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Objective: Historically, Chinook Salmon Oncorhynchus tshawytscha have supported important fisheries throughout the Yukon River basin, but dramatic declines in abundance since the late 1990s have resulted in smaller returns, severe reductions in harvests, and difficulties in meeting escapement goals. These observations coincide with major climatic changes in the northern Pacific, characterized by a general warming trend throughout the region. Our objective was to document the migratory patterns of the fish in relation to the environmental conditions encountered in order to assess the impact of climate change and help manage the returns. Methods: We used radio‐archival tags to track the distribution and movements of adult Chinook Salmon returning to the Yukon River to spawn. The tags were equipped with sensors that recorded the swimming depth of the fish and water temperatures encountered during the upriver migration. Spawning ground surveys and fishery returns were used to recover the tags to download the sensor data. Result: Ninety‐five (71.4%) of the 133 tags tracked upriver were recovered, including 35 (26.3%) returned by fishermen and 60 (45.1%) retrieved on the spawning grounds. Upriver movements were characterized by continuous and highly variable fluctuations in depth throughout the migration, ranging from <5 m to >20 m in the lower river and progressively less as fish moved upstream into shallower waters. Swimming depth was not influenced by time of day. Temperatures encountered by the fish were generally warmer in 2004, but this pattern was not consistent throughout the basin and was driven by conditions in the lower main stem, with temperatures frequently >18°C and periodically exceeding 21°C. There was no obvious behavioral response to the warm conditions, with comparable movements and survival rates when conditions were cooler. Temperatures in terminal tributaries often exceeded the upper range generally considered optimal during spawning (13°C), but signs of impaired behavior or prespawning mortality were not observed. A thermal diel pattern was evident as fish left the main stem and approached their spawning grounds, with temperatures declining from early evening to early morning and increasing during daylight hours, suggesting that assessments based on average daily temperature may not adequately reflect exposure to suboptimal conditions. Conclusion: Although the fish during our study frequently encountered temperatures associated with adverse effect on salmon, impaired behavior and increased mortality were not evident. However, the current warming trend occurring throughout the northern Pacific is predicted to continue and may impact salmon populations more severely. Our findings provide a baseline for comparing past conditions and migratory patterns with those of present and future returns. Radio‐archival tags not only provided site‐specific information, but substantially increased the number of tags recovered, with a recovery rate considerably higher than reported for most archival tag studies. The ability to obtain larger samples and more representative results is a major advantage for addressing many resource issues currently facing fishery managers and local communities. Impact Statement: Chinook Salmon returns to the Yukon River have declined dramatically in recent years, creating social and economic hardships in many rural communities. This decline coincides with the general warming trend observed throughout the northern Pacific. Although the long‐term effects of this trend are not fully understood, the impact on Pacific salmon may become increasingly severe. This paper looks at the upriver movements of Yukon River Chinook Salmon in relation to the water temperatures encountered, and examines the impact of elevated temperatures during the migration. Our findings provide a baseline for comparing past conditions and migratory patterns with those of present and future returns. [ABSTRACT FROM AUTHOR]

Adapting to the anticipated impacts of climate change is a pressing issue facing agriculture, as precipitation and temperature changes are expected to have major effects on agricultural production in many regions of the world. These changes will also affect soil organic matter decomposition and associated stocks of soil organic C (SOC), which have the potential to feed back to climate change and affect agroecosystem resiliency. This special section brings together multiple efforts to assess effects of climate change on SOC stocks around the globe in grassland, pasture, and crop agroecosystems under varying management practices. The overall goal of these efforts is to identify optimum practices to enhance SOC accumulation. In this article, we summarize the highlights of these papers and assess their broader implications for future research to enhance agroecosystem SOC accumulation and resiliency to climate change. Fourteen of the twenty contributions apply dynamic process-based models to assess climate and/or long-term management impacts on SOC stocks, and four papers use statistical SOC models across landscapes or regions. Also included are one meta-analysis and one long-term study. The models applied in this collection performed well when reliable input data were available, underlining the usefulness of modeling efforts to inform management decisions that enhance SOC stocks. Overall, the findings confirm that most agroecosystems have the potential to store SOC through improved management. However, this will be challenging, particularly for dryland agriculture, unless crop yield and crop biomass increase under projected climate change. [ABSTRACT FROM AUTHOR]

