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Filter Total Items: 2,154
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Year Published: 2018

Reductions in tree performance during hotter droughts are mitigated by shifts in nitrogen cycling

Climate warming should result in hotter droughts of unprecedented severity in this century. Such droughts have been linked with massive tree mortality, and data suggest that warming interacts with drought to aggravate plant performance. Yet how forests will respond to hotter droughts remains unclear, as does the suite of mechanisms trees use to...

Grossiord, Charlotte; Gessler, Arthur; Reed, Sasha C.; Borrego, Isaac; Collins, Adam D.; Dickman, Lee T.; Ryan, Max; Schönbeck, Leonie; Sevanto, Sanna; Vilagroso, Alberto; McDowell, Nate G.
Grossiord, C., Gessler, A., Reed, S.C., Borrego, I., Collins, A.D., Dickman, L.T., Ryan, M., Schönbeck, L., Sevanto, S., Vilagrosa, A., and McDowell, N.G., 2018, Reductions in tree performance during hotter droughts are mitigated by shifts in nitrogen cycling: Plant, Cell & Environment, online, https://doi.org/10.1111/pce.13389.

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Year Published: 2018

Biocrusts enhance soil fertility and Bromus tectorum growth, and interact with warming to influence germination

Background and aimsBiocrusts are communities of cyanobacteria, mosses, and/or lichens found in drylands worldwide. Biocrusts are proposed to enhance soil fertility and productivity, but simultaneously act as a barrier to the invasive grass, Bromus tectorum, in western North America. Both biocrusts and B. tectorum are sensitive to climate change...

Ferrenberg, Scott; Faist, Akasha M.; Howell, Armin J.; Reed, Sasha C.
Ferrenberg, S., Faist, A.M., Howell, A., and Reed, S.C., 2018, Biocrusts enhance soil fertility and Bromus tectorum growth, and interact with warming to influence germination: Plant and Soil, v. 429, no. 1-2, p. 77-90, http://dx.doi.org/10.1007/s11104-017-3525-1.

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Year Published: 2018

Long-term evolution of sand transport through a river network: Relative influences of a dam versus natural changes in grain size from sand waves

Temporal and spatial nonuniformity in supplies of water and sand in a river network leads to sand transport that is in local disequilibrium with the upstream sand supply. In such river networks, sand is transported downstream as elongating waves in which coupled changes in grain size and transport occur. Depending on the magnitude of each sand‐...

Topping, David; Mueller, Erich R.; Schmidt, John C.; Griffiths, Ronald; Dean, David; Grams, Paul E.
Topping, D.J., Mueller, E.R., Schmidt, J.C., Griffiths, R.E., Dean, D.J., and Grams, P.E., 2018, Long-term evolution of sand transport through a river network--Relative influences of a dam versus natural changes in grain size from sand waves: Journal of Geophysical Research--Earth Surface, v. 123, https://doi.org/10.1029/2017JF004534.

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Year Published: 2018

Spatially explicit patterns in a dryland's soil respiration and relationships with climate, whole plant photosynthesis and soil fertility

Arid and semiarid ecosystems play a significant role in regulating global carbon cycling, yet our understanding of the controls over the dominant pathways of dryland CO2exchange remains poor. Substantial amounts of dryland soil are not covered by vascular plants and this patchiness in cover has important implications for spatial patterns and...

Wertin, Timothy M.; Young, Kristina E.; Reed, Sasha C.
Wertin, T.M., Young, K., and Reed, S.C., 2018, Spatially explicit patterns in a dryland's soil respiration and relationships with climate, whole plant photosynthesis and soil fertility: Oikos, v. 127, no. 9, p. 1280-1290, https://doi.org/10.1111/oik.04935.

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Year Published: 2018

Quantifying geomorphic and vegetation change at sandbar campsites in response to flow regulation and controlled floods, Grand Canyon National Park, Arizona

Sandbars along the Colorado River in Grand Canyon National Park, USA, are an important recreational resource used as campsites by over 25,000 river runners and hikers annually. The number and size of campsites decreased following the completion of Glen Canyon Dam in 1963 due to reductions of sediment that replenish sandbars and increases in...

