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Booth EG, Loheide SP, Bart D. Fen ecohydrologic trajectories in response to groundwater drawdown with an edaphic feedback. Ecohydrology 2022; 15:e2471. [PMID: 37034387 PMCID: PMC10078336 DOI: 10.1002/eco.2471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 05/13/2022] [Accepted: 08/15/2022] [Indexed: 06/19/2023]
Abstract
Fens are high conservation value ecosystems that depend on consistent discharge of groundwater that saturates the near surface for most of the growing season. Reduced groundwater inputs can result in losses of native diversity, decreases in rare-species abundance and increased invasion by non-native species. As such, fen ecosystems are known to be particularly susceptible to changes in groundwater conditions including reduction in water levels due to nearby groundwater pumping. However, research is lacking on whether floristic degradation is influenced by feedbacks between hydrology and soil properties. We present a model of an archetype hillslope fen that couples a hydrological niche model with a variably saturated groundwater flow model to predict changes in vegetation composition in response to different groundwater drawdown scenarios. The model explores a potential edaphic feedback through the use of an observed relationship between fen floristic quality and soil/peat water retention characteristics that is attenuated with separate edaphic and floristic memory terms representing lags in biophysical responses to dewatering. Model parameters were determined based on data collected from six fens in Wisconsin under various states of degradation. We observed different water retention characteristics between sites that were minimally impacted versus degraded that are likely due to peat decomposition, oxidation and compaction at the degraded sites. These characteristics were also correlated with floristic quality. The results reveal a complex response to drawdown where changes in peat hydraulic properties following dewatering lead to even drier conditions and further shifts away from typical fen species.
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Affiliation(s)
- Eric G. Booth
- Department of Agronomy and Department of Civil and Environmental EngineeringUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - Steven P. Loheide
- Department of Civil and Environmental EngineeringUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - David Bart
- Department of Planning and Landscape ArchitectureUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
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Fergus CE, Brooks JR, Kaufmann PR, Pollard AI, Mitchell R, Geldhof GJ, Hill RA, Paulsen SG, Ringold P, Weber M. Natural and anthropogenic controls on lake water-level decline and evaporation-to-inflow ratio in the conterminous United States. Limnol Oceanogr 2022; 67:1484-1501. [PMID: 36212524 PMCID: PMC9533913 DOI: 10.1002/lno.12097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Lake water levels are integral to lake function, but hydrologic changes from land and water management may alter lake fluctuations beyond natural ranges. We constructed a conceptual model of multifaceted drivers of lake water-levels and evaporation-to-inflow ratio (Evap:Inflow). Using a structural equation modeling framework, we tested our model on 1) a national subset of lakes in the conterminous United States with minimal water management to describe natural drivers of lake hydrology and 2) five ecoregional subsets of lakes to explore regional variation in water management effects. Our model fit the national and ecoregional datasets and explained up to 47% of variation in Evap:Inflow, 38% of vertical water-level decline, and 79% of horizontal water-level decline (littoral exposure). For lakes with minimal water management, Evap:Inflow was related to lake depth (β = -0.31) and surface inflow (β = -0.44); vertical decline was related to annual climate (e.g., precipitation β = -0.18) and water management (β = -0.21); and horizontal decline was largely related to vertical decline (β = 0.73) and lake morphometry (e.g., depth β = -0.18). Anthropogenic effects varied by ecoregion and likely reflect differences in regional water management and climate. In the West, water management indicators were related to greater vertical decline (β = 0.38), whereas in the Midwest, these indicators were related to more stable and full lake levels (β = -0.22) even during drought conditions. National analyses show how human water use interacts with regional climate resulting in contrasting impacts to lake hydrologic variation in the US.