Forest landscapes across western North America (wNA) have experienced extensive changes over the last two centuries, while climatic warming has become a global reality over the last four decades. Resulting interactions between historical increases in forested area and density and recent rapid warming, increasing insect mortality, and wildfire burned areas, are now leading to substantial abrupt landscape alterations. These outcomes are forcing forest planners and managers to identify strategies that can modify future outcomes that are ecologically and/or socially undesirable. Past forest management, including widespread harvest of fire‐ and climate‐tolerant large old trees and old forests, fire exclusion (both Indigenous and lightning ignitions), and highly effective wildfire suppression have contributed to the current state of wNA forests. These practices were successful at meeting short‐term demands, but they match poorly to modern realities. Hagmann et al. review a century of observations and multi‐scale, multi‐proxy, research evidence that details widespread changes in forested landscapes and wildfire regimes since the influx of European colonists. Over the preceding 10 millennia, large areas of wNA were already settled and proactively managed with intentional burning by Indigenous tribes. Prichard et al. then review the research on management practices historically applied by Indigenous tribes and currently applied by some managers to intentionally manage forests for resilient conditions. They address 10 questions surrounding the application and relevance of these management practices. Here, we highlight the main findings of both papers and offer recommendations for management. We discuss progress paralysis that often occurs with strict adherence to the precautionary principle; offer insights for dealing with the common problem of irreducible uncertainty and suggestions for reframing management and policy direction; and identify key knowledge gaps and research needs. [ABSTRACT FROM AUTHOR]

Argonauts (informally known as "paper nautiluses") are a family of pelagic octopuses. Here, we report a stranding on 4 March 2022 of 18 I A argo i shells and one argonaut specimen with an associated shell (NMV F305014) across a 10-km stretch of beach near Gabo Island, Victoria. [Extracted from the article]

The article presents abstracts of various papers related to water research in the U.S. as of August 2005. It is reported that over the next quarter century, water utilities in the United States will face a number of developments that will put pressure on their resources, spur them to develop alternative supplies, and necessitate new approaches to how they conduct business. In the paper "Population Growth and Climate Change Will Pose Tough Challenges for Water Utilities," by Edward G. Means, Nicole West, and Roger Patrick, population growth and climate change are highlighted. The paper "Tapping Into the Knowledge of Frontline Employees," by Karen H. Cooper, Ann Dettmer and Rubi Leeds, offers suggestions for bringing water utility's field-service and customer-service areas together by detailing the experiences of American Water, the largest water utility in the United States, which launched a knowledge-sharing program in July 2004. In the paper "Optimizing System Operations," by Larry Jentgen, Steve Conrad, and Tony Lee, issues related to managing water systems are discussed.

The most significant factors currently affecting the Pacific walrus ( Odobenus rosmarus divergens) population are climate change and consequent changes in sea-ice morphology and dynamics. This paper integrates recent physical sea-ice change in the Bering Sea with biological and ecological conditions of walruses in their winter-spring reproductive habitat. Historically, walrus in winter-spring depended on a critical mass of sea-ice habitat to optimize social networking, reproductive fitness, feeding behavior, migration, and energetic efficiency. During 2003-2013, our cross-disciplinary, multiscale analysis from shipboard observations, satellite imagery, and ice-floe tracking, reinforced by information from indigenous subsistence hunters, documented change of sea-ice structure from a plastic continuum to a 'mixing bowl' of ice floes moving more independently. This fragmentation of winter habitat preconditions the walrus population toward dispersal mortality and will also negatively affect the availability of resources for indigenous communities. We urge an expanded research and management agenda that integrates walrus natural history and habitat more completely with changing sea-ice morphology and dynamics at multiple scales, while also meeting the needs of local communities. [ABSTRACT FROM AUTHOR]

As part of the 2014 US National Climate Assessment, over 60 subject-matter experts from government agen-cies, academia, nongovernmental organizations, and the private sector assessed the current and projected impacts of climate change on ecosystems, biodiversity, and ecosystem services. Here, we introduce and pro-vide context for the papers included in this Special Issue, drawing upon the key findings from separate assess-ments of biodiversity, ecosystem structure and function, ecosystem services, climate-change impacts in the context of other stressors, and societal responses to change (ie climate adaptation). We also explain the assess-ment process and show how the current state of knowledge can be used to identify risks and guide future research and management initiatives. [ABSTRACT FROM AUTHOR]

The article presents abstracts of papers presented at the July 2008 issue of the "Journal of Environmental Quality," which include the conversion of plowed, annual cropland to perennial pasture, the impact of climate changes on the quality of roots of forest plants and their subsequent decomposition in ecosystems, and the effects of irrigated crop management practices on nitrous oxide emissions from soil.

