possible interactive effects of conductivity and pH. We then expanded the distribution of the species by revisiting data originating from previous large-scale surveys targeting sodic habitats in Hungary. On the basis of our results, N. austriaca is a characteristic species for Central European soda waters, including the protected astatic soda pans, indicating their typical chemical and physical characteristics.</jats:p

Interesting diatoms from a special habitat

The epiphytic diatoms of the soda ponds of bomb craters were sampled in 2014. The small ponds (area: 7.1-86.5 m2, depth: 4 to 60 cm) are located in the northern part of the Kiskunság National Park (47°7.403 'N, 19°8.187'E), near the village of Apaj in Hungary. Their salinity ranges from fresh water to moderately saline levels (conductivity of 1.3 to 7.1 mS cm-1). This area has patchy surface salinization, because the flow pattern of groundwater results extensive surface salinization in those discharge areas where the infiltrating freshwater does not superimpose the upwelling saline water. The salts origin from the overpressured NaCl-type water of the Pre-Neogene basement and the NaHCO3-type water of the Neogene sediments. The ponds can be characterized by different areal extent, depth and salinity, various conductivity, hydroperiod (1–9 months, the deepest ones do not dry out in years with high amount of precipitation due to probably more or less continuous supply by groundwater), plant coverage and width of macrophyte belt. All of the ponds were sampled except for the ones with very short (shorter than one month) hydroperiod. A total of 80 diatom taxa, representing 33 genera, were identified in these ponds. The genus Nitzschia was represented by the largest number of species (16), followed by the genus Gomphonema with 9 taxa. IndVal analysis identified 15 species with significant indicator values for ponds. Some interesting, rare or new diatoms for Hungarian flora have also been recorded, including Gomphonema jadwigiae, Halamphora dominici, Navicula wiesneri, Nitzschia austriaca, N. vitrea, Surirella peisonis

Viszket a hátam

Az élet dolgaiban nagyon sokszor gondoljuk úgy, hogy pontosan tudjuk, mi a probléma, hol és mit kell csinálni, és hogyan kell azt megoldani. Ugyanakkor mégis gyakran tapasztaljuk, hogy ismétlődően újra és újra ugyanazok a problémák merülnek fel. Lehet, hogy a tudásunk mégsem áll olyan biztos alapokon

Dharma-beszéd a súnjatáról

Ez a szertartásos zen Dharma-beszéd a súnjatá fogalmáról szól. Arról a tanításról, ami a buddhizmus alaptanításának a három legfontosabbja közül a harmadik. A súnjatá szó jelentése az, hogy üresség. A fogalom gyakran hangzik el a zen szövegekben is, így a Szív-szútra szövegében is. A súnjatá tanítás a buddhizmus egyik igen alapvető felismerése, mely az emberi tudat szerepét foglalja egybe. A fogalom a matematikában is használatos, és kiváló példa arra, hogy a vallás hogyan termékenyíti meg a tudományt

Vízió

„A mai modern élethelyzetünkben a minket körülvevő világot nem elfogadni kell és nemcsak alkalmazkodni kell hozzá, de azt kellene tudatosítanunk, hogy mi magunk, az emberi tevékenységünkkel hoztuk létre, tartjuk fenn, és látnunk kellene azt is, hogy a mi kezünkben van az, hogy hogyan építjük ezt a világot a továbbiakban.