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Filter Total Items: 2,154
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Year Published: 2017

Survival of the endangered Pima pineapple cactus: Does clearing before prescribed fire alter survival postfire?

Federal land managers and ranchers often use prescribed fire as a tool to reduce invading woody plants within desert grasslands of the arid southwestern United States. Managers must evaluate the threat of the burn toward the health and survival of plants of concern including how preemptive clearing before prescribed fire might benefit these...

Thomas, Kathryn A.; Jarchow, Christopher; Crawford, Julie A.
Thomas, K.A., Jarchow, C.J., and Crawford, J.A., 2017, Survival of the endangered pima pineapple cactus—Does clearing before prescribed fire alter survival postfire?: The Southwestern Naturalist, v. 62, no. 3, p. 200-206, https://doi.org/10.1894/0038-4909-62.3.200.

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Year Published: 2017

The planetary data system

In the early 1980s, the Space Science Board (SSB) of the National Research Council was concerned about the poor and inconsistent treatment of scientific information returned from NASA’s space science missions. The SSB formed a panel [The Committee on Data Management and Computation (CODMAC)] to assess the situation and make recommendations to NASA...

Acton, Charles; Slavney, Susan; Arvidson, Raymond E.; Gaddis, Lisa R.; Gordon, Mitchell; Lavoie, Susan
Acton, C., Slavney, S., Arvidson, R., Gaddis, L., Gordon, M. and Lavoie, Susan, 2017, The Planetary Data System, Lunar and Planetary Information Bulletin, Issue 150, Sept. 2017, pp. 2-12.

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Year Published: 2017

Effects of environmental covariates and density on the catchability of fish populations and interpretation of catch per unit effort trends

Article for outlet: Fisheries Research. Abstract: Quantifying temporal and spatial trends in abundance or relative abundance is required to evaluate effects of harvest and changes in habitat for exploited and endangered fish populations. In many cases, the proportion of the population or stock that is captured (catchability or capture probability...

Korman, Josh; Yard, Mike
Korman, J., and Yard, M., 2017, Effects of environmental covariates and density on the catchability of fish populations and interpretation of catch per unit effort trends: Fisheries Research, v. 189, p. 18-34, http://dx.doi.org/10.1016/j.fishres.2017.01.005.

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Year Published: 2017

Modern landscape processes affecting archaeological sites along the Colorado River corridor downstream of Glen Canyon Dam, Glen Canyon National Recreation Area, Arizona

The landscape of the Colorado River through Glen Canyon National Recreation Area formed over many thousands of years and was modified substantially after the completion of Glen Canyon Dam in 1963. Changes to river flow, sediment supply, channel base level, lateral extent of sedimentary terraces, and vegetation in the post-dam era have modified the...

East, Amy E.; Sankey, Joel B.; Fairley, Helen C.; Caster, Joshua J.; Kasprak, Alan
East, A.E., Sankey, J.B., Fairley, H.C., Caster, J.J., and Kasprak, A., 2017, Modern landscape processes affecting archaeological sites along the Colorado River corridor downstream of Glen Canyon Dam, Glen Canyon National Recreation Area, Arizona: U.S. Geological Survey Scientific Investigations Report 2017–5082, 22 p., https://doi.org/10.3133/sir20175082.

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Year Published: 2017

Enhancing wind erosion monitoring and assessment for U.S. rangelands

On the GroundWind erosion is a major resource concern for rangeland managers because it can impact soil health, ecosystem structure and function, hydrologic processes, agricultural production, and air quality.Despite its significance, little is known about which landscapes are eroding, by how much, and when.The National Wind Erosion Research...

Webb, Nicholas P.; Van Zee, Justin W.; Karl, Jason W.; Herrick, Jeffrey E.; Courtright, Ericha M.; Billings, Benjamin J.; Boyd, Robert C.; Chappell, Adrian; Duniway, Michael C.; Derner, Justin D.; Hand, Jenny L.; Kachergis, Emily; McCord, Sarah E.; Newingham, Beth A.; Pierson, Frederick B.; Steiner, Jean L.; Tatarko, John; Tedela, Negussie H.; Toledo, David; Van Pelt, R. Scott
Webb, N.P., Van Zee, J.W., Karl, J.W., Herrik, J.W., Courtright, E.M., Billings, B.J., Boyd, R., Chappel, A., Duniway, M.C., Derner, J.D., Hand, J.L., Kachergis, E., McCord, S.E., Newingham, B.A., Pierson, F.B., Steiner, J.L., Tatarko, J., Tedela, N.H., Toledo, D., and Van Pelt, R.S., 2017, in press, v. (online), Enhancing Wind Erosion Monitoring and Assessment for U.S. Rangelands: Rangelands, https://doi.org/10.1016/j.rala.2017.04.001.

