摘要：A survey was carried out from November to December 2003 and May to June 2004 to determine the current status of macrovegetation and physicochemical parameters of Samaru stream in Zaria (7° 38E and 11° 11N), Nigeria. Five sampling stations were chosen at approximately equal distances from each other along the stream length. Temperature readings were 19.5±1.05 and 29.0±0.67°C; pH 7.496±0.11 and 7.07±0.07; EC 328.1±63.92 and 364±75.37 μS cm-1; TDS 163.3±31.99 and 185.5±37.20 mg L-1; DO 6.05±0.51 and 4.03±0.49 mg L-1; NO3-N 1.37±0.17 and 5.32±0.90 mg L-1; PO4-P 136.0±53.07 and 42.3±4.74 mg L-1; BOD 0.89±0.22 and 0.32±0.07 mg L-1 and Transparency 0.00 and 0.36±0.06 m in the dry and wet season respectively. Fifty three macrophyte species were recorded belonging to 26 families during the entire study. Ageratum conyzoides was the most frequent (80%) of all species observed in both wet and dry season. Very few true aquatic species were recorded during the study, these comprised Hydrophilla auriculata , Jussiae ripens , J. decurrens , Polygonum limbatum , P. linigerum , Oryza barthi and Ipomoea aquatica . The occurrence of macrophytes in the stream responded directly to eutrophication. This is because higher number species occurred in the dry season which significantly correlated (p≤0.05) with higher nutrient levels in the same season.
