Search Results for: genet h

Food‐animal production and the spread of antibiotic resistance: The role of ecology

Antibiotic‐resistant pathogens increasingly threaten human health. Widespread application of antibiotics to animal populations raised for food, including chickens, cattle, and pigs, selects for resistance and contributes to the evolution of those pathogens. Despite a half century of research establishing the mechanisms and pathways by which antibiotic‐resistant bacteria spread from food […]

Estimating taxon-specific population dynamics in diverse microbial communities

Understanding how population-level dynamics contribute to ecosystem-level processes is a primary focus of ecological research and has led to important breakthroughs in the ecology of macroscopic organisms. However, the inability to measure population-specific rates, such as growth, for microbial taxa within natural assemblages has limited ecologists’ understanding of how microbial […]

Deep Yedoma permafrost: A synthesis of depositional characteristics and carbon vulnerability

Permafrost is a distinct feature of the terrestrial Arctic and is vulnerable to climate warming. Permafrost degrades in different ways, including deepening of a seasonally unfrozen surface and localized but rapid development of deep thaw features. Pleistocene ice-rich permafrost with syngenetic ice-wedges, termed Yedoma deposits, are widespread in Siberia, Alaska, […]

Plant genotype influences aquatic-terrestrial ecosystem linkages through timing and composition of insect emergence

Terrestrial leaf litter provides aquatic insects with an energy source and habitat structure, and species differences in litter can influence aquatic insect emergence. Emerging insects also provide energy to riparian predators. We hypothesized that plant genetics would influence the composition and timing of emerging insect communities among individual genotypes of Populus angustifolia varying […]

Increases in mean annual temperature do not alter soil bacterial community structure in tropical montane wet forests

Soil bacteria play a key role in regulating terrestrial biogeochemical cycling and greenhouse gas fluxes across the soil-atmosphere continuum. Despite their importance to ecosystem functioning, we lack a general understanding of how bacterial communities respond to climate change, especially in relatively understudied ecosystems like tropical montane wet forests. We used […]

8: Measuring Nitrification, Denitrification, and Related Biomarkers in Terrestrial Geothermal Ecosystems

Research on the nitrogen biogeochemical cycle in terrestrial geothermal ecosystems has recently been energized by the discovery of thermophilic ammonia-oxidizing archaea (AOA). This chapter describes methods that have been used for measuring nitrification and denitrification in hot spring environments, including isotope pool dilution and tracer approaches, and the acetylene block […]

Potential role of Thermus thermophilus and T. oshimai in high rates of nitrous oxide (N2O) production in∼ 80° C hot springs in the US Great Basin

Ambient nitrous oxide (N2O) emissions from Great Boiling Spring (GBS) in the US Great Basin depended on temperature, with the highest flux, 67.8 ± 2.6 μmol N2O-N m−2 day−1, occurring in the large source pool at 82 °C. This rate of N2O production contrasted with negligible production from nearby soils and was similar to rates from […]