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An overview and participatory framework for choosing spatial boundaries in social–ecological systems modeling

A common challenge when modeling social–ecological systems (SESs) is defining the spatial extent of the system. Boundaries that do not adequately capture both social and ecological processes and their interactions can lead to mischaracterization of the system, while expanding boundaries too widely can impact model complexity and required resources. Socially, boundaries can invoke and influence identity, culture, power, and sense of place. Boundary decisions benefit from flexible, iterative approaches and the expertise of local communities. Here, we use a structured database search supplemented with citation searching to identify and review the literature that addresses choosing or defining spatial boundaries in SESs mapping or modeling and, when applicable, how participatory methods were used in the research process. In a review of the resulting 79 studies, we discovered that pre-existing social or ecological boundaries were used most frequently (36 and 18 publications, respectively). Twenty-one publications combined social and ecological boundaries or data to create custom boundaries, and four studies used an alternative approach to conventional boundaries. Informed by the literature review, we present a general framework for defining boundaries at the outset of SES research. We then connect the framework to a specific case study based on a collaborative project with Tribal, university, and federal scientists to develop a social–ecological climate adaptation plan. We present guiding questions alongside candidate boundaries for our study system and explore the tradeoffs of these boundary options, which can function as a useful template for other social–ecological research collaborations.

ISPRS International Journal of Geo-Information↗

Synthesis of tree swallow (Tachycineta bicolor) data for Beneficial Use Impairment (BUI) assessment at Wisconsin Areas of Concern

Assessment of the “Bird or Animal Deformities or Reproductive Problems” Beneficial Use Impairment (BUI) can be accomplished by (1) comparing tissue concentrations to established background and Lowest Observable Effect Level (LOEL) for reproductive effects, or (2) directly measuring reproductive success at Areas of Concern (AOCs) and statistically comparing those rates to minimally impacted reference locations (non-AOCs). Results from recent tree swallow ( Tachycineta bicolor) publications were used to evaluate this BUI based on both approaches. For both endpoints, a 95-percent confidence interval (CI) was used to test for significant differences. Additional information on BUIs, AOCs, and the program in general can be found in the Great Lakes Water Quality Agreement (2012). For the first metric, there are good background and reproductive effect threshold LOELs for tree swallow egg concentrations for polychlorinated biphenyls (PCBs), dioxins and furans (PCDD/Fs), and mercury, as well as, for some other organic and inorganic contaminants. For the second assessment, comparisons were made between AOC and non-AOC sites for reproductive success, which was measured as the daily probability of egg failure and the percentage of eggs laid that hatched. Multistate modeling was used to assess whether there was an association between the daily probability of egg failure and a suite of contaminants, including PCBs, but also whether there was an association with ecological variables, such as female age and date within season. Both of these ecological variables are known to affect hatching success in birds. The objective of this report is to synthesize the previously published information to assist in the assessment of the “Bird or Animal Deformities or Reproductive Problems” BUI at 16 sites within the 5 Wisconsin AOCs (table 1). The logic behind this interpretation is applicable to other AOCs as well.

Michigan, Minnesota, Wisconsin↗

Using models for the optimization of hydrologic monitoring

Hydrologists are often asked what kind of monitoring network can most effectively support science-based water-resources management decisions. Currently (2011), hydrologic monitoring locations often are selected by addressing observation gaps in the existing network or non-science issues such as site access. A model might then be calibrated to available data and applied to a prediction of interest (regardless of how well-suited that model is for the prediction). However, modeling tools are available that can inform which locations and types of data provide the most 'bang for the buck' for a specified prediction. Put another way, the hydrologist can determine which observation data most reduce the model uncertainty around a specified prediction. An advantage of such an approach is the maximization of limited monitoring resources because it focuses on the difference in prediction uncertainty with or without additional collection of field data. Data worth can be calculated either through the addition of new data or subtraction of existing information by reducing monitoring efforts (Beven, 1993). The latter generally is not widely requested as there is explicit recognition that the worth calculated is fundamentally dependent on the prediction specified. If a water manager needs a new prediction, the benefits of reducing the scope of a monitoring effort, based on an old prediction, may be erased by the loss of information important for the new prediction. This fact sheet focuses on the worth or value of new data collection by quantifying the reduction in prediction uncertainty achieved be adding a monitoring observation. This calculation of worth can be performed for multiple potential locations (and types) of observations, which then can be ranked for their effectiveness for reducing uncertainty around the specified prediction. This is implemented using a Bayesian approach with the PREDUNC utility in the parameter estimation software suite PEST (Doherty, 2010). The techniques briefly described earlier are described in detail in a U.S. Geological Survey Scientific Investigations Report available on the Internet (Fienen and others, 2010; http://pubs.usgs.gov/sir/2010/5159/). This fact sheet presents a synopsis of the techniques as applied to a synthetic model based on a model constructed using properties from the Lake Michigan Basin (Hoard, 2010).

