Holbrook Pond, Hebron

2004 Aquatic Plant Survey Map of Holbrook Pond

Transect Data | Water Data

Aquatic plants grow densely throughout Holbrook Pond, an 83-acre waterbody in Salmon River State Forest. The pond supports a very diverse community of aquatic plants. A total of 23 species were found during a 2004 survey, including three invasive species. The most abundant species recorded during the survey were white water lily (Nymphaea odorata) and the invasive fanwort (Cabomba caroliniana). Other abundant species included yellow water lily (Nuphar variegata), primarily along the shore, and watershield (Brasenia schreberi), which extended into the middle of the shallow lake, which has a maximum depth of 7.5 feet and a mean depth of 4.9 feet.

The western shore of the pond was choked with vegetation. Yellow water lily and white water lily were the most abundant species, extending from the shore into water as much as 5 feet deep. Watershield, common bladderwort (Utricularia macrorhiza), purple bladderwort (Utricularia purpurea), and humped bladderwort (Utricularia gibba) also were recorded. Fanwortgrew under the floating-leaved species through much of the area, along with individual plants and small patches of spotted pondweed (Potamogeton pulcher), floating-leaf pondweed (Potamogeton natans), coontail (Ceratophyllum demersum), Canadian waterweed (Elodea canadensis), and an invasive hybrid of variable-leaf watermilfoil and a southern species (Myriophyllum heterophyllum x M. laxum).          

The two northern coves of the pond also supported dense vegetation. Both were dominated by watershield and white water lily. Submerged species, including fanwort, the variable-leaf watermilfoil hybrid, and floating-leaf pondweed, were recorded only in the southern end of the northwestern cove. Fanwort was found under the floating-leaved species in the northeastern cove. The two coves supported several bladderwort species.           

White water lily, watershield, and fanwort were the most abundant species on the eastern side of Holbrook Pond. Occurring with these species were individual plants or small patches of variable-leaf watermilfoil hybrid, floating-leaf pondweed, spotted pondweed, Robbins' pondweed (Potamogeton robbinsii), ribbon-leaf pondweed (Potamogeton epihydrus), Canadian waterweed, and eelgrass (Vallisneria americana).  Four bladderworts – common bladderwort, floating bladderwort (Utricularia radiata), purple bladderwort and humped bladderwort – were recorded on the eastern side as well.

A dam and state boat ramp are located on the southern end of the lake, where fanwort was abundant, growing with white water lily, watershield, and yellow water lily.  Small patches or individual plants of floating-leaf pondweed, ribbon-leaf pondweed, spotted pondweed, small pondweed (Potamogeton pusillus), spikerush (Eleocharis species), eelgrass, common bladderwort, and purple bladderwort also were found. Patches of snailseed pondweed (Potamogeton bicupulatus) and southern naiad (Najas guadalupensis) were found near the boat launch. Deeper water in the middle of the pond was occupied by fanwort (Cabomba caroliniana).