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Browse more than 65,000 articles authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.

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Recent declines in genetic diversity with limited dispersal among coastal cactus wren populations in San Diego County, California Recent declines in genetic diversity with limited dispersal among coastal cactus wren populations in San Diego County, California

Habitat loss and fragmentation can lead to smaller and more isolated populations and reduce genetic diversity and evolutionary potential. Conservation programs can benefit from including monitoring of genetic factors in fragmented populations to help inform restoration and management. We assessed genetic diversity and structure among four major populations of the Cactus Wren...
Authors
Amy G. Vandergast, Barbara E. Kus, Julia G. Smith, Anna Mitelberg

Give and take: Effects of genetic admixture on mutation load in endangered Florida panthers Give and take: Effects of genetic admixture on mutation load in endangered Florida panthers

Genetic admixture is a biological event inherent to genetic rescue programs aimed at the long-term conservation of endangered wildlife. Although the success of such programs can be measured by the increase in genetic diversity and fitness of subsequent admixed individuals, predictions supporting admixture costs to fitness due to the introduction of novel deleterious alleles are necessary...
Authors
Alexander Ochoa, David P. Onorato, Melody E. Roelke-Parker, Melanie Culver, Robert R. Fitak

Trends analysis of Rangeland Condition Monitoring Assessment and Projection (RCMAP) fractional component time series (1985–2020) Trends analysis of Rangeland Condition Monitoring Assessment and Projection (RCMAP) fractional component time series (1985–2020)

Rangelands have a dynamic response to climate change, fire, and other anthropogenic disturbances. The Rangeland Condition, Monitoring, Assessment, and Projection (RCMAP) product aims to capture this response by quantifying the percent cover of eight rangeland components, associated error, and trends across the western United States using Landsat from 1985 to 2020. The current generation...
Authors
Hua Shi, Matthew B. Rigge, Kory Postma, Brett Bunde

Microbial community response to a bioaugmentation test to degrade trichloroethylene in a fractured rock aquifer, Trenton, N.J Microbial community response to a bioaugmentation test to degrade trichloroethylene in a fractured rock aquifer, Trenton, N.J

Bioaugmentation is a promising strategy for enhancing trichloroethylene (TCE) degradation in fractured rock. However, slow or incomplete biodegradation can lead to stalling at degradation byproducts such as 1,2-dichloroethene (cis-DCE) and vinyl chloride (VC). Over the course of 7 years, we examined the response of groundwater microbial populations in a bioaugmentation test where an...
Authors
Jennifer C. Underwood, Denise M. Akob, Michelle M. Lorah, Thomas E. Imbrigiotta, Ronald W. Harvey, Claire R. Tiedeman

Assessing population genomic structure and polyploidy: A crucial step for native plant restoration Assessing population genomic structure and polyploidy: A crucial step for native plant restoration

Establishing an effective restoration program requires baseline genetic information to make sound decisions for seed increase and transfer. For many plants this information is lacking, especially among native forbs that are critical for pollinator health. Erigeron speciosus is a widespread, perennial forb occupying montane environments in the western United States and Canada. This...
Authors
Bryce A. Richardson, Robert Massatti, Nurul Islam-Faridi, Skylar Johnson, Francis F. Kilkenny

Bedrock depth influences spatial patterns of summer baseflow, temperature and flow disconnection for mountainous headwater streams Bedrock depth influences spatial patterns of summer baseflow, temperature and flow disconnection for mountainous headwater streams

In mountain headwater streams, the quality and resilience of summer cold-water habitat is generally regulated by stream discharge, longitudinal stream channel connectivity and groundwater exchange. These critical hydrologic processes are thought to be influenced by the stream corridor bedrock contact depth (sediment thickness), a parameter often inferred from sparse hillslope borehole...
Authors
Martin A. Briggs, Phillip J. Goodling, Zachary Johnson, Karli M. Rogers, Nathaniel P. Hitt, Jennifer H. Fair, Craig D. Snyder

