Patterns of Periphyton Chlorophyll ? in AN Agricultural Nonpoint Source Impacted Stream

摘要: : An agricultural nonpoint source polluted stream in northern Idaho was examined to determine seasonal and longitudinal patterns of periphyton chlorophyll α. Chlorophyll a measured at eight sites along Lapwai Creek, fifth order impacted by runoff containing nutrients eroded soils. Seasonally, α lowest the spring (cumulative x= 60.4 mg m−2) highest summer 222 m−2). Winter concentrations were higher than expected 168.6 The headwaters, flowing through an open grassy meadow, had study (two-year 49.7 Immediately below small, eutrophic reservoir, increased markedly 155.8 remained high deep canyon (two year 135.5 down mouth 172.3 mg−2). Periphyton Creek least two times greater values reported literature for comparable, undisturbed streams. We suggest that nutrient via pollution light penetration from removal large, woody riparian vegetation have resulted continuum Creek.