Glacier Park researcher suggests bison could help native grasslands

Between 1999 and 2001, surveyors recorded the plant species in 155 plots on the east side meadows of Glacier National Park.

“Just the grasslands hold 31%, or almost a third of the diversity of the plant life in the park,” said Colorado State University PhD candidate Nico Matallana during his presentation for Waterton-Glacier’s Science and History Week last week. Matallana, with help from Glacier National Park, the National Science Foundation, Glacier Park Conservancy, CSU Ecology graduate program and Blackfeet Fish and Wildlife program to name a few, revisited 90 of the original plots to see what 20 years of change had done to the landscape’s plants.

Right off the bat, the new researchers found 52 more species than the initial survey.

“That’s a lot bigger than we expected, and most of those species are native. So, at first glance you might think a bunch of new native species are blooming into these grasslands ... I’m not quite so hopeful,” Matallana said.

Originally, surveyors used a textbook-sized guide called “Flora of the Pacific Northwest” published in 1960 to identify plants. It covered an area expanding south of Montana and all the way to the Pacific Coast. The book used for the recent survey, “Flora of Glacier National Park” by Peter Lesica, was much more usable for researchers.

“We were able to really take our time and figure out a lot of plant species that, if we only had [the original resource], we would have really struggled,” Matallana said, which might explain the extra plants counted.

Another theory for the increased plant variety is that climate change may have caused lower-elevation species to migrate upwards to more suitable growing spaces. However, the data collected showed a weak correlation towards higher elevation and abundance. ”I wouldn’t say that we can prove anything here,” Matallana pointed out.

With the general species increase, surveyors found that three more plots housed invasives than the 2000 study, with the median invasive cover growing from 2% initially to 7.3% now. Spotted knapweed in particular almost doubled its spread. Declines to beneficial native plants such as rough fescue, Idaho fescue and slender wheatgrass were also recorded.

The history of invasives goes beyond the 20-year span of this study. Matallana showed slides of historic campgrounds in the expansive meadows of St. Mary Flats, as well as a 1920 camp at Cosley Lake. The historic disturbances caused by irresponsible development lives on.

For example, invasive plants such as Kentucky bluegrass and Timothy grass were seeded in the park at one point for grazing livestock. European settlers also removed native grazers from the landscape. “[Domestic grazers] have a totally different relationship with the land and the plants there, and it’s not nearly as good for the landscape. To this day, there are still domestic grazers in the park, some of them grazing illegally, but some of them totally legally as well,” Matallana pointed out.

Woody plants also increased in abundance since the first study, with the median coverage growing from 3.4% in the initially to 13.4% recently. Trees and shrubs encroaching on grassland were once prevented by low-intensity grassfires, Matallana explained. Settlement also affected fire’s relationship with Glacier’s landscapes by reducing their frequency, and consequently affecting the burn cycle.

Four plots surveyed in 2000 were burned in the Red Eagle Fire of 2006 – all saw an increase of woody cover in Matallana’s survey. This shouldn’t happen, as fire typically provides a place for grasses to flourish while woody plants take longer to grow back. The cause for this was determined by examining two other plots burned in the 2015 Thompson Creek Fire. One plot saw a drop in woody cover from 75% to 5%, the other an increase from 40% to 80%.

Matallana found that in the woodier of the two plots, the fire never reached enough intensity to burn the low-lying bearberry shrub. “Fire doesn’t burn the same across the landscape, intensity matters… Fire doesn’t necessarily solve our woody plant issue,” Matallana said.

So what will solve the issue of outside plants encroaching on Glacier’s meadows? Matallana has a lot of hope that the Blackfeet bison restoration project initiated this year will eventually restore the role of native grazers in increasing native species richness. He and his team, aided by Blackfeet Community College, placed 20 new plots on the Chief Mountain allotments where the bison are expected to graze this summer with the hopes of proving that in the future.

After native grazers comes native disturbances, namely, fire. Then the support of restoration programs and limitation of development.

“Once a place is disturbed by humans, it never quite comes back, and that’s very evident in what we see,” Matallana said. “This is an opportunity for all of us to ask, can we tip the scale back? And maybe we can’t completely scale things back to the way they were, but at least we can try.”