After planning for more than six months, last summer my family took an epic camping trip across our beloved country. We made a giant loop starting and ending in Ohio with stops as far north as Montana and as far south as Arizona. True to form, my children still argue about which national park is the best.
Our first stop, Badlands National Park, was voted as the best by two of the four kids. After driving for days, we gladly stopped and set up camp in Badlands National Park outside of Rapid City, South Dakota. It was simply breathtaking; we had never seen anything like it.
Wind and water acted as tools in the sculptor’s hand in creating Badlands National Park through erosion and deposition of rock layers. In the foreground, prairie dogs darted about in and out of their burrows. In the distance, prairie grasses waved in the wind in front of massive geologic formations. We were drawn to complementary colors in the landscape. Specifically, tall and wispy grasses tipped with bright yellow blossoms looked stunning against the gray mounds and blue sky.
Invasive species
We soon learned the identification of the flowers from a park ranger; what we thought were wildflowers were actually yellow sweet clover blooms. More surprisingly, they were an invasive species, aliens from another land infiltrating the delicate prairie ecosystem. Yellow sweet clover is appealing to the eye but damaging to the land in a mixed-grass prairie. It is one of over 100 invasive species in Badlands National Park.
To put it simply, the “weeds” disrupt the balance of native plants and animals by overtaking the area. The plants can grow as tall as 4-6 feet, blocking shorter prairie grasses from much-needed sunlight. A variety of animals depend on prairie grasses for survival.
We saw pronghorn sheep grazing around the park and a herd of bison in the distance. We loved watching prairie dogs scuttle in and out of their underground colonies. These herbivores thrive by consuming seeds and grasses. On an even smaller scale, cicadas and grasshoppers make their home in the grassland too.
Not the right place
As visitors to Badlands National Park, we were eyewitnesses to a unique ecosystem, the largest protected mixed grass prairie in the United States. There are some beneficial qualities of sweet yellow clover and in some places it is appropriate to plant. It has to be at “the right place at the right time,” however, and the prairie is not the right place.
Originally intended to be a forage crop, sweet yellow clover blooms are also used to attract honey bees and increase honey production. While it is suitable for grouse, pheasants and ducks to use sweet yellow clover for nesting in other ecosystems, it is not favorable for the animals who call the grassland home.
Milton Haar, chief of Resource Management at Badlands National Park, described a study that is a part of their adaptive park management plan. The objective of the study is to determine how much, if any, yellow sweet clover is consumed by bison. Bison are the largest mammals in the park, weighing between 900 and 2,200 pounds and typically eat about 24 pounds of dry matter a day. Grazing in the wild, bison thrive on a diet of natural grasses. On a ranch, sweet yellow clover is consumed by cattle and the growth is controlled.
The proliferation of sweet yellow clover in the park indicates that if bison are consuming yellow sweet clover, it is a small amount compared to the natural grasses they prefer. Yellow sweet clover increases the amount of nitrogen in the soil. Paired with overshadowing native plants, changing the chemical makeup of the soil can limit the availability of native plants for bison to eat.
The summer of 2019 was the “perfect storm” for sweet yellow clover growth. A rainy spring led into an abnormally wet summer, which also happened to be a blooming year of the bi-annual blooming cycle of sweet yellow clover. The plants grew to new heights not seen in previous years.
We were deceived by the delicate blooms on the slender stalks of green; these plants do not belong in Badlands National Park. It is crucial for the park and animals that call it home that the growth is controlled and ultimately stopped.
Deceptive beauty blindsided us when we arrived at the park, but we left with the desire for preservation of the native plants and animals of Badlands National Park.
