Publications by authors named "Ryan T Choi"

Article Synopsis
  • - Understanding how biogeochemical cycles of carbon, nitrogen, and phosphorus interact is crucial, especially as human activities impact climate and these cycles, particularly in dryland ecosystems which cover over 40% of Earth's land surface.
  • - Research on the Colorado Plateau tested how water, carbon, nitrogen, and phosphorus influence soil carbon cycling. Results indicated that water, carbon, and nitrogen collectively support carbon cycling, with water being a key factor in generating a significant response when combined with carbon.
  • - The study revealed that nitrogen alone doesn't affect soil carbon cycling but enhances carbon cycling rates when combined with water and carbon, while phosphorus showed no impact. These findings highlight the complex interplay of resource limitations in dryland ecosystems.
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With warmer springs, herbivores migrating to Arctic breeding grounds may experience phenological mismatches between their energy demands and the availability of high quality forage. Yet, how the timing of the start of the season and herbivore arrival influences forage quality is often unknown. In coastal western Alaska, approximately one million migratory geese arrive each spring to breed, where foliar %N and C:N ratios are linked to gosling survival and population growth.

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The advancement of spring and the differential ability of organisms to respond to changes in plant phenology may lead to "phenological mismatches" as a result of climate change. One potential for considerable mismatch is between migratory birds and food availability in northern breeding ranges, and these mismatches may have consequences for ecosystem function. We conducted a three-year experiment to examine the consequences for CO exchange of advanced spring green-up and altered timing of grazing by migratory Pacific black brant in a coastal wetland in western Alaska.

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Theory predicts that intraspecific competition should be stronger than interspecific competition for any pair of stably coexisting species, yet previous literature reviews found little support for this pattern. We screened over 5400 publications and identified 39 studies that quantified phenomenological intraspecific and interspecific interactions in terrestrial plant communities. Of the 67% of species pairs in which both intra- and interspecific effects were negative (competitive), intraspecific competition was, on average, four to five-fold stronger than interspecific competition.

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