Saving our native prairies: A landscape conservation approach
By Ashley Spratt
The business of conservation is changing in the prairies. Conservationists recognize that collaborative, science-based management is necessary to ensure a future for our prairies and wetlands, and the unique wildlife these habitats support.
“North America’s grasslands are arguably the continent’s most endangered ecosystem due in part to the invasion of our native prairies and wetlands by Kentucky bluegrass, smooth brome grass, reed canary grass and other cool-season introduced species,” said Michael Olson.
Olson is the science coordinator for the Plains and Prairie Potholes Landscape Conservation Cooperative (LCC), a partnership of federal, state and nongovernmental organizations vested in working together to improve conservation and management across jurisdictional boundaries in the prairie pothole region.
“Restoration and maintenance of prairies and wetland habitats requires an understanding of factors contributing to current ecosystem dysfunction and those necessary for restoring ecosystem health,” Olson said.
Through the integration of an adaptive management approach, partners of the Plains and Prairie Potholes LCC are improving management by building science support tools to help land managers make the best decisions about when, where and how to treat invasive species. National wildlife refuge managers across the prairie pothole landscape are using these science support tools to make management decisions to protect and restore native prairie and wetland habitats.
U.S. Fish and Wildlife Service wildlife biologist Socheata Lor represents a multi-partner team leading the effort to save our native prairies by combining the expertise of scientists and land managers across agencies through the Native Prairie Adaptive Management Project. The team’s work is made possible through financial and partnership support from the Plains and Prairie Potholes LCC and federal funding through U.S. Geological Survey (USGS) and the U.S. Fish and Wildlife Service.
“We share the goal of saving our native prairies. By linking the scientific process to the decisions of land managers, we can better respond to the ever-present threat invasive species pose to our native ecosystems,” Lor said.
Lor says the Native Prairie Adaptive Management Project is the gold standard in how adaptive management should be set up and carried out. “Our hope is that the protocols and recommendations for management decisions at national wildlife refuges and wetland management districts may be modified for use by lands beyond the National Wildlife Refuge System, to include privately and publicly managed lands throughout the prairie pothole region.”
Cami Dixon, wildlife biologist with the USFWS in North Dakota, serves as the coordinator for the Native Prairie Adaptive Management Project. Dixon says nearly 115,000 data points are collected annually in a centralized database from 20 national wildlife refuges and wetland management districts across four states in the prairie pothole region. The database allows researchers to compile information on the composition of native and non-native vegetation across prairie units.
The database stores valuable monitoring data and keeps track of management actions taken on specific refuge and wetland management district units over time. The data can then be input into predictive models that generate specific management recommendations for refuge managers for the upcoming year. Specific management recommendations for controlling invasive vegetation and increasing native vegetation include grazing, burning or a combination of both.
Audubon National Wildlife Refuge in North Dakota is utilizing the modeling recommendations to manage invasive species at four waterfowl production areas (WPAs) within the Audubon Wetland Management District. Refuge deputy project leader Todd Frerichs has been making management decisions at those WPAs based on the modeling tool for the past four years.
“We know that models are never 100 percent correct, but the more data we feed into the models over time, the more accurate they will become,” Frerichs said. “The beauty of participating in this project is that we are all learning together, working our way toward the answer to a question that was too big for any one of us tackle on our own.”
When native prairie sits idle, brome and Kentucky bluegrass can take over, providing little to no sustainable habitat for grassland and wetland wildlife. “You can reach a point of no return,” Frerichs said. “By teaming up and combining our data across refuges in the prairie pothole region, we are heading in the right direction to save our prairies.”
Many grassland birds including the Sprague’s Pipit, a candidate for listing as threatened under the Endangered Species Act, require large blocks of prairie to survive. Habitat fragmentation caused by urbanization and agricultural expansion continues to threaten remaining prairies and wetlands, making national wildlife refuges and other federally protected lands so critical to ecosystem health. Invasive species like Kentucky bluegrass and brome add fuel to the fire, invading native prairie habitat and limiting prairie productivity. Less productive prairie means less habitat available to sustain resident and migratory wildlife populations.
“Although it sounds cliché, our prairies really are a national treasure. A good portion of North America used to be covered by prairie ecosystems, which support a unique group of birds and other wildlife,” Dixon said. “When we break these habitats up, we don’t get them back.”
Butterflies and other pollinators also rely on many native prairie plants for both nectar and reproduction. The Powershiek Skipperling, also a candidate for listing under ESA, uses native prairie plants like the little bluestem and purple coneflower as nutrient or nectar sources. High quality prairie is critical for the long-term survival of these declining grassland species.
Prairies and wetlands also offer significant benefits to humans by contributing to water quality and storing carbon. “Prairie plants have large root systems, making what’s below ground much like an inverted rainforest,” Dixon said. Big bluestem roots can extend more than 12 feet below the surface.
Ryan Frohling, project leader at Detroit Lakes Wetland Management District in western Minnesota, is one of many USFWS project leaders participating in the Native Adaptive Management Project. He says the adaptive management approach supports his mission to preserve the small pieces of remnant prairie left on refuge lands.
“The historic tallgrass prairie was very diverse. When you consider the potential threats posed by climate change and other stressors across the landscape, it’s important to have the diversity provided by native prairies to sustain species over the long term. Prairies support everything from birds to butterflies, from meadowlarks to mallards,” said Frohling. He explains that although invasive grasses can provide habitat for some native species in the short-term, they can’t sustain healthy populations over time.
Frohling says contributing to the data collected through the Native Prairie Adaptive Management Project helps fuel a discussion across regions and management districts about invasive species management.
“By working with our neighbors across the prairies and across state and other jurisdictional lines, we can slowly begin to paint a fuller picture of what works, what doesn’t and what we may be up against in the future given new environmental stressors.”
Every year, Frohling, Frerichs and other managers at national wildlife refuges and wetland management districts across the prairie pothole region implement the recommendations made through the Native Prairie Adaptive Management Project.
“By inputting monitoring data and following through on our management decisions, we participate in a feedback loop,” Frohling said. “We monitor and model with data collected from the previous year, and decide how to manage based on our knowledge about how different invasive grasses respond to different management techniques.”
For example, Kentucky bluegrass is more likely to be controlled through burning, as overgrazing has been documented to increase the invasive species’ spread.
Dixon explains how management decision-making is continuing to evolve to benefit the prairies by putting the scientific research and monitoring components of adaptive management to practical use. “Historically, a land manager would commonly make management decisions based on a subjective process or on small-scale monitoring efforts,” she said. “By implementing such an expansive and collaborative effort using a standardized monitoring protocol, natural resource managers have the opportunity to use information from a landscape-level dataset to drive management decisions.”
Biologists and land managers across the prairie pothole region agree that the Native Prairie Adaptive Management Project will improve predictive modeling efforts and promote scientifically-based management actions over the long term.
Frohling and Frerichs both say they will continue to utilize the database and modeling tools to guide management of prairie units on their wetland management districts. They say each year of additional data gets them closer to ensuring they are making management decisions to save the prairies based on sound science.
Dixon says the enthusiasm shown by both USFWS and USGS staff, combined with the financial support and guidance provided by the Plains and Prairie Pothole LCC, has built a solid foundation for this large-scale effort to save our prairies and the unique and diverse wildlife they support.
“The scale and synergy facilitated by all of our partners has been essential to making this effort realizable.”