Quaternary Hydroclimate Records of Spring Ecosystems Active
Desert springs and wetlands are among the most biologically productive, diverse, and fragile ecosystems on Earth. They are home to thousands of rare, endemic, and endangered plants and animals and reflect the availability and health of emergent groundwater. Despite the ecological importance of these wetlands, our knowledge of how they might respond to predicted future climate change is limited. This project seeks to understand how springs and wetlands in the Mojave Desert responded to past abrupt warming events, which may be analogs for future conditions. To accomplish this, USGS scientists will reconstruct the hydrologic history of ancient spring ecosystems and establish patterns and rates of change in groundwater availability by investigating paleowetland deposits dating to the latest Pleistocene and Holocene. The results will provide critical information for developing strategies aimed at managing these fragile ecosystems and mitigating the effects of climate change in the arid lands of the American Southwest.
Statement of Problem: The southwestern U.S. is the hottest and driest region in North America and is especially susceptible to drought. Climate models predict this region will become progressively hotter and drier throughout the remainder of the 21st century, and future droughts will be more frequent, intense, and longer lasting than what has been recorded thus far in the historical record. Higher temperatures and changes in the amount and spatial patterns of rainfall and snowpack will affect the lives and economies of more than 50 million people currently living in the region, forcing increased competition for limited water supplies between agriculture and energy sectors, urban populations, and plant and animal life. This presents a tremendous challenge for managing water resources for human consumption while anticipating and minimizing the potential impact on fragile desert ecosystems.
Why this Research is Important: Desert springs and wetlands provide windows into the health of aquifers and groundwater-fed ecosystems in arid environments. They are exceptionally sensitive to changes in climate and can act as harbingers for future conditions, but only if we quantitatively understand how they responded to abrupt climate events in the past. This study will establish the first regional-scale, multi-proxy hydroclimate record for the Mojave Desert that spans the time interval from the latest Pleistocene to Holocene and historical times (approximately the past 15,000 years). The results will provide critical input for federal, state, and local resource managers and other stakeholders for developing strategies aimed at protecting spring ecosystems in light of projected future conditions. In addition, the results will provide robust, ground-truthed data that can be used to test climate models and improve constraints on regional climate projections.
Objective(s): The primary objective of this project is to understand how spring ecosystems responded to subtle and short-lived episodes of abrupt climate change during the recent geologic past. To accomplish this, we will document the response of desert spring ecosystems to climate variability and land-use changes during the late Quaternary. The resulting data will be synthesized to create the first regional-scale hydroclimate record for the southwestern U.S. that spans this time period. These efforts will contribute to the USGS national-scale effort to quantify Holocene hydroclimate conditions and provide critical context to inform current and future management and conservation of extant desert springs and wetlands.
Methods: We will reconstruct past hydroclimate conditions at multiple locations throughout the Mojave Desert by taking a novel approach that combines investigations of paleowetland deposits exposed in geological outcrops and sediment cores taken near active springs. The opportunity to combine these methodologies at sites that are in geographic proximity to one another is rare and will result in more complete and detailed high-resolution hydroclimate records than what could be obtained from either method alone. Sediments exposed in outcrops and in the cores will be described and measured, sampled for geophysical (grain size, density, magnetic susceptibility), geochemical (major and trace elements, stable isotopes), and biological (ostracodes, diatoms, and gastropods) analyses, and dated using a combination of radiocarbon, luminescence, and tephrochronologic techniques. The proxy data will be combined on common temporal scales and compared to existing high-resolution paleowetland records elsewhere in the region, as well as other sources of past climate information such as ice cores, lakes, speleothems, and marine records, to improve our understanding of ecosystem response to abrupt warming events.
Below are other science projects associated with this project.
Below are publications associated with this project.
The geology and paleontology of Tule Springs Fossil Beds National Monument, Nevada
Examining the relationship between portable luminescence reader measurements and depositional ages of paleowetland sediments, Las Vegas Valley, Nevada
Desert wetlands record hydrologic variability within the Younger Dryas chronozone, Mojave Desert, USA
The Great Acceleration and the disappearing surficial geologic record
The Tule Springs local fauna: Rancholabrean vertebrates from the Las Vegas Formation, Nevada
Vertebrate paleontology, stratigraphy, and paleohydrology of Tule Springs Fossil Beds National Monument, Nevada (USA)
Geology and vertebrate paleontology of Tule Springs Fossil Beds National Monument, Nevada, USA
First records of Canis dirus and Smilodon fatalis from the late Pleistocene Tule Springs local fauna, upper Las Vegas Wash, Nevada
Desert wetlands—Archives of a wetter past
Dynamic response of desert wetlands to abrupt climate change
Desert wetlands in the geologic record
Below are partners associated with this project.
