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Efforts aim to save unique South Rim plant

The Park Service and U.S. Fish and Wildlife Office have developed a plan that they hope will bring back a humble, rock-hugging plant that has nearly been trampled to extinction.

The sentry milk vetch, whose Latin name means "watchman of the gorge," exists in only three small populations on the South Rim. There are 332 plants at Maricopa Point, 220 plants around "Lollipop Point" on the East Rim and just three near Grandview Point. This perennial herb grows in shallow deposits on shelves of Kaibab limestone, blossoming with purple flowers twice a year ­ once in the spring and again following the monsoon rains.

For 45 years after it was first discovered, it was considered to be abundant, but a pair of biologists recognized its rarity in 1947. Placed on the endangered species list in 1990, it is Grand Canyon's only threatened plant.

According to Mima Falk of the Fish and Wildlife Department, the plant has suffered a decline due to loss of habitat, trampling and drought. It is also a low producer, propagated only by seeds that have a one-in-1,000 chance of making it.

"It has such low numbers in itself, then a long history of heavy use by park visitors walking out to Powell Point," she said. "The plant doesn't produce a lot of seeds and they have low reproductive potential."

According to Chief of Natural Resources and Research Cole Crocker-Bedford, the park began efforts to document and protect the plant around the mid-1980s, drafting the first recovery plan in 1993.

Part of that plan included surveying for more populations. Biologists have surveyed much of the South Rim from Hermits Rest to a little beyond Grandview Point, without success. Because of its unobtrusive nature, it is difficult to spot.

Part of that plan included surveying for more populations. Biologists have surveyed much of the South Rim from Hermits Rest to a little beyond Grandview Point, without success. Because of its unobtrusive nature, it is difficult to spot.

"It's a tricky plant to look for," said Crocker-Bedford. "If you're moving at a reasonable pace, you're likely to walk right over it. You have to move really slowly and you can't cover much distance."

Though the plant was only documented on the South Rim, biologists know of a population of about 1,000 similar plants near Cape Final on the North Rim. Crocker-Bedford said these are genetically distinct enough to be considered a different subspecies, though no one can tell if it is endangered as well.

"This population seems to be healthier but we have not surveyed all of the rims to really see," he said. "We'd like to."

Other milk vetch subspecies exist in limestone outcroppings near Marble Canyon but these are not endangered, said Falk.

While efforts in the 1990s helped reverse some of the physical damage the plants suffered, attempts to add new ones through seeding and transplanting seedlings were unsuccessful.

"One of the difficulties of the plant is that it grows in a harsh environment and to get something to establish is a trick," said Crocker-Bedford. "In a greenhouse, its growth form becomes different. It grows in a stunted, low form in the wild and in a greenhouse, it is way more robust."

The Park Service and Fish and Wildlife are working with the Arboretum of Flagstaff, which is growing more plants with seeds collected from the wild over the past two summers. They plan to establish a seed bank, as well as to continue efforts to establish cultivated seedlings in the wild. Along with bolstering existing populations, they plan to establish a fourth in a likely habitat across the road from Maricopa Point, which they will support with a drip irrigation system for the first couple of years.

"The operational question is how to transplant from the greenhouse to a wild situation," Crocker-Bedford said. "It's something that has not yet been figured out but we're trying to figure it out."

To compensate for the genetic weaknesses in the subspecies, Crocker-Bedford said they will cross pollinate between the Maricopa and Lollipop point populations.

"The difference between those populations will enhance the genetic diversity between individuals," he said. "There has been no gene flow for a long time, though there could have been before Grand Canyon Village development."

One of the biggest obstacles has been funding, but biologists were able to renew their efforts last year through the environmental assessment for the Hermit Road restoration project.

Funding going forward is coming from a variety of sources, including the U.S. Department of Fish and Wildlife, the park and the Arboretum of Flagstaff, which had received some grants for their work. Crocker-Bedford said three more grant proposals are pending at the regional level.

"The recovery plan the Fish and Wildlife Service has recently signed gives Grand Canyon National Park a higher probability of getting money out of the Washington office," he said. "All parks compete funding, and if a species already has a recovery plan written, it's recognized there's a lot of thought put into how to recover it."

Over the next five years, it's estimated that recovery efforts will cost close to $1 million, a steep figure but not as costly as bringing an animal back from the brink of extinction.

"A plant doesn't roam large areas so it's a lot easier," he said. "It doesn't take heroic efforts and huge amounts of money. But this needs more effort than what it's had."

To further protect the plant at Maricopa Point, the park has chosen a preferred alternative for Hermit Road that would close the lookout, move the parking lot and pull out the pavement where plants are believed to have grown before. The shuttle stop would remain.

The sentry milk vetch will be downlisted from endangered to threatened once biologists establish four viable populations of 1,000 plants each. It will be considered recovered when there are eight viable populations of 1,000 plants each. Crocker-Bedford said those are milestones that are decades in the future.

"That's so far out there that I don't imagine the planning that far," he said. "We're in more of a crisis mode. The species in a very bad way but it's thought that it can come back. But it's going to take some work."


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