Carbon Sequestration in Sagebrush Steppe

Friends of mine called the drive from Boise to Mountain Home, ID, “The Big Ugly.” The one who wasn't driving tried to be asleep by the time they passed the outlet mall on the eastern fringe of Boise. The sleeping friend didn’t have to see the expanses of exotic, invasive cheatgrass that dominate the 40-mile stretch.

This grass was able to invade after the native vegetation was killed by the fires that splash blackened smudges across the area most summers. Green for only a few weeks in spring, cheatgrass spends most of its life as a blanket of short, brown stems, leaves, and bristled seeds. The seeds attach to your socks and work their way down into your boots. They use their travelling tricks to spread into other areas where the native plants have been killed or weakened, where they take root.

My friends had lived in Boise long enough that they remembered when the trip east out of Boise was lush with a shrub forest of sagebrush, tall native bunchgrasses, and evanescent wildflowers in spring. The varied plants wove a tapestry of different shades of green that woke up from winter in waves: first the bluegrass, then the squirrel tail, then the needlegrass and wheatgrass filled the areas between the shrubs. The forbs took turns showing off. Some years the balsamroot astonished my friends with washes of yellow across the hills. Other years the lupines gave it their all and created a pointillist painting with touches of blue. On some trips the red paintbrushes shone and other times it was the yellow ones.

My friends lived next door to each other and worked together for years; they knew each other's stories. But the sagebrush and grasses and wildflowers spun them a new tale each time they traveled to Mountain Home and beyond.

In addition to entertaining my friends, the native sagebrush vegetation also did a far better job of capturing and sequestering carbon dioxide than the carpet of cheatgrass now does. The Big Ugly contains much less carbon in its soil than it did previously, researchers from Boise State University have found.

You can learn more about the study in a piece I wrote for BSU’s Division of Research and Economic Development.

Rare Idaho Wildflower Gets National Coverage

Although it is rooted to a southern Idaho mountaintop, Christ’s paintbrush (rhymes with “mists”) has gone national. The U.S. Forest Service has highlighted the plant on its Celebrating Wildflowers webpage for the Intermountain West.

Christ’s paintbrush, which only grows in one small area, is an unusual kind of hybrid plant. In her Master’s degree research at Boise State University, Danielle Clay found that it is a homoploid hybrid. Although closely related plant species often cross breed, they rarely produce new homoploid hybrid species.

Many hybrid offspring have two sets of chromosomes, one from each parent. But homoploid hybrid offspring end up with just one set and so have the same number of chromosomes as both of their parents. This usually results in homoploid hybrid offspring crossing back with one or both of their parental species until their unique genome disappears. But occasionally, as with Christ's paintbrush, homoploid hybrid offspring are so different from both of their parental species that they cannot cross breed and a new homoploid hybrid species can develop.

After I wrote about Danielle’s work for BSU’s Division of Research and Economic Development, the university allowed us to reprint the piece, with Danielle’s photos, in the Idaho Native Plant Society's newsletter. he Forest Service saw the article and BSU gave the agency permission to use the story and photos from the INPS newsletter on their website.

Celebrating and Learning about Wildflowers

While Christ’s paintbrush boasts a unique origin, all paintbrushes are unusual plants. We talk about their red, yellow, pink, or purple flowers, but what we really see are the colorful flower bracts that nearly hide the tiny, green flowers. If we looked at the roots of one of these plant under a microscope, we would see finger-like structures called haustoria. Paintbrushes use these to tap into the roots of other plants to obtain water and minerals. These colorful wildflowers are not true parasites because they have green leaves that produce food through photosynthesis; paintbrushes are called hemiparasites, or partial parasites. This is why we find them sprinkled across landscapes like paprika and growing next to other plants, such as the sagebrush in the photograph.

The Celebrating Wildflowers website introduces Mycotrophic Wildflowers. These are true parasites, as they have no chlorophyll. This frees them from the green color scheme of most other plants and lets them explore other options. For instance, Indian pipe, or ghost plant, is a translucent, ghostly white. This unusual plant was Emily Dickinson's favorite flower.

Unlike most true parasites, mycotrophic plants do not get food and water directly from other plants. Instead, they tap into the mycorrhizal fungi that coat the roots of many plants. The fungi, with their masses of tiny filaments, or mycelia, help the plants absorb soil water and minerals, especially phosphorus. The plants return the favor by providing the fungi with food produced by their photosynthesizing leaves.

If Emily Dickinson had known how Indian pipe obtains its food, I believe she would have been even more impressed with this plant.