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Vegetation - Stratified Random Sampling 2002

2002 Results in Pool 5 of the Upper Mississippi River

Sampling Effort

Sampling in Pool 5 began on July 18 and ended on August 5, 2002. All 404 sites targeted for sampling at the beginning of the season were sampled (Figure 3).

Submersed Aquatic Vegetation

Submersed aquatic vegetation (SAV) covered about 28.5% of the shallow water areas poolwide (Table 3; Figure 4). Contiguous backwaters had the highest percent frequency of SAV (51.8%). Impounded areas (27.2%), main channel border (15.5%), and secondary channels (14.0%) followed in decreasing order. Sizable beds were found throughout most of the shallow water areas, except in the lower portion of the impounded stratum where SAV was nearly absent.

A total of 14 species were recorded in the entire pool. Contiguous backwaters (13) had the most species recorded followed by impounded areas (10), secondary channels (8), and main channel borders (7).

Sago pondweed (10.5%) was the most frequently recorded species in Pool 5 followed by water stargrass (9.5%), coontail (9.2%), and Canadian waterweed (9.2%). Coontail (36.4%), Eurasian watermilfoil (28.2%), and Canadian waterweed (26.4%) were commonly found in contiguous backwaters while sago pondweed (13.3%) and water stargrass (10.4%) were the most frequently encountered species in impounded areas. Coontail (12.0%) was the most commonly encountered species in secondary channels, while Canadian waterweed (7.0%) was the most frequently found species in main channel border areas.

Rooted Floating-Leaf Vegetation

White waterlily, American lotus, and yellow pond-lily were the three rooted floating-leaf species recorded. Together, the three species had a cover of 2.7% and a frequency of 9.8% of the shallow water areas of Pool 5.

The percent frequency of rooted floating-leaf species was the highest in the contiguous backwaters (40.0%), followed by impounded areas (5.2%) and secondary channels (4.0%). Rooted floating-leaf species were not found in main channel border sites

The contiguous backwater stratum was the only area to contain yellow pond-lily (1.8%), American lotus (10.0%), and white waterlily (32.7%). American lotus (3.5%) and white waterlily (2.9%) were found minimally in the impounded area, while white waterlily (4.0%) was the only recorded species in secondary channels.

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Content manager: Danelle Larson

Page Last Modified: April 17, 2018