Development, structure, and behavior of a perched lava channel at Kīlauea Volcano, Hawaiʻi, during 2007 Development, structure, and behavior of a perched lava channel at Kīlauea Volcano, Hawaiʻi, during 2007

Channelized lava flows are commonly produced during the early stages of basaltic eruptions. These channels usually maintain their morphology until the eruption ends or discharge is diverted. In some instances, narrower channels can roof over, developing into lava tubes. We report here on a channelized flow erupted at Kīlauea volcano in 2007 that evolved into a “perched lava channel”...
Authors
Tim R. Orr, Edward W. Llewellin, Matthew R. Patrick

Science facilitation: Navigating the intersection of intellectual and interpersonal expertise in scientific collaboration Science facilitation: Navigating the intersection of intellectual and interpersonal expertise in scientific collaboration

Today’s societal challenges, such as climate change and global pandemics, are increasingly complex and require collaboration across scientific disciplines to address. Scientific teams bring together individuals of varying backgrounds and expertise to work collaboratively on creating new knowledge to address these challenges. Within a scientific team, there is inherent diversity in...
Authors
Amanda E. Cravens, Megan Siobhan Jones, Courtney Ngai, Jill Zarestky, Hannah B. Love

Low levels of hybridization between sympatric cold-water-adapted Arctic cod and Polar cod in the Beaufort Sea confirm genetic distinctiveness Low levels of hybridization between sympatric cold-water-adapted Arctic cod and Polar cod in the Beaufort Sea confirm genetic distinctiveness

As marine ecosystems respond to climate change and other stressors, it is necessary to evaluate current and past hybridization events to gain insight on the outcomes and drivers of such events. Ancestral introgression within the gadids has been suggested to allow cod to inhabit a variety of habitats. Little attention has been given to contemporary hybridization, especially within cold...
Authors
Robert E. Wilson, Sarah A. Sonsthagen, P. Lavretsky, A. Majewski, E. Arnason, K. Halldorsdottir, A.W. Einarsson, K. Wedemeyr, Sandra L. Talbot

Distribution and trends of endemic Hawaiian waterbirds Distribution and trends of endemic Hawaiian waterbirds

Four endemic species of wetland-dependent waterbirds occur on the main Hawaiian Islands, all of which have experienced sharp population declines and are listed as endangered species. Twice per year, state-wide surveys are conducted to count waterbirds, but these surveys are evaluated only infrequently. We used a state-space approach to evaluate long-term (1986–2016) and short-term (2006...
Authors
Eben H. Paxton, Kevin W. Brinck, Adonia Henry, Afsheen Siddiqi, Rachel A. Rounds, Jennifer Chutz

Understory plant communities show resistance to drought, hurricanes, and experimental warming in a wet tropical forest Understory plant communities show resistance to drought, hurricanes, and experimental warming in a wet tropical forest

Global climate change has led to rising temperatures and to more frequent and intense climatic events, such as storms and droughts. Changes in climate and disturbance regimes can have non-additive effects on plant communities and result in complicated legacies we have yet to understand. This is especially true for tropical forests, which play a significant role in regulating global...
Authors
Aura M. Alonso-Rodriguez, Tana E. Wood, Jamarys Torres-Diaz, Molly A. Cavaleri, Sasha C. Reed, Benedicte Bachelot

A comprehensive assessment of mangrove species and carbon stock on Pohnpei, Micronesia A comprehensive assessment of mangrove species and carbon stock on Pohnpei, Micronesia

Mangrove forests are the most important ecosystems on Pohnpei Island, Federated States of Micronesia, as the island communities of the central Pacific rely on the forests for many essential services including protection from sea-level rise that is occurring at a greater pace than the global average. As part of a multi-component assessment to evaluate vulnerabilities of mangrove forests...
Authors
Victoria Woltz, Elitsa I. Peneva-Reed, Zhiliang Zhu, Eric L. Bullock, Richard A. MacKenzie, Maybeleen Apwong, Ken Krauss, Dean B. Gesch
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