Upper Midwest Environmental Sciences Center
2002 Results in La Grange Pool of the Illinois River
Sampling Efforts
Sampling in La Grange Pool began on June 17 and ended on August 9, 2002. Of the 430 sites targeted for sampling at the beginning of the season, 428 were sampled (Figure 16).
Submersed Aquatic Vegetation
Submersed aquatic vegetation (SAV) was not collected in the contiguous and isolated backwaters of La Grange Pool in 2002. However, SAV was recorded at 79.9% of the isolated lake sites (Table 9; Figure 17). Sizable beds were found throughout most of the lake areas, except in the areas with extreme water depths. Isolated lakes (13) housed all of the species recorded within the pool. Eurasian watermilfoil (72.9%) was the most frequently recorded species in isolated lakes of La Grange Pool followed by coontail (57.6%), common bladderwort (11.9%), and chara (11.9%).
Rooted Floating-Leaf Vegetation
White waterlily, American lotus, and wingleaf primrose-willow were the three rooted floating-leaf species recorded. The three species together covered about 18% of the isolated lakes. The percent frequency of rooted floating-leaf species was the highest in the isolated lake stratum (37.3%). American lotus dominated the isolated lakes and contiguous backwaters followed by wingleaf primrose-willow. White waterlily was only sampled in the isolated lake stratum.
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Page Last Modified: April 17, 2018