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USGS2003

Estimation of change in populations and communities from monitoring survey data

Monitoring surveys provide fundamental information for use in environmental decision making by permitting assessment of both current population (or community) status and change in status, by providing a historical context of the present status, and by documenting response to ongoing management. Conservation of species and communities has historically been based upon monitoring information, and prioritization of species and habitats for conservation action often requires reliable, quantitative results. Although many monitoring programs exist for populations, species, and communities, as well as for biotic and abiotic features of the environment, estimation of population and community change from surveys can sometimes be controversial, and demands on monitoring information have increased greatly in recent years. Information is often required at multiple spatial scales for use in geographic information systems, and information needs exist for description of regional patterns of change in populations, communities, and ecosystems. Often, attempts are made to meet these needs using information collected for other purposes or at inappropriate geographic scales, leading to information that is difficult to analyze and interpret. In this chapter, we address some of the constraints and issues associated with estimating change in wildlife species and species groups from monitoring surveys, and use bird surveys as our primary examples.

Book chapter↗

USGS2015

Predicting ecological responses of the Florida Everglades to possible future climate scenarios: Introduction

Florida’s Everglades stretch from the headwaters of the Kissimmee River near Orlando to Florida Bay. Under natural conditions in this flat landscape, water flowed slowly downstream as broad, shallow sheet flow. The ecosystem is markedly different now, altered by nutrient pollution and construction of canals, levees, and water control structures designed for flood control and water supply. These alterations have resulted in a 50 % reduction of the ecosystem’s spatial extent and significant changes in ecological function in the remaining portion. One of the world’s largest restoration programs is underway to restore some of the historic hydrologic and ecological functions of the Everglades, via a multi-billion dollar Comprehensive Everglades Restoration Plan. This plan, finalized in 2000, did not explicitly consider climate change effects, yet today we realize that sea level rise and future changes in rainfall (RF), temperature, and evapotranspiration (ET) may have system-wide impacts. This series of papers describes results of a workshop where a regional hydrologic model was used to simulate the hydrology expected in 2060 with climate changes including increased temperature, ET, and sea level, and either an increase or decrease in RF. Ecologists with expertise in various areas of the ecosystem evaluated the hydrologic outputs, drew conclusions about potential ecosystem responses, and identified research needs where projections of response had high uncertainty. Resource managers participated in the workshop, and they present lessons learned regarding how the new information might be used to guide Everglades restoration in the context of climate change.

Florida↗

USGS1989

Interrelationships among hydrologic-budget components of a northern Wisconsin seepage lake and implications for acid-deposition modeling

Components of the hydrologic budget for a northern Wisconsin seepage lake were analyzed by applying correlation and regression techniques to monthly data. Analyses for the 1981–83 water years revealed a statistically significant, direct relationship between storage change and precipitation-evaporation balance. Ground-water outflow was negatively correlated with ground-water inflow, and this relationship was influenced by similar relationships for both hydraulic gradients and cross-sectional areas in outflow versus inflow regions of the lake. Neither ground-water outflow nor inflow was significantly related to precipitation, evaporation, storage change, or lake stage; this may reflect a lag in response time of the ground-water system compared to the lake. The results (1) emphasize the complexity of factors that influence ground-water interactions with seepage lakes and (2) suggest the importance of completing detailed hydrologic studies of these systems before mechanistic models, such as those developed to predict effects of acid deposition, are applied.