Fact Sheet↗

Estimated water use and general hydrologic conditions for Oregon, 1985 and 1990

Water-use information is vital to planners, engineers, and hydrologists in water resources. This report is a compilation of water-use information for Oregon for calendar years 1985 and 1990. The report presents water-use data by geographic region for several categories of use, including public supply, domestic, commercial, industrial, mining, thermoelectric power, hydroelectric power, live-stock, irrigation, reservoir evaporation, and wastewater treatment. Hydroelectric power is the only instream use discussed; all other uses are considered offstream. The Appendix presents 1985 and 1990 data by region and by drainage basin for the previously mentioned categories of use. The Cascade Range divides Oregon into two distinct climatic zones. The area west of the Cascade Range has an average annual precipitation that ranges from 40 to 200 inches, and precipitation in the area east of the Cascade Range ranges from 10 to 20 inches. The differences in precipitation and geology have an effect on the sources, uses, and amounts of water withdrawn. Most of the large public-supply systems west of the Cascade Range rely on surface water, whereas many of the large public-supply systems east of the Cascade Range use on wells or springs. Irrigators west of the Cascade Range rely primarily on nearby surface- water sources; however, irrigators east of the Cascade Range use primarily surface water that commonly is delivered from distant sources through irrigation ditches. A variety of methods was used to estimate water-use information. Most withdrawals for public-water suppliers were metered; however, irrigation withdrawals usually were estimated by using information on crops, climate, application efficiencies, and conveyance losses. The accuracy of the estimated total withdrawal values for public supply was estimated to be within 4 percent of the values that would be obtained if all public-supply withdrawals were metered. Total withdrawals for irrigation were estimated to be within 40 percent of metered irrigation withdrawals. The estimates-of-error are presented to show the relative, rather than absolute, accuracy of the data for each water-use category. A total of 8,400 million gallons of water per day was withdrawn in Oregon during 1990, about 1,900 million gallons per day more than the 6,500 million gallons per day withdrawn in 1985. Whereas actual water use increased in 1990, the major differences between 1985 and 1990 were attributed to the inclusion of offstream fish hatcheries, the use of different crop coefficients to estimate irrigation, and the availability of more detailed information in the 1990 estimates. Surface-water withdrawals accounted for 92 percent of the total withdrawals in 1990; irrigation was the largest category of water use, accounting for 82 percent of the total withdrawals.

Water-Resources Investigations Report↗

U.S. Geological Survey Trace Elements and related reports through 1953

This report combines and brings up-to-date the information previously given in Trace Elements Investigations Report 325, "Numerical list of U.S. Geological Survey Trace Elements Reports to April 30, 1953," and Trace Elements Investigations Report 301, "Topical index and bibliography of U.S. Geological Survey Trace Elements and related reports." Part I is a numerical list of U.S. Geological Survey Trace Elements Investigations and Memorandum reports. It supersedes TEI-325. This part lists not only reports (followed by a date) that have been transmitted to the U.S. Atomic Energy Commission, but also reports in preparation (followed by an asterisk) for which tentative titles were available on December 31, 1953. Reports that have been published are indicated by the abbreviation of the medium of publication. (See also part II.) Part II is a reference guide to Trace Elements and related reports that are available to the public; this part supersedes Part 2 of the TEI-301 (published as Geological survey Circular 281). These reports are grouped according to the type of publication or release. Abstracts published in Nuclear Science Abstracts are not included in Part II, although certain TEI and TEM reports, the abstracts of which have been published in NSA, are so indicated in Part I. Publications in process on December 31, 1953, are designated by an asterisk. Part III is a finding list of states, areas, and subjects. It is based on information derived mostly from the titles of reports and, where titles are of a general nature, from a cursory review of the reports. This list is not a complete index of the information given in Trace Elements and related reports, but is designed to find subjects of major interest. Because of the numerous entries for Colorado and Utah, information has been listed by counties and, where possible, by subject under these states. Other states have county listings only if a county is included in the title of a report; otherwise, areas may be listed separately under the state. Major subjects are listed separately in the index and also where appropriate under states. Analytical methods and subjects related to analytical research are listed under Analytical Methods and Research, but not separately throughout the index. Most mineralogic studies are included under the heading Mineralogy, but are not necessarily listed according to location. Part IV is a finding list of authors. The words “with” and “and” are used to indicate seniority of authorship. For example, a listing of Jones and Brown indicates that Jones is the senior author. A listing of Jones with Brown indicates that Brown is the senior author. In both parts III and IV all Trace Elements reports are listed, as well as other related reports that have not been issued as Trace Elements reports. The following standard abbreviations have been used: TEI, Trace Elements Investigations report; TEM, Trace Elements Memorandum report; P, Professional Paper; B, Bulletin; C, Circular; J, Journal; OF, open file; TIS, Technical Information Service release; NSA, Nuclear Science Abstracts; QM, Quadrangle Map Series; and OM, Oil and Gas map or Mineral Investigations map or report.

