Original paper

A comparison of epiphytic communities on natural and artificial substrates in a large subtropical lake (Lake Okeechobee, USA)

Rodusky, A.J.; Anderson Jr, R.T.

Abstract

Epiphytes on acrylic rods and on Schoenoplectus and Potamogeton were compared in Lake Okeechobee, USA between July 1999 and November 2000. During the study, water levels fluctuated and Hurricane Irene passed near the lake. Epiphytic communities on all substrates were dominated by diatoms and filamentous chlorophytes. The highest mean epiphytic biovolumes typically occurred on the top rods and coincided with the lowest water levels, suggesting that changes in the light regime and vertical position may have been the most influential factors in epiphytic growth. Substrate morphology also appeared to influence the epiphytes. Epiphytic biovolume was generally highest on rods at Schoenoplectus sites and was typically higher on Schoenoplectus than on Potamogeton. The rods also typically had a greater abundance of early succession taxa relative to that on Schoenoplectus while having a lower abundance of later succession taxa compared to that found on Potamogeton. Epiphytic communities on the rods appeared to be more similar to those on Potamogeton. Although the rods were a useful surrogate substrate to evaluate epiphytic colonization patterns and growth on both macrophytes, the epiphytic community structure on the rods was generally more reflective of earlier stages of community succession relative to that found on both macrophytes.

Keywords

artificial substratesepiphyteslake okeechobeepotamogetonschoenoplectus