Explore the vast range of titles available.

Canopy-forming shrubs are reported to be increasing at sites around the circumpolar Arctic. Our results indicate expansion in canopy cover and height of willows on Herschel Island located at 70° north on the western Arctic coast of the Yukon Territory. We examined historic photographs, repeated vegetation surveys, and conducted monitoring of long-term plots and found evidence of increases of each of the dominant canopy-forming willow species (Salix richardsonii, Salix glauca and Salix pulchra), during the twentieth century. A simple model of patch initiation indicates that the majority of willow patches for each of these species became established between 1910 and 1960, with stem ages and maximum growth rates indicating that some patches could have established as late as the 1980s. Collectively, these results suggest that willow species are increasing in canopy cover and height on Herschel Island. We did not find evidence that expansion of willow patches is currently limited by herbivory, disease, or growing conditions.

Understanding the responses of tundra systems to global change has global implications. Most tundra regions lack sustained environmental monitoring and one of the only ways to document multi-decadal change is to resample historic research sites. The International Polar Year (IPY) provided a unique opportunity for such research through the Back to the Future (BTF) project (IPY project #512). This article synthesizes the results from 13 papers within this Ambio Special Issue. Abiotic changes include glacial recession in the Altai Mountains, Russia; increased snow depth and hardness, permafrost warming, and increased growing season length in sub-arctic Sweden; drying of ponds in Greenland; increased nutrient availability in Alaskan tundra ponds, and warming at most locations studied. Biotic changes ranged from relatively minor plant community change at two sites in Greenland to moderate change in the Yukon, and to dramatic increases in shrub and tree density on Herschel Island, and in subarctic Sweden. The population of geese tripled at one site in northeast Greenland where biomass in non-grazed plots doubled. A model parameterized using results from a BTF study forecasts substantial declines in all snowbeds and increases in shrub tundra on Niwot Ridge, Colorado over the next century. In general, results support and provide improved capacities for validating experimental manipulation, remote sensing, and modeling studies.

Understanding population vital rates is fundamental to the evaluation of conservation options for wolverines (Gulo gulo). We estimated survival rates and causes of wolverine mortality in trapped and untrapped populations within montane, boreal, and tundra environments using data from 12 North American radiotelemetry studies conducted between 1972 and 2001. Rates were based on data for 62 mortalities of 239 radiomarked wolverines. Mortalities included 22 wolverines that were trapped or hunted, 3 road or rail killed, 11 that were predated, 18 that starved, and 8 deaths of unknown cause. Annual survivorship rates were estimated for sex and age class using Kaplan-Meier staggered-entry techniques. Survival was substantially lower in trapped (<0.75 for all age–sex classes) than in untrapped (>0.84 for all age–sex classes) populations. Human-caused mortality was mostly additive to natural mortality for wolverines in a management context. Logistic growth rate estimates indicated that trapped populations would decline (λ ≅ 0.88) in the absence of immigration from untrapped populations (λ ≅ 1.06). We recommend a system of spatial harvest controls in northern, continuous populations of wolverines and reduction of harvest along with more spatially explicit conservation measures in southern metapopulations.

