Abstract Detail

Biogeography

Hellquist, C. Eric [1], Hellquist, C. Barre [2], Anderson, Heidi [3].

The aquatic macrophytes of Yellowstone and Grand Teton National Parks: Floristic diversity and distribution patterns associated with water chemistry.

Aquatic vascular plants (hydrophytes including the Potamogetonaceae, Haloragaceae, Hydrocharitaceae etc.) provide habitat structure and food that is critical for wildlife in Yellowstone (YNP) and Grand Teton (GRTE) National Parks. Despite their importance to aquatic ecosystems and food webs, aquatic plant diversity is typically understudied. Since 2008, we have been surveying the aquatic vascular flora of YNP and GRTE. We have located over 75 hydrophyte species in GRTE and over 100 species in YNP at more than 300 sites in both parks. We have yet to find any invasive aquatic species in either park. We have located over 175 sites for state listed species of concern or species new to state floras. We have also collected over 3000 specimens for regional herbaria. In addition, we have been examining relationships of aquatic plant abundance to water chemistry parameters that include alkalinity, conductivity, pH, and trace metals. In general, Northern Range and Hayden Valley sites of YNP have some of the greatest aquatic plant diversity. Northern Range sites were more basic (ca. pH 8.0 or greater) and had higher ranges of alkalinity (typically > 125 mg CaCO₃ l^-1) and conductivity (typically > 200 mS cm^-1) compared to other areas of YNP. Many of the rare aquatic plants in YNP were found in Northern Range waters that also had high concentrations of trace metals. To date, ranges (ppb) of trace metals prominent in Northern Range waters included Rb (2-10), Sr (76-546), Ba (31-179), Fe (27-105), Ni (0.2-9), Zn (1-33), and As (2-5). As expected, the composition of macrophyte communities shifted as water chemistry changed. For example, compared to the Northern Range, the concentrations of trace metals (ppb) in Yellowstone Lake and vicinity were less variable, e.g. Rb (5-7), Sr (35-45), Ba (6-7), Fe (5-8), Ni (0.4-0.5), and Zn (0.6-3). Although floristically diverse and chemically distinct, many of the YNP Northern Range sites show evidence of prolonged drying including constricting shorelines, low water levels, and remnant aquatic and wetland plant communities. Similar patterns of habitat constriction due to drought have been observed in GRTE as well. Our herbarium collections, in combination with our ecological data, help provide a comprehensive understanding of aquatic macrophyte distributions as aquatic habitats in the Greater Yellowstone Ecosystem are impacted by a climate projected to become increasingly arid.

1 - State University Of New York Oswego, Biological Sciences, 324 Shineman Science Center, Oswego, NY, 13126, USA
2 - Massachusetts College of Liberal Arts, Biology, 375 Church St., North Adams, MA, 01247, USA
3 - Yellowstone National Park, Yellowstone Center for Resources, Yellowstone National Park, WY, 82190, USA

Keywords:
Aquatic plants
Potamogetonaceae
Greater Yellowstone Ecosystem
Water chemistry.

Presentation Type: Oral Paper
Session: 13, Biogeography
Location: Sundance 3/Omni Hotel
Date: Monday, June 26th, 2017
Time: 3:45 PM
Number: 13008
Abstract ID:340
Candidate for Awards:None