Wisconsin↗

USGS2021

Individual and seasonal variation in the movement behavior of two tropical nectarivorous birds

Background Movement of animals directly affects individual fitness, yet fine spatial and temporal resolution movement behavior has been studied in relatively few small species, particularly in the tropics. Nectarivorous Hawaiian honeycreepers are believed to be highly mobile throughout the year, but their fine-scale movement patterns remain unknown. The movement behavior of these crucial pollinators has important implications for forest ecology, and for mortality from avian malaria ( Plasmodium relictum ), an introduced disease that does not occur in high-elevation forests where Hawaiian honeycreepers primarily breed. Methods We used an automated radio telemetry network to track the movement of two Hawaiian honeycreeper species, the ʻapapane ( Himatione sanguinea ) and ʻiʻiwi ( Drepanis coccinea ). We collected high temporal and spatial resolution data across the annual cycle. We identified movement strategies using a multivariate analysis of movement metrics and assessed seasonal changes in movement behavior. Results Both species exhibited multiple movement strategies including sedentary, central place foraging, commuting, and nomadism , and these movement strategies occurred simultaneously across the population. We observed a high degree of intraspecific variability at the individual and population level. The timing of the movement strategies corresponded well with regional bloom patterns of ‘ōhi‘a ( Metrosideros polymorpha ) the primary nectar source for the focal species. Birds made long-distance flights, including multi-day forays outside the tracking array, but exhibited a high degree of fidelity to a core use area, even in the non-breeding period. Both species visited elevations where avian malaria can occur but exhibited little seasonal change in elevation (< 150 m) and regularly returned to high-elevation roosts at night. Conclusions This study demonstrates the power of automated telemetry to study complex and fine-scale movement behaviors in rugged tropical environments. Our work reveals a system in which birds can track shifting resources using a diverse set of movement behaviors and can facultatively respond to environmental change. Importantly, fidelity to high-elevation roosting sites minimizes nocturnal exposure to avian malaria for far-ranging individuals and is thus a beneficial behavior that may be under high selection pressure.

Hawaii↗

USGS2011

Cobalt mineral exploration and supply from 1995 through 2013

The global mining industry has invested a large amount of capital in mineral exploration and development over the past 15 years in an effort to ensure that sufficient resources are available to meet future increases in demand for minerals. Exploration data have been used to identify specific sites where this investment has led to a significant contribution in global mineral supply of cobalt or where a significant increase in cobalt production capacity is anticipated in the next 5 years. This report provides an overview of the cobalt industry, factors affecting mineral supply, and circumstances surrounding the development, or lack thereof, of key mineral properties with the potential to affect mineral supply. Of the 48 sites with an effective production capacity of at least 1,000 metric tons per year of cobalt considered for this study, 3 producing sites underwent significant expansion during the study period, 10 exploration sites commenced production from 1995 through 2008, and 16 sites were expected to begin production by 2013 if planned development schedules are met. Cobalt supply is influenced by economic, environmental, political, and technological factors affecting exploration for and production of copper, nickel, and other metals as well as factors affecting the cobalt industry. Cobalt-rich nickel laterite deposits were discovered and developed in Australia and the South Pacific and improvements in laterite processing technology took place during the 1990s and early in the first decade of the 21st century when mining of copper-cobalt deposits in Congo (Kinshasa) was restricted because of regional conflict and lack of investment in that country's mining sector. There was also increased exploration for and greater importance placed on cobalt as a byproduct of nickel mining in Australia and Canada. The emergence of China as a major refined cobalt producer and consumer since 2007 has changed the pattern of demand for cobalt, particularly from Africa and Australasia. Chinese companies are increasingly becoming involved in copper and cobalt exploration and mining in Congo (Kinshasa) and Zambia as well as nickel, copper, and other mining in Australia and the South Pacific. Between 2009 and 2013, mines with a cumulative capacity of more than 100,000 metric tons per year of cobalt were proposed to come into production if all sites came into production as scheduled. This additional capacity corresponds to 175 percent of the 2008 global refinery production level. About 45 percent of this cobalt would be from primary nickel deposits, about 32 percent from primary copper deposits, and about 21 percent from primary cobalt deposits. By 2013, about 40 percent of new capacity was expected to come from the African Copperbelt; 38 percent, from Australia and the South Pacific countries of Philippines, Indonesia, New Caledonia, and Papua New Guinea; 11 percent, from other African countries; 5 percent, from North America; and 6 percent, from other areas.

