Overview
Size: 133,882 hectares
Elevation range: 305–1,463 meters
Organ Pipe Cactus National Monument, in southwestern Arizona, was established by presidential proclamation in 1937 to preserve approximately 330,000 acres of the Sonoran Desert for the public interest.
The monument is a refuge for plants and animals that have adapted to the region's extreme temperatures, intense sunlight, and sparse rainfall. Twenty-six species of cactus live in the monument, including the park's namesake organ pipe cactus and the giant saguaro.
Located in the Sonoran Desert ecoregion, the monument is part of four biomes: desert, thornscrub, semi-desert grassland, and Madrean evergreen woodland. Average annual precipitation is 9.6 inches (245 mm).
The Sonoran Desert Network monitors air quality, climate, groundwater, landbirds, springs, seeps, and tinajas, and vegetation and soils at Organ Pipe Cactus National Monument. The results of this work can be found in a variety of publications and other information. The network also maintains species lists for the park.
Key Issues
Natural resource concerns at the park include border-related impacts (including thousands of miles of unauthorized roads and trails, associated damage to soils and vegetation, interruption of natural ecological processes, disturbance to wildlife movements, an abundance of trash, and impacts to surface hydrology related to the pedestrian fence); highway impacts to wildlife and adjacent habitats; human-caused fire; invasive exotic plants; a lack of knowledge about visitor use; and adjacent land-use trends.
Undesignated roads and trails
As of 2010, there were an estimated 2,553 miles of undesignated roads and trails through the wilderness of Organ Pipe Cactus National Monument. These incursions damage soils, vegetation, and wildlife habitat. Park managers are working to understand the extent and nature of these impacts, and are collecting baseline data on un-impacted areas to facilitate ongoing and long-range restoration plans.
Pedestrian Fence
In spring 2008, the U.S. Department of Homeland Security constructed a five-mile section of pedestrian barrier fence along Organ Pipe Cactus National Monument's south boundary, adjacent to the U.S./Mexico border.
Due to concerns that the fence, made of steel mesh and grate, could disrupt overland water and debris flow at wash crossings during flood events, six permanent monitoring sites measuring cross-section elevation were installed at major wash channels along the fence in April 2008. Four cross-sections at each wash were measured before fence construction and post-construction in 2008, 2009, and 2010.
A major monsoon storm event in July 2008 caused flooding at the Lukeville port of entry, debris piles at the pedestrian fence, road damage, and downstream scouring. Cross-section measurements in fall 2008 showed increased sedimentation and washbed elevation after this event. Measurements in 2009 and 2010 showed a continuing trend of decreased capacity for channel flow in proximity to the pedestrian fence, with the long-term potential for channel realignment and effects to riparian vegetation.
Quick Reads
Showing results 1-6 of 6
- Locations: Organ Pipe Cactus National Monument
- Offices: Sonoran Desert Inventory & Monitoring Network
Sonoran Desert Network scientists monitor key resources and weather at Organ Pipe Cactus National Monument by taking measurements throughout the year, which helps us notice changes over time. This report summarizes weather, groundwater, and springs data from Water Year 2022. The data indicate the park's springs contained near-average levels of water, but high levels of several water chemistry parameters. WY2022 was warm and dry overall, with fewer cold days than average.
- Locations: Chiricahua National Monument, Coronado National Memorial, Fort Bowie National Historic Site, Gila Cliff Dwellings National Monument, Montezuma Castle National Monument, more »
- Offices: Inventory and Monitoring Division, Natural Resource Stewardship and Science Directorate, Sonoran Desert Inventory & Monitoring Network
At nine southwestern parks, Sonoran Desert Network staff are performing environmental DNA (eDNA) sampling. By analyzing the genomes present in a water sample, eDNA sampling allows us to learn which species use a given area without the use of capture, hair snares, or cameras. The results of this inventory will help NPS staff to prioritize springs for monitoring and conservation.
- Locations: Arches National Park, Aztec Ruins National Monument, Bandelier National Monument, Bent's Old Fort National Historic Site, Big Bend National Park, more »
- Offices: Chihuahuan Desert Inventory & Monitoring Network, Climate Change, Climate Change Response Program, Inventory and Monitoring Division, Mediterranean Coast Inventory & Monitoring Network, more »
When the climate changes enough, the vegetation communities growing in any given place will also change. Under an expanded bimodal climate zone, some plant communities in western national parks are more likely to change than others. National Park Service ecologists and partners investigated the future conditions that may force some of this change. Having this information can help park managers decide whether to resist, direct, or accept the change.
- Locations: Organ Pipe Cactus National Monument
- Offices: Inventory and Monitoring Division, Sonoran Desert Inventory & Monitoring Network
At National Park Service units across the Sonoran Desert and Apache Highlands, the Sonoran Desert Network is monitoring small and mid-sized mammals using remote wildlife camera traps. Find out what we're learning about wildlife occupancy at Organ Pipe Cactus National Monument.
- Locations: Capitol Reef National Park, Little Bighorn Battlefield National Monument, Organ Pipe Cactus National Monument
Long-term environmental monitoring usually requires complex sampling designs. By necessity, these designs sample a limited set of conditions on just a fraction of the landscape, which results in missing data. This article summarizes recent research that applies Bayesian modeling to three case studies in national parks. This approach allows park ecologists and analysts to move beyond missing data to support data-driven management and monitoring of natural resources.
- Locations: Big Bend National Park, Carlsbad Caverns National Park, Casa Grande Ruins National Monument, Chiricahua National Monument, Coronado National Memorial, more »
It might come as a surprise to learn that in the sublime expanses of the Sonoran and Chihuahuan deserts, some of the most interesting life around can be found in the dirt right in front of your feet! Biological soil crusts form a living groundcover that is the foundation of desert plant life.
Source: Data Store Saved Search 4920 (results presented are a subset). To search for additional information, visit the Data Store.
Source: Data Store Saved Search 4922 (results presented are a subset). To search for additional information, visit the Data Store.
Last updated: November 1, 2022