It’s early June, and the wildflowers in Elk Meadow are just beginning to bloom.
Many of the delicate yellow clusters of mountain parsley are still on the cusp of opening, only a few ready to show themselves to the world.
A lone prairie bluebell provides a spot of color in a sea of grass and scrub. The pollinators, too, are slow to arrive this year — a dive-bombing hummingbird is more interested in reflective sunglasses than the early flowers.
University of Colorado Boulder assistant professor Julian Resasco has been using snowshoes since late May to trek up to the meadow near the Mountain Research Station north of Nederland. It’s a snow-free hike now, though a few shaded patches can still be spotted.
Resasco has visited this meadow dozens of times since 2015. Every spring, summer and fall, after the snow melts and before it falls again, he takes weekly hikes to catalog the flowers and pollinators in six areas of the subalpine meadow. His trips are so regular that by midsummer, curious Google Map viewers can see the paths he treads throughout the meadow on satellite images.
The more than 4,000 interactions between plants and pollinators cataloged over five years of those trips are the subject of a new research study published this spring in the journal Ecology, written by Resasco and coauthored by Argentinian researchers Natacha P. Chacoff, of the National University of Tucumán, and Diego P. Vázquez, of the National University of Cuyo.
Resasco’s research found that some of the most common flowers, like mountain parsley, and pollinators, like flies, play a crucial role in the meadow’s ecosystem and could serve as cornerstones of stability when those systems see big changes.
“Despite their pivotal roles, common and generalist species are often taken for granted and lack conservation protections that are conventionally aimed at rare species,” Resasco and his co-authors wrote.
But their abundance doesn’t mean they are immune to all environmental impacts, and these species could still face decline and extinction, putting ecological communities in further jeopardy. Conservation efforts, Resasco writes, “should not overlook the pivotal roles that generalists play in supporting biodiversity across time and space.”
While every trip to the meadow follows the same pattern, Resasco said he’s still learning new things.
For one, he has to start checking on the plants early in the season so that they don’t sneak up on him with early flowers. This spring’s abundant precipitation and cool weather means the meadow is off to a slow start.
“Every year teaches you something different,” Resasco said. “You think you have it figured out and then, oh, OK, maybe I don’t. Or you have an idea of what the baseline is, and then you’ll get a crazy year where it’s really different, or you think you’ve seen all the species you’re going to see out here and then new ones pop up every year.”
The meadow is an uphill hike from the Mountain Research Station, across a creek and along an unmarked path. The clearing is at approximately 9,500 feet elevation, likely created by a fire long ago. Trees have been slow to return, though there are some new stands of aspens starting to grow along the edges.
There are six plots marked off with small flags and twine throughout the meadow, each about 6 feet wide and 65 to 100 feet long — unless a wandering moose dislodges the borders. Resasco walks the perimeter, looking for flowers.
This is the first trip of the year that he’s seen any at all. Most of the buds are still closed or have yet to fully open, and Resasco doesn’t count them until they’re ready for a visit from a pollinator.
A fly crawling along the green, unopened leaves of Indian paintbrush, for example, doesn’t count.
Then Resasco walks around each plot for 15 minutes to see what kind of pollinators he can spot. He collects them with a net or an aspirator, which is a small tube with a screen in the middle used to suck up small bugs so they can be taken back to the lab for identification.
Over five years Resasco and his colleagues have catalogued 4,261 interactions consisting of 267 species of animal visitors and 41 species of plants. The most common pollinators were from the hymenoptera family, which includes bees, sawflies and wasps, and the diptera family, which are flies.
The next most common pollinators included beetles, insects, butterflies and moths, while the most rare were grasshoppers, a snakefly and a hummingbird. The study tracked flowering plants from 16 families, the most common of which was asteraceae, the family to which yarrow, daisies and dandelions belong.
This kind of long-term data set is rare in ecology, Resasco said, because of fluctuating funding cycles or researchers moving on or losing interest. That makes the information particularly valuable for understanding things like climate change and other trends.
“Part of what keeps me coming out year after year is seeing new things, learning more about this ecosystem and the dynamics of what happens from year to year,” he said. “Having those long-term data sets can teach us a lot.”
Resasco said wants to keep tracking the data as long as he can, though he wants to recruit a student to help as he works on other field projects.
But for this summer, at least, it will just be him on those bright Colorado summer mornings, clipboard in hand and aspirator at the ready, chronicling the ebb and flow of life in a mountain meadow.
