Aquatic biofilms are an understudied component of northern peatlands and are expected to play a more prominent role in ecosystem processes in areas where aquatic habitat is expanding. The goal of this study was to investigate how hydrologic history influences biofilm diversity and functional genes. This study was conducted in a long‐term water table manipulation that simulates drought (lowered water table treatment) and floodi...

The cognitively-intact oldest-old (85 +) may be the most-resilient members of their birth cohort; due to survivorship effects (e.g., depletion of susceptibles), risk factors associated with brain aging biomarkers in younger samples may not generalize to the cognitively-intact oldest-old. We evaluated associations between established aging-related risk factors and brain-predicted age difference (brainPAD) in a cross-sectional c...

Purpose of Review We review how ‘abrupt thaw’ has been used in published studies, compare these definitions to abrupt processes in other Earth science disciplines, and provide a definitive framework for how abrupt thaw should be used in the context of permafrost science. Recent Findings We address several aspects of permafrost systems necessary for abrupt thaw to occur and propose a framework for classifying permafrost process...

To better understand linkages between hydrology and ecosystem carbon flux in northern aquatic ecosystems, we evaluated the relationship between plant communities, biofilm development, and carbon dioxide (CO 2 ) exchange following long‐term changes in hydrology in an Alaskan fen. We quantified seasonal variation in biofilm composition and CO 2 exchange in response to lowered and raised water table position (relative to a contro...

Permafrost degradation in peatlands is altering vegetation and soil properties and impacting net carbon storage. We studied four adjacent sites in Alaska with varied permafrost regimes, including a black spruce forest on a peat plateau with permafrost, two collapse scar bogs of different ages formed following thermokarst, and a rich fen without permafrost. Measurements included year‐round eddy covariance estimates of net carbo...

Shifts in plant functional groups associated with climate change have the potential to influence peatland carbon storage by altering the amount and composition of organic matter available to aquatic microbial biofilms. The goal of this study was to evaluate the potential for plant subsidies to regulate ecosystem carbon flux (CO 2 ) by governing the relative proportion of primary producers (microalgae) and heterotrophic decompo...

Peatlands at high latitudes have accumulated >400 Pg carbon (C) because saturated soil and cold temperatures suppress C decomposition. This substantial amount of C in Arctic and Boreal peatlands is potentially subject to increased decomposition if the water table (WT) decreases due to climate change, including permafrost thaw‐related drying. Here, we optimize a version of the Organizing Carbon and Hydrology In Dynamic Ecosyste...

Affecting behavioural change is a common underlying goal across environmental and agricultural sciences, from climate change mitigation and adaptation, biodiversity conservation, water management, to crop diversification. However, many projects fail to drive or sustain change despite sound science and good intentions. This paper draws on existing theories of behavioural change to construct a conceptual framework that explores...

Argininosuccinate lyase (ASL) is essential for the NO-dependent regulation of tyrosine hydroxylase (TH) and thus for catecholamine production. Using a conditional mouse model with loss of ASL in catecholamine neurons, we demonstrate that ASL is expressed in dopaminergic neurons in the substantia nigra pars compacta, including the ALDH1A1 + subpopulation that is pivotal for the pathogenesis of Parkinson disease (PD). Neuronal l...

Much of our knowledge on regulatory impacts of DNA methylation has come from laboratory‐bred model organisms, which may not exhibit the full extent of variation found in wild populations. Here, we investigated naturally‐occurring variation in DNA methylation in a wild avian species, the white‐throated sparrow ( Zonotrichia albicollis ). This species offers exceptional opportunities for studying the link between genetic differe...

Peatlands are the most efficient natural ecosystems for long‐term storage of atmospheric carbon. Our understanding of peatland carbon cycling is based entirely on bottom‐up controls regulated by low nutrient availability. Recent studies have shown that top‐down controls through predator‐prey dynamics can influence ecosystem function, yet this has not been evaluated in peatlands to date. Here, we used a combination of nutrient...

Widespread changes in arctic and boreal Normalized Difference Vegetation Index ( NDVI ) values captured by satellite platforms indicate that northern ecosystems are experiencing rapid ecological change in response to climate warming. Increasing temperatures and altered hydrology are driving shifts in ecosystem biophysical properties that, observed by satellites, manifest as long‐term changes in regional NDVI . In an effort to...

Rich fens are common boreal ecosystems with distinct hydrology, biogeochemistry and ecology that influence their carbon (C) balance. We present growing season soil chamber methane emission ( F CH 4 ), ecosystem respiration ( ER ), net ecosystem exchange ( NEE ) and gross primary production ( GPP ) fluxes from a 9‐years water table manipulation experiment in an Alaskan rich fen. The study included major flood and drought years,...