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Ecuadorian Hydroelectric Plant Could Cause Extinction of Rare Plant

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


A planned hydroelectric project on Ecuador's Rio Topo will generate 22 megawatts of energy for the surrounding area, but building it also will likely wipe out a rare plant.

The plant, a mosslike liverwort called Myriocolea irrorata that lives only in the region, was first discovered on the banks of the Rio Topo in 1857 by Scottish explorer Richard Spruce. It then went unseen for nearly 150 years. After years of searching, botanists Rob Gradstein, Noelle Noske and Lou Jost rediscovered it in 2002 further upstream from where Spruce had seen it, just about the same time the hydroelectric project was first announced.

Not a lot is known about the species. It's tiny—about 2.5 centimeters across—and its role in the food chain of the area remains a mystery. But scientists may not have a chance to learn more if the hydroelectric project alters its unique habitat.


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"The hydroelectric project will affect about 75 percent to 80 percent of the population [of the liverwort]," says Jost, who has lived in Ecuador for 13 years studying the endemic plants of the Baños region. The project will funnel the river into a series of tunnels, which will remove 90 percent of the water from the riverbed, leaving just 10 percent of the natural flow. That may not be enough water for M. irrorata.

Rio Topo is an unusual river and provides an ideal habitat for the liverwort. The river is located in one of the rainiest areas of Ecuador, and its granite and limestone watershed and low gradient combine to create a river that changes its volume dramatically throughout the year, often tripling or quadrupling its width in the course of an hour, but also allowing shoreline vegetation to grow without being torn away by fast currents.

These factors create what Jost calls a "unique ecological niche" that has allowed several plants to evolve to suit the area. M. irrorata "apparently has to be frequently covered by spray or water. But at the same time it requires a stable riverbed, so that its host shrub, cuphea, can root in the bed," he says.

M. irrorata is fairly common within a very tight area around an eight-kilometer stretch of the river. The cuphea shrub there has a population density of 30 plants per square meter, and Jost says each shrub could contain 10 to 100 Myriocolea plants—but the Myriocolea population drops off dramatically just a few meters from the water. "There are no plants more than about 10 meters from the river," he says.

If the hydroelectric project changes the flow of the river and the constant spray of water disappears, the main population of M. irrorata may disappear with it.

Another, smaller population does exist further upstream. "That upstream portion, however, is not as dense as the downstream population, and may not form a viable population," Jost says. He also discovered a tiny population of the plants on the adjacent Rio Zunac, but its entire habitat there is just one square meter. "This population is so small, and occurs in such a dynamic landscape, that it has no conservation value," he says.

Jost says the unique factors that allow M. irrorata to thrive in this tiny stretch of riverbank would be very difficult to reproduce, making cultivation of the plant outside of its habitat hard, if not impossible.

Although Ecuador has a shortage of electricity, residents of the El Topo village and their lawyer Oscar Valenzuela have spent years fighting the project in the courts (they lost) and the last several months blockading roads and preventing construction equipment from entering the region. One protestor told the El Comercio newspaper in June that the Baños area is about tourism, not electricity, but the president of nearby Rio Negro Parish told the paper that the project will create 120 local jobs and generate hundreds of thousands of dollars for the region over the next 30 years.

Two weeks ago, according to Jost, police entered the region and forcibly removed the protestors, most of whom were women.

Jost argues that the hydroelectric project will wipe out M. irrorata and other endemic species and provide little real energy value. "The township which includes the Topo already produces more than 200 megawatts from other dams, and one single dam in the planning stages in northeast Ecuador will generate 1,600 megawatts," he says.

But with the protestors removed, and the project fully supported by Ecuador's government, Jost sees little hope for the tiny plant he has fought for. "The project will be built, and the newly rediscovered plant will probably become extinct."

Access roads for the hydroelectric project are currently being built, with construction expected to begin as early as January.

And so river of progress flows...

Myriocolea irrorata photo by and courtesy of Lou Jost

John R. Platt is the editor of The Revelator. An award-winning environmental journalist, his work has appeared in Scientific American, Audubon, Motherboard, and numerous other magazines and publications. His "Extinction Countdown" column has run continuously since 2004 and has covered news and science related to more than 1,000 endangered species. John lives on the outskirts of Portland, Ore., where he finds himself surrounded by animals and cartoonists.

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