THE LONGITUDINAL IMPACT OF MULTIPLE STRESSORS ON THE BENTHIC INVERTEBRATE COMMUNITY IN THE BEDNJA RIVER

doctoral thesis

• Title (english): UTJECAJ VIŠESTRUKIH STRESORA NA ZAJEDNICU MAKROZOOBENTOSA DUŽ TOKA RIJEKE BEDNJE
• Author: Iva Vidaković Maoduš
• Mentor: Zlatko Mihaljević (mentor)
• Committee member: Marko Miliša (predsjednik povjerenstva)
• Committee member: Ivan Čanjevac (član povjerenstva)
• Committee member: Vlatka Mičetić Stanković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2022-09-25, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology
• Universal decimal classification (UDC): 57 - Biological sciences. Physical anthropology. Biodiversity

Abstract

The impact of water quality, landuse, hydromorphology on benthic macroinvertebrate
assemblages of the Bednja River was studied. 20 longitudinally distributed study sites
were sampled using the AQEM multihabitat sampling method resulting in the collection
and identification of 193,638 benthic macroinvertebrate individuals belonging to 259
taxa. Diversity and assemblage composition greatly varied between the study sites and
microhabitats. There was no grouping of communities based on river type. . Two separate
assessment systems for hydromorphological modification were tested on the same river
reach. RHS scores explained more variation in assemblages than EN 15843:2010 scores.
The two assessment systems gave differing results regarding the extent of
hydromorphological modification, but never the less had highly correlated subscores.
Several water quality and nutrient parameters followed a longitudinal gradient but
hydromorphological modification did not, showing that degradation is present along the
entire course of the river. Benthic invertebrate diversity and functional metrics generally
poorly correlated with hydromorphological modification scores. Assemblages on
technolithal differed from but those on natural lithal substrate. The high diversity
supported by technolithal is explained by the presence of periphyton. The correlation of
hydromorphological modification with predators is due to Hydrachnidia which are
associated with technolithal. The response gradient shows an improvement in Ecological
Status with increased HQA scores.

Abstract (english)

Istražen je utjecaj kakvoće voda, korištenja zemljišta i hidromorfologije na zajednicu
makrozoobentosa rijeke Bednje. Uzorkovano je 20 longitudinalno raspoređenih postaja
korištenjem AQEM “multihabitat” metode čime je sakupljeno i identificirano 193,638
jedinki i 259 svojti makrozoobentosa. Raznolikost i sastav zajednice uvelike se
razlikovala između postaja i mikrostaništa. Bray Curtis indeks sličnosti nije grupirao
zajednice prema dvaju riječna tipa rijeke Bednje. Dvije različite metode za ocjenu
hidromorfološkog stanja primijenjene su na istim riječnim odsječcima. RHS ocjene su
objasnile više varijacije u zajednicama od EN 15843:2010 ocjena. Iako su dvije metode
ishodile različite rezultate vezano za stupanj hidromorfološke degradacije, njihove ocjene
svejedno visoko međusobno koreliraju. Više parametra kakvoće voda i hranjivih tvari
pratilo je longitudinalni gradijent što se nije pokazalo i kod hidromorfološke degradacije
koja je prisutna duž toka cijele rijeke. Raznolikost i funkcionalne metrike su uglavnom
loše korelirale sa hidromorfološkim stanjem. Zajednice tehnolitala razlikovale su se od
zajednica prirodnog litala. Visoka raznolikost koju podržava tehnolital obrazložena je
prisutnošću perifitona. Korelacija hidromorfološke degradacije sa predatorima jer radi
skupine Hydrachnidia koja je povezana s tehnolitalom. Gradijent promjena ukazuje na
poboljšanje ekološkog stanja s povećanjem HQA ocjena.

• Keywords: Bednja River / hydromorphology / water quality / landuse / benthic macrozoobenthos
• Keywords (english): rijeka Bednja / hidromorfologija / kakvoća vode / korištenje zemljišta / makrozoobentos
• Language: english
• URN:NBN: urn:nbn:hr:217:380670
• Promotion: 2022
• Study programme: Title: Biology; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje biologija (doktor/doktorica znanosti, područje prirodnih znanosti, polje biologija)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-11-17 11:39:39