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Year Published: 2017

Changes in projected spatial and seasonal groundwater recharge in the upper Colorado River Basin

The Colorado River is an important source of water in the western United States, supplying the needs of more than 38 million people in the United States and Mexico. Groundwater discharge to streams has been shown to be a critical component of streamflow in the Upper Colorado River Basin (UCRB), particularly during low-flow periods. Understanding...

Tillman, Fred; Gangopadhyay, Subhrendu; Pruitt, Tom
Tillman, F. D., Gangopadhyay, S. and Pruitt, T., 2017, Changes in projected spatial and seasonal groundwater recharge in the upper Colorado River basin: Groundwater v. 55, no., 4, p. 506-518.

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Year Published: 2017

Hierarchical, quantitative biogeographic provinces for all North American turtles and their contribution to the biogeography of turtles and the continent

Our study represents the first attempt to describe biogeographic provinces for North American (México, United States, and Canada) turtles. We analyzed three nested data sets separately: (1) all turtles, (2) freshwater turtles, and (3) aquatic turtles. We georeferenced North American turtle distributions, then we created presence–absence matrices...

Ennen, Joshua R.; Matamoros, Wilfredo A.; Agha, Mickey; Lovich, Jeffrey E.; Sweat, Sarah C.; Hoagstrom, Christopher W.
Ennen, J.R., Matamoros, W.A., Agha, M., Lovich, J.E., Sweat, S.C., and Hoagstrom, C.W., 2017, Hierarchical, Quantitative Biogeographic Provinces for All North American Turtles and Their Contribution to the Biogeography of Turtles and the Continent: Herpetological Monographs v. 31, no. 1, p. 114-140, https://doi.org/10.1655/HERPMONOGRAPHS-D-16-00013.

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Year Published: 2017

An evaluation of sampling and full enumeration strategies for Fisher Jenks classification in big data settings

Large data contexts present a number of challenges to optimal choropleth map classifiers. Application of optimal classifiers to a sample of the attribute space is one proposed solution. The properties of alternative sampling-based classification methods are examined through a series of Monte Carlo simulations. The impacts of spatial...

Rey, Sergio J.; Stephens, Philip A.; Laura, Jason R.
Rey SJ, Stephens P, Laura J. An evaluation of sampling and full enumeration strategies for Fisher Jenks classification in big data settings. Transactions in GIS. 2017;21:796–810. https://doi.org/10.1111/tgis.12236

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Year Published: 2017

Geochemical characterization of groundwater discharging from springs north of the Grand Canyon, Arizona, 2009–2016

A geochemical study was conducted on 37 springs discharging from the Toroweap Formation, Coconino Sandstone, Hermit Formation, Supai Group, and Redwall Limestone north of the Grand Canyon near areas of breccia-pipe uranium mining. Baseline concentrations were established for the elements As, B, Li, Se, SiO2, Sr, Tl, U, and V. Three springs...

Beisner, Kimberly R.; Tillman, Fred D.; Anderson, Jessica R.; Antweiler, Ronald C.; Bills, Donald J.
Beisner, K.R., Tillman, F.D., Anderson, J.R., Antweiler, R.C., and Bills, D.J., 2017, Geochemical characterization of groundwater discharging from springs north of the Grand Canyon, Arizona, 2009–2016: U.S. Geological Survey Scientific Investigations Report 2017–5068, 58 p., https://doi.org/10.3133/sir20175068.

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Year Published: 2017

Evapotranspiration by remote sensing: An analysis of the Colorado River Delta before and after the Minute 319 pulse flow to Mexico

The unique hydrologic conditions characterizing riparian ecosystems in dryland (arid and semi-arid) areas help maintain high biodiversity and support high levels of primary productivity compared to associated uplands. In western North America, many riparian ecosystems have been damaged by altered flow regimes (e.g., impoundments and diversions)...