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Affiliation(s)
- C. Emi Fergus
- Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Corvallis, OR
- Corresponding author at: 200 SW 35 St, Corvallis, OR 97333, USA,
| | - J. Renée Brooks
- US EPA, Office of Research and Development, Center for Public Health and Environmental Assessment, Pacific Ecological Systems Division
| | - Philip R. Kaufmann
- US EPA, Office of Research and Development, Center for Public Health and Environmental Assessment, Pacific Ecological Systems Division
- Oregon State University, Department of Fisheries, Wildlife and Conservation Science, Corvallis, OR
| | | | | | - G. John Geldhof
- Oregon State University, College of Public Health and Human Sciences, Corvallis, OR
| | - Ryan A. Hill
- US EPA, Office of Research and Development, Center for Public Health and Environmental Assessment, Pacific Ecological Systems Division
| | - Steven G. Paulsen
- US EPA, Office of Research and Development, Center for Public Health and Environmental Assessment, Pacific Ecological Systems Division
| | - Paul Ringold
- US EPA, Office of Research and Development, Center for Public Health and Environmental Assessment, Pacific Ecological Systems Division
| | - Marc Weber
- US EPA, Office of Research and Development, Center for Public Health and Environmental Assessment, Pacific Ecological Systems Division
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Murphy CA, Taylor G, Pierce T, Arismendi I, Johnson SL. Short-term reservoir draining to streambed for juvenile salmon passage and non-native fish removal. Ecohydrology 2019; 12:e2096. [PMID: 31762869 PMCID: PMC6853229 DOI: 10.1002/eco.2096] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 04/10/2019] [Accepted: 04/10/2019] [Indexed: 06/10/2023]
Abstract
Fish passage out of reservoirs is a critical issue for downstream movement of juvenile salmonids and other migratory species. Reservoirs can delay downstream migrations by juvenile salmon for months or years. Here, we examine whether a novel management activity implementing annual short-term draining of a reservoir to streambed improves timely downstream migration of juvenile salmonids. We analyse 12 years of fish capture data from a screw trap located downstream of Fall Creek Reservoir (Oregon, USA) to examine changes in timing of passage out of the reservoir and to compare fish species composition pre- and post-draining. We observed a contraction in the timing of downstream migration for juvenile Chinook Salmon and reduction of yearlings in years following draining. We suggest that briefly draining the reservoir to streambed leads to reduced abundance of warm-water invasive fishes in the reservoir after it refills. These changes could decrease predation and shift competition between invasive and resident riverine-adapted native fishes in the reservoir. Collectively, our findings suggest that this low-cost reservoir management option may improve passage and connectivity for juvenile Chinook Salmon while also decreasing the abundance of invasive fish species in the reservoir. This case study underscores the crucial need for further evaluations of reservoir draining in other systems and contexts.
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Affiliation(s)
| | - Gregory Taylor
- Willamette Valley ProjectUS Army Corps of EngineersLowellOR
| | - Todd Pierce
- Willamette Valley ProjectUS Army Corps of EngineersLowellOR
| | - Ivan Arismendi
- Department of Fisheries and WildlifeOregon State UniversityCorvallisOR
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Auble GT, Shafroth PB, Scott ML, Roelle JE. Early vegetation development on an exposed reservoir: implications for dam removal. Environ Manage 2007; 39:806-18. [PMID: 17453277 PMCID: PMC1866215 DOI: 10.1007/s00267-006-0018-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2006] [Accepted: 09/01/2006] [Indexed: 05/15/2023]
Abstract
The 4-year drawdown of Horsetooth Reservoir, Colorado, for dam maintenance, provides a case study analog of vegetation response on sediment that might be exposed from removal of a tall dam. Early vegetation recovery on the exposed reservoir bottom was a combination of (1) vegetation colonization on bare, moist substrates typical of riparian zones and reservoir sediment of shallow dams and (2) a shift in moisture status from mesic to the xeric conditions associated with the pre-impoundment upland position of most of the drawdown zone. Plant communities changed rapidly during the first four years of exposure, but were still substantially different from the background upland plant community. Predictions from the recruitment box model about the locations of Populus deltoides subsp. monilifera (plains cottonwood) seedlings relative to the water surface were qualitatively confirmed with respect to optimum locations. However, the extreme vertical range of water surface elevations produced cottonwood seed regeneration well outside the predicted limits of drawdown rate and height above late summer stage. The establishment and survival of cottonwood at high elevations and the differences between the upland plant community and the community that had developed after four years of exposure suggest that vegetation recovery following tall dam removal will follow a trajectory very different from a simple reversal of the response to dam construction, involving not only long time scales of establishment and growth of upland vegetation, but also possibly decades of persistence of legacy vegetation established during the reservoir to upland transition.
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Affiliation(s)
- Gregor T Auble
- United States Geological Survey, Fort Collins, CO 80526, USA.
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