Raznolikost dijatomeja rijeke Krke

master's thesis

• Title (english): Diatoms of Krka river
• Author: Stefani Kukić
• Mentor: Marija Gligora Udovič (mentor)
• Mentor: Zlatko Levkov (mentor)
• Committee member: Marija Gligora Udovič (predsjednik povjerenstva)
• Committee member: Renata Matoničkin Kepčija (član povjerenstva)
• Committee member: Sofia Ana Blažević (član povjerenstva)
• Committee member: Marko Miliša (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2019-02-14, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Unatoč čestoj uporabi dijatomeja u procjeni ekološkog stanja kopnenih tekućica u Hrvatskoj, znanje glede raznolikosti, ekologije i strukture zajednica bentičkih dijatomeja još uvijek je oskudno. Ovo istraživanje baziralo se na raznolikosti, ekološkim preferencijama i strukturi zajednica slatkovodnih bentičkih dijatomeja, lentičkih i lotičkih staništa rijeke Krke. Svjetlosnom i skenirajućom elektronskom mikroskopijom analizirano je ukupno 44 uzoraka sakupljenih na različitim mikrostaništima. Determinirano je 276 svojti (vrsta, varijeteta i formi), svrstanih u 69 rodova. Florom bentičkih dijatomeja dominiraju rodovi Navicula Bory sensu stricto (učestalost 100 %) i Gomphonema Ehrenberg (93,2 %). Najučestalije zabilježene vrste su Navicula cryptotenella Lange-Bertalot, N. radiosa Kützing i Pantocsekiella ocellata (Pantocsek) K.T. Kiss & E. Ács. Svojte specifične za rijeku Krku opisane su na temelju morfometrije i morfoloških struktura valve. Priložen je sažeti morfološki opis najčešćih rodova dijatomeja zabilježenih u rijeci Krki. Priložene su i mikrofotografije svojti sa svjetlosnog i skenirajućeg elektronskog mikroskopa. Prema Crvenoj listi, 31,96 % analiziranih svojti procijenjene su ili kao (visoko) ugrožene, vrlo rijetke, rizične ili u regresiji. Prema ekološkim zahtjevima, najveći broj svojti rijeke Krke su alkalifilne, ß-mezosaprobne i eutrafentne s kontinuirano visokim zahtjevima za kisikom. Kako bi se analizirala razlika između zajednica dijatomeja prema različitim okolišnim čimbenicima, koristila se je nMDS metoda. Dijatomejske zajednice pokazale su snažnu specifičnost prema tipu staništa i tipu supstrata. Rezultati su pokazali utjecaj okolišnih uvjeta (temperatura, brzina strujanja vode) na raznolikost bentičkih dijatomeja.

Abstract (english)

Despite the frequent application of diatoms in assessing the ecological status of inland running waters in Croatia, knowledge concerning the diversity, ecology and community associations of benthic diatom flora is still scarce. In the present study, the diversity, ecological preferences and community structure of the freshwater benthic diatom flora from lentic and lotic habitats of river Krka were studied. In total, 44 samples were collected and examined using light and scanning electron microscopy. Altogether, 276 taxa (species, varieties and forms), from 69 genera were identified. Benthic diatom flora dominated by genera Navicula Bory sensu stricto (frequency 100 %) and Gomphonema Ehrenberg (93,2 %) were observed. The most frequent species were Navicula cryptotenella Lange-Bertalot, N. radiosa Kützing and Pantocsekiella ocellata (Pantocsek) K.T. Kiss & E. Ács. Taxa specific for river Krka are discussed in terms of morphometrics and valve morphological features. A brief morphological description of the most frequent genera of river Krka diatoms was given. LM and SEM microphotographs of species are provided. According to The Red List, 31,96 % of examined taxa were assessed as either (highly) endangered, extremely rare, at risk or in regression. According to their ecological requirements, most of the taxa of river Krka were alkaliphilous, ß-mezosaprobic and eutraphentic with continuosly high oxygen requirements. To examine differences between diatom assemblages based on different environmental factors, nMDS was performed. Diatom assemblages displayed strong both habitat and substrata specifities. The results also demonstrated effect of environmental conditions (temperature, current velocity) on diversity of benthic diatoms.

• Keywords: bentičke dijatomeje; rijeka Krka; struktura zajednice; ekološke preferencije; Crvena lista
• Keywords (english): benthic diatoms; river Krka; community structure; ecological preferences; Red List
• Language: croatian
• URN:NBN: urn:nbn:hr:217:833718
• Study programme: Title: Ecology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra ekologije i zaštite prirode (magistar/magistra ekologije i zaštite prirode)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-03-26 09:22:55