Trace Elements Investigations↗

Database for the east half of "Preliminary Geologic Map of the Blythe 30' by 60' quadrangle, California and Arizona"

This digital map database was prepared from the published Preliminary Geologic Map of the Blythe 30' by 60' Quadrangle, California and Arizona (U.S. Geological Survey Open-File Report 90-497). This database represents the east half of the original published map. The database contains exactly the same scientific content as the original map; no data have been added to, subtracted from, or modified from the original map. Like the original paper map, this database represents the general distribution of bedrock and surficial deposits in the mapped area. It provides information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the original published map limits the spatial resolution (scale) of the database to 1:100,000 or smaller.

Arizona, California↗

Essential information: Uncertainty and optimal control of Ebola outbreaks

Early resolution of uncertainty during an epidemic outbreak can lead to rapid and efficient decision making, provided that the uncertainty affects prioritization of actions. The wide range in caseload projections for the 2014 Ebola outbreak caused great concern and debate about the utility of models. By coding and running 37 published Ebola models with five candidate interventions, we found that, despite this large variation in caseload projection, the ranking of management options was relatively consistent. Reducing funeral transmission and reducing community transmission were generally ranked as the two best options. Value of information (VoI) analyses show that caseloads could be reduced by 11% by resolving all model-specific uncertainties, with information about model structure accounting for 82% of this reduction and uncertainty about caseload only accounting for 12%. Our study shows that the uncertainty that is of most interest epidemiologically may not be the same as the uncertainty that is most relevant for management. If the goal is to improve management outcomes, then the focus of study should be to identify and resolve those uncertainties that most hinder the choice of an optimal intervention. Our study further shows that simplifying multiple alternative models into a smaller number of relevant groups (here, with shared structure) could streamline the decision-making process and may allow for a better integration of epidemiological modeling and decision making for policy.

Proceedings of the National Academy of Sciences of↗

Research, monitoring, and evaluation of emerging issues and measures to recover the Snake River Fall Chinook salmon ESU

