Science Articles

With over 250 species of birds recorded from Joshua Tree National Park, it is understandable that the park affords a rewarding place to study them. This is especially true during the winter months when migrants abound.

Biodiversity in bird communities has declined drastically over the past century in the Mojave Desert, according to a recent landmark study by researchers at the University of California, Berkeley. They found an average 43 percent decline in bird species diversity. Reduced precipitation, a consequence of climate change, seems to be driving the declines.

Desert bighorn sheep live on islands of mountain habitat and use surrounding desert for travel and food. These same desert areas contain a variety of human-made barriers that threaten the area’s individual bighorn herds. Researchers are collecting data that will provide telling information about how we can help support and protect bighorn populations across the Mojave Desert into the future.

Compilation clips of a desert tortoise walking and eating.

Biologists in Joshua Tree National Park have been collaborating with the U.S. Fish and Wildlife Service to monitor Mojave desert tortoises (Gopherus agassizii) with radiotelemetry since 2003—one of the longest-running tortoise monitoring programs in the nation.

The GIS program at Joshua Tree National Park (JTNP) maintains accurate geospatial data for the park, produces high-quality maps, collects and processes a wide variety of data, and supports the effective use of GIS for park management and operations.

Scrambling to the top of boulders in Joshua Tree can get you a great view.

Scrambling to the top of boulders in Joshua Tree can get you a great view.

Take in views of the park's iconic Joshua trees and rock outcrops in Lost Horse Valley.

Take in views of the park's iconic Joshua trees and rock outcrops in Lost Horse Valley.

The namesake species of Joshua Tree National Park is threatened on multiple fronts. With a warming climate, habitat suitable for Joshua trees (Yucca brevifoia var. brevifolia) within the park is predicted to shrink by 80-85% by the end of the century in a moderate warming scenario (Sweet et al., 2019).

Gathering Vegetation Sign at Black Rock Campground

Gathering Vegetation Sign at Black Rock Campground

The wide-open desert of Joshua Tree National Park makes for stunning sunsets.

The wide-open desert of Joshua Tree National Park makes for stunning sunsets.

Take in views of the park's iconic Joshua trees and rock outcrops in Lost Horse Valley.

Take in views of the park's iconic Joshua trees and rock outcrops in Lost Horse Valley.

The Joshua tree, iconic symbol of the Mojave Desert, is being discussed as an endangered species at both a State and Federal level by the state of California and United States Fish and Wildlife.

Timelapse of the setting sun over fallen Joshua tree near the West Entrance

NPS/Cathy Bell

Water is one of the scarcest resources in Joshua Tree National Park (JTNP), shaping the Mojave and Colorado desert ecosystems within the park. The park’s surface water and groundwater resources are monitored to understand the impact of climate change on water resources and to identify potential management activities that may help protect natural resources that are threatened by dropping groundwater levels.

The GIS program at Joshua Tree National Park (JTNP) maintains accurate geospatial data for the park, produces high-quality maps, collects and processes a wide variety of data, and supports the effective use of GIS for park management and operations.

Joshua Tree National Park is collaborating with outside scientists to better understand the effects of climate change on plants and animals in the park.

Visitors to Joshua Tree National Park expect clean desert air and beautiful views. But though the park is protected in many ways, air pollution ignores boundaries. Haze often obscures mountain vistas, and in hot weather, ozone concentrations sometimes exceed levels safe for people to breathe.

Air quality profile for Joshua Tree National Park. Gives specific information about air quality and air pollution impacts for Joshua Tree NP as well as the studies and monitoring conducted for Joshua Tree NP.

Meet our narrators, Donovan Smith and Ian Chadwick, as they explore some of the park's unique and special resources through interviews with experts in the field. The episodes cover various topics, from night skies to wildlife and so much more. The podcast's title, "Where Two Deserts Meet," refers to the transition zone between the Colorado and the Mojave Deserts within Joshua Tree National Park. Listen in and explore the wonders of the deserts and ways we can help preserve them for future generations.

Environmental changes are occurring at increasing rates over the last century in the Mojave Desert. Examples include rising temperature, decreasing precipitation, and more frequent extreme events like wildfire and flooding. Learn more about what we are monitoring in the Mojave Desert Network parks, some early changes we are seeing, and how what we are learning can be used to help managers plan for the future.

