Browsing by Author "Zimmer, Kyle D"

Now showing 1 - 4 of 4
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    Data and R code supporting "A hidden Markov model for ecosystems exhibiting alternative stable states"
    (2021-01-20) Vitense, Kelsey; Hanson, Mark A; Herwig, Brian R; Zimmer, Kyle D; Fieberg, John R; viten003@umn.edu; Vitense, Kelsey
    This repository contains the data and R code used to conduct the analyses in the article "Using hidden Markov models to inform conservation and management strategies in ecosystems exhibiting alternative stable states" in Journal of Applied Ecology.
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    Data and R code supporting "Uncovering state-dependent relationships in shallow lakes using Bayesian latent variable regression"
    (2017-10-03) Vitense, Kelsey; Hanson, Mark A; Herwig, Brian R; Zimmer, Kyle D; Fieberg, John R; viten003@umn.edu; Vitense, Kelsey
    This repository contains the data and R code used to conduct the analyses in the article "Uncovering state-dependent relationships in shallow lakes using Bayesian latent variable regression" in Ecological Applications.
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    Data supporting "Predicting total phosphorus levels as indicators for shallow lake management"
    (2018-07-18) Vitense, Kelsey; Hanson, Mark A; Herwig, Brian R; Zimmer, Kyle D; Fieberg, John R; kelsey.vitense@gmail.com; Vitense, Kelsey
    This repository contains data supporting "Predicting total phosphorus levels as indicators for shallow lake management" in Ecological Indicators.
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    High Frequency Oxygen Data from Eight Shallow Prairie Pothole Lakes, 2009-2013
    (2020-10-15) Rabaey, Joseph S; Cotner, James B; Zimmer, Kyle D; Domine, Leah M; Rabae005@umn.edu; Rabaey, Joseph S; University of Minnesota Cotner Lab
    Dissolved oxygen controls important processes in lakes, from chemical reactions to organism community structure and metabolism. In shallow lakes, small volumes allow for large fluctuations in dissolved oxygen concentrations, and the oxygen regime can greatly affect ecosystem-scale processes. This data includes high frequency dissolved oxygen measurements that we used to examine differences in oxygen regimes between two alternative stable states that occur in shallow lakes. We compared annual oxygen regimes in four macrophyte-dominated, clear state lakes to four phytoplankton-dominated, turbid state lakes by quantifying oxygen concentrations, anoxia frequency, and measures of whole-lake metabolism. Oxygen regimes were not significantly different between lake states throughout the year except for during the winter under-ice period. During winter, clear lakes had less oxygen, higher frequency of anoxic periods, and higher oxygen depletion rates. Oxygen depletion rates correlated positively with peak summer macrophyte biomass. Due to lower levels of oxygen, clear shallow lakes may experience anoxia more often and for longer duration during the winter, increasing the likelihood of experiencing fish winterkill. These observations have important implications for shallow lake management, which typically focuses efforts on maintaining the clearwater state.