Resource Management


To help plants and wildlife, refuge staff uses a variety of habitat management techniques to maintain, recover or enhance plant and wildlife values.

The Buenos Aires National Wildlife Refuge is divided into three management units.The main portion of the refuge encompasses approximately 110,000 of the 117,464 acre refuge. This tract is made up Sonoran semi-desert grassland. The other two units are the Brown Canyon Unit and the Arivaca Unit, which includes Arivaca Creek and the adjacent Arivaca Cienega. An important objective of the refuge is to protect and restore these three habitat types. Management strategies focus on improving habitat for a variety of species with an emphasis on the masked bobwhite quail. The following are some of the ways in which the refuge is helping protect and restore these landscapes for the benefit of wildlife.

Prescribed Burning
Historic records indicate that this formerly open grassland was maintained by wildfires caused by lightning strikes during the summer monsoon season. The size and frequency of wildfires declined after 1882, mostly likely because of the changes to the landscape from human settlement. As a result, during the last century the grassland ecosystem has been invaded by mesquite trees and other shrubby vegetation. To mimic what used to occur naturally, the refuge uses prescribed burning, in conjunction with other habitat management strategies, to inhibit the growth and spread of mesquite trees and to remove small shrubs (snakeweed and burrowed). Fires return nutrients from burned plant material into the soil to nourish new grass. Fire benefits the wildlife by restoring native grasses and stimulating the growth of important food plants.

The refuge is attempting to control invasive and exotic plants that outcompete the native vegetation. These aggressive plants grow quickly and often have no natural predators so they quickly outgrow the native plants. They also are of limited value to native wildlife who have typically evolved to feed on native grasses and seeds. One species of particular concern is Lehmann's lovegrass, a South African grass planted in the 1970's to control erosion. This exotic species now dominates the landscape and has been rapidly replacing native grasses. The refuge is implementing an aggressive restoration effort to protect and restore the native grasses through seeding projects.

Erosion Control
One of the functions of the vegetation is to stabilize soil. Due to the extreme grazing and loss of the native grass cover, this grasslands landscape has lost a lot of topsoil to erosion. The refuge is partnering with local landowners to install some erosion control structures throughout the entire Altar Valley in the hopes of stabilizing the banks of washes and roads.

The refuge maintains existing stock ponds that remain from when the refuge was a ranch. In addition, several new water impoundments have been constructed to catch rain water. These sources of water are extremely important to wildlife in this dry environment. And as water tables in the Valley drop due to human consumption, they become even more important.

Fence Removal
The refuge is removing or altering barbed wire fences left over from ranching days to allow deer and pronghorn to move freely. Many volunteers and wildlife organizations assist the refuge in many of the fence removal projects.