Hadley, Daniel R.; Grams, Paul E.; Kaplinski, Matthew A.
Hadley, D.R, Grams, P.E., Kaplinski, M.A.,2018, Quantifying geomorphic and vegetation change at sandbar campsites in response to flow regulation and controlled floods, Grand Canyon National Park, Arizona: River Research and Applications, online, https://doi.org/10.1002/rra.3349.

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Year Published: 2018

Geomorphometry in landscape ecology: Issues of scale, physiography, and application

Topographic measures are frequently used in a variety of landscape ecology applications, in their simplest form as elevation, slope, and aspect, but increasingly more complex measures are being employed. We explore terrain metric similarity with changes in scale, both grain and extent, and examine how selecting the best measures is sensitive to...

Ironside, Kirsten E.; Mattson, David J.; Arundel, Terence R.; Theimer, Tad; Holton, Brandon; Peters, Michael; Edwards, Thomas C.; Hansen, Jered R.

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Year Published: 2018

Phenology and abundance of Northern Tamarisk Beetle, Diorhabda carinulata affecting defoliation of Tamarix

Timing and spatial dynamics of tamarisk (Tamarix spp. L.) defoliation by the biological control agent Diorhabda carinulata (Desbrochers) were evaluated. Relative abundance of D. carinulata and the phenology of tamarisk along the San Juan and Colorado rivers were recorded in 2011–2012. D. carinulata began...

Jamison, Levi R.; Johnson, Matthew J.; Bean, Dan W.; van Riper, Charles
Jamison, L.R., Johnson, M.J., Bean, D.W., and van Riper III, C., 2018, Phenology and Abundance of Northern Tamarisk Beetle, Diorhabda carinulata Affecting Defoliation of Tamarix: Southwestern Entomologist, v. 43, no. 3, p. 571-584, https://doi.org/10.3958/059.043.0302.

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Year Published: 2018

Key morphological features favor the success of nonnative fish species under reduced turbidity conditions in the lower Colorado River Basin

As a result of anthropomorphic alterations to the lower Colorado River basin and other southwestern rivers, water turbidity has been greatly reduced and introduced, nonnative fishes thrive in these waterways. To quantify key morphological features that may allow nonnative fishes to displace native fishes, we compared eye diameter (a proxy for...

Moran, Clinton J.; Ward, David L.; Gibb, Alice C.
Moran, C.J., Ward, D.L., and Gibb, A.C., 2018, Key morphological features favor the success of non-native fish species under reduced turbidity conditions in the lower Colorado River Basin: Transactions of the American Fisheries Society, online, https://onlinelibrary.wiley.com/doi/abs/10.1002/tafs.10079.

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Year Published: 2018

Sediment transport and deposition

Sediment transport and deposition (sedimentation) occurs from natural and anthropogenic sources in rivers, lakes, and reservoirs. Substantial changes in sediment transport (such as a major increase or decrease in sediment supply) can impact aquatic ecosystems that depend on a particular sediment quantity and particle size, for example, through...

Sankey, Joel B.; East, Amy E.; Kreitler, Jason R.; Tague, Christina (Naomi)
Sankey, J.B., East, A., Kreitler, J., and Tague, C., 2018, Sediment transport and deposition, in Landgridge, R., ed., Central Coast Summary Report--California’s Fourth Climate Change Assessment: Santa Cruz, Publication number: SUM-CCCA4-2018-006, p. 31-33.

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Year Published: 2018

Species-specific nitrogenase activity in lichen-dominated biological soil crusts from the Colorado Plateau, USA

Background and aimBiological soil crusts (biocrusts) play numerous crucial roles in drylands, which comprise over 40% of Earth’s terrestrial surface. Among these key contributions is the fixation of atmospheric nitrogen. Yet, relatively little is known about the N2 fixation capabilities of different lichen species that are found in late...

Torres-Cruz, Terry J.; Howell, Armin J.; Reibold, Robin H.; McHugh, Theresa A.; Eickhoff, Mackenzie A.; Reed, Sasha C.
Torres-Cruz, T.J., Howell, A.J., Reibold, R.H., McHugh, T.A., Eickhoff, M.A., and Reed, S.C., 2018, Species-specific nitrogenase activity in lichen-dominated biological soil crusts from the Colorado Plateau, USA: Plant and Soil, v. 429, no. 1-2, p. 113-125, https://doi.org/10.1007/s11104-018-3580-2.

