Published: July 26, 2023 By

Niwot Ridge is a place of grandeur. The mountains are tall and steep. The sky is bright and open. In this land, most people instinctively look up and out. A research group from the University of Georgia, however, spends their summer days on the ridge looking down.

The group, led by postdoc Meredith Zettlemoyer, is looking at alpine cushion plants—compact green mounds with small leaves and ephemeral flowers that hug Niwot Ridge and are found in many alpine areas across the world. They are studying how the flowering time and reproduction of these plants is changing as the climate warms and snowmelt advances.

Zettlemoyer, PhD student Emma Chandler, and master’s student Emma Horne begin each morning driving up the bumpy Niwot Ridge Road from the Mountain Research Station. Then they begin the climb. One early summer morning, the meltwater and rain has claimed the path as its own, so they weave from dry patch to dry patch, or just plod through the water. Hiking over some lingering snow and around short, windblown pines, they arrive at their plots.

The group mapped where 600 plants were in each of their nine plots. They marked the plants’ locations using colorful plastic toothpicks topped with flamingos, swords, and playing card suits, depending on the plant species. Kneeling in the plots with purple knee pads for protection against the sharp rocks, they check on the plants each day to record whether they are flowering: whether the Silene has burst into pink, the Phlox into light purple, the Minuartia into white. At the end of the season, they will take additional measurements to assess the plants’ fitness—their size, the number of fruits, and the number of seeds per fruit. “The methods are like most things in ecology—a lot of counting,” says Zettlemoyer.

The blue of the sky is broken only by one small cloud on the horizon, and the wind is bellowing. Zettlemoyer and Chandler hold tightly onto their clipboards with their precious data sheets. Just a few hours in, it is easy to understand why the plants grow so low to the ground, sheltered from the wind. Their response to environmental change, however, is more difficult to understand.

So far, the group is finding that as snowmelt advances, the alpine cushion plants are flowering earlier and their fitness is increasing, likely because they have more time to reproduce during a longer growing season. Zettlemoyer expects that there will be some limit to this trend, a point where the plants flower so early that they get covered by frost or there are no pollinators out, both which would decrease their fitness.

Generations of alpine cushion plants are not evolving to flower earlier—they live for hundreds of years and cannot keep up with the pace of climate change. Rather, they are changing their behavior over the course of a single generation.

In addition to observing these plants, the group hopes to experiment with changing when the snow melts and seeing how the plants respond. In doing so, they will be able to isolate the effects of snowmelt from other environmental variables. Changing when the snow melts, however, is easier said than done. They placed black tarps over the snow to speed up snowmelt, but one year the tarps blew away and another they froze onto the snow. They were going to shovel some snow off this year, but there was not enough snow to do so by the time they arrived. Next year, they will try slowing down snowmelt instead by placing white bins over the snow.

But the group has more immediate problems at hand. They rush to collect the rest of their data and hike down in time for the shuttle back to the Mountain Research Station. When they return, their work is not yet complete. They transfer their data from the clipboards to a spreadsheet and prepare to do it all again the next day. Meanwhile, on Niwot Ridge, the wind picks up, and the alpine cushion plants sway softly.