Controlling Giant River Cane to Economic Advantage

By
Jim Earhart, Ph.D.
Director of the Rio Grande International Study Center Cane Control Project

Unfortunately for the vegetation and wildlife of the riparian habitat along the Rio Grande this American heritage river was made part of the border between the United States and Mexico. The historic economic disparity between the two countries, coupled with the recent “war on terrorism,” has created a “war” on water quality and habitat for native plants and animals along the river.

The United States Department of Homeland Security is spending large quantities of tax dollars to stop the flow of illegal traffic across the border. This expenditure includes a proposal to eradicate giant river cane (Arundo donax, A. donax) by mechanical removal with heavy equipment and by aerial application of a broad spectrum herbicide by helicopter.
We agree that this invasive plant provides concealment for illegal activity, replaces indigenous plants that provide habitat for native species, and uses large quantities of water that could be used by farms and cities, but we believe the means suggested by the federal government will be highly detrimental to the ecology of the Rio Grande.

River cane has replaced willow and other riparian trees that serve as sources of food and nesting for important bird species. Small U. S. populations of Groove-billed Ani, Altamira Oriole, Elf Owl, Ferruginous Pygmy Owl, Brown Jay, Gray Hawk, Chachalaca, Ringed Kingfisher, Hook-billed Kite, and White-tipped Dove are confined to a relatively small area in South Texas, mostly along the river. Increasing acreage of A. donax will be detrimental to these species. Cane should be controlled, but aerial spraying, the method of choice by Homeland Security, will kill native vegetation that serves as habitat for native species.

Giant river cane was introduced into the Americas by the early Spanish settlers who used it to construct crude housing, weave baskets and mats, make musical instruments, and, very likely, to feed livestock. Because of its prolific growth in warm, moist environments that lack natural enemies, A. donax has been far more successful in America than in its native Mediterranean region. Dense stands of the cane extend for hundreds of miles along the Rio Grande.

The Rio Grande International Study Center, in conjunction with Laredo Community College (LCC), is investigating the potential use of this invasive species of giant grass as food for livestock. Most local ranchers along the U. S. river bank do not graze livestock on the cane for fear of theft or for fever tick infestation or because they believe animals will not eat the cane.

Our work was stimulated by reports that goats have been used with some success in controlling cane growth in California. Furthermore, we have seen horses, goats, cattle, and donkeys drinking from the river in Mexico across from the LCC Campus and concomitantly we have observed very little cane growing on the Mexican river bank. Rather than cane the Mexican bank is lined with large trees that shade the flowing water.

These observations prompted two of our members, Tom Miller, Director of the Lamar Bruni Vergara Environmental Science Center and Dr. Tom Vaughan, Texas A&M .