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Folders: ROOT > ScienceBase Catalog > John Wesley Powell Center for Analysis and Synthesis ( Show direct descendants )

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Plants convert carbon dioxide into sugars for food during photosynthesis, and this provides food for all animal life. However, photosynthesis is inhibited when a plant’s enzymes use oxygen instead of carbon dioxide. To avoid this use of oxygen, some plants developed a photosynthetic adaptation – called C4 photosynthesis – to concentrate carbon dioxide around the enzymes. While less than 5% of plants use the C4 photosynthetic pathway, they make up ~20% of global terrestrial gross primary productivity. Due to their high productivity, C4 plants have a profound impact on ecosystems, economies, the carbon cycle, and our climate. Corn and sugarcane are both C4 plants, as are foundational western livestock and wildlife...
All files can be opened in ArcGIS. (Combination of grid files and shapefiles) brte_gb_av1km: 1 km native resolution AVHRR map for the Great Basin. Methods described in Bradley & Mustard, 2005, Remote Sensing of Environment brte_bg_avhrr: 4 km resolution AVHRR map for the Great Basin in a standard coordinate system projection. Map published in Bradley & Mustard, 2008, Global Change Biology brte_nv_lndst: 90 m resolution (downgraded from 30 m for the sake of space) Landsat map from 2001. Based on data from Eric Peterson (some unpublished, some in E.B. Peterson, 2005, International Journal of Remote Sensing) and calibrated with point data collected by BB in 2004/2005. Only northern Nevada included because southern...
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Sea-level rise and storms cause major changes on coastal landscapes, including shifts in elevation, ecosystem type (for example, dunes and tidal wetlands), soils, and plant communities. Because these changes can have impacts on human communities, the local economy, and ecosystems, understanding how, when, and why these changes occur can be important for informing policy and natural resource management decisions. However, much is still unknown in our understanding of and ability to forecast coastal landscape change, and many current modeling approaches do not include important feedbacks between the physical landscape and the species inhabiting it. Examples of these types of feedbacks include the rapid development...
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Despite the proven efficacy of geothermal energy as a city-scale heating and cooling resource, the relative newness of most city-scale applications using diverse technologies has resulted in limited widespread adoption. We aim to develop authoritative information suitable for city-managers and other decision-makers. Geothermal resources are ubiquitous and diverse, with technologies available both for harvesting ambient heat or for storing thermal energy. These local low-carbon, baseload energy sources provide resilience, security, and jobs. The project team proposes to accelerate understanding and possibly energy-solution adoption by developing an international systematic nomenclature to describe the range of...
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Fresh water is arguably the most valuable resource on the planet, but human activities threaten freshwater ecosystems. For example, use of synthetic chemicals, such as pesticides, road salts, and nutrients, has led to the ubiquitous contamination of aquatic systems, jeopardizing the integrity of ecological communities. Given the importance biodiversity plays in maintaining ecosystem health and function and the continued decline of freshwater species, it is vital to understand the direct, indirect, and lasting effects of synthetic contaminants on biota in freshwater systems. The majority of our knowledge regarding contaminant effects is comprised of short-term, single-contaminant laboratory toxicity tests that describe...
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A revolution is underway in seismology that transforms fiber-optic cables into arrays of thousands of seismic sensors. Compared to the traditional monitoring networks using inertial seismometers, the fiber-optic approach can increase the spatial data density by orders of magnitude and enable data processing methodologies that require a high-fidelity wavefield. The Working Group aims to advance the USGS, along with several academic and industry partners, towards effective utilization of fiber-optic sensing techniques to understand earthquake hazards and improve monitoring and real-time warning systems. We will conduct synthesis studies that demonstrate the potential gains for various applications, including earthquake...
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The USGS “Did You Feel It” (DYFI) is an extremely popular way for members of the public to contribute to earthquake science and earthquake response. DYFI has been in operation for nearly two decades (1999-2019) in the U.S., and for nearly 15 years globally. During that period the amount of data collected is astounding: Over 5 million individual DYFI intensity reports—spanning all magnitude and distance ranges—have been amassed and archived. Several of these types of surveys have been developed by international seismological institutions as well and many of these institutions have implemented algorithms to interpret intensity evaluations automatically, as a rapid and easy way to obtain a geographical distribution...