Climate is changing across a range of scales, from local to global, but ecological consequences remain difficult to understand and predict. Such projections are complicated by change in the connectivity of resources, particularly water, nutrients, and propagules, that influences the way ecological responses scale from local to regional and from regional to continental. This paper describes ecological responses to expected changes in four key meso-scale drivers that influence the ecosystems of the North American continental interior: drought, warming, snowpack disappearance, and altered fire regimes. Changes in these drivers will affect, for example, atmospheric smoke, dust, and reactive nitrogen concentrations; stream discharge; nitrate concentrations; sediment loads; and the vector-borne spread of invasive species and infectious diseases. A continental network of sensors and simulation models is required to detect changes in the transport vectors - atmospheric, hydrologic, and mechanized - that connect spatial scales. Knowledge of these downwind, downstream, and down-corridor effects will be critical if we are to understand and forecast responses to climate change at regional to continental scales. [ABSTRACT FROM AUTHOR]

Catchment Flood Management Plans involve a high-level assessment of current flood risk and attempt to demonstrate how this risk could change with time. An influencing factor will be the changes to rural and urban land use on catchment hydraulics. By assessing a range of land use and urban-growth scenarios catchment wide, a catchment flood? management plan' can demonstrate the cumulative effect on downstream flood-risk areas. 'Catchment flood management plan' methods also indicate how long-term land-use and climate changes can expose new areas to more frequent flooding. Techniques to assess these issues, up to a 50-year horizon, have been established as part of these pilot studies. In addition to briefly describing how land-use concerns are integrated into such concepts, this paper outlines how floodmanagement planning must evolve as a dynamic tool, to fulfil an ongoing requirement for future development assessment. [ABSTRACT FROM AUTHOR]

Understanding the uncertainties and risks from climate change is necessary for managing and adapting to those risks. Climate-change scenarios provide a starting point for assessing climate-change vulnerability, impact and adaptation. In April 2002, the UK Climate Impacts Programme released new future climate scenarios and was based on modelling at the Hadley Centre, which included temperature, soil moisture, rainfall, runoff, sea-level rise and wind speed. These data provide a consistent source of information for use in UK climate-change impact studies. This paper (a) summarises some of the results from this programme, (b) explores their implications, and (c) recommends how these results could be applied in UK flood and coastal defence. The opinions of about twenty selected individuals, who were involved in flood and coastal defence, were collated to assess current practice in the use of climatechange information, requirements of climate-change scenarios, and comparison of the content of UKCIP02 with those requirements. [ABSTRACT FROM AUTHOR]

The paper describes the application of a numerical model to the prediction of seasonal temperature and moisture content changes in the ground. The results are compared with measured values taken over a two year period at the site of a monitored field experiment. Blind predications have been carried out on the basis of assumed material parameters. It is concluded that the analysis is largely capable of modelling the phenomena observed. Certain limitations are, however, exposed. [ABSTRACT FROM AUTHOR]

The article invites papers which discuss how ecologists should respond to the concept of environmental change in the U.S. The papers, which will be published in "Ecological Applications," should be a good example of how ecologists are viewing a changing world. Papers should use the archaeological and evolutionary information from the past to develop an informed guide to the future. In addition, papers using climatic and biological scenarios are also welcome given the fact that the publication will be publishing papers dealing with the changing climate, nitrogen cycle, and patters of development in the coming year.

This paper summarizes the present position of agricultural spray irrigation in England and Wales, providing (a) national statistics and regional information, (b) the reasons why farmers irrigate, (c) the place of agriculture in the economy, and (d) the value of irrigation. Areview of the Ministry of Agriculture, Fisheries and Food irrigationsurveys highlights the important crops in terms of area and volume of water used, sources of water and storage, and application methods. The predictions for the future, including the effects of climate change are reviewed with examples of how farmers, the EA, and the agricultural industry, are helping to overcome problems. [ABSTRACT FROM AUTHOR]

Abating climate change is an enormous international public goods problem with a classical "free rider" structure. But it is also a global "free driver" problem because geoengineering the stratosphere with reflective particles to block incoming solar radiation is so cheap that it could essentially be undertaken unilaterally by one state perceiving itself to be in peril. This exploratory paper develops the main features of a "free driver" externality in a simple model motivated by the asymmetric consequences of type-I and type-II errors. I propose a social-choice decision architecture embodying the solution concept of a supermajority voting rule and derive its basic properties., Economics