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Diatom flora of an Australian river system:spatial patterns and environmental relationships
Author(s) -
CHESSMAN BRUCE C.
Publication year - 1986
Publication title -
freshwater biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 156
eISSN - 1365-2427
pISSN - 0046-5070
DOI - 10.1111/j.1365-2427.1986.tb01018.x
Subject(s) - diatom , species richness , nitzschia , ecology , navicula , streams , drainage basin , turbidity , environmental science , nutrient , biology , geography , phytoplankton , computer network , cartography , computer science
SUMMARY. 1. Qualitative diatom samples from various microhabitatswere collected at fifty‐three sites on the La Trobe River. Victoria, and itstributaries in late summer and early autumn. Measurements of severalphysico‐chemical variables of likely significance to diatom distributionwere also made. 2. Principal components analysis of the physico‐chemical data showedthat the dominant environmental pattern in the river system was agradient from cool, dilute upland streams to warmer, more turbid andenriched lowland waters. 3. A total of 267 diatom species was recorded; most were cosmopolitan and Navicula and Nitzschia were the dominant genera. Clusteranalysis allowed the sampling sites to be divided into six groups on the basis of their floras. These groupings corresponded closely to flow. landuse and wastewater discharge patterns and there were clearphysico‐chemical differences between the groups. Multiple discriminant analysisfound thataltitude. temperature. biochemical oxygen demand. turbidity, non‐filterable residue, pH. major ions, phosphorus and nitrogenwere important factors in distinguishing between site groups. 4. Diatom species richness was lowest in relatively undisturbed, forested upland streams, probably as a result of nutrient limitation. Forthe catchment as a whole significantcorrelations were establishedbetween species richness and altitude, temperature, biochemical oxygendemand, turbidity. non‐filterable residue, conductivity, calcium, alkalinity, organic nitrogen and phosphorus.