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Recent climate warming in the Arctic is enhancing microbial decomposition of soil organic matter, which may result in globally significant greenhouse gas releases to the atmosphere. To better predict future impacts, bacterial and fungal community structures in both the bulk soil and the rhizosphere of Arctic birch, Betula glandulosa, were determined in control, greenhouse summer warming, and annual factorial nitrogen (N) and phosphate (P) addition treatments twelve years after their establishment. DNA sequence analyses at multiple taxonomic levels consistently indicated substantial bulk soil and rhizosphere microbial community differences among the fertilization treatments but no significant greenhouse effects. These results suggest that climate warming will likely increase the activity rates of soil microbial decomposers but without substantially altering the structure of either the bacterial or fungal communities. Differential abundance testing revealed changes in ectomycorrhizal fungal species of the genus Thelephora in both bulk soil and rhizosphere, with increases in their relative abundance in P and N + P amended plots compared with warming and controls. Because birch is the principal low Arctic ectomycorrhizal host, our results suggest that these fungi may promote this shrub’s competitiveness where tundra soil nutrient availability is enhanced by warming or other means, ultimately contributing to arctic vegetation “greening.”

Nitrification, the oxidation of ammonia to nitrate via nitrite, is important for many engineered water treatment systems. The sequential steps of this respiratory process are carried out by distinct microbial guilds, including ammonia-oxidizing bacteria (AOB) and archaea (AOA), nitrite-oxidizing bacteria (NOB), and newly discovered members of the genus Nitrospira that conduct complete ammonia oxidation (comammox). Even though all of these nitrifiers have been identified within water treatment systems, their relative contributions to nitrogen cycling are poorly understood. Although AOA contribute to nitrification in many wastewater treatment plants, they are generally outnumbered by AOB. In contrast, AOA and comammox Nitrospira typically dominate relatively low ammonia environments such as drinking water treatment, tertiary wastewater treatment systems, and aquaculture/aquarium filtration. Studies that focus on the abundance of ammonia oxidizers may misconstrue the actual role that distinct nitrifying guilds play in a system. Understanding which ammonia oxidizers are active is useful for further optimization of engineered systems that rely on nitrifiers for ammonia removal. This review highlights known distributions of AOA and comammox Nitrospira in engineered water treatment systems and suggests future research directions that will help assess their contributions to nitrification and identify factors that influence their distributions and activity.

Background: Autistic students may seek out additional supports to successfully complete their postsecondary education. While all institutions of higher education in the United States offer disability-related supports, some schools provide targeted services specifically designed to meet the needs of autistic students., Methods: This study used qualitative and quantitative methods to identify supports most valued by autistic students seeking a postsecondary degree. We interviewed 12 postsecondary students enrolled in a postsecondary education support program at a single university. We also reviewed student visitation records from the program to identify the nature of supports provided to students during an entire academic year., Results: Three primary themes emerged from the data. Students valued Individualized Services , which may include guidance, one-on-one meetings, and advocacy from program staff. A second theme, A Place to Call Home , recognizes the value of a dedicated space where students can complete work, engage socially, and surround themselves with other people who understand autism. In addition, the theme Supports Outside of the Program highlights the importance of services autistic students receive beyond those provided by the autism-specific program., Conclusions: Students enrolled in postsecondary education value supports offered by a program designed for autistic students and supports offered through disability services. Professionals interested in developing programs to support these academic endeavors should focus on the delivery of supports tailored to the unique needs of individual students. In addition, offering a physical location that offers an autism-friendly environment is an important feature of a support program for autistic students., Competing Interests: The A.R.S. and M.M.L. have no conflicts of interest to disclose. L.G. is the director of the program from which participants were enrolled. To address this as a potential conflict of interest, this author was not involved with data analysis. As such, the results were found without direct involvement from this author. However, L.G. was asked to review the findings before article submission as a credibility check. Nothing was altered as a result of this credibility check., (Copyright 2019, Mary Ann Liebert, Inc., publishers.)