Here we describe the evolution of a community- researcher partnership that defines the Government of Canada International Polar Year (IPY) investigation on \"Environmental change and traditional use of the Old Crow Flats in northern Canada (Yeendoo Nanh Nakhweenjit K'atr'ahanahtyaa; hereafter referred to as YNNK)\"-one of very few fully endorsed programs led by northern-based individuals or aboriginal organizations in Canada (Church, 2009). The YNNK project, led by the Vuntut Gwitchin Government in collaboration with Yukon Environment, Parks Canada, and a multidisciplinary team of southernbased researchers, focuses on addressing the complexities of climate change impacts on the OCF and the nearby First Nation community of Old Crow. Research expertise spans the disciplines of Quaternary paleontology, dendroclimatology, permafrost science, hydroecology, terrestrial ecology, wildlife biology, community health, and traditional knowledge of the land and its processes. Overarching goals are to (1) document the history of environmental change in the OCF from a unique assemblage of archives that record natural history from the last interglacial to the present; (2) assess the distribution and abundance of vegetation and wildlife and identify the processes linking these to the changing physical environment; (3) evaluate the impact of changes in the physical and biological environment on traditional food sources of the VGFN and community adaptation options; and (4) develop a long-term environmental monitoring program for the OCF conducted by the VGFN through the IPY and into the future. During the community-researcher meeting of winter 2009 in Old Crow, the researchers and their graduate students had a special opportunity to participate in a very successful outreach program. Organized by leaders of the Arctic Health Research Network (including an Old Crow community member), with funding from Health Canada, the \"Our Changing Homelands, Our Changing Lives\" youth conference brought ~25 students from Whitehorse (many originally from Old Crow) to Old Crow to participate in the annual community-researcher meeting. A major focus of the conference was climate change workshops (including Historical Air Photos, Permafrost, Wildlife, Fossils, Tree Rings and Hydrology; Fig. 3) conducted by YNNK team members. Each research team was challenged to construct an interactive, fun workshop that would run for two to three hours and present research in a way that young people could easily understand. The northern students who participated in these workshops became much more aware of both the changes that are occurring in their traditional territory and the natural science approaches researchers are using to understand how the Old Crow Flats landscape is responding to a warming climate. For instance, one of the workshops used sprouts (representing moss) and broccoli (representing trees), among other ingredients, to examine the effects of different surface features on thawing \"ice-cream\" permafrost. This workshop was particularly effective in delivering its scientific message (and made for an interesting post-experiment snack for workshop participants!). Senior members of the community of Old Crow also participated in these workshops and made important contributions. For example, during the Tree Ring workshop, a YNNK coinvestigator was showing samples of tree cores collected from the OCF, all of which displayed remarkably thicker growth rings over the last few decades (as described above). After the presenter explained that these rings are thicker than any other decade since ~AD 1700 because of the positive growth response to recent climate warming, a community elder remarked that his personal experience also told him that changes in the Flats began in the 1950s. Thus, findings from a natural science IPY-supported study and traditional knowledge converged, and the youth who attended the workshop had the special opportunity to experience this firsthand. Committed local leadership combined with the creativity of researchers and their graduate students in workshop design generated considerable energy that translated into a memorable experience for all.

Understanding the responses of tundra systemsto global change has global implications. Most tundraregions lack sustained environmental monitoring and oneof the only ways to document multi-decadal change is toresample historic research sites. The International PolarYear (IPY) provided a unique opportunity for such researchthrough the Back to the Future (BTF) project (IPY project#512). This article synthesizes the results from 13 paperswithin this Ambio Special Issue. Abiotic changes includeglacial recession in the Altai Mountains, Russia; increasedsnow depth and hardness, permafrost warming, andincreased growing season length in sub-arctic Sweden;drying of ponds in Greenland; increased nutrient availabilityin Alaskan tundra ponds, and warming at mostlocations studied. Biotic changes ranged from relativelyminor plant community change at two sites in Greenland tomoderate change in the Yukon, and to dramatic increasesin shrub and tree density on Herschel Island, and in subarcticSweden. The population of geese tripled at one sitein northeast Greenland where biomass in non-grazed plotsdoubled. A model parameterized using results from a BTFstudy forecasts substantial declines in all snowbeds andincreases in shrub tundra on Niwot Ridge, Colorado overthe next century. In general, results support and provideimproved capacities for validating experimental manipulation,remote sensing, and modeling studies.

The Women-Centered Program for Women of Color, a culturally congruent sexual health intervention, was implemented in 2018 in Los Angeles County, California, according to the principles of community-based participatory research: enhancing community capacity, establishing sustainable programs, and translating research findings to community settings. Participants exhibited significantly increased knowledge of and interest in preexposure prophylaxis (PrEP) and postexposure prophylaxis (PEP) over time, but no significant change in condom use was evident. Booster sessions are needed to maintain interest in PrEP and PEP given concerns about reproductive and sexual health. (Am J Public Health. 2023;113(S2):S110–S114. https://doi.org/10.2105/AJPH.2023.307296 )

Examines the ways in which public perceptions of political violence are molded and actual forms taken by violence against the innocent to intimidate for political gain; focus on Northern Ireland, the US, and the Middle East; 13 articles. Topics include cyberterrorism, terrorist use of weapons of mass destruction, the 1996 US counter-terrorism bill, negative stereotyping of Muslims and Arabs in the US media, state terrorism, Jewish/Zionist terrorism, and tools of conflict resolution.