Climate change is expected to have significant effects on the phenology of vectors of arthropod-borne diseases, particularly mosquitoes. However, forecasting the direction and magnitude of future phenological shifts requires a more detailed understanding of the climate drivers of mosquito phenology. Addressing this knowledge gap is particularly salient for mosquitoes, as they have the potential to affect human health through transmission of zoonotic disease. While models based on climate and mosquito life history have been created at local or regional scales, national-scale predictions of the timing of mosquito activity are not readily available for the U.S. Our workshop proposes to synthesize primary data on mosquito...
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The Cascadia Subduction Zone, located in the U.S. Pacific Northwest and southwestern British Columbia, has hosted magnitude ≥8.0 megathrust earthquakes in the geologic past, a future earthquake is imminent, and the potential impacts could cripple the region. Subduction zone earthquakes represent some of the most devastating natural hazards on Earth. Despite substantial knowledge gained from decades of geoscience research, the size and frequency of Cascadian earthquakes remain controversial, as do the physics of earthquake rupture, the effects of earthquake shaking, and the effect of resultant tsunamis. This translates into major uncertainties in earthquake hazard assessments that can lead to ineffective preparedness...
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Terrestrial evapotranspiration (ET), the second-largest component of the terrestrial water cycle, links water, energy, and carbon cycles and influences the productivity and health of our ecosystems. Despite the importance of ET, the dynamics of ET across a spectrum of spatiotemporal scale and their controls are uncertain. During an international ET workshop held in November 2021 by AmeriFlux, the scientific community identified key challenges to improve our understanding of ET dynamics. Participants underscored the need for an integrated understanding of ET across the different research disciplines: in-situ measurements, remote sensing, and modeling. Here, we propose the synthesis of the three research areas to...
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Despite the critical services freshwater systems provide, freshwater biodiversity has been vastly under-studied compared to terrestrial and marine biomes. In fact, systematic compilations of freshwater zooplankton are surprisingly rare despite the critical roles zooplankton play in regulating and supporting ecosystem services, serving as key indicator species, and consequently, influencing emergent system properties such as water quality and food web structure. We have compiled and harmonized the most temporally and spatially extensive freshwater zooplankton dataset available to date, designed to seamlessly integrate with a suite of in-lake and remote sensing data and modeling products. Our international team will...
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Subsurface preferential flow (PF = water bypassing the soil matrix) provides rapid flowpaths for water and any substances transported with it, thereby profoundly impacting the recharge of aquifers, the spreading of contaminants, the health of the soil, and the functioning of ecosystems. It involves a complexity of processes that are poorly understood to the degree that current science provides no reliable way to predict its occurrence and magnitude. This effort will address the fundamental question of where and when PF occurs, taking advantage of two recent scientific developments: availability of high frequency (at least every 30 minutes), multi-depth soil moisture data suitable to detect preferential flow events...
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Our ability to effectively manage natural resources is founded in an understanding of how our actions and the environment influence populations, communities, and ecosystems. Current practices use monitoring data from the past to determine key ecological relationships and make predictions about the future with the assumption that those relationships will remain constant. However, many natural systems are undergoing rapid changes due to external factors including climate change, urbanization, and energy development, leading to a situation in which our observations of the past are poor predictors of the future. Ignoring such changes could lead to management decisions that are sub-optimal at best or detrimental at worst....
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Drought impacts on terrestrial ecosystems have increased globally in the 21st century, and droughts are expected to become more frequent, extreme, and spatially extensive in the future. Historical site-based observations are inadequate to predict how future extreme water deficits will affect the global terrestrial surface, because future droughts and their impacts may be more extreme than they have been historically and reach well beyond a single ecosystem. This USGS Powell Center working group will conduct the first comprehensive synthesis of ecosystem impacts across a coordinated, globally distributed drought experiment network of over 100 sites that have imposed an extreme multi-year drought. Knowledge about...
Groundwater plays a critical role in the water balance, however the groundwater component of the hydrologic cycle is frequently overlooked at basin scales because it is difficult to observe and quantify. We address this problem through a novel framework that combines existing hydrological models and data sets with groundwater flux estimates across Earth's largest system of lakes; the Laurentian Great Lakes. Aside from serving as a template for combining surface and ground water data and models, the Laurentian Great Lakes recently transitioned from a period characterized by water scarcity (water levels on the lakes were persistently below average from 1998 through 2013) to extreme water abundance (all-time high...