Scientific Investigations Report↗

USGS2016

Effects of Climate and land use on diversity, prevalence, and seasonal transmission of avian hematozoa in American Samoa

The indigenous forest birds of American Samoa are increasingly threatened by changing patterns of rainfall and temperature that are associated with climate change as well as environmental stressors associated with agricultural and urban development, invasive species, and new introductions of avian diseases and disease vectors. Long term changes in their distribution, diversity, and population sizes could have significant impacts on the ecological integrity of the islands because of their critical role as pollinators and seed dispersers. We documented diversity of vector borne parasites on Tutuila and Ta‘u Islands over a 10-year period to expand earlier observations of Plasmodium, Trypanosoma , and filarial parasites, to provide better parasite identifications, and to create a better baseline for detecting new parasite introductions. We also identified potential mosquito vectors of avian Plasmodium and Trypanosoma , determined whether land clearing and habitat alterations associated with subsistence farming within the National Park of American Samoa can influence parasite prevalence, and determined whether parasite prevalence is correlated with seasonal changes in rainfall, temperature and wind speed. Three taxonomically distinct lineages of Plasmodium were identified from mosquito vectors and forest birds based on partial sequence data from parasite mitochondrial genes. All three have been described from passerine and galliform birds in Australasia. Two lineages, SCEDEN01 and ORW1, had elongate gametocytes and large schizonts that were consistent with species of Plasmodium in the subgenus Giavannolaia, but were taxonomically distinct from known morphological species of Plasmodium based on a Bayesian phylogenetic analysis of a 478 bp region of the parasite cytochrome b gene. Both are candidates for description as new species. The third lineage (GALLUS02) was detected only in mosquito vectors on Tutuila and was similar in cytochrome b sequence to P. juxtanucleare , a pathogenic species of Plasmodium from chickens and other galliform birds from Australasia, Africa, and South America. Plasmodium relictum , the malarial parasite that has had such a devastating impact on Hawaiian forest birds, was not detected. We observed large, striated trypanosomes in avian hosts from both Tutuila and Ta‘u Islands that fell within the same taxonomic clade as T. corvi and T. culicavium based on 18S ribosomal DNA sequence. We also observed sheathed microfilariae with pointed tails that had some morphological similarities to microfilaria from species of Pelecitus, Struthiofilaria and Eulimdana , but identification will require recovery and examination of adult filarial worms from the connective tissue or body cavities of infected birds. We also observed one or more species of haemococcidians (Isospora, synonym = Atoxoplasma ) within circulating lymphocytes from multiple avian host species. Overall prevalence of Plasmodium was higher on Ta‘u (22%, 75/341) than Tutuila (9.2%, 27/294), with most infections occurring in Polynesian starlings, Samoan starlings, Wattled honeyeaters, and Cardinal honeyeaters. Prevalence was relatively constant from year to year and between seasons at individual study sites, but varied among study sites, with highest rates of infection in areas with agricultural activity at Faleasao (37.4%, 73/195, Ta‘u Island) and Amalau Valley (9.7%, 21/216, Tutuila Island). Prevalence in more remote areas of the National Park of American Samoa was lower, ranging from 1.4% (2/146) at Laufuti and Luatele on Ta‘u to 7.7% (6/78) at Olo Ridge on Tutuila. Similar trends were evident for infections with Trypanosoma and filarial worms. Overall prevalence was not influenced significantly by warmer, wet (summer) or cooler, dry (winter) season. We detected Plasmodium infections in Culex sitiens and C. quinquefasciatus through either salivary gland and midgut dissections or PCR amplification of parasite cytochrome b genes in pooled or individual samples of mosquitoes that were collected on Tutuila. Pooled or individual Aedes oceanicus, A. polynesiensis, A. tutuilae, A. upolensis, A. nocturnus, Aedes (Finlaya) (mixed pools of A. samoanus, A. oceanicus, A. tutuilae), Aedes (Stegomyia) (mixed pools of A. aegypti, A. upolensis, A. polynesiensis ), and C. annulirostris were negative for Plasmodium , but we detected infections with Trypanosoma through midgut and salivary gland dissections in a single C. sitiens from Amalau Valley, Tutuila and three A. oceanicus from Faleasao, Ta‘u. Two of the A. oceanicus from Faleasao amplified successfully with Trypanosoma primers, but sequences were distinctly different from those obtained from avian hosts. We found a strong association between land use and prevalence of mosquito-transmitted parasites on Ta‘u Island with odds of being infected more than 20 times greater in agricultural plots than more remote native forest. This relationship was evident on Tutuila Island but not statistically significant because of the close proximity of study sites and observed movement of birds between native forest and agricultural land. Our data support previous studies that have suggested that Plasmodium and other vector-borne parasites are part of the indigenous parasite fauna in American Samoa. Transmission dynamics appear to be affected by environmental changes associated with land use practices.

