A UNIQUE NATURAL AND CULTURAL LANDSCAPE IN SOUTHERN AZ February 2012 Bureau of Land Management – Tucson Field Office
Jan 11, 2016
A UNIQUE NATURAL AND CULTURAL LANDSCAPE IN SOUTHERN AZFebruary 2012Bureau of Land Management – Tucson Field Office
Ironwood Forest National Monument
• Established June 9, 2000 by President Bill Clinton
• Preserve an important desert ecosystem and evidence of human occupation spanning 5,000 years
• Managed by the Department of Interior, BLM-Tucson
• Encompasses approx. 128,400 acres (almost 300 square miles)
• Over 600 species of plants and animals
Silverbell Mtn’s
Sawtooth Mtn’s
West Silverbell Mtn’s
Samaniego Hills
Roskruge Mtn’s
Ragged Top
Waterman Mtn’s
Avra Valley Rd.
Silverbell Rd.
Wolcott Peak and Ragged Top
Ragged Top is one of the dominate features in the landscape.
Example of a “volcanic neck”, or plug22 million years old rhyolite vent
Elevation: 4,261 ft
Microclimates resulting from weathering of rock creating deep crevasses
Waterman Mountains
Sawtooth Mountains
Ironwood Ecological ValueRoosting sites for hawks and owls
Leaves foraged by bighorn sheep, pronghorn antelope and mule deer
Flowers for native bees
Dense canopy for nesting of white winged doves and other birds
Symbiotic bacteria and fungi create “islands of fertility”
Leaf litter provides nitrogen and organic matter for soil enrichment
Trellis for vines
Lower branches protect nursery plants from being trampled and foraged by larger animals
Protection against sunburn for night blooming cerus and other nursery plants
Protection against freezes for saguaro and senita
Wildflower nursery foraged by rabbits and bighorn
Burrows for tortoises in and around roots
Seeds for doves, quail, and rodents
= microhabitat
Air temperatures may be 15 degrees cooler under ironwoods than in the open desert sun five feet away.
Ironwood Tree• Found only in the Sonoran
desert• Ironwood Forest NM contains
the highest density of these trees ever recorded
• Member of the legume family• A hardy, slow-growing tree,
can live to 800 years or longer• Evergreen with pink to
lavender flowers in May• Flowers and roots used as
medicine• Population is dwindling in U.S.
and Mexico due to woodcutting, development, and invasive species.
Bufflegrass: Enemy of the Desert
• Buffelgrass is native to arid and semi-arid regions of Africa, Asia and the Middle East
• Grows densely and crowds out native plants of similar size
• The Sonoran Desert evolved without fire as an ecological factor and most of its plants cannot tolerate it
• A single buffelgrass fire kills nearly all native plants in its path
• Rapidly converting formerly rich biological communities into monocultural wastelands
Wildlife
Desert Tortoise
Big Horn Sheep
Gila MonsterLesser Long Nosed Bat
Rattlesnake
Mule Deer
Ecological Highlights
Organ Pipe Cactus
Elephant Tree
Barrel Cactus in bloom
Turk Head CactusNichols
Nichols Turks Head Cactus is seen in the limestone rich Waterman mountains, and is on the endangered species list.
There is only one organ pipe cactus in the monument, causing a person to wonder how it came to be here.
Botanical Diversity• The steep, rugged, shady canyons on Ragged Top
support a remarkably diverse flora includes over 70% of the total Ironwood Forest NM plant varieties
• A total of 76 plant varieties in the Monument were found only on Ragged Top
Saguaro• The largest cactus in the
USA • Can live to be hundreds of
years old• Plays an integral part of the
desert, providing food and shelter for many desert species
• Ironwood Forest NM has extensive forests of saguaros, growing in densities exceeded only in Saguaro National Park.
Hohokam Culture• Hohokam is a Pima (O'odham) word
used by archaeologists to identify a group of people that lived in the Sonoran Desert.
• There is evidence from campsites to villages suggesting the Hohokam people had settlements in the area.
History of Silverbell • Silvebrell Mountains,24 miles
west of Marana, AZ• High grade ore discovered in
1860s• Established as Silverbell in 1904 • In 1910 the population was listed
at 1,118 persons in 327 households
• Chain of ownership: Development Company of America (DCA)Imperial Copper CompanySouthern Arizona Smelting Company
(ASARCO)
For More Information
Bureau of Land Managementhttp://www.blm.gov/az/st/en/prog/blm_special_areas/natmon/ironwood.htmlLaura Olais – Acting ManagerIronwood Forest National Monument3201 E. Universal WayTucson, AZ 85756(520) 258-7242Fax: (520) 258-7238
HANDS ON THE LAND www.handsontheland.orgGail W. Corkill, Ed D – Education ConsultantNorth Star Learning Solutions, LLCP.O. Box 243Sonoita, AZ [email protected](520) 490-0760
5/1/2012