Jarchow, Christopher J.; Nagler, Pamela L.; Glenn, Edward P.; Ramirez-Hernandez, Jorge; Rodriguez-Burgueno, Eliana
Christopher J. Jarchow, Pamela L. Nagler, Edward P. Glenn, Jorge Ramírez-Hernandez, Eliana Rodríguez-Burgueño, Evapotranspiration by remote sensing: An analysis of the Colorado River Delta before and after the Minute 319 pulse flow to Mexico, Ecological Engineering, 2016, http://dx.doi.org/10.1016/j.ecoleng.2016.10.056.

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Year Published: 2017

Greenup and evapotranspiration following the Minute 319 pulse flow to Mexico: An analysis using Landsat 8 Normalized Difference Vegetation Index (NDVI) data

In the southwestern U.S., many riparian ecosystems have been altered by dams, water diversions, and other anthropogenic activities. This is particularly true of the Colorado River, where numerous dams and agricultural diversions have affected this water course, especially south of the U.S.–Mexico border. In the spring of 2014, 130 million cubic...

Jarchow, Christopher J.; Nagler, Pamela L.; Glenn, Edward P.
Christopher J. Jarchow, Pamela L. Nagler, Edward P. Glenn, Greenup and evapotranspiration following the Minute 319 pulse flow to Mexico: An analysis using Landsat 8 Normalized Difference Vegetation Index (NDVI) data, Ecological Engineering, 2016, ISSN 0925-8574, http://dx.doi.org/10.1016/j.ecoleng.2016.08.007.

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Year Published: 2017

Competition amplifies drought stress in forests across broad climatic and compositional gradients

Forests around the world are experiencing increasingly severe droughts and elevated competitive intensity due to increased tree density. However, the influence of interactions between drought and competition on forest growth remains poorly understood. Using a unique dataset of stand-scale dendrochronology sampled from 6405 trees, we quantified how...

Gleason, Kelly; Bradford, John B.; Bottero, Alessandra; D'Amato, Tony; Fraver, Shawn; Palik, Brian J.; Battaglia, Michael; Iverson, Louis R.; Kenefic, Laura; Kern, Christel C.
Gleason, K.E., Bradford, J.B., Bottero, A., D’Amato, A.W., Fraver, S., Palik, B.J., Battaglia, M.A., Iverson, L., Kenefic, L., and Kern, C.C., 2017, Competition amplifies drought stress in forests across broad climatic and compositional gradients: Ecosphere, v. 8, no. 7, http://dx.doi.org/10.1002/ecs2.1849.

Filter Total Items: 239
Image: White Pelicans
March 6, 2008

White Pelicans

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: White Pelicans
March 6, 2008

White Pelicans

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: White Pelicans
March 6, 2008

White Pelicans

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Ancient Lake Cahuilla High Water Mark
January 24, 2008

Ancient Lake Cahuilla High Water Mark

Lake Cahuilla was an ancient freshwater lake in the Salton Trough of southern California. It covered parts of the Coachella, Imperial and Mexicali valleys and was formed when the Colorado River overflowed its banks or was diverted northwest by its own sediments, which temporarily blocked the flow to the Gulf of California (Sea of Cortez). Although there have been a few

...
Attribution: Southwest
Photograph of Natural Bridges State Beach, Santa Cruz, CA
January 21, 2008

Natural Bridges State Beach, Santa Cruz, California

Photograph of the coastal region of Natural Bridges State Beach in Santa Cruz, California

Image: White Pelicans
December 13, 2007

White Pelicans

Birds found in and around the Salton Sea, California.

Attribution: Southwest
USGS scientists navigate personal water craft around San Francisco Bay, collecting bathymetric data.
October 26, 2007

Collecting Bathymetric Data in San Francisco Bay

USGS scientists Patrick Barnard (left) and Jeff Hansen navigate personal watercraft equipped with GPS and echo sounders through the waters of San Francisco Bay. They are collecting bathymetric, or depth, information in order to create maps of the bottom of the Bay. The maps will be used to determine how the morphology or shape of the Bay floor changes through time.

Image: Dowitcher
August 23, 2007

Dowitcher

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Great Egret Fishing
July 31, 2007

Great Egret Fishing

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Roseate Spoonbill
July 27, 2007

Roseate Spoonbill

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Wood Stork with Fish
July 27, 2007

Wood Stork with Fish

Birds found in and around the Salton Sea, California.

Attribution: Southwest
Image: Wood Storks
July 24, 2007

Wood Storks

Birds found in and around the Salton Sea, California.

Attribution: Southwest

Nine USGS Science Centers are administered by the Pacific Regional office, which is headquartered in Sacramento, California.