Beavers support freshwater conservation and ecosystem stability


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One of the most comprehensive studies conducted on beavers has conclusively shown that beavers are essential to freshwater conservation and ecosystem stability by creating and maintaining aquatic and wet environments in Minnesota. This new research from the Natural Resources Research Institute (NRRI) at the University of Minnesota Duluth was recently published in the journal Ultrasound.

“While there are many studies on how beavers alter ecosystems, the scale of this study – spanning 70 years in five different watersheds – is truly unprecedented and, therefore, has given us the opportunity. unique to understand how beavers transform and modify ecosystems over a long period of time. periods of time and large spatial scales, ”said Tom Gable, study co-author and postdoctoral researcher in the Department of Fisheries, Wildlife and Conservation at the University of Minnesota. “We believe this work will be valuable to many environmentalists, scientists and citizens who wish to understand how reintroduced or recovering beaver populations can positively affect their ecosystems. “

Understanding how ecosystems become more resilient is a key goal for conservationists, as it can provide information on how ecosystems can respond to human impacts and climate change. This study suggests that beavers, as ecosystem engineers, may be a biological tool that helps protect ecosystems from disturbance and alteration.

Ecosystem engineers are ecologically important species that benefit other species by physically altering their environment. Although ecosystem engineers are relatively rare, they are not uncommon: they exist in most large ecosystems.

Most previous research on ecosystem engineers has suggested that their ecological impact does not vary over time or space. However, this research team led by Sean Johnson-Bice, who studied beavers for his masters at the University of Minnesota Duluth, determined that the impact of beavers on ecosystems can vary depending on the scale at which they are studied. In other words, the ecological role of beavers varies according to local and regional perspectives.

“In combination with other recent research we have conducted on the dynamics of beaver populations in northern Minnesota, our study demonstrates the resilience and stability of beaver populations in landscapes,” said Johnson-Bice, author principal of the study and currently a doctoral candidate at the University of Manitoba. “Their landscape-scale populations appear relatively unaffected by environmental conditions and, as such, they can be key drivers of freshwater habitat diversity and the promotion of ecosystem stability.”

In the study, researchers assessed how beavers influence water storage along the north shore of Lake Superior using aerial images of five watersheds over 70 years (1948-2017). This period included the full recovery and subsequent stabilization of beaver populations in the area. They found that:

  • Beavers are the primary drivers of water retention in ecosystems, suggesting that restoring beaver populations in ecosystems they no longer inhabit may be a valuable method that managers and conservationists could use to freshwater conservation objectives.
  • The more beavers are present in an ecosystem, the more old and abandoned ponds contribute to water storage; Although these abandoned ponds no longer contain beavers, their dams can still hold water, allowing the pond to store water.
  • At large spatial scales, beaver populations are resilient to moderate environmental and human disturbances.
  • Although the beaver populations in each of the five watersheds studied showed considerable variation in population size, water storage remained stable throughout the region. Essentially, changes in the size of the beaver population in one watershed would be offset by changes in other watersheds, which would help stabilize the amounts of water stored on the north shore of Lake Superior.

“The digitization of nearly 800 historical and recent aerial photos from 1948 represents a considerable effort on the part of Sean and the SIG NRRI and Twin Cities laboratories,” added George Host, now retired director of the Forest and Land laboratory. NRRI Initiative and Geographic Information System. a member of the research team. “The resulting dataset provided important information on the essential role beavers play in regulating water storage along the North Shore. “

Beavers are heading north and impacting the arctic landscape

More information:

Sean M. Johnson-Bice et al, Relics of the Beaver Past: Time and Population Density Drive Scale-Dependent Ecosystem Engineering Models, Ultrasound (2021). DOI: 10.1111 / ecog.05814

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Beavers support freshwater conservation and ecosystem stability (2022, January 4)
retrieved January 5, 2022

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