HI↗

USGS2015

Fire activity as a function of fire–weather seasonal severity and antecedent climate across spatial scales in southern Europe and Pacific western USA

Climate has a strong influence on fire activity, varying across time and space. We analyzed the relationships between fire–weather conditions during the main fire season and antecedent water-balance conditions and fires in two Mediterranean-type regions with contrasted management histories: five southern countries of the European Union (EUMED)(all fires); the Pacific western coast of the USA (California and Oregon, PWUSA)(national forest fires). Total number of fires (≥1 ha), number of large fires (≥100 ha) and area burned were related to mean seasonal fire weather index (FWI), number of days over the 90th percentile of the FWI, and to the standardized precipitation-evapotranspiration index (SPEI) from the preceding 3 (spring) or 8 (autumn through spring) months. Calculations were made at three spatial aggregations in each area, and models related first-difference (year-to-year change) of fires and FWI/climate variables to minimize autocorrelation. An increase in mean seasonal FWI resulted in increases in the three fire variables across spatial scales in both regions. SPEI contributed little to explain fires, with few exceptions. Negative water-balance (dry) conditions from autumn through spring (SPEI8) were generally more important than positive conditions (moist) in spring (SPEI3), both of which contributed positively to fires. The R2 of the models generally improved with increasing area of aggregation. For total number of fires and area burned, the R2 of the models tended to decrease with increasing mean seasonal FWI. Thus, fires were more susceptible to change with climate variability in areas with less amenable conditions for fires (lower FWI) than in areas with higher mean FWI values. The relationships were similar in both regions, albeit weaker in PWUSA, probably due to the wider latitudinal gradient covered in PWUSA than in EUMED. The large variance explained by some of the models indicates that large-scale seasonal forecast could help anticipating fire activity in the investigated areas.

California, Oregon↗

USGS2022

A framework to integrate innovations in invasion science for proactive management

Invasive alien species (IAS) are a rising threat to biodiversity, national security, and regional economies, with impacts in the hundreds of billions of U.S. dollars annually. Proactive or predictive approaches guided by scientific knowledge are essential to keeping pace with growing impacts of invasions under climate change. Although the rapid development of diverse technologies and approaches has produced tools with the potential to greatly accelerate invasion research and management, innovation has far outpaced implementation and coordination. Technological and methodological syntheses are urgently needed to close the growing implementation gap and facilitate interdisciplinary collaboration and synergy among evolving disciplines. A broad review is necessary to demonstrate the utility and relevance of work in diverse fields to generate actionable science for the ongoing invasion crisis. Here, we review such advances in relevant fields including remote sensing, epidemiology, big data analytics, environmental DNA (eDNA) sampling, genomics, and others, and present a generalized framework for distilling existing and emerging data into products for proactive IAS research and management. This integrated workflow provides a pathway for scientists and practitioners in diverse disciplines to contribute to applied invasion biology in a coordinated, synergistic, and scalable manner.

