Filtering by
- All Subjects: Desert conservation
- All Subjects: Sonoran Desert--Ecology
- All Subjects: Hayden, Carl Trumbull, 1877-1972
- Creators: Fonseca, Julia
- Creators: Cameron, Ralph H.
Letter from Ralph H. Cameron to Carl Hayden thanking him for forwarding Senate Bill No. 390 with the report of March 31st, 1918, and expressing interest in their upcoming meeting in Washington.
Letter from Ralph H. Cameron to Carl Hayden requesting a delay on the introduction of the Grand Canyon bill until he can meet with himself and Senator Ashurst in Washington.
Letter from Ralph H. Cameron asking to speak to Carl Hayden concerning a matter relevant to the bill granting National Park status to the Grand Canyon.
This report examines how effectively Pima County’s natural open-space acquisitions have addressed priorities for conserving species’ habitats and landscape features identified in the Sonoran Desert Conservation Plan. The scope of this study is beyond the County's Multi-Species Conservation Plan, which is a subset of the overall Sonoran Desert Conservation Plan.
The purpose of this study is to provide the U.S. Fish & Wildlife Service with an analysis that identifies anticipated impacts to each of the covered species and asks the question: How effectively will the County's mitigation lands include the specific habitats of covered species under the Multi-Species Conservation Plan?
Develops the methods for using the National Land Cover Dataset to report change by jurisdictions and land ownership by utilizing an existing dataset. Local GIS-based measures of development based on tax assessor records do not provide direct measures of habitat loss.
Chronicles how the intention to conserve a relic population of Gila topminnow under current resource conditions is generally insufficient. We have let the resource base degrade too far to expect project and site specific responses to stem losses, much less lead to recovery. The Gila topminnow was considered to be among the most common of fishes in the Santa Cruz River system in the early 1940s. Three decades later is was considered endangered; and in another three decades time, its recovery is not foreseeable, given the piecemeal approach to protection efforts.
If one species had to be chosen to preserve and restore, perhaps it should be cottonwood. Cottonwood-willow forests, where they exist and are healthy, indicated the presence of a viable riparian area, which is in turn the key to conserving great proportions of our native species. A reflection of the dire status of our riparian systems is that the Sonoran cottonwood-willow and Sonoran mesquite-cottonwood forests.
Two studies that describe the progress of riparian mapping that is being developed as part of the Sonoran Desert Conservation Plan.