- Overview
Desert springs and wetlands are among the most biologically productive, diverse, and fragile ecosystems on Earth. They are home to thousands of rare, endemic, and endangered plants and animals and reflect the availability and health of emergent groundwater. Despite the ecological importance of these wetlands, our knowledge of how they might respond to predicted future climate change is limited. This project seeks to understand how springs and wetlands in the Mojave Desert responded to past abrupt warming events, which may be analogs for future conditions. To accomplish this, USGS scientists will reconstruct the hydrologic history of ancient spring ecosystems and establish patterns and rates of change in groundwater availability by investigating paleowetland deposits dating to the latest Pleistocene and Holocene. The results will provide critical information for developing strategies aimed at managing these fragile ecosystems and mitigating the effects of climate change in the arid lands of the American Southwest.
Statement of Problem: The southwestern U.S. is the hottest and driest region in North America and is especially susceptible to drought. Climate models predict this region will become progressively hotter and drier throughout the remainder of the 21st century, and future droughts will be more frequent, intense, and longer lasting than what has been recorded thus far in the historical record. Higher temperatures and changes in the amount and spatial patterns of rainfall and snowpack will affect the lives and economies of more than 50 million people currently living in the region, forcing increased competition for limited water supplies between agriculture and energy sectors, urban populations, and plant and animal life. This presents a tremendous challenge for managing water resources for human consumption while anticipating and minimizing the potential impact on fragile desert ecosystems.
Why this Research is Important: Desert springs and wetlands provide windows into the health of aquifers and groundwater-fed ecosystems in arid environments. They are exceptionally sensitive to changes in climate and can act as harbingers for future conditions, but only if we quantitatively understand how they responded to abrupt climate events in the past. This study will establish the first regional-scale, multi-proxy hydroclimate record for the Mojave Desert that spans the time interval from the latest Pleistocene to Holocene and historical times (approximately the past 15,000 years). The results will provide critical input for federal, state, and local resource managers and other stakeholders for developing strategies aimed at protecting spring ecosystems in light of projected future conditions. In addition, the results will provide robust, ground-truthed data that can be used to test climate models and improve constraints on regional climate projections.
Objective(s): The primary objective of this project is to understand how spring ecosystems responded to subtle and short-lived episodes of abrupt climate change during the recent geologic past. To accomplish this, we will document the response of desert spring ecosystems to climate variability and land-use changes during the late Quaternary. The resulting data will be synthesized to create the first regional-scale hydroclimate record for the southwestern U.S. that spans this time period. These efforts will contribute to the USGS national-scale effort to quantify Holocene hydroclimate conditions and provide critical context to inform current and future management and conservation of extant desert springs and wetlands.
Methods: We will reconstruct past hydroclimate conditions at multiple locations throughout the Mojave Desert by taking a novel approach that combines investigations of paleowetland deposits exposed in geological outcrops and sediment cores taken near active springs. The opportunity to combine these methodologies at sites that are in geographic proximity to one another is rare and will result in more complete and detailed high-resolution hydroclimate records than what could be obtained from either method alone. Sediments exposed in outcrops and in the cores will be described and measured, sampled for geophysical (grain size, density, magnetic susceptibility), geochemical (major and trace elements, stable isotopes), and biological (ostracodes, diatoms, and gastropods) analyses, and dated using a combination of radiocarbon, luminescence, and tephrochronologic techniques. The proxy data will be combined on common temporal scales and compared to existing high-resolution paleowetland records elsewhere in the region, as well as other sources of past climate information such as ice cores, lakes, speleothems, and marine records, to improve our understanding of ecosystem response to abrupt warming events.
- Science
Below are other science projects associated with this project.
- Data
- Publications
Below are publications associated with this project.