Biological Reviews↗

USGS2015

A conceptual framework and monitoring strategy for movement of saltwater in the coastal plain aquifer system of Virginia

A conceptual framework synthesizes previous studies to provide an understanding of conditions, processes, and relations of saltwater to groundwater withdrawal in the Virginia Coastal Plain aquifer system. A strategy for monitoring saltwater movement is based on spatial relations between the saltwater-transition zone and 612 groundwater-production wells that were regulated during 2013 by the Virginia Department of Environmental Quality. The vertical position and lateral distance and direction of the bottom of each production well’s screened interval was calculated relative to previously published groundwater chloride iso-concentration surfaces. Spatial analysis identified 81 production wells completed in the Yorktown-Eastover and Potomac aquifers that are positioned in closest proximity to the 250-milligrams-per-liter chloride surface, and from which chloride concentrations are most likely to increase above the U.S. Environmental Protection Agency’s 250-milligrams-per-liter secondary maximum-contaminant level. Observation wells are specified to distinguish vertical upconing from lateral intrusion among individual production wells. To monitor upconing, an observation well is to be collocated with each production well and completed at about the altitude of the 250-milligrams-per-liter chloride iso-concentration surface. To monitor lateral intrusion, a potential location of an observation well is projected from the bottom of each production well’s screened interval, in the lateral direction to the underlying chloride surface to a distance of 1 mile. Monitoring potential withdrawal-induced movement of saltwater in the Virginia Coastal Plain aquifer system is needed to detect increases in chloride concentration before groundwater-production wells become contaminated. An investigation was undertaken during 2014 by the U.S. Geological Survey in cooperation with the Virginia Department of Environmental Quality, to provide a sound scientific understanding of saltwater movement and guidance to implement a monitoring program. Previous studies have theorized that the saltwater originated primarily from seawater repeatedly emplaced within aquifer sediments during the past about 65 million years. Subsequent flushing by fresh groundwater has been impeded across sediments filling the Chesapeake Bay impact crater. The resulting saltwater-transition zone has been mapped to exhibit a warped and steeply mounded dome shape about centered on the impact crater, and flanked by a nearly level and shallow plateau shape to the southeast. Groundwater chloride concentrations have historically fluctuated during periods of weeks to months, probably as a result of localized vertical upconing beneath individual production wells. Lateral intrusion takes several decades or more to horizontally displace groundwater across distances of about 1 mile toward production wells. Upconing is relatively immediate, but reversible, whereas lateral intrusion under the regionally landward hydraulic gradient may slowly, but permanently reposition the saltwater-transition zone. Upconing coupled with lateral intrusion is theorized to produce composite chloride-concentration trends that vary widely over time in response to changing water demands, and evolve dynamically from hydraulic interactions among multiple neighboring production wells. Some aspects of observation-well construction and sampling are of particular importance to monitoring saltwater movement in the Virginia Coastal Plain aquifer system. Observation wells should feature screened intervals generally of no more than 10 feet that isolate distinct parts of the aquifer, and be thoroughly developed for removal of drilling fluid and introduced water. Presample purging should fully displace stratified saltwater in the well casing upward to the pump. Stable flow should be maintained as field parameters are measured and sample containers are filled with filtered water isolated from the atmosphere and unaffected by surface temperature. Groundwater samples from both upconing and lateral-intrusion observation wells should initially be collected four times per year when wells are newly established, but can be more optimally timed with withdrawal once responses in chloride concentrations can be reliably predicted. Concentrations of major ions (1) determine the dominant chemical composition of groundwater at each well, (2) establish the relative position of the well within the saltwater-transition zone, and (3) provide data quality control by calculation of sample charge balance. For these reasons, samples initially collected for the first year from newly established observation wells should be analyzed for calcium, magnesium, sodium, and potassium cations and chloride, bicarbonate, carbonate, sulfate, fluoride, and bromide anions. Inflection-point titration for alkalinity should be completed in the field. Analysis of chloride and field parameters may be adequate on a long-term basis once the dominant chemical composition at each well is established. Specific conductance may also provide a surrogate for chloride concentration depending on regulatory policy. The saltwater-movement monitoring strategy is limited and constrained. Relative monitoring needs among groundwater-production wells, and construction of observation wells, depend on the accuracy of previously mapped groundwater chloride iso-concentration surfaces. Production wells in similar proximity to saltwater can differ in aquifer hydraulic conductivity, rates of withdrawal, and screened-interval lengths. Only production wells making withdrawals reported to the Virginia Department of Environmental Quality have been accounted for; undocumented production wells can result in spurious changes in groundwater chloride concentration. Upconing observation wells should be as close as possible to corresponding production wells, so long as production wells are not damaged by borehole deviation. Projected locations of some lateral-intrusion observation wells may be precluded and require adjustment. Depths of upconing and lateral-intrusion observation wells may also require adjustment to be within the same aquifer as their corresponding production wells. Existing unused wells can be adapted as observation wells if differences from specified locations and construction are kept to a minimum and are accounted for. Where multiple production wells are in proximity, a modified monitoring approach may be needed to determine their net effect on changes in chloride concentration, and may require more than one lateral-intrusion observation well depending on the vertical positions of production-well screened intervals.

