scholarly journals Seed Bank Viability in Jackson Lake Grand Teton National Park, Wyoming

1996 ◽  
Vol 20 ◽  
pp. 31-34
Author(s):  
Carol Brewer ◽  
Melissa Brown
Keyword(s):  
Plant Community ◽  
Seed Bank ◽  
National Park ◽  
Aquatic Plant ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Disturbance Regime ◽  
Grand Teton National Park ◽  
Macrophyte Community ◽  
Macrophyte Growth

The submersed plant community in Jackson Lake is an important resource in Grand Teton National Park for both terrestrial and aquatic organisms. Since the early 1900's, Jackson Lake has been influenced by a series of drawdowns of varying magnitude that influenced the composition and extent of the macrophyte community in the littoral zone. While many physical conditions have been linked to macrophyte growth and distribution in lakes (e.g., light, sediments, nutrients, slope) recent work suggests that the magnitude and timing of water level fluctuations may be the most important factor regulating macrophyte community processes at shallower depths in regulated reservoirs (Brewer and Parker 1990; Gasith and Gafny 1990; Rerslett 1984, 1987). Because of the importance of the aquatic plant community in Jackson Lake as a food source and shelter for wildlife (waterfowl, fish,invertebrates, mammals), the factors affecting growth and recovery after disturbance have received periodic attention since the late 1960's (Hayden 1969; Brewer 1986; Brewer and Rerslett 1987; Brewer and Parker 1990; Brewer and Thompson 1994). Initial work on plant community dynamics in Jackson Lake has shown that the aquatic plant community in Jackson Lake has been exposed to a varied disturbance regime that has impacted recolonization, species diversity and peak biomass development. Because the extent of littoral habitat suitable for macrophyte growth in regulated lakes depends on the timing and magnitude of seasonal and long-term drawdowns, drawdown schedules and resulting fluctuating water levels may be selecting for a plant community characterized by low diversity and patchy distribution. Peak production under such conditions in Jackson Lake tends to be shifted into deeper waters (Brewer and Parker 1990; Brewer and Thompson 1994). Furthermore, clonal, weedy species with reduced value for wildlife (e.g., Elodea canadensis, Myriophyllum sibericum) have enhanced opportunities for dispersal under such a disturbance regime and are favored when maximum drawdown occurs during the period of peak standing crop. While historical records describing changing patterns of macrophyte distribution are available for Jackson Lake, few data are available to evaluate the influence of fluctuating water levels on the seed bed, and the potential for recruitment after disturbance from this source. The objective for our work was to establish protocols and collect preliminary data on the potential for recruiting macrophytes from the littoral seed bank by measuring germination of seeds from lake sediments.

scholarly journals Assessment of the Aquatic Plant Community in Jackson Lake, Grand Teton National Park, Wyoming: 1991 Status Report

1991 ◽  
Vol 15 ◽  
pp. 139-143
Author(s):  
Carol Brewer
Keyword(s):  
Water Level ◽  
Plant Community ◽  
Aquatic Plant ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Status Report ◽  
Littoral Habitat ◽  
Macrophyte Community ◽  
The Status ◽  
Annual Changes