The portion of the Snake River fall Chinook salmon Oncorhynchus tshawytscha evolutionary significant unit (ESU) that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 1992–2020 in response to U.S. Endangered Species Act recovery efforts and other federally mandated actions. This annual report focuses on changes in population abundance and habitat use by natural- and hatchery-origin spawners. Typically, we also report on population attributes of natural-origin juveniles, but data on juveniles were not collected in 2020 due to Covid-19. Spawners have located and used most of the available spawning habitat and that habitat is gradually approaching the point that no more redds can be supported. Timing of spawning and fry emergence have been relatively stable, but effects of density dependence are evident in juvenile life stages. Apparent abundance of juvenile fall Chinook salmon has increased and we noted the following changes: parr dispersal from riverine rearing habitat into Lower Granite Reservoir has become earlier; growth rate (g/d) and dispersal size of parr has declined; and passage timing of smolts from the two Snake River reaches has become earlier and downstream movement rate has increased. These findings coupled with stock-recruitment analyses presented in this report provide evidence for density-dependence in the Snake River reaches and in Lower Granite Reservoir resulting from the expansion of the recovery program. The long-term goal is to use this information in a comprehensive modeling effort to conduct action-effectiveness and uncertainty research and to inform Fish Population, Hydrosystem, Harvest, Hatchery, and Predation and Invasive Species Management Research, Monitoring, and Evaluation (RM&E) programs. In 2020, the U.S. Geological Survey (USGS) focused survey efforts in the Snake River on deepwater redd searches and fish collection for parentage-based tagging (PBT) analyses. We use a boat-mounted underwater video camera to count 170 deepwater redds at 19 of the 28 sites surveyed. Redd depths averaged 4.2 m. We collected genetic samples from 297 live fall Chinook salmon and 16 carcasses at 44 unique geographic locations that spanned 89 river kilometers. Seventy-two fish were recovered at Eureka Bar (rkm 307.1) and Corral Creek (rkm 349.7), which accounted for 23% of all collected fish in 2020. Most (238 fish) post-spawned salmon were collected from early to mid-November just after peak spawning. A summary of 2019 PBT results can be found in Appendix A.1. In 2020, we PIT tagged subyearling fall Chinook salmon in the Clearwater River to obtain population and growth data. In the Clearwater River, we tagged 2,192 subyearlings and recaptured 79 (3.6%) fish in the river and 187 fish (78 tagged by the U.S. Geological Survey, 109 tagged by the Nez Perce Tribe) at Lower Granite Dam during October which provided information for growth estimation. Within riverine habitats, growth in both length and mass were higher for fish tagged with 8-mm tags than with 9- and 12-mm tags. Estimated growth in length and mass of subyearlings was generally lower in Lower Granite Reservoir than in riverine habitats. Information on prey resources and juvenile fall Chinook salmon prey consumption was collected to better understand the growth opportunity of late-migrating fish in Lower Granite Reservoir. Zooplankton and surface drifting prey were collected from three reservoir locations from July through October during 2019 and 2020. Fall Chinook salmon diet data were collected from angled fish using gastric lavage. Cladocera and Copepoda were the most abundant zooplankton taxa collected while Diptera was the most common invertebrate taxon collected in surface drift samples. Totals of 49 and 94 juvenile fall Chinook salmon were captured in 2019 and 2020, respectively, and most fish were caught in the lower reach of the reservoir in October of each year. Juvenile fall Chinook salmon consumed mainly dipterans in July and October 2019 and mainly Daphnia during August–October in 2020. Fish showed selection mainly for dipterans in 2019 but strong selection for Daphnia during October 2020. Stomach fullness values were relatively low (<1.1%) during both years. Results show that prey resources are adequate in Lower Granite Reservoir to support positive fish growth during late summer and early autumn.

Idaho, Oregon, Washington↗

Accounting for false-positive acoustic detections of bats using occupancy models

1. Acoustic surveys have become a common survey method for bats and other vocal taxa. Previous work shows that bat echolocation may be misidentified, but common analytic methods, such as occupancy models, assume that misidentifications do not occur. Unless rare, such misidentifications could lead to incorrect inferences with significant management implications. 2. We fit a false-positive occupancy model to data from paired bat detector and mist-net surveys to estimate probability of presence when survey data may include false positives. We compared estimated occupancy and detection rates to those obtained from a standard occupancy model. We also derived a formula to estimate the probability that bats were present at a site given its detection history. As an example, we analysed survey data for little brown bats Myotis lucifugus from 135 sites in Washington and Oregon, USA. 3. We estimated that at an unoccupied site, acoustic surveys had a 14% chance per night of producing spurious M. lucifugus detections. Estimated detection rates were higher and occupancy rates were lower under the false-positive model, relative to a standard occupancy model. Un-modelled false positives also affected inferences about occupancy at individual sites. For example, probability of occupancy at individual sites with acoustic detections but no captures ranged from 2% to 100% under the false-positive occupancy model, but was always 100% under a standard occupancy model. 4. Synthesis and applications. Our results suggest that false positives sufficient to affect inferences may be common in acoustic surveys for bats. We demonstrate an approach that can estimate occupancy, regardless of the false-positive rate, when acoustic surveys are paired with capture surveys. Applications of this approach include monitoring the spread of White-Nose Syndrome, estimating the impact of climate change and informing conservation listing decisions. We calculate a site-specific probability of occupancy, conditional on survey results, which could inform local permitting decisions, such as for wind energy projects. More generally, the magnitude of false positives suggests that false-positive occupancy models can improve accuracy in research and monitoring of bats and provide wildlife managers with more reliable information.

