Distribution of two invasive alien diatom species Achnanthidium delmontii and Achnanthidium druartii in Slovenia | Razširjenost dveh invazivnih tujerodnih vrst diatomej Achnanthidium delmontii in Achnanthidium druartii na območju Slovenije

Inglés. The distribution of two invasive diatom species in Slovenia, Achnanthidium delmontii (ADMO) and Achnanthidium druartii (ADRU), was investigated in this study. Data from 87 rivers and 11 lakes collected between years 2019 and 2024 in the frame of national monitoring of ecological status of surface waters were included. ADMO was present in 46% of the rivers and was dominant (>5% relative abundance) in 27 rivers (31%), with the highest abundance reaching 77% in the Bolska River. It was rare in lakes, detected in only three lakes. ADRU was detected in 14% of the rivers and was dominant in four rivers, with the highest abundance reaching 27% in the Drava River. In contrast, ADRU was common in lakes (73%), dominating in the Lake Slivniško Jezero and the Lake Perniško jezero. ADMO presence was associated with reduced diatom species richness and evenness, although no direct ecological impact was observed. ADMO was present mainly in upper river sections, while ADRU was more frequent in lowland river sections, lakes and reservoirs. The results of this study confirmed the invasive character of ADMO, whereas ADRU did not affect species richness and evenness of the diatom assemblages, and thus its invasive character could not be confirmed.

Esloveno. V raziskavi smo proučevali razširjenost dveh invazivnih vrst diatomej v Sloveniji, Achnanthidium delmontii (ADMO) in Achnanthidium druartii (ADRU). V raziskavo smo vključili podatke iz 87 rek in 11 jezer zbranih med letoma 2019 in 2024 v okviru nacionalnega monitoringa ekološkega stanja površinskih voda. ADMO je bil prisoten v 46 % rek, dominantna vrsta (>5 % relativne abundance) je bil v 27 rekah (31 %), pri čemer je s 77 % v reki Bolski dosegel najvišjo zastopanost. ADMO je bil v jezerih redek, zaznan je bil le v treh jezerih. ADRU je bil prisoten v 14 % rek, dominantna vrsta je bil v štirih rekah, z največjo zastopanostjo 27 % v reki Dravi. V jezerih je bil ADRU pogost (73 %), prevladoval je v Slivniškem in Perniškem jezeru. Prisotnost ADMO je bila povezana z zmanjšano vrstno pestrostjo in enakomernostjo združb diatomej, čeprav neposrednega negativnega vpliva na okolje nismo zaznali. ADMO se je večinoma pojavljal v povirnih delih rek, medtem ko je bil ADRU pogostejši v nižinskih delih rek, jezerih in akumulacijah. Rezultati potrjujejo invazivni značaj ADMO, medtem ko invazivnost ADRU ni bila potrjena, saj njegova prisotnost ni pomembno vplivala na sestavo združb diatomej.