Light availability and growth of wildcelery (Vallisneria americana) in upper Mississippi River backwaters

Abstract

Large beds of Vallisneria americana declined in the backwaters of the Upper Mississippi River after a drought that occurred between 1987 and 1989. One hypothesis for this decline is that low light availability may have decreased net photosynthesis to the extent that overwintering tubers were not formed. Following the decline, light availability remained low. To determine what light levels would be necessary for the re-establishment of Vallisneria in the Upper Mississippi River, the long-term growth of plants in a backwater lake and in an experimental pond was measured while the surface and subsurface light were monitored continuously. Plants grown from tubers transplanted to 0.5, 1.0 and 1.5m depth in the lake grew and produced tubers only at 0.5m depth (9% of surface light). At I-Om, light availability was less than 1 % of the surface light. Plants grown from tubers in experimental ponds with four shade treatments (2,5,9 and 25% of surface light) for the same growing period produced replacement-weight tubers in 9% light. For a longer growing season, plants also produced replacement-weight tubers in treatments with at least 5% of surface light.An average light-extinction coefficient of 4.64 m-' was calculated for the backwater lake based on continuous data collected during 94 days during the growing season from eight widely separated sites. Using equations based on the average extinction coefficient for the lake and average leaf lengths of plants grown in experimental ponds, we predict that in years with comparable turbidity, plants grown from locally collected tubers will grow and produce replacement tubers only at depths of 0.8 m or less.

The Relationship Between Shoreline Armoring and Adjacent Submerged Aquatic Vegetation in Chesapeake Bay and Nearby Atlantic Coastal Bays

“…2 and 3) may be due to differences in the dominant SAV species (Moore et al 2000) and their habitat requirements (Kemp et al 2004). In the oligohaline zone, Eurasian water milfoil (Myriophyllum spicatum) and hydrilla (Hydrilla verticillata) are both canopy-forming species, and wild celery (Vallisneria americana) requires 2-9 % of incident light to reach its leaves (Steward 1991;Kimber et al 1995). All three of these dominant oligohaline species are substrate indifferent, growingly equally well in sand or silt bottoms.…”

Interannual variation in submerged aquatic vegetation and its relationship to water quality in subestuaries of Chesapeake Bay

“…Broader understanding of spatial and temporal variation in stressors and SAV responses will help meet the restoration goals for the entire estuary (Batiuk et al 1992(Batiuk et al , 2000 and will help to inform restoration efforts in other systems with complex SAV dynamics. The Chesapeake Bay is a diverse system with 23 SAV species, which differ in substrate preference, morphology, minimum light requirement, heat tolerance, sensitivity to waves and other physical forces, growth rate, and dispersal capability (Bourn 1932, Backman & Barilotti 1976, Congdon & McComb 1979, Goldsborough & Kemp 1988, Steward 1991, Kimber et al 1995, Moore et al 2000, Kemp et al 2004. Dividing the estuary into salinity zones helps account for some of those differences (Moore et al 2000, Orth et al 2010, Patrick et al 2014, 2015 in SAV responses to stressors.…”

Will the Three Gorges Dam affect the underwater light climate of Vallisneria spiralis L. and food habitat of Siberian crane in Poyang Lake?

“…These fluctuations were caused by variations (D) and (E) represent a limit of 9% surface radiation during sunshine period (Kimber et al, 1995;Dobberfuhl, 2007), the threshold for tuber production in V. americana in irradiance reaching the water surface, water level, attenuation within the water column, and height of the V. spiralis vegetation. Irradiance at the water surface varied strongly from day to day, but ANOVA revealed that it did not vary significantly between years.…”

“…Tuber production requires a higher light intensity. Kimber et al (1995) reported for V. americana a threshold of 5-9% of surface irradiance for tuber production under temperate climatological conditions, which forms the lower limit of the 9% surface irradiance threshold cited for V. americana occurrence in temperate North-Florida (Dobberfuhl, 2007).…”