Oregon, Washington↗

Partly cloudy with a chance of mosquitoes: Developing a flexible approach to forecasting mosquito populations

Climate-induced shifts in mosquito phenology and population structure have important implications for the health of humans and wildlife. The timing and intensity of mosquito interactions with infected and susceptible hosts are a primary determinant of vector-borne disease dynamics. Like most ectotherms, rates of mosquito development and corresponding phenological patterns are expected to change under shifting climates. However, developing accurate forecast of mosquito phenology under climate change that can be used to inform management programs remains challenging despite an abundance of available data. As climate change will have variable effects on mosquito demography and phenology across species it is vital that we identify associated traits which may explain the observed variation. Here, we review a suite of modeling approaches that could be applied to generate forecasts of mosquito activity under climate change and evaluate the strengths and weaknesses of the different approaches. We describe four primary life-history and physiological traits that can be used to constrain models and demonstrate how this prior information can be harnessed to develop a more general understanding of how mosquito activity will shift under changing climates. Combining a trait-based approach with appropriate modeling techniques can allow for the development of actionable, flexible, and multi-scale forecasts of mosquito population dynamics and phenology for diverse stakeholders.

Michigan, Wisconsin↗

Potash brines in the Great Salt Lake Desert, Utah

During and immediately after the war the brines of the Salduro Marsh, in the Great Salt Lake Desert, were a source of considerable potash for the domestic supply. Although no potash has been produced from these brines in the last few years, a continued interest in the area has been shown by a large number of filings, in different parts of the desert, under the potash law of October 2, 1917 (40 Stat. 297), and the regulations issued under that law by the Department of the Interior on March 21, 1918, in Circular 594 (46 L. D. 323). As the basis for appropriate action on these permit, lease, and patent filings the Department of the Interior required information concerning the mode of occurrence, distribution, and general characteristics of the potassium-bearing brines in this region. Field investigation was accordingly undertaken for the primary purpose of satisfying these requirements. The work was done by the Geological Survey and the General Land Office in cooperation with the Bureau of Mines. The Bureau of Mines furnished an autotruck and a mechanic, who also assisted in the field work, and, for a period of a month, a mine rescue car, which permitted the establishment of headquarters in parts of the desert far from sources of supplies and water. The General Land Office surveyed the boundaries of townships over the desert and located the drill holes from which samples of brine were taken. The writer directed the work for the Geological Survey, and the analyses of the samples of brine were made in the Survey's chemical laboratory. The greater part of the field work was done between April 17 and July 7, 1925, and the work was finished during the two periods August 17-26 and September 30 to October 2 . Adverse weather throughout the season hindered the work.

Utah↗

U.S. Geological Survey archived data recovery in Texas, 2008-11

The 2008&ndash;11 data rescue and recovery efforts by the U.S. Geological Survey (USGS) Texas Water Science Center resulted in an efficient workflow process, database, and Web user interface for scientists and citizens to access archived environmental information with practical applications. Much of this information is unique and has never been readily available to the public. The methods developed and lessons learned during this effort are now being applied to facilitate recovering archived information requested by USGS scientists, cooperators, and the general public.

Texas↗

Map showing the thickness of loosely packed sediments and the depth to bedrock in the Sugar House quadrangle, Salt Lake County, Utah

This map provides information on the location and distribution of three general types of geologic materials in part of Salt Lake County, including the southeastern part of Salt Lake City, Utah. These materials have different physical properties that are pertinent to comprehensive planning and zoning, land-use studies, and engineering usage. The map should be of use in preliminary studies to determine the depth to different general types of foundation material and to determine the potential for settlement of the ground surface during major earthquakes, which could result in damage to waterlines, gaslines, large buildings, and other major engineering structures. The lines on the map are generalized. Lines showing the thickness of loosely packed sediments are based on drillers’ logs of 27 water wells in and near the 35-square-mile part of the quadrangle west of the mountains – less than one data point for each square mile. Lines showing the depth to bedrock are based on indirect geophysical data, and the data points are more widely scattered. The map may be useful as a general guide in planning, but investigations by qualified specialists should be made for detailed evaluations of specific areas. references to other reports of possible interest to the reader are included at the end of this text.

