(full paper is archived in the Miller Library)
Title: Rhodoglossum affine (Rhodophyta): Intertidal distribution and physiological ecology
Student Author(s): Danek, Susan L.
Faculty Advisor(s): Burnett, Robin
Location: Final Papers Biology 175H
Date: June 1979
Keywords: midtide forest community
Abstract: Rhodoglossum affine (Rhodophyta) is a midintertidal alga of the Pacific Coast; its position is +0.5 to +4.5 ft. tidal level. The most abundant life phase is male plus sterile occuring higher than females in the same region. Tetrasporangial plants are sparse, possibly due to the season. Morphological measurements were taken which show plants higher in position have shorter fronds with larger holdfast area containing more fronds per holdfast than lower zoned plants. Stress tolerances of Rhodoglossum were examined noting the physiological changes of the plants in relation to vertical height and exposure. Higher level plants tolerated increased temperatures with greater survival than lower plants. Desiccation effects of Rhodoglossum were studied as a function of net photosynthetic rates. More exposed plants have higher rates after 1 and 5 hours of drying compared to calmer sites. Higher level plants exhibit a recovery of photosynthesis after 3 hours of desiccation.