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Year Published: 2018

Southern Rockies Landscape Conservation Cooperative unit watershed erosion potential prioritization for check-dam installation

Changes in land-use practices and the extirpation (local extinction) of beaver populations in the early 20th century during European settlement are believed to have resulted in many changes in how streams in the Western United States function. Some of the negative changes that have resulted include stream channelization, soil erosion, changing...

Ironside, Kirsten E.
Ironside, K.E., 2018, Southern Rockies Landscape Conservation Cooperative unit watershed erosion potential prioritization for check-dam installation: U.S. Geological Survey Open-File Report 2018–1127, 15 p., https://doi.org/10.3133/ofr20181127.

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Year Published: 2018

Elevated aeolian sediment transport on the Colorado Plateau, USA: The role of grazing, vehicle disturbance, and increasing aridity

Dryland wind transport of sediment can accelerate soil erosion, degrade air quality, mobilize dunes, decrease water supply, and damage infrastructure. We measured aeolian sediment horizontal mass flux (q) at 100 cm height using passive aspirated sediment traps to better understand q variability on the Colorado Plateau. Measured q‘...

Nauman, Travis W.; Duniway, Michael C.; Webb, Nichloas P.; Belnap, Jayne
Nauman, T.W., Duniway, M.C., Webb, N.P., and Belnap, J., 2018, Elevated aeolian sediment transport on the Colorado Plateau, USA-- the role of grazing, vehicle disturbance, and increasing aridity: Earth Surface Processes and Landforms, online, https://doi.org/10.1002/esp.4457.

Filter Total Items: 239
December 31, 2016

Resilient Voices: Adaptation Across Worldviews

The Department of the Interior Pacific Islands Climate Science Center and the University of Hawaiʻi at Hilo developed and hosted a Climate Change Boot Camp that showcased collaborative research efforts within UH Hilo’s Tropical Conservation Biology and Environmental Science graduate program that are driven by local natural resource managers across Hawaiʻi Island. The event

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man pointing to image on computer screen in an office setting
December 31, 2016

Geologist explains photo analysis of Calif. coastal cliffs

USGS research geologist Jon Warrick explains how his team applied structure-from-motion analysis to photos from the California Coastal Records Project to measure coastal change. Jon Warrick explains a “difference map” constructed from structure-in-motion data. Red areas indicate loss of material (erosion); blue areas show addition of material (deposition).

View looks out from a boat with instruments mounted on the side, over the water and in the far distance are snow-capped peaks.
December 31, 2016

Seafloor mapping in southeastern Alaska

Mount Crillon in the backdrop during a multibeam bathymetry survey of the Queen Charlotte-Fairweather Fault, offshore southeastern Alaska.

Large waves crashing on rocks at beach.
December 31, 2016

Storm waves in Santa Cruz

Large storm waves crashing on the rocks near Santa Cruz, California

November 17, 2016

PubTalk 11/2016 — Ecological Stressors

Ecological Stressors: It's a Lot of 'WERC'
"There's is no place like California" by A. Keith Miles, Center Director, USGS Western Ecological Research Center

Highlights of the science of the USGS Western Ecological Research Center: 

  • Wildlife, drought, sea level rise
  • Endangered species, species of concern
  • Alternate energy,
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October 27, 2016

PubTalk 10/2016 — Rockfalls in California's Sierra Nevada

Rock falls in California’s Sierra Nevada - Pursuing explanations for exfoliation and seemingly spontaneous fracture of rock
 

October 19, 2016

B-roll Sampling and Coring in San Pablo Bay

All clips show the deck of a barge in San Pablo Bay, California.

  • Clip 1 - USGS technicians lower and raise a grab sampler
  • Clips 2, 3, 4 - USGS technicians lower and raise a vibracore
  • Clip 5 - Tanker passes as USGS technicians work on anchor lines
  • Clip 6 - USGS technicians raise anchor, while another works on a vibracore tube
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July 28, 2016

July Public Lecture — USGS CalVO: It's not just earthquake country!

