Habitat Shifts in Montane Riparian Areas in the Centennial Mountains of Southwest Montana

Deciduous riparian communities (DRC) are functionally and biologically unique habitats that influence ecosystems at local and watershed scales. Since Euro-American settlement, fire exclusion has shifted montane forests in the Centennial Mountains of the Greater Yellowstone Ecosystem from mosaics with variable stand structure and composition, including deciduous communities, to more homogeneous, closed-canopy coniferous forests. Deciduous riparian communities differ from coniferous riparian habitats many ways: fire behavior, post-fire recovery, insect and bird diversity, contributions to aquatic detritus, light regimes of aquatic ecosystems, and habitat suitability for beaver. To characterize the extent of current and historic deciduous riparian communities, we sampled riparian communities along three priority montane streams in the Centennial Mountains, mapped willow and aspen skeletons, and dated dominant conifers. We found widespread shifts in the dominant vegetation at mid-elevation montane sites upstream of the sagebrush-forest ecotone, though less evidence of vegetation change at higher elevation montane sites. The shifts we documented have only occurred in recent decades due to the decomposition of our primary evidence: dead wood. The lower primary productivity associated with these shifts affects native westslope cutthroat trout, birds, bats, and ungulates. Shifts from deciduous shrubs and trees to closed-canopy conifer forest also increases likelihood of local high-intensity fires and increases recovery times after those disturbances. Promoting deciduous riparian communities through prescribed fire and mechanical removal of conifers can increase the productivity of riparian and aquatic systems, while also reducing threats to these systems from climate change, including uncharacteristically severe fire and water shortages

Determining Resilient Watersheds for Long-Term Conservation in a Changing Climate

Streams and riparian areas are highly productive habitats for wildlife and fish. To maintain these critical habitats, rigorous prioritization of conservation and restoration efforts is necessary to make the best use of limited resources. In a changing climate, identifying sites with the ability to buffer change is essential for managing Rocky Mountain water resources. Watersheds in the northern Rockies require persistent snowpack for late-season stream flows and cool water temperatures, yet snowpacks are declining and climate models forecast that this trend will continue. We hypothesize that in the US Northern Rocky Mountains, high-elevation watersheds that receive less solar radiation due to slope, aspect, and shading by steep slopes will have significantly greater ability to maintain cooler water temperatures and higher late summer discharges under warming climate conditions. We also hypothesize that the magnitude of the aspect-shading effect will override other controlling variables. A GIS model of southwest Montana was developed to select sites for preliminary testing of our framework. Discharge data was collected for six paired watersheds with opposing aspects, similar high elevation area, and similar geology. Preliminary results show that basins dominated by steep north and northeast slopes (> 50 %) produce baseflow discharges that are 2 to 4 times larger than baseflows in basins dominated by steep southerly aspects. The project is ongoing, but our framework based on topographic attributes may be successfully used to inform land managers and restoration efforts about which watersheds are most likely to support stream and riparian habitats under changing climate conditions

Salmonella Enteritidis in Broiler Chickens, United States, 2000–2005

TOC summary line: Greater sampling and monitoring efforts are needed to reverse a significant increase in prevalence

Coherent long-range transfer of angular momentum between magnon Kittel modes by phonons

We report ferromagnetic resonance in the normal configuration of an electrically insulating magnetic bilayer consisting of two yttrium iron garnet (YIG) films epitaxially grown on both sides of a 0.5-mm-thick nonmagnetic gadolinium gallium garnet (GGG) slab. An interference pattern is observed and it is explained as the strong coupling of the magnetization dynamics of the two YIG layers either in phase or out of phase by the standing transverse sound waves, which are excited through a magnetoelastic interaction. This coherent mediation of angular momentum by circularly polarized phonons through a nonmagnetic material over macroscopic distances can be useful for future information technologies

Institutions and the uneven geography of the first wave of the COVID-19 pandemic

This paper examines the uneven geography of COVID-19-related excess mortality during the first wave of the pandemic in Europe, before assessing the factors behind the geographical differences in impact. The analysis of 206 regions across 23 European countries reveals a distinct COVID-19 geography. Excess deaths were concentrated in a limited number of regions —expected deaths exceeded 20% in just 16 regions— with more than 40% of the regions considered experiencing no excess mortality during the first six months of 2020. Highly connected regions, in colder and dryer climates, with high air pollution levels, and relatively poorly endowed health systems witnessed the highest incidence of excess mortality. Institutional factors also played an important role. The first wave hit regions with a combination of weak and declining formal institutional quality and fragile informal institutions hardest. Low and declining national government effectiveness, together with a limited capacity to reach out across societal divides, and a frequent tendency to meet with friends and family were powerful drivers of regional excess mortality

Probing scrambling using statistical correlations between randomized measurements

We propose and analyze a protocol to study quantum information scrambling using statistical correlations between measurements, which are performed after evolving a quantum system from randomized initial states. We prove that the resulting correlations precisely capture the so-called out-of-time-ordered correlators and can be used to probe chaos in strongly-interacting, many-body systems. Our protocol requires neither reversing time evolution nor auxiliary degrees of freedom, and can be realized in state-of-the-art quantum simulation experiments.Comment: This version v2 (8 pages, 7 figures) includes important new results compared to our original submission. (1) We present a protocol and corresponding mathematical proof to access OTOCs with local operations, and which can be realized in quantum simulation experiments with available technology. (2) We illustrate the realization of the protocols with different examples for Hubbard and spin model