Utah↗

Multitemporal L- and C-Band synthetic aperture radar to highlight differences in water status among boreal forest and wetland systems in the Yukon Flats, Interior Alaska

Tracking landscape-scale water status in high-latitude boreal systems is indispensable to understanding the fate of stored and sequestered carbon in a climate change scenario. Spaceborne synthetic aperture radar (SAR) imagery provides critical information for water and moisture status in Alaskan boreal environments at the landscape scale. When combined with results from optical sensor analyses, a complementary picture of vegetation, biomass, and water status emerges. Whereas L-band SAR showed better inherent capacity to map water status, C-band had much more temporal coverage in this study. Analysis through the use of L- and C-band SARs combined with Landsat Enhanced Thematic Mapper Plus (ETM+) enables landscape stratification by vegetation and by seasonal and interannual hydrology. Resultant classifications are highly relevant to biogeochemistry at the landscape scale. These results enhance our understanding of ecosystem processes relevant to carbon balance and may be scaled up to inform regional carbon flux estimates and better parameterize general circulation models (GCMs).

Open-File Report↗

Terrestrial Ecosystems of the Conterminous United States

The U.S. Geological Survey (USGS), with support from NatureServe, has modeled the potential distribution of 419 terrestrial ecosystems for the conterminous United States using a comprehensive biophysical stratification approach that identifies distinct biophysical environments and associates them with known vegetation distributions (Sayre and others, 2009). This standardized ecosystem mapping effort used an ecosystems classification developed by NatureServe (Comer and others, 2003). The ecosystem mapping methodology was developed for South America (Sayre and others, 2008) and is now being implemented globally (Sayre and others, 2007). The biophysical stratification approach is based on mapping the major structural components of ecosystems (land surface forms, topographic moisture potential, surficial lithology, isobioclimates and biogeographic regions) and then spatially combining them to produce a set of unique biophysical environments. These physically distinct areas are considered as the fundamental structural units ('building blocks') of ecosystems, and are subsequently aggregated and labeled using the NatureServe classification. The structural footprints were developed from the geospatial union of several base layers including biogeographic regions, isobioclimates (Cress and others, 2009a), land surface forms (Cress and others, 2009b), topographic moisture potential (Cress and others, 2009c), and surficial lithology (Cress and others, in press). Among the 49,168 unique structural footprint classes that resulted from the union, 13,482 classes met a minimum pixel count threshold (20,000 pixels) and were aggregated into 419 NatureServe ecosystems using a semiautomated labeling process based on rule-set formulations for attribution of each ecosystem. The resulting ecosystems are those that are expected to occur based on the combination of the bioclimate, biogeography, and geomorphology. Where land use by humans has not altered land cover, natural vegetation assemblages are expected to occur, and these are described in the ecosystems classification. The map does not show the distribution of urban and agricultural areas - these will be masked out in subsequent analyses to depict the current land cover in addition to the potential distribution of natural ecosystems. This map depicts the smoothed and generalized image of the terrestrial ecosystems dataset. Additional information about this map and any data developed for the ecosystems modeling of the conterminous United States is available online at: http://rmgsc.cr.usgs.gov/ecosystems/.

Scientific Investigations Map↗

Spatially referenced models of streamflow and nitrogen, phosphorus, and suspended-sediment loads in streams of the midwestern United States

