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 85637northstarlearn@gmail.com(520) 490-0760

5/1/2012