Walking Mountains Curious Nature

Under Attack: The DeBeque Milkvetch Struggles for Survival

Written by Walking Mountains | Aug 3, 2015 3:32:01 PM

Today I would like to draw to your attention the DeBeque milkvetch, the elusive, and hopefully not soon-to-be evanescent, seemingly humble nitrogen-fixing powerhouse of a plant. The DeBeque milkvetch is an endemic species. Endemic means that the species only occurs naturally in one place. The DeBeque milkvetch is endemic to Garfield County, Colorado, a mere 2,956 square miles. To be clear, there are less than 3,000 square miles on this planet where an entire species can occur naturally. This plant is hyper endemic.

And it may be in huge trouble. Not only is this plant’s native range small, but invasive weeds, livestock grazing, roads, recreation, and of course, the indelible mark of society’s heavy hand, contributes to this plant’s increasing rarity. Oil and natural gas drilling in the Roan Plateau area are of particular concern. Located in Garfield County, some view the Roan Plateau as a treasure trove of American energy. Somewhat controversially, others view this Plateau as one of the few places the DeBeque milkvetch can call home.

While a landmark settlement was reached in November 2014 that prohibits the establishment of new oil and natural gas drilling sites on the Roan Plateau for the foreseeable future, things may change in years to come and the DeBeque milkvetch needs protection now (and later). In 2004, two prominent environmental organizations, Rocky Mountain Wild and the Colorado Native Plant Society, petitioned U.S Fish and Wildlife to protect the DeBeque milkvetch under the Endangered Species Act. Perhaps because it lacks the charisma of a cuddly polar bear, the petition was promptly denied. And so what? Another one bites the dust? However, it may shock you to learn how important the DeBeque milkvetch is to other organisms.

The DeBeque milkvetch fixes nitrogen. What? The DeBeque milkvetch, a legume, makes nitrogen, arguably one of the most important elements for life on Earth, available to organisms. Nitrogen makes up roughly 80 percent of our atmosphere, but it primarily exists in its inert form, meaning that living things cannot use it. Enter the milkvetch. Milkvetch species, like most legumes, have tiny bundles on their roots called nodules that contain symbiotic bacteria called nitrogen fixers. These nitrogen fixers are responsible for the conversion of nitrogen (N2) gas, the atmospheric form of nitrogen, into ammonium (NH4+), the form of nitrogen that organisms can actually use.

Nitrogen forms the “backbone” of DNA. Without the biologically available form of nitrogen, our genetic material, the recipe for our very existence, would fail to exist. But that is only the tip of the iceberg. Nitrogen also abounds in proteins, and considering that almost every process in our bodies involves a protein, it becomes clear that fixed nitrogen, brought to us by legumes like the DeBeque milkvetch, is darn valuable.

So once nitrogen is fixed, there are many ways in which it can be spread through the ecosystem.

1. Plant roots leak. Fixed nitrogen seeps out of plant roots and into the soil, where other plants proceed to snatch that nitrogen up and assimilate it into their cellular matrix. People come along and harvest those plants, and voila! You just ate a delicious salad rich with fixed nitrogen. Your DNA and proteins can thank you later.

2. Animals love nitrogen-rich plants. Herbivores that roam the Roan Plateau are probably thrilled to come across the DeBeque milkvetch because it is chock-full of the fixed nitrogen they need. If people come along and hunt the animals chomping away on these same plants, they can benefit from the fixed nitrogen in the bodies of the animals they consume.

You and I may not be clamoring for the DeBeque milkvetch like they’re soybeans (after all, people don’t eat this legume), but this attractive, low-flowering plant provides nitrogen to animals throughout Garfield County. The nutrients the DeBeque milkvetch can provide are not trivial. And neither is this plant’s conservation.

Emily Stuchiner is a Naturalist at the Walking Mountains Science Center in Avon, CO. She enjoys identifying plants and understanding the interactions between organisms in the Rocky Mountains.