Minirhizotrons took these photos depicting root growth over a three-week period in the summer of 2011. Image courtesy of ORNL.

Teeny little video cameras called minirhizotrons snapped these photos of wetland plant roots. The cameras will help scientists anticipate how the plants might respond to climate change.

Minirhizotrons give scientists at the Oak Ridge National Laboratory a technological boost by allowing them to study living roots, especially the really small ones, without harming the plants. By tracking the life and death of roots in their real-life soil environments, with a few manipulations here and there, scientists can better understand what effects increasing temperatures and carbon dioxide levels will have on wetland ecosystems.

The specific wetlands in question are bogs, which are carbon-rich, but nutrient-poor environments. In other words, bogs collect a lot of carbon deep in their soil due to large buildups of dead plant matter. However, their soils don’t have a lot of nutrients to give back to living plants, making them tricky places for plants to grow.

Roots are responsible for transporting water and nutrients to the rest of the plant. So, in bogs, they have to work extra hard to keep plants alive.

Scientists will use the minirhizotrons in one of Minnesota’s black spruce bogs to track how roots react to their climate-change-mimicking manipulations.

Bogs cover only 3 percent of the Earth’s surface. So, why should we care what happens to them?

Because they store nearly one-third of our terrestrial carbon. Thus, if the planet continues to warm, scientists predict these bogs will dry out and release tons of carbon into the atmosphere, exacerbating warming.

Yikes.

Image courtesy of ORNL. Source: Method of studying roots rarely used in wetlands improves ecosystem research

Some plants, notably catnip, make cats feel good, Sawchuk says. “If I eat this, I am going to get spacy, and I like that feeling.” Some cats also like spider plants, which contain compounds related to opium. “Or cats learn that certain plants will act as a purgative, causing them to vomit if they have an upset stomach,” Sawchuk says.

But plants can also be poisonous. Asiatic lilies, including Easter lilies, are a key cause of concern. “Ingesting even a tiny amount can put a cat into kidney failure,” Sawchuk says.

Owners should separate cats from toxic plants, but also deal with the many cats that like plants. Owners may want to offer their cats edible sprouts, chopped lettuce, or the “kitty grass” sold in pet stores. Sawchuk recommends that cat owners check reputable web sites for lists of toxic and nontoxic plants, and make sure to place any toxic plants well beyond reach.

Reader beware: The ASPCA says aloe vera causes vomiting, depression, diarrhea and other symptoms among cats.

However, dandelions may be a special case, he says, since they seem perfectly suited to conditions in this area.

“I’ve only been in Wisconsin for two years, but I am amazed at how common dandelions are,” Renz says. “I have never lived in a place where the environmental conditions are just right for dandelions to explode like this in the spring.”

Dandelion seeds can drift on a breeze of just 4 miles per hour, and the plants can live for several years, so they can survive poor years and jump up the next spring.

The ecological role of weeds is to occupy new ground, and dandelions “are really good at invading sites,” Renz says. “Wherever they land, if there is bare ground, when it warms up, they will start germinating.”

In many years, dandelion seeds have already sprouted by February or March, he says.

The bad news is that an acre of pure dandelions can produce about one-quarter billion seeds, Renz says. The good news is that, “in the grand scheme of things, there are a lot worse plants than dandelions.”

Pollination is the transfer of pollen (the plant equivalent of sperm) to eggs. Some plants rely on wind or gravity, but many require animals to do the transportation. The smell of the flower alerts pollinators that the plant is ready to be pollinated, and when the animals arrive to collect pollen and/or nectar, pollen gets transferred.

Plants and pollinators often display a long history of mutual evolution, Iltis adds. When Charles Darwin saw a flower with a foot-long tube during the 1800s, he predicted the existence of a moth with an equally long “tongue” that could reach the female parts at the bottom of the tube. This moth was discovered more than a century later!

The minty, oily or sharp smells produced when you crush a leaf or stem play a defensive role, Iltis says. These smells come from chemicals that are often toxic to animals, and thus serve as a one-two punch: they smell (and taste) terrible, and then they make you sick if you ignore your senses and take a bite.

During the long struggle for existence, Iltis says, evolution has shaped every part of plants – including their chemical composition. But pollination is a troublesome subject: many crops are under threat as honeybees succumb to “colony collapse disorder.” Although the cause is unknown, environmental disturbance likely plays a role, Iltis says.

Cyrtobagous salviniae

This CSI is Salvinia molesta, or Giant Salvinia, a fast-growing, free-floating aquatic fern that is native to Brazil. Instead of roots, the Salvinia uses a three-leaf or frond approach: two water resistant fronds float atop the surface while the third frond is divided into sections and submersed in the water, serving as a “root.”

This giant fern is generally found in fresh water ponds and lakes. The fern forms floating mats up to 2 feet thick that block sunlight and reduce oxygen content to other water-dwelling organisms. The fern’s rapid growth rate can completely cover the surface of lakes and streams, and it has the ability to double its surface area in five days. These mats also muck up boating, fishing and swimming.

The Salvinia is hardy and difficult, if not impossible to kill or control once it is established a home for itself. It appears to be resistant to most chemicals, but new biological controls may help correct the problem. A tiny weevil, Cyrtobagous salviniae, is under study as a biocontrol for the invasive Salvinia.

While cool to look at, the Salvinia is viewed as a dangerous pest. U.S. Federal and state laws prohibit the importation, transportation, and cultivation of the Species.

Photo by Scott Bauer. Courtesy USDA.