HR: 1330h
AN: B33C-07    [Abstracts]
TI: Physical Factors Influencing Periphyton Accrual in a Prairie Stream
AU: * Murdock, J N
EM: murdockj@ksu.edu
AF: Kansas State University, 232 Ackert, Manhattan, KS 66506 United States
AU: Dodds, W K
EM: wkdodds@ksu.edu
AF: Kansas State University, 232 Ackert, Manhattan, KS 66506 United States
AB: Physical characteristics can constrain periphyton colonization and accumulation. Unglazed tiles set at three orientations (0°, 45°, and 90° from horizontal) and six substrata of varying surface roughness (glass, glazed tiles (2), unglazed tile, brick, and natural stone) were deployed in a Kansas prairie stream for three weeks. Substrata were analyzed for loosely attached, tightly attached, and total periphyton chlorophyll a. 90° substrata averaged 80 mg chl a m^-2, 34% and 37% less periphyton than 0° and 45° tiles respectively. Additionally, variability among 0° and 45° tiles was more than twice that of 90° tiles (SD = 18.6, 25.3, and 8.8 respectively). Periphyton biomass increased with increasing surface roughness, ranging from 47 mg chl a m^-2 on glass, to 130 mg chl a m^-2 on stones. Linear regression analysis of surface roughness versus chl a showed a better correlation for tightly attached (R² = 0.85, p = <.001) than total (R² = 0.76, p = <.001), or loosely attached (R² = 0.34, p = .001) periphyton. The physical characteristics of stream substrata (roughness and proportion vertical area) should be considered when designing stream periphyton studies, particularly when artificial substrata are used to sample biomass accrual rates.
DE: 1845 Limnology
SC: Biogeosciences [B]
MN: 2005 Joint Assembly