Tamarisk  (Tamarisk parviflora and T. ramosissima) is highly invasive in the riparian ecosystems of the Desert Southwest. Riparian stands of  the native cottonwood/willow association have become vanishingly rare - now inhabiting less than 5% of their original area (by some estimates.).  One of the culprits is the highly invasive Tamarisk, especially successful in flood-prone high disturbance regimes of Southwestern river banks, where high alkalinity and salinity also work in their favor. The Aravaipa Canyon in south central Arizona is host to one of the few perennial rivers in the State, and the river banks are home to a pristine riparian forest of cottonwood and willow overstory.  Tamarisk has begun to gain a foothold, but - by all reports - it is still early enough in its invasion to control its spread. 

The AZ NPS has rtaken on the task of cataloguing and GPS-ing the existing stands of Tamarisk in the canyon, as a volunteer effort.  The canyon is more than 12 miles long and the only way to get in is on foot.  The people at the BLM Safford Office (whose job it is to administer the canyon) have been welcoming and helpful.  They do not have the staff or the funds to conduct the survey themselves.  They  have promised to field an eradication team once the survey is complete.  Follow-up surveys by the NPS will assess the success of ongoing eradication efforts.  A long term database of the fate of these Tamarisk stands may add to our understanding of Tamrisk control statewide, and beyond. 

At present, the primary survey is more than 25% complete.  Further field work in October should complete the survey.  Meanwhile, AZ NPS members have been placed on planning teams for the BLM's new Aravaipa Management Plan.  Control of invasive plants in the entire management area has become a priority shared across interest groups - from ranchers to conservationsists - who are stakeholders in the area.