There are several ways to remove invasive species from native areas. The trick is finding the best way to help native species thrive in those areas once invasive species take them over.

To find the best solution, the United States Department of Defense's Strategic Environmental Research and Development Program recently awarded a $2.2 million grant to two researchers in Oklahoma State University's Department of Natural Resource Ecology and Management and collaborators from the University of Indiana-Bloomington.

"There are millions of acres of highly disturbed and invaded rangelands in the world, so identifying the causes of why native species are not re-establishing, and then developing methods to re-establish these plants will have huge economic and environmental impacts," said Keith Owens, NREM department head.

While this five-year grant is for research on three different military bases in Oklahoma, Kansas and Illinois, Karen Hickman and Gail Wilson, NREM professors awarded the grant, think the research will apply to all domestic lands.

"All of the research sites have invasive species problems," Hickman said. "It's a problem that is widespread throughout most of the United States."

Research has shown that plant diversity is lower when invasive species are present, resulting in reduced bird abundance, fewer insects, fewer pollinators, fewer small mammals, etc. Re-establishing native species would improve ecosystem services from top to bottom.

"These invasive species often invade diverse, native grasslands, developing a monoculture of the invasive," Wilson said. "This funding allows us to look at different ways to restore these invaded areas."

Native plant species will not successfully establish without the presence of the correct soil microbes. Once the invasive plants are eradicated, it is very difficult to re-establish the natives. Native species will not germinate in soil previously occupied by invasive species.

"Our research suggests that the establishment of the natives can be improved through the addition of native soil to re-establish the native soil microbes," Wilson said. "However, we have so little native grassland, can we afford to destroy what we have left and dig up soil from native grassland areas to use in restoration projects like this? Our research will develop new methods to re-establish natives without impacting native grasslands."

The researchers will begin data collection in August and begin exploring the most effective way to restore soil health for native plant species, improve ecosystem function and support greater ecosystem resilience.

"Federal funding for research is being reduced, so gaining support of this magnitude speaks very well about the quality of the proposed research and the capabilities of the investigators," Owens said. "This research grant is a large step in the invasive species program in the Department of Natural Resource Ecology and Management and furthers our leadership in this field."