Habititat Architecture of<i>Myriophyllum spicatum</i>L. as an Index to Habitat Quality for Fish and Macroinvertebrates

Abstract

ABSTRACT Plant architecture, described on the basis of the number, morphometry, and arrangement of stems, branches, and leaves, exhibits temporal and spatial variability within species. In order to assess the extent of this variability within an individual lake, the distribution and architecture of Myriophyllum spicatum was measured on five dates during 1990 in Fish Lake, Wisconsin. These data were used to develop an index of plant habitat quality and quantity to describe 1) horizontal visibility within macrophyte beds, 2) the amount of shading afforded by the surface canopy, 3) the amount of available habitat for macroinvertebrate attachment, 4) the relative amount of protection afforded fish by the plants, and 5) the degree of crowding or compaction among plants. The methodology employed in developing this index could be adaptable to other aquatic plants. Temporal changes in the architecture of M. spicatum during the growing season and differences in architecture within one macrophyte bed in Fish Lake were substantial and may have influenced habitat use by fish and macroinvertebrates.