Removal of benthic barriers one to two years following installation allowed a systematic study of macrophyte recolonization. Within grids installed in the barren zone, species presence and relative abundance were recorded at 30-day intervals through two growing seasons. At each site, colonization of the 18 m(2) grid systems was observed, with typically 9 to 12 species found 30 days post benthic barrier removal. Sixty days post barrier removal (August), both the number of species (averaging 4.7 m(2)) and plant cover peaked (49% cover). A decline in species number and average percent cover observed after 120 days (October) was related to seasonal patterns of growth and die back of annual species. In the second growing season, the number of species stabilized while overall average percent cover (areal coverage) continued to increase. Eurasian watermilfoil colonized all sites, with 71% of all grid squares containing milfoil by the end of the second growing season, representing an average percent cover of 13.6% while total community percent cover averaged 74%. Removal of benthic barrier allowed for the rapid recolonization of both native species and Eurasian watermilfoil.
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