Joshua Tree National Park is collaborating with outside scientists to better understand the effects of climate change on plants and animals in the park.

The namesake species of Joshua Tree National Park is threatened on multiple fronts. With a warming climate, habitat suitable for Joshua trees (Yucca brevifoia var. brevifolia) within the park is predicted to shrink by 80-85% by the end of the century in a moderate warming scenario (Sweet et al., 2019).

Water is one of the scarcest resources in Joshua Tree National Park (JTNP), shaping the Mojave and Colorado desert ecosystems within the park. The park’s surface water and groundwater resources are monitored to understand the impact of climate change on water resources and to identify potential management activities that may help protect natural resources that are threatened by dropping groundwater levels.

Biodiversity in bird communities has declined drastically over the past century in the Mojave Desert, according to a recent landmark study by researchers at the University of California, Berkeley. They found an average 43 percent decline in bird species diversity. Reduced precipitation, a consequence of climate change, seems to be driving the declines.

Scientists have identified the Southwest as a climate-change hotspot. Its climate, already warm and dry, may be particularly vulnerable to rising global temperatures. Small changes in temperature and precipitation can greatly affect sensitive desert plants and animals. Read on for an introduction to climate change in the Southwest, or visit the Science of the American Southwest Climate Change webpage to learn about specific climate change projects.

Deserts, by definition, get scant rainfall. Add the effects of a record drought, and it's crucial that desert dwellers and visitors alike focus on conserving water ... even when El Niño brings rains to some parts of California.

Water conservation is always important in the desert, but saving water is even more critical during the current period of historic drought in the state of California. We can learn about how to be water-wise by looking to the example of native desert species, which have evolved to cope with rains that are not only scarce but unpredictable.

Parks are responding to the effects of climate change using an active approach to wilderness stewardship. This study describes the level and diversity of the stewardship responses and the effects they have on wilderness character.

National parks are special lands that are designated to permanently protect things that are part of our collective heritage like stunning views, unique wildlife, endangered species, areas of recreation, and wilderness. Seventeen national parks in the United States were created partly to protect the fossils found in them. Joshua Tree National Park is one of these!

In the western United States, packrat middens are one of the best tools for reconstructing recent environments and climates. These accumulations of plant fragments, small vertebrate remains, rodent droppings, and other fossils can be preserved for more than 50,000 years. Packrat middens have been found in at least 41 National Park Service units.

All across the park system, scientists, rangers, and interpreters are engaged in the important work of studying, protecting, and sharing our rich fossil heritage. Park Paleontology news provides a close up look at the important work of caring for these irreplaceable resources.

• Contribute to Park Paleontology News by contacting the newsletter editor
• Learn more about Fossils & Paleontology
• Celebrate National Fossil Day with events across the nation

The Western Science Center in Hemet, California serves as a repository for fossils from several land management agencies. It is currently running an exhibit, “Fossils from Your Public Lands”, to showcase examples of these fossils with the cooperation of additional parks and repositories.

The National Park System contains a magnificent record of geologic time because rocks from each period of the geologic time scale are preserved in park landscapes. The geologic time scale is divided into four large periods of time—the Cenozoic Era, Mesozoic Era, Paleozoic Era, and The Precambrian.

Massive ice sheets advanced and retreated across North America during much of the Quaternary, carving landscapes in many parks. Bering Land Bridge National Preserve contains geologic evidence of lower sea level during glacial periods, facilitating the prehistoric peopling of the Americas. The youngest rocks in the NPS include the lava of Hawaii Volcanoes National Park and the travertine at Yellowstone National Park, which can be just a few hours old.

Some of the finest Neogene fossils on the planet are found in the rocks of Agate Fossil Beds and Hagerman Fossil Beds national monuments.

The Precambrian was the "Age of Early Life." During the Precambrian, continents formed and our modern atmosphere developed, while early life evolved and flourished. Soft-bodied creatures like worms and jellyfish lived in the world's oceans, but the land remained barren. Common Precambrian fossils include stromatolites and similar structures, which are traces of mats of algae-like microorganisms, and microfossils of other microorganisms.

The Cenozoic Era (66 million years ago [MYA] through today) is the "Age of Mammals." North America’s characteristic landscapes began to develop during the Cenozoic. Birds and mammals rose in prominence after the extinction of giant reptiles. Common Cenozoic fossils include cat-like carnivores and early horses, as well as ice age woolly mammoths.