Since the construction of the first dam at the Snake River outlet at Jackson Lake in the early 1900's, the littoral habitat has been subjected to numerous perturbations of varying intensities. Changing water levels, a consequence of reservoir drawdown schedules, alter plant community species composition and distribution over time. From the perspective of a plant, water level changes present a challenge to growth and community persistence. A plant which begins the growing season 2 m deep may be under 4 m of water after spring runoff fills the reservoir. Later in the summer, the same plant may be left at a depth of only 1 m as water is removed from the reservoir during summer drawdown. The magnitude and timing of water level fluctuations may be one of the most important factors regulating macrophyte community processes upslope on the vertical gradient in Jackson Lake (Brewer and Parker 1990). Under normal regulation, annual changes of 3-4 m are sufficient to select for a plant community with a typically weedy phenology (e.g., Elodea canadensis). In natural lakes with substantially lower annual changes in water levels, species that produce seeds annually are favored (e.g., Potamogeton species). Moreover, drawdowns greater than several meters substantially reduce the lake bed area suitable for the development of extensive shallow water plant beds. The most recent perturbations to the littoral habitat in Jackson Lake began in 1978, when the water level was lowered first from 2065 m (normal pool) to somewhere between 2060 - 2062 m. Then in 1985, the surface elevation of Jackson Lake was further lowered to 2057 m to facilitate repair and modification of the Jackson Lake dam. The entire lake bed was seriously impacted during the four years that the dam was being restored. While the lake bed in the borrow zone and the area adjacent to the dam were obviously impacted by repair activities, the entire shallow littoral zone was severely perturbed when previously inundated sediments were exposed for four years. In 1989, repair was completed and the reservoir was allowed to fill back to the normal pool elevation of 2065 m. Because of severe impacts to the littoral habitat and significant reduction of the submergent plant community caused by restoration of the dam, the status of the aquatic plant community was monitored during the summers of 1989-1991. This report summarizes the status of the aquatic plant community three years after repair of the dam was completed.

scholarly journals Assessment of the Littoral Macrophyte Community in Jackson Lake, Grand Teton National Park,Wyoming

1990 ◽  
Vol 14 ◽  
pp. 79-82
Author(s):  
Carol Brewer
Keyword(s):  
Water Level ◽  
Plant Community ◽  
National Park ◽  
Aquatic Plant ◽  
Current Status ◽  
Grand Teton National Park ◽  
Bureau Of Reclamation ◽  
Littoral Habitat ◽  
Macrophyte Community ◽  
The Status

Beginning in 1978, the water level of Jackson Lake, Grand Teton National Park, Wyoming, was lowered first from 2064.5 m (normal pool) to somewhere between 2060-2061 m, and then in 1985 to 2057 m. The purpose of these drawdowns was to facilitate repair and modification of the Jackson Lake dam. In 1989, repair was completed and the reservoir was allowed to fill back to the normal pool elevation of 2065 m. Because of impacts to the littoral habitat in Jackson Lake caused by restoration of the dam at the Snake River outlet, the status of the aquatic plant community was assessed in August, 1989 and 1990. Previous investigations conducted in 1983 (prior to reconstruction) and 1985 (immediately following drawdown to 2055 m) served as a baseline for comparisons. this report summarizes findings from the 1989 and 1990 studies on impacts to the littoral macrophyte community caused by the repair-related drawdowns. To evaluate the current status of the plant community in Jackson Lake, the following objectives were addressed during August, 1990: 1. Re-examine sites sampled in 1989; 2. Examine sites planted during the summers of 1989 and 1990 by the Bureau of Reclamation.

scholarly journals Assesment of the Littoral Macrophyte Community in Jackson Lake, Grand Teton National Park, Wyoming Following Reconstruction of the Jackson Lake Dam

1989 ◽  
Vol 13 ◽  
pp. 90-95
Author(s):  
Carol Brewer
Keyword(s):  
Plant Community ◽  
National Park ◽  
Aquatic Plant ◽  
Detailed Report ◽  
Grand Teton National Park ◽  
Littoral Habitat ◽  
Macrophyte Community ◽  
The Status ◽  
The U.S

Beginning in 1978, the water level of Jackson Lake, Grand Teton National Park, Wyoming, was lowered first from 2064.5m (normal pool) to between 2060.3m-2061.8m, and then in 1985 to 2057.2m. The purpose of these drawdowns was to facilitate repair and modification of the Jackson Lake dam. In 1989, repair was completed and the reservoir was allowed to fill back to the normal pool elevation of 2064.5m Because of impacts to the littoral habitat in Jackson Lake caused by restoration of the dam at the Snake River outlet, the status of the aquatic plant community was assessed in August, 1989, to follow up to investigations conducted in 1983 (prior to reconstruction) and 1985 (immediately following drawdown to 2055.4m) by Brewer (1986). This report summarizes findings from the 1989 study on impacts to the littoral macrophyte community caused by the repair-related drawdowns. A detailed report assessing current physical and biological conditions in Jackson Lake was submitted to the U.S. Fish and Wildlife Service in October (Brewer, 1989).