Volcanic eruptions occur int he State about as frequently as the large San Andreas Fault Zone earthquakes. California's "watch list" volcanoes are dispersed throughout the State and future eruptions are inevitable—the likelihood of renewed volcanism is on the order of one in a few hundred to one in a few thousand annually.

With Margaret Mangan, Scientist-in-Charge,

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July 24, 2016

Kīlauea Volcano, Halemaʻumaʻu Crater, Summit Vent Lava Lake (4K)

Stunning 4K aerial and ground b-roll of the Kīlauea Volcano Halemaʻumaʻu Crater Summit Vent Lava Lake taken between July 24 and July 31, 2016. 

Here is the shotlist: 
00:11 Kīlauea summit lava lake spatter, night, medium shot 
00:33 Lava lake spatter, night medium shot 
00:43 Lava lake wide shot, night, spatter on right of frame 
1:01 Wide shot,

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Aerial view of a lava vent seen from a helicopter
June 16, 2016

Lava Vent Aerial over Puʻu ʻŌʻō, Hawaiʻi

Though difficult to photograph, aerial views showed that this open vent was but a small window into a large, hot cavity beneath Puʻu ʻŌʻō's northeast flank in Hawaii Inside, streams of lava from an unseen source (or sources) closer to the crater rim (visible at lower right) were cascading toward the upper left into unknown depths. This view, looking almost straight down,

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Research and technical support provided by USGS makes a difference Some recent press releases and media advisories from the Pacific Region are highlighted below.

Filter Total Items: 72
Glacier National Park
September 7, 2016

A team of USGS scientists spent 10 days in the wilderness, exploring one of the fastest-moving faults in America

two men wearing hard hats carrying a 4-foot long auger in a grassy field
September 7, 2016

MEDIA ADVISORY: Faculty and students from California State University, East Bay, U.S. Geological Survey scientists, and community volunteers are conducting an experiment to visualize the subsurface in and around the Hayward Fault and measure how the ground in different neighborhoods responds to earthquake shaking.

Photograph showing San Pedro Riparian National Conservation Area.
August 18, 2016

Streamflow and groundwater levels are declining in some locations along the San Pedro River near Sierra Vista, Arizona, according to a new report by the U.S. Geological Survey.

Photo of the Colorado River near Moab, Utah
August 15, 2016

Future groundwater replenishment in the Upper Colorado River Basin may benefit from projected increases in future basin-wide precipitation under current climate projections, according to a recent study by the U.S. Geological Survey and Bureau of Reclamation.

An image of Hi'iaka Montes and Hi'iaka Patera on Jupiter's volcanic moon Io.
May 19, 2016

Mountains on Io, Jupiter’s volcanic moon, are formed by a unique geologic mechanism not found elsewhere in the solar system, according to a new study by the U.S. Geological Survey.

Irrigation ditch alongside an agricultural field.
May 18, 2016

If past patterns of California land-use change continue, projected water needs by the year 2062 will increase beyond current supply.

Topographic Map of Mercury
May 6, 2016

The first topographic map of Mercury was released today by the U.S. Geological Survey, Arizona State University, Carnegie Institute of Washington, Johns Hopkins University Applied Physics Laboratory and NASA.

USGS science for a changing world
May 4, 2016

Elevated levels of trace metals such as iron, lead, nickel and zinc were found in streams of the San Gabriel Mountains north of Los Angeles, California, at water-quality levels higher than the Environmental Protection Agency’s Aquatic Life Ambient Water Quality Criteria, according to a new U.S. Geological Survey study. 

Map of Magnitude 7.0 Earthquake in Japan, April 2016
April 15, 2016

A magnitude 7.0 earthquake struck Japan on April 16, 2016 at 1:25 a.m. local time (April 15, 16:25 UTC).

USGS
April 11, 2016

Methane emissions from restored wetlands may offset the benefits of carbon sequestration a new study from the U.S. Geological Survey suggests. 

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

The Pacific Region works with a wide array of partners across the country, including other Federal and state agencies, regional and local governments, academic institutions, research organizations, non-governmental organizations, and more.

Filter Total Items: 66