Land-use influence on stream water quality and diatom communities in Victoria, Australia: a response to secondary salinization

摘要: Diatom communities were analyzed in 39 streams located drainages with varied land-use practices throughout Victoria, Australia. Thirteen water quality parameters also measured each stream. Most had low HCO3 1− concentrations (low buffering capacity) >90% of the waters dominated by Na1+ and Cl1−. Phosphate ranged from 0.003 to 2.0 mg/L. (245 taxa) strongly correlated practices, i.e. historic clear cutting, secondary salinization. Streams influenced heavy irrigation dryland farming reduced species diversity richness compared systems moderate land use. A nonmetric multidimensional ordination diatom was conducted. An ANOSIM on showed that upland watersheds native forest canopies salinization, lowland cleared canopies, agricultural utilization areas high salinization all significantly different (p<0.001) one another. Community techniques both specific conductance (salinity) phosphorus interacted determine stream community structure Drainages activity nutrients, but a wide range salinities strong associations taxa Amphora coffeaeformis, Cymbella pusilla Entomoneis paludosa, whereas, regions Bacillaria paradoxa, Nitzschia hungarica, N. frustulum Aulacoseira granulata as numerically important diatoms. In contrast, Rhizosolenia eriensis, Frustulia rhomboides, Eunotia pectinatus Tabellaria flocculosa associated fast current, relatively O-PO4 3− concentrations, pH, salinity, temperature. general, saline (≥3 mS) similar those previously reported lakes Victoria.