scholarly journals The Submersed Aquatic Plant Community in Jackson Lake, Grand Teton National Park, Wyoming

1995 ◽  
Vol 19 ◽  
pp. 14-18
Author(s):  
Carol Brewer
Keyword(s):  
Water Level ◽  
Plant Community ◽  
Aquatic Plant ◽  
Nutrient Status ◽  
Growing Season ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Species List ◽  
Spring Runoff ◽  
Macrophyte Community

Submergent macrophyte distribution in lakes is usually related to depth. At lower depths (downslope on the littoral lake bed), macrophyte distribution and growth have been related to light (Spence 1982), substrate texture, nutrient status (Carpenter and Adams 1977), and lake morphometry (Duarte and Kalff 1986). Factors limiting distribution and growth at shallower depths (upslope on the littoral shore) are not as well understood. Meaningful descriptions of plant distributions in reservoirs are problematic because water levels vary through the course of a year (Brewer and Rerslett 1987). Water level fluctuations are a challenge to plant growth. A plant which begins the growing season at a depth of 3 m may be under 6 m of water after spring runoff fills the reservoir. Later in the summer, the same plant may be left at a depth of only 1 m as water is removed from the reservoir during summer drawdown. In reservoirs, where lake levels fluctuate substantially durin_g the growing season, the physical environment is characterized by increased spatial and temporal heterogeneity. Disturbances associated with changing water levels include ice scour during winter drawdown, abrasion due to increased erosion along the lake shore and wave action. Recent work suggests that the magnitude and timing of water level fluctuations may be the most important factor regulating macrophyte community processes at shallower depths in reservoirs (Gasith and Gafny 1990; Brewer and Parker 1990; Rorslett 1984). The status of the aquatic plant community in Jackson Lake was re-evaluated from June - August, 1995. During this time, we compiled a species list and mapped the distribution of macrophyte species.

scholarly journals Effects of Domestic Livestock and Native Wildlife Grazing in Grand Teton National Park

1993 ◽  
Vol 17 ◽  
pp. 91-95
Author(s):  
Michael Smith ◽  
Jerrold Dodd ◽  
Paul Meiman
Keyword(s):  
Plant Community ◽  
National Park ◽  
Mule Deer ◽  
Snake River ◽  
Grand Teton National Park ◽  
Jackson Hole ◽  
Domestic Livestock ◽  
Wildlife Populations

The Snake River plains and foothill areas of Jackson Hole have been grazed by domestic livestock since settlement of the area. Wildlife populations, including elk, mule deer, and antelope have historically used and continue to use the area. Moose are currently relatively abundant and a small herd of bison have been introduced. Currently, livestock use part of the area contained in Grand Teton National Park either as a concession or due to authorization by Park enabling legislation. Park managers need information concerning the effects of grazing by large ungulates on vegetation resources to assist in effectively managing grazing to service forage needs and achieve desired plant community goals.

scholarly journals Factors Controlling Macrophyte Breakage in Jackson Lake, Grand Teton National Park, Wyoming

1984 ◽  
Vol 8 ◽  
pp. 63-68
Author(s):  
Michael Parker ◽  
Carol Brewer ◽  
Thomas Thompson
Keyword(s):  
Littoral Zone ◽  
National Park ◽  
Water Movement ◽  
Structure And Function ◽  
Main Axis ◽  
Grand Teton National Park ◽  
Macrophyte Community ◽  
Second Year ◽  
The Absolute ◽  
And Function

The research described here is part of a two year study to characterize the structure and function of the littoral macrophyte community in Jackson Lake, Wyoming. The objectives for the second year were to perform experiments to: 1) Index water movement in the littoral zone of the lake; 2) Identify the zones where the greatest plant breakage occured; 3) Determine the mechanisms and the absolute force required to break the main axis of a plant, and; 4) Measure the productivity of several species of macrophytes.

scholarly journals Effects of Domestic Livestock and Native Wildlife Grazing in Grand Teton National Park