Virginia↗

USGS2012

Stratiform chromite deposit model

A new descriptive stratiform chromite deposit model was prepared which will provide a framework for understanding the characteristics of stratiform chromite deposits worldwide. Previous stratiform chromite deposit models developed by the U.S. Geological Survey (USGS) have been referred to as Bushveld chromium, because the Bushveld Complex in South Africa is the only stratified, mafic-ultramafic intrusion presently mined for chromite and is the most intensely researched. As part of the on-going effort by the USGS Mineral Resources Program to update existing deposit models for the upcoming national mineral resource assessment, this revised stratiform chromite deposit model includes new data on the geological, mineralogical, geophysical, and geochemical attributes of stratiform chromite deposits worldwide. This model will be a valuable tool in future chromite resource and environmental assessments and supplement previously published models used for mineral resource evaluation. Stratiform chromite deposits are found throughout the world, but the chromitite seams of the Bushveld Complex, South Africa, are the largest and most intensely researched. The chromite ore is located primarily in massive chromitite seams and, less abundantly, in disseminated chromite-bearing layers, both of which occur in the ultramafic section of large, layered mafic-ultramafic stratiform complexes. These mafic-ultramafic intrusions mainly formed in stable cratonic settings or during rift-related events during the Archean or early Proterozoic, although exceptions exist. The chromitite seams are cyclic in nature as well as laterally contiguous throughout the entire intrusion. Gangue minerals include olivine, pyroxenes (orthopyroxene and clinopyroxene), plagioclase, sulfides (pyrite, chalcopyrite, pyrrhotite, pentlandite, bornite), platinum group metals (mainly laurite, cooperite, braggite), and alteration minerals. A few deposits also contain rutile and ilmenite. The alteration phases include serpentine, chlorite, talc, magnetite, kaemmererite, uvarovite, hornblende, and carbonate minerals, such as calcite and dolomite. Stratiform chromite deposits are primarily hosted by peridotites, harzburgites, dunites, pyroxenites, troctolites, and anorthosites. Although metamorphism may have altered the ultramafic regions of layered intrusions postdeposition, only igneous processes are responsible for formation. From a diagnostic standpoint and for assessment purposes, they have no temporal or spatial relation to sedimentary rocks. The exact mechanisms responsible for the development of stratiform chromite deposits and the large, layered mafic-ultramafic intrusions where they are found are highly debated. The leading argument postulates that a parent magma mixed with a more primitive magma during magma chamber recharge. The partially differentiated magma could then be forced into the chromite stability field, resulting in the massive chromitite layers found in stratiform complexes. Contamination of the parent magma by localized assimilation of felsic country rock at the roof of the magma chamber has also been proposed as a mechanism of formation. Others suggest that changes in pressure or oxygen fugacity may be responsible for the occurrence of massive chromitite seams in layered mafic, ultramafic intrusions. The massive chromitite layers contain high levels of chromium and strong associations with platinum group elements. Anomalously high magnesium concentrations as well as low sodium, potassium, and phosphorus concentrations are also important geochemical features of stratiform chromite deposits. The presence of orthopyroxenite in many of the deposits suggests high silica and high magnesium concentrations in the parent magma. Most environmental concerns associated with the mining and processing of chromite ore focus on the solubility of chromium and its oxidation state. Although trivalent chromium (Cr 3+ ) is an essential micronutrient for humans, hexavalent chromium (Cr 6+ ) is highly toxic. Chromium-bearing solid phases that occur in the chromite ore-processing residue, for example, can effect the geochemical behavior and oxidation state of chromium in the environment.