In this report, SPAtially Referenced Regression On Watershed attributes (SPARROW) models developed to describe long-term (2000–14) mean-annual streamflow, total nitrogen (TN), total phosphorus (TP), and suspended-sediment (SS) transport in streams of the Midwestern part of the United States (the Mississippi River, Great Lakes, and Red River of the North Basins) are described. The nutrient and suspended-sediment models have a base year of 2012, which means they were developed based on source inputs and management practices similar to those existing during or near 2012 and average hydrological conditions detrended to 2012 (2000–14), whereas the streamflow model has base years of 2000–14, which means it was developed based on the average input precipitation minus actual evapotranspiration from 2000 to 2014. In developing the models, several updates and improvements were made to the data inputs and statistical approaches used to calibrate/develop the models from those used in the previous 2002 SPARROW models. The 2012 SPARROW models were constructed using a higher resolution stream network, which resulted in a mean catchment size of 2.7 square kilometers compared to 480 square kilometers in the 2002 models; more detailed and updated wastewater treatment plant contribution estimates; inputs from background phosphorus sources that were not included in the 2002 model; and more accurate loads for calibration that were computed using a modified Beale ratio-estimator technique whenever no trend in load was determined. Statistical approaches were added to compensate for the unequal effect of each monitoring site during the calibration process by adjusting for the fraction of the basin included in other upstream monitored sites (nested share) and thinning the calibration sites if a negative statistical correlation between nearby sites was determined. Results from 2012 SPARROW models describe how much of each water, TN, TP, and SS source was delivered to the stream network, and the major landscape factors that affected their delivery. Atmospheric deposition and natural (background) sources of TN and TP, respectively, were the dominant sources in anthropogenically unaffected areas (especially in the Rocky Mountains and north-central areas of the Midwest), whereas fertilizers, manure, and fixation were dominant sources in agricultural areas, especially in the Corn Belt and near the Mississippi River. Urban sources of TN and TP were typically localized, but they were still important for some large areas, especially the Lake Erie Basin. All of the land-to-water delivery variables in the nutrient and sediment SPARROW models, such as runoff, soil erodibility, basin slope, and the amount of tile drains, are commonly included in process-driven models. In the SPARROW TN and TP models, best management practices (BMPs) reduced the delivery of these nutrients to streams. Long-term mean-annual flows and nutrient and sediment loads were simulated in streams throughout the Midwest. The simulated flows from the SPARROW flow model were used in the SPARROW TN, TP, and SS models to help describe nutrient and sediment transport from the watershed and through the stream network. Outputs from the TN, TP, and SS models describe loads and yields of these constituents throughout the Midwest, and from major drainage basins throughout the Midwest. Highest TN, TP, and SS yields and delivered yields were from the Lake Erie, Ohio River, Upper Mississippi River, and Lower Mississippi River Basins, whereas lowest yields were spread over most other areas. Losses during downstream delivery resulted in part of the TN, TP, and SS that reach the stream network not reaching the downstream receiving bodies: 14, 15, and 28 percent of the TN, TP, and SS, respectively, are lost during delivery to the Great Lakes and 19, 23, and 52 percent of the TN, TP, and SS, respectively, are lost during delivery to the Gulf of Mexico. The largest losses of nutrients and sediments during transport were in the Missouri and Arkansas River Basins. Information from these SPARROW models can help guide nutrient and sediment reduction strategies throughout the Midwest. Model results provide information on what may be the most appropriate general type of actions to reduce total loading by describing the relative importance of each source, and where to most efficiently place the efforts to reduce loading by describing the distribution of nutrient and sediment loading. By implementing management efforts addressing the major sources of the loads in areas contributing the highest loads, it may be possible to reduce nutrient loading throughout the Mississippi River Basin and thus reduce the size of the hypoxic zone in the Gulf of Mexico; reduce nutrient loading into lakes, and thus reduce the occurrence of harmful algal blooms; and reduce sediment losses, and thus improve the benthic habitat in streams and rivers throughout the Midwest.

Scientific Investigations Report↗

Analyses of meteorological and hydrological records support Tribal members’ accounts of changing climate on the Fort Apache Reservation, east–central Arizona