1991 ◽  
Vol 15 ◽  
pp. 165-168
Author(s):  
Michael Smith ◽  
Jerrold Dodd ◽  
Uyapo Omphile ◽  
Paul Meiman
Keyword(s):  
Plant Community ◽  
National Park ◽  
Mule Deer ◽  
Snake River ◽  
Grand Teton National Park ◽  
Jackson Hole ◽  
Domestic Livestock ◽  
Wildlife Populations

The Snake River plains and foothill areas of Jackson Hole have been grazed by domestic livestock since settlement of the area. Wildlife populations, including elk, mule deer, and antelope have historically used and continue to use the area. Moose are currently relatively abundant and a small herd of bison have been introduced. Currently, livestock continue to use part of the area contained in Grand Teton National Park either as a concession or due to authorization by Park enabling legislation. Park managers need information concerning the effects of grazing by large ungulates on vegetation resources to assist in effectively managing grazing to achieve desired plant community goals.

scholarly journals Distribution of Littoral Macrophytes in Jackson Lake, Wyoming

1983 ◽  
Vol 7 ◽  
pp. 73-76
Author(s):  
C. Brewer ◽  
M. Parker
Keyword(s):  
Plant Species ◽  
National Park ◽  
Structure And Function ◽  
Distribution Data ◽  
Grand Teton National Park ◽  
Littoral Habitat ◽  
Macrophyte Community ◽  
Field Season ◽  
Relative Abundances ◽  
And Function

The research described here is part of a 2-year study to characterize the structure and function of the littoral macrophyte community in Jackson Lake, Grand Teton National Park. The objectives for the 1st year were: 1) to identify the plant species occuring in the lake; 2) to quantify their relative abundances; 3) to characterize the littoral habitat, and; 4) to construct a detailed map of macrophyte distribution. Data collected during the first field season will be used to help evaluate results of experiments conducted during year two on mechanisms affecting macrophyte segregation.

scholarly journals Long-Term Effects of the Harvesting of Trapa natans on Local Water Quality and Aquatic Macrophyte Community in Lake Erhai, China

2021 ◽  
Vol 9 ◽  
Author(s):  
Changbo Yuan ◽  
Xiaohu Bai ◽  
Tianshun Zhu ◽  
Zihao Wen ◽  
Te Cao ◽  
...  
Keyword(s):  
Water Quality ◽  
Plant Community ◽  
Aquatic Plant ◽  
Aquatic Macrophyte ◽  
Erhai Lake ◽  
Long Term Effects ◽  
Macrophyte Community ◽  
Local Water ◽  
Aquatic Macrophyte Community

Trapanatans is one of the main species causing the swamping in the littoral zones of Erhai Lake. It commonly forms a dense canopy on the water surface in the growing season (June–September), which hampers the local water quality and habitat of submerged macrophytes, and releases nutrients to the water after death in autumn and winter, resulting in the deterioration of local water quality. At present, there are many and positive research studies on the short-term effects of harvesting water chestnut on water quality and aquatic plants, but long-term observation results are lacking. In response to the above problems, we studied responses of water quality and aquatic plant community to the removal of Trapa in littoral zone of a northern bay in Erhai from August 2014 to January 2017. This could be the first attempt to discover the long-term effects of floating-leaved vegetation management in the freshwater ecosystem. The results showed that the artificial removal of Trapa significantly improved the local water quality in the growing season, for example, the concentrations of total nitrogen (TN), dissolved nitrogen (DN), total phosphorus (TP), and dissolved phosphorus (DP) in the non-Trapa zone (NTZ) were much lower than the concentrations of those in the adjacent Trapa zone (TZ). And the biomass of aquatic macrophyte community (BAMC) was significantly increased in the NTZ, up to the maximum value of about 21 kg/m2 in fresh weight. However, the diversity indexes of the community in the NTZ declined. Therefore, we suggested that although the removal of Trapa improved the water quality and increased the productivity of the submerged aquatic plant community, it reduced the species diversity of the aquatic plant community in the long run. This is another issue that we need to pay attention to in the later management in Erhai Lake.

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