Back to the bosque: the Rio Grande's cottonwood forests are threatened treasures. Here's how they're being saved - Travel Making a Better West

Sunset, Oct, 2002 by Sharon Niederman

Majestic cottonwood trees, their shimmering heart-shaped leaves blazing gold in the autumn sunlight, stand in regal splendor along the banks of the Rio Grande in New Mexico. A breeze rustles the leaves, and for a moment the cottonwoods, some more than 80 feet tall, seem to come alive, whispering secrets of the seasons gleaned from years of watching over the waters.

Known by its Spanish name, bosque, this venerable cottonwood forest stretches some 160 miles along the Rio Grande from Cochiti Lake in the north to just below Elephant Butte Reservoir. The bosque may have a timeless visage, but New Mexico's native forest is dying: only mature and aging trees live there. Most of the cottonwoods are 40 to 80 years old, and natural regeneration is not replacing them. According to bosque restoration pioneer Cliff Crawford, "If current trees are not replaced by their offspring, the cottonwood bosque will be overwhelmed by non-native species and disappear within this century."

The trouble is on the banks of the Rio Grande itself Decades of taming the roughly 1,900-mile-long river have severely curtailed its movement. Where it once meandered over an ancient floodplain up to 4 miles across, the river is now constrained to a mere 1/4 mile in most areas, effectively eliminating the mosaic of cottonwoods and willows of varying ages that once grew there. In addition, the water flowing downstream from Cochiti Dam and other diversion dams has gouged and lowered the riverbed as far south as Elephant Butte Reservoir, depriving cottonwoods of their historic habitat--riverbanks low enough to be flooded with some regularity in late spring.

"Cottonwoods evolved with the river," says Crawford, "so their 2- to 3-week germination window coincides with historical spring peak water flows of the Rio Grande." Because of damming, channel-building, and urban development, the seasonal river fluctuations that once nurtured cottonwood seedlings no longer occur.

The other big problem is increasing competition from water-guzzling, non-native plants introduced in the early 20th century Tamarisk (salt cedar), Russian olive, and Siberian elm are all taking a toll on the bosque.

The river does all the work

These are serious problems. But in 1996, Crawford and his colleagues came up with a potential remedy--the Albuquerque Overbank Project. Along the Rio Grande in Albuquerque's South Valley, 41/2 acres were cleared of Russian olive and salt cedar, and 21/2 acres of riverbank were lowered to re-create the natural floodplain. The result: flooding took place, and cottonwood seeds that landed on the wet soil after the water receded produced about 10,000 seedlings. Three years later, about 9,000 still survived. "We let the river and the cottonwoods do all the work, and what we expected would happen is happening," says Crawford.

Northwest of Albuquerque, Pueblo of Santa Ana is working to reclaim the bosque along the 6-mile stretch of the Rio Grande that runs through tribal lands. In 1996, the tribe began removing all exotic species within the bosque and re-establishing natives such as cottonwood and black and coyote willow, as well as many species of grasses and shrubs. Portions of the riverbed are also being lowered to permit seasonal flooding.

The fruit of this labor is clear to strollers on a tranquil new mile-long trail accessible from the back door of the Hyatt Regency Tamaya Resort and Spa. Meandering through 350 acres of restored native grasslands and cottonwood forest, the trail is testimony to the benefits of restoration. Here, visitors discover the healthy bosque much as Santa Ana tribal administrator Roy Montoya remembers it: rich with plants and wildlife, dominated by a canopy of native cottonwoods.

Farther south, at Bosque del Apache National Wildlife Refuge, the goal is also to mimic the natural flow of the river and its spring floods, but the approach is slightly different. "It's like irrigating," explains U.S. Fish & Wildlife Service ecologist Regina Dello Russo. She notes that since the project began in 1987, they have restored 1,500 acres of diverse riparian habitat.

The 1-mile Rio Viejo Trail at the north end of Marsh Loop, 1 1/2 miles east of the refuge entrance, leads through one restored area--a 13-year-old cottonwood forest along the old river channel. Trees topping 40 feet wave in the wind. From here, immense flocks of snow geese, sandhill cranes, and other waterfowl may be seen, having safely made the journey to their winter home, sheltered by the timeless cottonwoods.

RELATED ARTICLE: Autumn cottonwood hikes

Bosque trails are accessible year-round, but fall, with its glorious color, may be the best season to appreciate the forest. Temperatures through October may reach the 70s or even the 80s at midday. Take hat, sunscreen, and water.

Bosque del Apache National Wildlife Refuge. From U.S. 380 at San Antonio (1 mile east of 1-25) take Old State Hwy. 1 south 8 miles to visitor center. $3 per vehicle. (505) 835-1828 or www.fws.gov.

Basque Restoration Demonstration Project. Five acres of riparian forest on the east side of the Rio Grande between Central and Bridge, SW, have been restored adjacent to Tingley Or. From Central turn south on Tingley and drive about 1/2 mile to parking and a 1/2-mile trail. (505) 266-3609 or (505)452-5210.