Scientific Investigations Report↗

USGS2005

A regional classification scheme for estimating reference water quality in streams using land-use-adjusted spatial regression-tree analysis

Various approaches are used to subdivide large areas into regions containing streams that have similar reference or background water quality and that respond similarly to different factors. For many applications, such as establishing reference conditions, it is preferable to use physical characteristics that are not affected by human activities to delineate these regions. However, most approaches, such as ecoregion classifications, rely on land use to delineate regions or have difficulties compensating for the effects of land use. Land use not only directly affects water quality, but it is often correlated with the factors used to define the regions. In this article, we describe modifications to SPARTA (spatial regression-tree analysis), a relatively new approach applied to water-quality and environmental characteristic data to delineate zones with similar factors affecting water quality. In this modified approach, land-use-adjusted (residualized) water quality and environmental characteristics are computed for each site. Regression-tree analysis is applied to the residualized data to determine the most statistically important environmental characteristics describing the distribution of a specific water-quality constituent. Geographic information for small basins throughout the study area is then used to subdivide the area into relatively homogeneous environmental water-quality zones. For each zone, commonly used approaches are subsequently used to define its reference water quality and how its water quality responds to changes in land use. SPARTA is used to delineate zones of similar reference concentrations of total phosphorus and suspended sediment throughout the upper Midwestern part of the United States. ?? 2006 Springer Science+Business Media, Inc.

Environmental Management↗

USGS1997

Understory plant species composition in remnant stands along an urban-to-rural land-use gradient

We examined the understory species composition of 24 remnant forest stands along an urban-to-rural gradient in the metropolitan Milwaukee, Wisconsin region to determine the relationships between plant community composition, human disturbance, and contrasting types of land use along a gradient of urbanization. A significant difference was found in shrub species community composition among three contrasting land-use categories but no significant difference was found in herbaceous community composition. Significant differences in human activity existed among rural, urban, and urbanizing land-use categories, but this index of disturbance was not significantly correlated to gradients in species composition. All stands in this study had been subjected to various types of human activity and environmental disturbances in the past. Our data suggest that differences in the relative importance of understory species exist among stands but these differences may not be caused by the impacts of urbanization alone. Changes in the natural disturbance regime of this landscape, along with the impacts associated with urbanization, have led to an individualistic response in the compositional dynamics of forest stands.

Wisconsin↗

USGS2007

Surface temperature patterns in complex terrain: Daily variations and long-term change in the central Sierra Nevada, California

A realistic description of how temperatures vary with elevation is crucial for ecosystem studies and for models of basin-scale snowmelt and spring streamflow. This paper explores surface temperature variability using temperature data from an array of 37 sensors, called the Yosemite network, which traverses both slopes of the Sierra Nevada in the vicinity of Yosemite National Park, California. These data indicate that a simple lapse rate is often a poor description of the spatial temperature structure. Rather, the spatial pattern of temperature over the Yosemite network varies considerably with synoptic conditions. Empirical orthogonal functions (EOFs) were used to identify the dominant spatial temperature patterns and how they vary in time. Temporal variations of these surface temperature patterns were correlated with large-scale weather conditions, as described by National Centers for Environmental Prediction-National Center for Atmospheric Research Reanalysis data. Regression equations were used to downscale larger-scale weather parameters, such as Reanalysis winds and pressure, to the surface temperature structure over the Yosemite network. These relationships demonstrate that strong westerly winds are associated with relatively warmer temperatures on the east slope and cooler temperatures on the west slope of the Sierra, and weaker westerly winds are associated with the opposite pattern. Reanalysis data from 1948 to 2005 indicate weakening westerlies over this time period, a trend leading to relatively cooler temperatures on the east slope over decadal timescale's. This trend also appears in long-term observations and demonstrates the need to consider topographic effects when examining long-term changes in mountain regions. Copyright 2007 by the American Geophysical Union.

