Ironwood Forest National Monument
From Wikipedia, the free encyclopedia
| Ironwood Forest National Monument | |
|---|---|
| IUCN Category III (Natural Monument) | |
  |
|
| Location | Pima County & Pinal County, Arizona, USA |
| Nearest city | Tucson, AZ |
| Coordinates | |
| Area | 129,022 acres (522 km²) |
| Established | June 9, 2000 |
| Governing body | U.S. Bureau of Land Management |
Ironwood Forest National Monument is located in the Sonoran Desert and the U.S. state of Arizona. Created by William Jefferson Clinton by Presidential Proclamation 7320 on June 9, 2000, the 129,022 acre (522 km²) monument is managed by the U.S. Bureau of Land Management, an agency within the U.S. Department of the Interior. Although the National Monument status applies only to federal lands, the monument perimeter surrounds about 189,000 acres (765 km²) contiguous of federal and private land holdings, including Arizona State School Trust lands. A significant concentration of Ironwood (also known as Desert Ironwood, Olneya tesota) trees is found in the monument, along with two federally recognized endangered animal and plant species. More than 200 Hohokam and paleoindian archaeological sites have been identified in the monument, dated between 600 and 1450 A.D.
The Ironwood is a long-lived tree, with some specimens estimated to be more than 800 years old.[1] Ironwood is a pivotal species because it provides a nursery environment of shade and protection that enables young seedlings of other species to become established despite the harsh desert climate where night-time low temperatures can exceed 105 degrees Fahrenheit. The Ironwood also provides shade and roosting areas for birds. Its smoky lavender-colored blossoms provide nectar for bees and other insects, as well as forage for animals. The blossoms give way to bean pods which also provide food for desert animals.
According to Proclamation 7320, 674 plant and animal species have been identified in the Silverbell Mountains within the monument, including 64 species of mammals and 57 species of birds, although the Bureau of Land Management has been unable to verify those claims. Recent studies by the Arizona-Sonora Desert Museum, however, have documented 560 plant species.[2] Resident birdwatchers have documented more than 80 species of migratory and non-migratory birds.[3] The Arizona Desert Bighorn Sheep herd located within the monument is the last remaining relict population of desert bighorn sheep in southeastern Arizona, having first migrated into North America during the Pleistocene epoch. One or two specimens of the Cactus Ferruginous Pygmy Owl, which was listed as an endangered species in March 1997 and delisted by court order April 14, 2006, have been found within and near the monument by licensed surveyors.[4] One specimen of the endangered Lesser Long-nosed Bat(Leptonycteris curasoae) and a night roost were documented within the monument by bat researchers Karen Krebbs and Yar Petryszyn. They concluded that while the monument may be an important feeding stopover during spring migrations, the presence of L. curasoae in the monument is probably low or incidental.[5]Leptonycteris curasoae is one of only a few bat species that migrate long distances, coming from as far south as Jalisco, Mexico, more than 1,600 miles (2,570 km). Small populations of the endangered Nichols Turk's Head Cactus, although not found among Ironwood trees, occur in very localized limestone-rich areas within the Monument.
The Ironwood Forest National Monument is managed for multiple uses including recreation, cattle grazing and mining, although new mining claims and motorized off-road travel are prohibited by the establishing Proclamation. Livestock grazing, which has occurred continuously for at least the last 125 years within the monument, is currently managed at very light or conservative levels of approximately one cow per every 300 to 400 acres. Domestic sheep and goats are prohibited as a protection to the bighorn sheep. The Monument offers almost no surface water but contains sufficient groundwater resources. The cattle ranchers maintain more than 80 individual man-made water sources within the monument, in addition to the 14 water sources maintained by the Arizona Game and Fish Department and the Arizona Desert Bighorn Sheep Society. The presence of human-supplied water supports the exceptional abundance of birds, mule deer, coyotes, foxes, bobcats, mountain lions and other wildlife found in the monument.[6] The Hohokham people were the first miners in the area. They mined andesite, which was useful for making agave knives. Andesite knives that originated from Hohokham mines within the monument perimeter have been found as far south as the Sea of Cortez in Mexico. Silver and copper mining began in the Silverbell Mountains around 1850 and continues today. Bighorn sheep ewes prefer mine tailings for lambing grounds because the high, steep and open terrain enables them to see and escape from predators.
[edit] References
- ^ "The Importance of Olneya tesota as a Nurse Plant in the Sonoran Desert", Humberto Suzan, Gary P. Nabhan, Duncan T. Patten, Journal of Vegetation Science, Vol. 7, No. 5 (Oct., 1996), pp. 635-644 doi:10.2307/3236375
- ^ Biological Survey of Ironwood Forest National Monument, Vascular Flora. Thomas R. Van Devender, John F. Wiens, and Mark Dimmitt.
- ^ Public comments submitted to Bureau of Land Management regarding the Ironwood Forest National Monument Draft Resource Management Plan and Environmental Impact Statement, May 30, 2007.
- ^ Cactus Ferruginous Pygmy Owl records of US Fish and Wildlife Service
- ^ Biological Survey of Ironwood Forest National Monument, Karen Krebbs and Yar Petryszyn, Arizona Sonora Desert Museum
- ^ "Wildlife Water Developments and Desert Bighorn Sheep in the Southwestern United States." 2005. Arizona Desert Bighorn Sheep Society. *[1]
[edit] External links
- Ironwood Forest National Monument Proclamation. U.S. Bureau of Land Management. Retrieved on 2006-08-13.
- Ironwood Forest National Monument Fact Sheet. U.S. Bureau of Land Management. Retrieved on 2007-07-06.
- Biological Survey of Ironwood Forest National Monument Vascular Flora. Arizona Sonora Desert Museum. Retrieved on 2007-07-06.
- Cactus Ferruginous Pygmy Owl. U.S. Fish and Wildlife Service. Retrieved on 2007-07-06.
- Biological Survey of Ironwood Forest National Monument: Lesser Long-Nosed Bat. Arizona Sonora Desert Museum. Retrieved on 2007-07-06.
- Arizona Desert Bighorn Sheep Society, a nonprofit organization committed to increasing bighorn sheep populations in Arizona
- Crossley, John. Ironwood Forest National Monument. Retrieved on 2006-08-13.