Filter Total Items: 23The geology and paleontology of Tule Springs Fossil Beds National Monument, Nevada
On December 19, 2014, Tule Springs Fossil Beds National Monument, located in the Las Vegas Valley of southern Nevada, was established by Congress as the 405th unit of the National Park Service to “conserve, protect, interpret, and enhance for the benefit of present and future generations the unique and nationally important paleontological, scientific, educational, and recreational resources and vaAuthorsKathleen B. Springer, Jeffrey S. Pigati, Eric ScottExamining the relationship between portable luminescence reader measurements and depositional ages of paleowetland sediments, Las Vegas Valley, Nevada
Portable luminescence readers are exciting new tools that have the potential to rapidly determine the age structure of late Quaternary stratigraphic columns. This is important because high-resolution age profiling can reveal details about the temporal dynamics of climate cause and ecosystem effect, often while researchers are still in the field. In this paper, we compare new portable luminescenceAuthorsHarrison J. Gray, Shannon A. Mahan, Kathleen B. Springer, Jeffrey S. PigatiDesert wetlands record hydrologic variability within the Younger Dryas chronozone, Mojave Desert, USA
One of the enduring questions in the field of paleohydrology is how quickly desert wetland ecosystems responded to past episodes of abrupt climate change. Recent investigations in the Las Vegas Valley of southern Nevada have revealed that wetlands expanded and contracted on millennial and sub-millennial timescales in response to changes in climate during the late Quaternary. Here, we evaluate geolAuthorsJeffrey S. Pigati, Kathleen B. Springer, Jeffrey S. HonkeThe Great Acceleration and the disappearing surficial geologic record
The surficial geologic record is the relatively thin veneer of young (<~1 Ma) and mostly unconsolidated sediments that cover portions of Earth’s terrestrial surface (Fig. 1). Once largely ignored as “overburden” by geologists, surficial deposits are now studied to address a wide range of issues related to the sustainability of human societies. Geologists use surficial deposits to determine the freAuthorsJason A. Rech, Kathleen B. Springer, Jeffrey S. PigatiThe Tule Springs local fauna: Rancholabrean vertebrates from the Las Vegas Formation, Nevada
A middle to late Pleistocene sedimentary sequence in the upper Las Vegas Wash, north of Las Vegas, Nevada, has yielded the largest open-site Rancholabrean vertebrate fossil assemblage in the southern Great Basin and Mojave Deserts. Recent paleontologic field studies have led to the discovery of hundreds of fossil localities and specimens, greatly extending the geographic and temporal footprint ofAuthorsEric Scott, Kathleen B. Springer, James C. SagebielVertebrate paleontology, stratigraphy, and paleohydrology of Tule Springs Fossil Beds National Monument, Nevada (USA)
Tule Springs Fossil Beds National Monument (TUSK) preserves 22,650 acres of the upper Las Vegas Wash in the northern Las Vegas Valley (Nevada, USA). TUSK is home to extensive and stratigraphically complex groundwater discharge (GWD) deposits, called the Las Vegas Formation, which represent springs and desert wetlands that covered much of the valley during the late Quaternary. The GWD deposits recoAuthorsKathleen B. Springer, Jeffery S. Pigati, Eric ScottGeology and vertebrate paleontology of Tule Springs Fossil Beds National Monument, Nevada, USA
Tule Springs Fossil Beds National Monument (TUSK) preserves 22,650 acres of the upper Las Vegas Wash in the northern Las Vegas Valley, Nevada, USA. TUSK is home to extensive and stratigraphically complex groundwater discharge (GWD) deposits, called the Las Vegas Formation, which represent springs and desert wetlands that covered much of the valley during the late Quaternary. The GWD deposits recorAuthorsKathleen B. Springer, Jeffrey S. Pigati, Eric ScottFirst records of Canis dirus and Smilodon fatalis from the late Pleistocene Tule Springs local fauna, upper Las Vegas Wash, Nevada
Late Pleistocene groundwater discharge deposits (paleowetlands) in the upper Las Vegas Wash north of Las Vegas, Nevada, have yielded an abundant and diverse vertebrate fossil assemblage, the Tule Springs local fauna (TSLF). The TSLF is the largest open-site vertebrate fossil assemblage dating to the Rancholabrean North American Land Mammal Age in the southern Great Basin and Mojave Desert. Over 60AuthorsEric Scott, Kathleen B. SpringerDesert wetlands—Archives of a wetter past
Scientists from the U.S. Geological Survey (USGS) are finding evidence of a much wetter past in the deserts of the American Southwest using a most unlikely source—wetlands. Wetlands form in arid environments where water tables approach or breach the ground surface. Often thought of as stagnant and unchanging, new evidence suggests that springs and wetlands responded dynamically to past episodes ofAuthorsJeffery S. Pigati, Kathleen B. Springer, Craig R. MankerDynamic response of desert wetlands to abrupt climate change
Desert wetlands are keystone ecosystems in arid environments and are preserved in the geologic record as groundwater discharge (GWD) deposits. GWD deposits are inherently discontinuous and stratigraphically complex, which has limited our understanding of how desert wetlands responded to past episodes of rapid climate change. Previous studies have shown that wetlands responded to climate change onAuthorsKathleen B. Springer, Craig R. Manker, Jeffrey S. PigatiDesert wetlands in the geologic record
Desert wetlands support flora and fauna in a variety of hydrologic settings, including seeps, springs, marshes, wet meadows, ponds, and spring pools. Over time, eolian, alluvial, and fluvial sediments become trapped in these settings by a combination of wet ground conditions and dense plant cover. The result is a unique combination of clastic sediments, chemical precipitates, and organic matter thAuthorsJeff S. Pigati, Jason A. Rech, Jay Quade, Jordon Bright - Partners
Below are partners associated with this project.