by Jeff Stern

This time of year, as winter in the San Luis Valley grudgingly gives way to the first warm days of spring. Rancher Benny Martinez keeps an especially close eye on his cattle grazing along the Alamosa River. Martinez wants to make sure cows don’t nip the cottonwood saplings and fragile young willow shoots that have emerged in his riparian pastures the past few years. His efforts could lead the way to a river-wide resurgence of woody vegetation, which in recent decades has declined due to the overuse of riparian an areas and the insidious effects of channel straightening.
In October 1997, the Colorado Riparian Association awarded Martinez a plaque recognizing the Conejos County,. Colorado, native for his “exemplary management and restoration efforts on the Alamosa River.”
“For me, it’s more important to have a river that works well and looks nice than to add an extra few head [of livestock],” said Martinez, who helps run a family-owned construction business in addition to operating the ranch. “You can’t take everything out of an area without putting something back.”
The first few years after Martinez purchased his river property in the early 1990s, he noticed there weren’t any young cottonwoods growing up to replace trees that were toppled by windstorms or old age. Closer insepection revealed that cattle ate the saplings that emerge from rhizomes, or root suckers.
“When trees are budding, cattle hit them hard and it really sets them back,” Martinez said. “Early spring is probably the most critical time.” He has found that the best time to graze his riparian pastures with minimal damage to emerging cottonwood trees is from December through February. In the summers of 1996 and ’97, Martinez leased pasture away from the river and gave his bottomland a much-needed breather.
Eventually, after saplings grow to about six feet, a height they’re approaching after just two seasons’ worth of undisturbed growth, Martinez plans to graze his riparian pastures a little longer and harder. Cattle may nip the side branches of six-foot cottonwoods, he said, but the leader at the top of the plant should be out of reach by then.
“If people could get their cows off the river before the growing season starts, the trees would come back.” The problem comes, Martinez believes, when ranchers leave livestock in riparian areas through lune. Sometimes this is more out of necessity than by choice, due to the scarcity of supplemental range.
Even in winter, a season when emergent cottonwood offer neither succulent buds nor leaves to tempt cattle, Martinez discovered he must monitor the herd closely. “In winter, cattle might thin out grasses after about three weeks. Then they’ll start on the trees. Once they taste them, they’ll hit them harder. As soon as I notice them hitting the trees, I pull them out right away.”
He estimated that he loses about 20 percent of the grazing capacity in each of his riparian pastures because he removes cattle at the first sign they’re zeroing in on the trees, rather than letting livestock linger long enough, maybe for another week or so, to strip them.
It’s a question of long term versus short term benefits. By not squeezing every available scrap of forage out of his pasture now, Martinez is laying the groundwork for a healthy plant community in the years to come. He’s seen how trees shade grasses that grow beneath them. Even during the worst droughts, grasses stay green and grow taller. Forage production for livestock and wildlife is enhanced.
In addition to overuse, the riparian corridor along the Alamosa River is still reeling from the effects of a channelization project buiIt nearly 30 years ago. A two-mile swath of the once meandering river was straightened to prevent flooding in the tiny town of Capulin. Channelization set in motion a disastrous chain of events. Where flows once were slowed as the Alamosa River wound around meanders, water began ripping through the straightened stretch at a high velocity, scouring a deeper channel. As the river dropped, so did the water table in adjacent riparian areas, which dessicated the plant community. Stream banks collapsed. Roads, bridges, irrigation headgates and land have been, and continue to be, damaged.
Martinez serves on the steering committee for the Alamosa River Watershed Project, sponsored by the Conejos County Soil Conservation District. This grassroots project aims to develop a coordinated plan to restore the entire portion of the river hurt by channelization. The damage has spread to encompass 12 miles.
In 1996. Martinez allowed the Alamosa River Watershed Projectto use a portion of his property for an erosion-control demonstration site. A series of vortex rock weirs and rock veins designed by Dave Rosgen of Wildland Hydrology in Pagosa Springs, Colorado, were installed in the river. These structures slow the velocity of flows, which helps recharge the water table, and direct flows away from vulnerable stream banks.
Demonstrating the latest thinking in erosion control has spurred discussion in the broader community. Thanks to the efforts of Martinez and others on the watershed proiect steering committee, people are realizing that sound management of riparian pastures will help stabilize the river, as well as improve forage production and beautify their land. Healthy plants growing along the banks reduce erosion.
Of his grazing management experiments. Martinez said. “I’m still learning.” Maybe so, but on a river where the riparian zone, in places, is as closely cropped as a gulf course and where the harsh summer sun scorches treeless, de-watered pasture, his work offers hope for the renewal of the Alamosa River’s endangered cottonwood forest after decades of decline.

Colorado Riparian Association