Article
Biodiversity Conservation
Laura C. Streib, Jeffery R. Stone, Eva C. Lyon, Hung H. Quang, Kevin M. Yeager, Susan R. H. Zimmerman, Michael M. McGlue
Summary: This study analyzed lake sediment records from the eastern Sierra Nevada over the past three millennia to reveal ecological changes driven by hydroclimate oscillations. Results showed that hot-dry conditions of the Industrial Era altered lake state, leading to profound impacts on high-elevation lakes and the ecosystem services they provide.
GLOBAL CHANGE BIOLOGY
(2021)
Article
Ecology
James W. Roche, Kristen N. Wilson, Qin Ma, Roger C. Bales
Summary: This study evaluates the uncertainties in water balances across 52 watersheds in the Central Sierra Nevada and highlights the importance of evapotranspiration as a central metric of water-balance change and variability.
FRONTIERS IN FORESTS AND GLOBAL CHANGE
(2022)
Article
Limnology
Elisabet Perez-Coronel, Stephen C. Hart, J. Michael Beman
Summary: The study found that methane concentrations in lakes below 3000m were strongly related to temperature, nitrite concentrations, and elevation, while lakes above 3000m showed a relationship between methane and dissolved inorganic nitrogen to dissolved inorganic phosphorus ratios and elevation.
Article
Plant Sciences
Jaycie C. Fickle, R. Brandon Pratt, Anna L. Jacobsen
Summary: Xylem structure and hydraulics were compared between individuals at different elevations in a steep transect in the southern Sierra Nevada, California, USA. Environmental differences led to significant changes in the ratio of stem xylem area to leaf area between elevations. Co-occurring species showed different xylem traits, suggesting diverse strategies to cope with the Mediterranean-type climate region.
PHYSIOLOGIA PLANTARUM
(2023)
Article
Environmental Sciences
Ryan M. Ferrell, Scott Devine, Anthony T. T. O'Geen
Summary: The deep root system of forests allows them to withstand insufficient precipitation. However, there is limited documentation regarding the spatial distribution of regolith thickness in forest ecosystems. A study in the southern Sierra Nevada estimated regolith thickness using hand auger measurements across a 543-ha watershed and found that more than 55% of the area had a depth greater than 5 m. The study also revealed a correlation between topography and spatial trends in regolith thickness.
VADOSE ZONE JOURNAL
(2023)
Article
Microbiology
Mia R. Maltz, Chelsea J. Carey, Hannah L. Freund, Jon K. Botthoff, Stephen C. Hart, Jason E. Stajich, Sarah M. Aarons, Sarah M. Aciego, Molly Blakowski, Nicholas C. Dove, Morgan E. Barnes, Nuttapon Pombubpa, Emma L. Aronson
Summary: Dust provides significant input of nutrients in ecosystems, and is also a vector for dispersing microorganisms. This study found that the composition and diversity of dust-associated microorganisms differ by elevation and are influenced by landscape topography and droughts in source areas.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Environmental Sciences
Steven Pestana, Jessica D. Lundquist
Summary: Thermal infrared imagery from GOES satellites provides an opportunity to observe mountain surface temperatures. Orthorectification is necessary to correct for the parallax effect in off-nadir imagery. ABI brightness temperatures closely match those of forest canopy temperatures.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Biochemistry & Molecular Biology
Yi-Ming Weng, David H. Kavanaugh, Sean D. Schoville
Summary: The evolutionary histories of alpine species are closely related to their response to glaciation, with population structure influenced by drainage basins. Taking into account species' ecological preferences is crucial for understanding their response to climate fluctuations.
Article
Ecology
Margarita Huesca, Susan L. Ustin, Kristen D. Shapiro, Ryan Boynton, James H. Thorne
Summary: This study used airborne hyperspectral imagery to identify the most important wavelength regions predicting drought-induced tree mortality in blue oak woodlands. The best metric for predicting canopy stress was found to be a normalized ratio using specific spectral bands, with a correlation of R-2 = 0.83. The study also revealed that tree mortality prediction accuracy was highest between 1% and 10% mortality rates.
Article
Geosciences, Multidisciplinary
Barbara E. Wortham, Isabel P. Montanez, Kimberly Bowman, Daphne Kuta, Nora Soto Contreras, Eleana Brummage, Allison Pang, John Tinsley, Greg Roemer-Baer
Summary: By monitoring and analyzing the chemical variations in drip water and calcite deposits in caves in California, the impact of local and regional precipitation and temperature changes on the site can be better understood. Despite significant variability in surface conditions, the cave environment remains constant. Drip water compositions within the cave respond to seasonal changes, while trace element concentrations can serve as indicators of seasonal weather changes.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Environmental Studies
Bryant C. Baker, Chad T. Hanson
Summary: There is debate about the effectiveness of commercial thinning as a wildfire management strategy, with conflicting studies on the severity of thinned forests during wildfires. Our study in the Caldor Fire of 2021 found significantly higher cumulative severity in commercially thinned areas compared to unthinned forests. Further research is needed to determine if this pattern holds true for other large wildfires in the western US.
Article
Biodiversity Conservation
Kevin G. Kelly, Connor M. Wood, Kate McGinn, Anu Kramer, Sarah C. Sawyer, Sheila Whitmore, Dana Reid, Stefan Kahl, Aimee Reiss, Jonathan Eiseman, William Berigan, John J. Keane, Paula Shaklee, Lief Gallagher, Thomas E. Munton, Holger Klinck, R. J. Gutierrez, M. Zachariah Peery
Summary: Monitoring population size at ecosystem scales is challenging for most species of conservation concern. This study demonstrates a method for estimating population size using passive acoustic monitoring and local density monitoring for native California spotted owls and invasive barred owls.
ECOLOGICAL INDICATORS
(2023)
Article
Geochemistry & Geophysics
Benjamin Z. Klein, Oliver Jagoutz
Summary: The Bear Valley Intrusive Suite (BVIS) in the Southernmost Sierra Nevada represents a unique snapshot of magmatic processes within continental arc crust, with a fundamental dichotomy found between the lower crust composed of mafic cumulates and the middle/upper crust composed of tonalites. Modeling results suggest that BVIS magmas must have cooled below 900 degrees C near 7 kbars depth before rapidly emplacing in the upper crust along near-isothermal paths. The Sierra Nevada Arc magmas are thought to have cooled and differentiated at greater depths than the BVIS magmas, based on seismic velocity observations.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Forestry
Phillip J. van Mantgem, Anthony C. Caprio, Nathan L. Stephenson, Adrian J. Das
Summary: Prescribed fire reduces fire hazards by removing dead and live fuels, while also potentially increasing trees' ability to survive drought. Studies show that reductions in forest density following prescribed fire treatments, combined with mechanical treatments, may help lessen competition and improve tree survival rates.
Article
Ecology
Rebecca B. Wayman, Hugh D. Safford
Summary: The study found that in mixed-conifer forests in California's Sierra Nevada, there is a relationship between wildfire severity and severity of prefire tree mortality, and this relationship may vary under different weather conditions.
ECOLOGICAL APPLICATIONS
(2021)