Ecology of small marshes using three different water sources

Thesis (M.S.)--Humboldt State University, Wildlife Management, 1992Waterbird use and aquatic vegetation were studied during seven seasons and in five units representing three water types at Arcata Marsh and Wildlife Sanctuary (AMWS), 1 July 1990-30 June 1991. Dominant vegetation types were cover-mapped and sampled for species composition, biomass, and stem density. The PH, salinity, turbidity, and water depth measurements also were taken at appropriate vegetation plots. The five study units represented, a saline basin (Klopp Lake) filled with water from Humboldt Bay, a freshwater unit (Butcher Slough Log Pond, BSLP) filled with well water; and three freshwater units filled with treated domestic wastewater effluent. \ud The PH was greatest in the units in late spring except BSLP where it was highest in late fall. Salinity was greatest in Klopp Lake in mid fall. All four freshwater units had salinities of less than one ppt. The BSLP was significantly less (p<0.05) turbid than the wastewater units from late fall through summer. \ud Dominant vegetation types included marsh pennywort (Hydrocotyle ranunculoides), lesser duckweed (Lemna minor), broad-leaved cattail (Typha latifolia), hard-stemmed bulrush (Scirpus acutus), and sago pondweed (Potamogeton pectinatus). Marsh pennywort and lesser duckweed also commonly occurred as understory species in the emergent cover types. Mean stem densities of broad-leaved cattail and hard-stemmed bulrush were greatest in summer and were greater in the wastewater units (p