Browsing by Author "Elmore, Andrew J."

Now showing 1 - 3 of 3
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    Convergence of soil nitrogen isotopes across global climate gradients
    (2015-02) Craine, Joseph M.; Elmore, Andrew J.; Wang, Lixin; Augusto, Laurent; Baisden, W. Troy; Brookshire, E. N. J.; Cramer, Michael D.; Hasselquist, Niles J.; Hobbie, Erik A.; Kahmen, Ansgar; Koba, Keisuke; Kranabetter, J. Marty; Mack, Michelle C.; Marin-Spiotta, Erika; Mayor, Jordan R.; McLauchlan, Kendra K.; Michelsen, Anders; Nardoto, Gabriela B.; Oliveira, Rafael S.; Perakis, Steven S.; Peri, Pablo L.; Quesada, Carlos A.; Richter, Andreas; Schipper, Louis A.; Stevenson, Bryan A.; Turner, Benjamin L.; Viani, Ricardo A. G.; Wanek, Wolfgang; Zeller, Bernd
    Quantifying global patterns of terrestrial nitrogen (N) cycling is central to predicting future patterns of primary productivity, carbon sequestration, nutrient fluxes to aquatic systems, and climate forcing. With limited direct measures of soil N cycling at the global scale, syntheses of the 15N:14N ratio of soil organic matter across climate gradients provide key insights into understanding global patterns of N cycling. In synthesizing data from over 6000 soil samples, we show strong global relationships among soil N isotopes, mean annual temperature (MAT), mean annual precipitation (MAP), and the concentrations of organic carbon and clay in soil. In both hot ecosystems and dry ecosystems, soil organic matter was more enriched in 15N than in corresponding cold ecosystems or wet ecosystems. Below a MAT of 9.8°C, soil δ15N was invariant with MAT. At the global scale, soil organic C concentrations also declined with increasing MAT and decreasing MAP. After standardizing for variation among mineral soils in soil C and clay concentrations, soil δ15N showed no consistent trends across global climate and latitudinal gradients. Our analyses could place new constraints on interpretations of patterns of ecosystem N cycling and global budgets of gaseous N loss.
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    Isotopic evidence for oligotrophication of terrestrial ecosystems
    (Nature, 2018) Craine, Joseph; Elmore, Andrew J.; Wang, Lixin; Aranibar, Julieta; Bauters, Marijn; Boeckx, Pascal; Crowley, Brooke E.; Dawes, Melissa A.; Delzon, Sylvain; Fajardo, Alex; Fang, Yunting; Fujiyoshi, Lei; Gray, Alan; Guerrieri, Rossella; Gundale, Michael J.; Hawke, David J.; Hietz, Peter; Jonard, Mathieu; Kearsley, Elizabeth; Kenzo, Tanaka; Makarov, Mikhail; Marañón-Jiménez, Sara; McGlynn, Terrence P.; McNeil, Brenden E.; Mosher, Stella G.; Nelson, David M.; Peri, Pablo L.; Roggy, Jean Christophe; Sanders-DeMott, Rebecca; Song, Minghua; Szpak, Paul; Templer, Pamela H.; Van der Colff, Dewidine; Werner, Christiane; Xu, Xingliang; Yang, Yang; Yu, Guirui; Zmudczyńska-Skarbek, Katarzyna; Earth Sciences, School of Science
    Human societies depend on an Earth system that operates within a constrained range of nutrient availability, yet the recent trajectory of terrestrial nitrogen (N) availability is uncertain. Examining patterns of foliar N concentrations and isotope ratios (δ15N) from more than 43,000 samples acquired over 37 years, here we show that foliar N concentration declined by 9% and foliar δ15N declined by 0.6–1.6‰. Examining patterns across different climate spaces, foliar δ15N declined across the entire range of mean annual temperature and mean annual precipitation tested. These results suggest declines in N supply relative to plant demand at the global scale. In all, there are now multiple lines of evidence of declining N availability in many unfertilized terrestrial ecosystems, including declines in δ15N of tree rings and leaves from herbarium samples over the past 75–150 years. These patterns are consistent with the proposed consequences of elevated atmospheric carbon dioxide and longer growing seasons. These declines will limit future terrestrial carbon uptake and increase nutritional stress for herbivores.
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    Leveraging the NEON Airborne Observation Platform for socio-environmental systems research
    (Wiley, 2021) Ordway, Elsa M.; Elmore, Andrew J.; Kolstoe, Sonja; Quinn, John E.; Swanwick, Rachel; Cattau, Megan; Taillie, Dylan; Guinn, Steven M.; Chadwick, K. Dana; Atkins, Jeff W.; Blake, Rachael E.; Chapman, Melissa; Cobourn, Kelly; Goulden, Tristan; Helmus, Matthew R.; Hondula, Kelly; Hritz, Carrie; Jensen, Jennifer; Julian, Jason P.; Kuwayama, Yusuke; Lulla, Vijay; O’Leary, Donal; Nelson, Donald R.; Ocón, Jonathan P.; Pau, Stephanie; Ponce-Campos, Guillermo E.; Portillo-Quintero, Carlos; Pricope, Narcisa G.; Rivero, Rosanna G.; Schneider, Laura; Steele, Meredith; Tulbure, Mirela G.; Williamson, Matthew A.; Wilson, Cyril; Geography, School of Liberal Arts
    During the 21st century, human–environment interactions will increasingly expose both systems to risks, but also yield opportunities for improvement as we gain insight into these complex, coupled systems. Human–environment interactions operate over multiple spatial and temporal scales, requiring large data volumes of multi-resolution information for analysis. Climate change, land-use change, urbanization, and wildfires, for example, can affect regions differently depending on ecological and socioeconomic structures. The relative scarcity of data on both humans and natural systems at the relevant extent can be prohibitive when pursuing inquiries into these complex relationships. We explore the value of multitemporal, high-density, and high-resolution LiDAR, imaging spectroscopy, and digital camera data from the National Ecological Observatory Network’s Airborne Observation Platform (NEON AOP) for Socio-Environmental Systems (SES) research. In addition to providing an overview of NEON AOP datasets and outlining specific applications for addressing SES questions, we highlight current challenges and provide recommendations for the SES research community to improve and expand its use of this platform for SES research. The coordinated, nationwide AOP remote sensing data, collected annually over the next 30 yr, offer exciting opportunities for cross-site analyses and comparison, upscaling metrics derived from LiDAR and hyperspectral datasets across larger spatial extents, and addressing questions across diverse scales. Integrating AOP data with other SES datasets will allow researchers to investigate complex systems and provide urgently needed policy recommendations for socio-environmental challenges. We urge the SES research community to further explore questions and theories in social and economic disciplines that might leverage NEON AOP data.