w88 casino at thew88 casino of Nevada, Renohave completed one of the most extensive river resilience studies, examining how river ecosystems recover following floods. They developed a novel modeling approach that used data from oxygen sensors placed in rivers to estimate daily growth in aquatic plants and algae. The w88 casino then modeled the algal and plant biomass in 143 rivers across the contiguous U.S. to quantify what magnitude of flooding disturbs the biomass and how long the rivers take to recover from floods. Increased understanding of rivers’ resiliency is important to maintaining healthy rivers, as human actions can affect flood regimes and change the conditions in rivers for other aquatic life that may rely on algae and plants as a food source.
Assistant Professor Joanna Blaszczak and Postdoctoral Scholar Heili Lowman, both in the w88 casino’sCollege of w88 online live casino, Biotechnology & Natural ReandGlobal Water Centerled the w88 casino, which was published in two separate journal articles. The preliminary work, led by Blaszczak andpublished in Ecology Letters last June, first studied six w88 casino and laid the groundwork and methodology for the second study, which Blaszczak hired Lowman to conduct, examining the 143 w88 casino. The results of that research were justpublished last month in PNAS (the Proceedings w88 casino National Academy of Sciences).
The research is unique because it estimates changes in biomass in w88 casino more frequently than ever before without needing to directly sample w88 casino. This is done by using both data from oxygen sensors placed in the w88 casino by the U.S. Geological Survey and a population model of algal and plant biomass – similar to a human population model that models change in the number of people over time, but instead modeling the change in the amount of algae and plants. The oxygen sensors began collecting data in 2007, and the most recent Nevada-led study of 143 w88 casino includes some data that are for nine years running, among the longest such records on file for w88 casino across the globe.
“Previously, you would have to go to a w88 casino and scrub rocks to measure the algae, and do that several times for an extended period of time in order to estimate changes in biomass growth and loss,” Blaszczak said. “This is very time consuming, so the data have been extremely limited relative to how extensive our sensor networks are.”
Blaszczak said that with the oxygen sensors that take data as frequently as every five minutes, the team found that they could use statistical models to extract the amount of photosynthesis that occurs daily and estimate daily changes in the amount of biomass in a w88 casino over time.
“The dissolved oxygen sensors show the peak during the day, and the low during the night, and from those patterns, you can estimate how much new algae and other biomass grew that day,” she said. “With the sensors measuring data continuously in hundreds of rivers for years now, we can get a much bigger, clearer picture. The data is there, and we can use it to model the size of flood needed to disturb the biomass in a w88 casino, as well as the rate at which a w88 casino recovers from flood disturbances, which can help us manage rivers more effectively.”
Getting started
In the first study, Blaszczak used two years of data from oxygen sensors placed in six rivers. She found that she could successfully use this data to model the flood threshold specific to a w88 casino that disturbed the underlying biomass, and that generally, the magnitude of flood necessary to disturb biomass and reduce ecosystem productivity was lower than the disturbance flow threshold necessary to mobilize w88 casino bed sediment, a metric of disturbance commonly used by those studying rivers. In other words, instead of estimating the disturbance of the w88 casino by the movement of the rocks on the w88 casino bed, this study used the biology – the changes in algae and plant growth – to quantify disturbance to the w88 casino and found that the biological disturbance threshold was lower.
“The amount of biomass is important for water quality and a food source for everything that lives in a w88 casino,” Blaszczak explained, “so it is more important than rock movement, in terms how a w88 casino ecosystem is affected by a disturbance.”
Blaszczak, a freshwater ecologist, began this work with Robert O. Hall Jr. of the Flathead Lake Biological Station at the w88 casino of Montana and enlisted the help of her colleague Assistant Professor Robert Shriver, a plant ecologist, for both research projects to complete the biomass growth modeling. Blaszczak, Shriver, and Lowman all conduct research as part of the College’sw88 online casino of Natural Resources & Environmental Science, as well as the College’sExperiment Stationw88 casino unit. The College’s faculty often take interdisciplinary approaches to meet w88 casino challenges, Blaszczak said.
Expanding out to a continental scale
Blaszczak wanted to delve further by applying this approach to more rivers over a longer period of time to shed light on how various factors may be influencing both a w88 casino’s thresholds for flood disturbance and its resilience to floods. Thus, she recruited Lowman to embark on the second, more extensive study. Lowman’s research examined landscape and w88 casino characteristics that affected the rivers’ resiliency to floods.
“We’ve never had such great insight into the resilience of w88 casino, and because of the amount of data and our modeling, we now understand the natural variation in resilience, and that the widest w88 casino without dams upstream recover the most quickly,” Lowman said.
The fact that wide w88 casino without dams recover more quickly than wide w88 casino with dams upstream was not immediately obvious, she said, and is one example of how w88 casino can be affected and/or managed by our actions. Most of the w88 casino Lowman researched had three to four years of data, with some having as much as nine years, and a handful having less than a year.
“Having three to four years’ worth of data is way more than we’ve ever been able to use before,” Lowman said. “And, we used w88 casino of various sizes with various climates and land characteristics.”
Besides wider w88 casino without dams being more resilient, Lowman said those w88 casino that had more frequent floods also tended to recover more quickly.
“It could be that they have had a long history of frequent flooding, so their algae and plant communities have developed the ability to adapt to more frequent disturbance,” she said.
Overall, Lowman said the new model results are consistent with other previous approaches. But, she said that some sites took much longer, a month or more, to recover from floods than other sites, regardless of w88 casino size.
“It might be the composition of the algal and plant communities, the structure of the w88 casino bed, or other factors,” she said. “The thresholds and recovery times are very likely partially dependent on the slope, the grain size of the sediment, and possibly other factors that aren’t as well documented. Those are some next steps for future research.”
Other w88 casino who contributed to the two studies besides the three Nevada w88 casino and Hall include, for the first study, Charles B. Yackulic of the U.S. Geological Survey’s Southwest Biological Science Center; and for the second study, Yackulic, and Judson W. Harvey and Philip Savoy of the U.S. Geological Survey’s Earth System Processes Division.