The Fort Apache Reservation in east–central Arizona, home to the White Mountain Apache Tribe of the Fort Apache Reservation, Arizona, contains several climate zones because of the large variation in surface elevation within the reservation. This study was carried out in cooperation with the White Mountain Apache Tribe of the Fort Apache Reservation, Arizona, to raise awareness of how the changing climate affects the Fort Apache Reservation. This report documents the evaluation of existing multidecadal meteorological and hydrological datasets for the Fort Apache Reservation, used to evaluate the effects of a changing climate on the reservation. In this evaluation, near-surface air temperature, snow depth, snow water equivalent, precipitation, and streamflow datasets were analyzed for monotonic trends indicative of changing climatic conditions during specified periods of time. The results of these trend analyses were then compared with the Tribal community's memories of the changing climate. Trend analysis of near-surface air temperatures from a U.S. Historical Climatological Network station on the Fort Apache Reservation at Whiteriver, Arizona, indicated that mean annual air temperatures have increased by an average of 2.48 degrees Fahrenheit from 1980 to 2023. Records from the same station also indicated that average monthly maximum temperatures recorded for March increased by 5.39 degrees Fahrenheit for the same time period. Annual precipitation at the five precipitation stations used in this study decreased greatly from the 1980s to 2023. The largest total decrease was 10.07 inches, or 34.7 percent. However, only one of the two precipitation stations with longer term data available prior to 1980 had a significant negative trend when data from the entire period of record, from 1901 to 2023, were analyzed. Trend analyses show a decrease in the annual maximum snow water equivalent and an earlier disappearance of the snowpack at two Natural Resources Conservation Service snow telemetry stations in the mountainous region just east of the Fort Apache Reservation from 1981 to 2023. Based on the trend analyses, the average annual maximum snow water equivalent has decreased by more than 40 percent at both stations, and the average date when the snowpack was fully melted at the stations in the spring has moved earlier in time from late April to early April or late March. However, a statistically significant trend was not determined for the early April snow water equivalent measured at a nearby Natural Resources Conservation Service snow course across its period of record, indicating that the history of mountain snowpack in this area is not fully understood. Analysis of snowfall data from a National Oceanic and Atmospheric Administration Cooperative Observer Program network station on the Fort Apache Reservation at McNary 2N, AZ (station 025412) indicated that, on average, the measured total annual snowfall at the station decreased 42.4 percent from 1935 to 2023. Streamflow data from six U.S. Geological Survey streamgages on the Fort Apache Reservation were analyzed for trends. For most streamflow gages, statistically significant trends were not determined for tested parameters when the entire streamflow period of record was used for stations with records going back to at least the 1960s. However, when the data from 1980 to 2023 was tested, most of the streamflow parameters had statistically significant negative trends. All six streamgages showed a decrease in average annual runoff of at least 50 percent from 1980 to 2023; one streamgage showed an 81.8 percent decrease. A similar statistical finding was observed in the analysis of the annual spring snowmelt peak from one of the six streamgages used in the study and located in an area receiving measurable amounts of snowmelt runoff. When data from the entire period of record (1958–2023) was used, no trend in streamflow was determined; however, a significant negative trend was determined from 1980 to 2023, indicating a decrease in average annual springtime runoff of 62.6 percent. Statistical analysis on the timing of the annual spring snowmelt peak at the same streamgage indicated the snowmelt peak is happening on average about 12 days earlier now (2023) than it did in the past. The trend results for the timing of the annual spring snowmelt peak were the same and statistically significant for both periods tested (1958–2023 and 1980–2023). Two of the streamflow records from the Fort Apache Reservation were compared to the Palmer Hydrological Drought Index computed for Arizona Climate Division 4 (East Central) by the National Centers for Environmental Information. The comparison showed that the streamflow records generally tracked the Palmer Hydrological Drought Index. In interviews, Tribal community members living on the Fort Apache Reservation described the changes in climate that they observed during their lifetimes. Common themes reported were that air temperatures have become warmer, and the weather is less predictable with changes in seasonal patterns. Drier conditions, lower snowfall, shorter winters, and lower river levels were also reported. These community member observations align with the results of this study.

Arizona↗

Rare and endangered species of Hawai`i Volcanoes National Park; endangered, threatened, and rare animal, plant, and community handbook

Introduction Hawai`i Volcanoes National Park (HAVO) is the largest area in the State of Hawai`i protected for its geology and landscapes and its native flora and fauna. The park covers approximately 135,000 hectares or 333,000 acres in all. These lands stretch from the seacoast of Kīlauea Volcano to far above timberline on the summit of Mauna Loa (Figure 1). This vast area includes expanses of forests, woodlands, shrublands, and barren lava flows that represent an array of native ecosystems. Contained within these communities are a great many species of rare animals and plants, most of them unique to the island of Hawai`i, and some of them surviving only in the park. These are the biological treasures of Hawai`i Volcanoes National Park. Our book is a guide to all animal and plant species in HAVO that are specially recognized as endangered species in the general sense. (The official designations at four levels and the unofficial designation of species of concern are explained later.) There are 23 such animal species and 71 plant species covered in the handbook, including six species planted in HAVO but not naturally occurring. In addition, we describe seven rare communities. In some cases, HAVO offers the best opportunity to save these species and communities from extinction. Increasingly, the park has attempted to restore rare populations by conducting surveys to locate them, controlling threats such as feral livestock, and bolstering existing populations or creating new ones by planting nursery stock. To aid such efforts, our original intent was to publish an identification guide for researchers and field management personnel. Particularly, we wanted to familiarize the reader with the many rare plant species which otherwise are known mainly from the technical literature. Because we soon came to realize that this handbook would be useful to a much larger, general readership, our aim is to make this information available to anyone interested in endangered animals and plants at Hawai`i Volcanoes National Park.

Hawaii↗