Journal of Geophysical Research D: Atmospheres↗

USGS2026

Potential for bird-based biotic indices in watershed assessments: A review of methods, applications, and suggestions for improvement

Birds are sensitive to changes in environmental conditions, and metrics such as species diversity, abundance, and guild composition that describe community-level responses to anthropogenic disturbance can be useful indicators of ecosystem condition. We reviewed published studies (56) of bird-based biotic indices developed for diverse ecosystems in 14 countries to evaluate their efficacy for bioassessments. The major categories of indices used included the index of biotic integrity (IBI; 18% of studies), the bird community index (BCI; 13%), and the index of ecological condition (IEC; 7%), with numerous specialized variants comprising the remaining 62% of studies, including indices adapted for specific ecosystems such as grasslands, wetlands, and urban areas. Index performance varied geographically, highlighting the importance of localized calibration. While few studies applied bird indices at landscape and regional scales, applications that included guild-based classification and habitat-specific metrics demonstrated potential for bird-based ecosystem monitoring and assessment. Bird communities were reliable ecological indicators at regional scales when indices incorporated locally derived disturbance and habitat gradients. This regional reliability indicates that expanding bird-based indices to watershed extents is feasible, especially given the availability of extensive resources such as citizen science bird data. There is an abundance of citizen science bird monitoring programs that potentially provide data for use in watershed-scale avian IBIs. Avian indices that combine data from multiple taxa, community-based metrics, and variables describing habitat quality can provide rigorous tools for watershed bioassessment and evidence-based conservation policy implementation.

Environmental Reviews↗

USGS2021

Developing species-age cohorts from forest inventory and analysis data to parameterize a forest landscape model

Simulating long-term, landscape level changes in forest composition requires estimates of stand age to initialize succession models. Detailed stand ages are rarely available, and even general information on stand history often is lacking. We used data from USDA Forest Service Forest Inventory and Analysis (FIA) database to estimate broad age classes for a forested landscape to simulate changes in landscape composition and structure relative to climate change at Fort Drum, a 43,000 ha U.S. Army installation in northwestern New York. Using simple linear regression, we developed relationships between tree diameter and age for FIA site trees from the host and adjacent ecoregions and applied those relationships to forest stands at Fort Drum. We observed that approximately half of the variation in age was explained by diameter breast height (DBH) across all species studied ( r 2 = 0.42 for sugar maple Acer saccharum to 0.63 for white ash Fraxinus americana ). We then used age-diameter relationships from published research on northern hardwood species to calibrate results from the FIA-based analysis. With predicted stand age, we used tree species life histories and environmental conditions represented by ecological site types to parameterize a stochastic forest landscape model (LANDIS-II) to spatially and temporally model successional changes in forest communities at Fort Drum. Forest stands modeled over 100 years without significant disturbance appeared to reflect expected patterns of increasing dominance by shade-tolerant mesophytic tree species such as sugar maple, red maple ( Acer rubrum ), and eastern hemlock ( Tsuga canadensis ) where soil moisture was sufficient. On drier sandy soils, eastern white pine ( Pinus strobus ), red pine ( P. resinosa ), northern red oak ( Quercus rubra ), and white oak ( Q. alba ) continued to be important components throughout the modeling period with no net loss at the landscape scale. Our results suggest that despite abundant precipitation and relatively low evapotranspiration rates for the region, low soil water holding capacity and fertility may be limiting factors for the spread of mesophytic species on excessively drained soils in the region. Increasing atmospheric temperatures projected for the region could alter moisture regimes for many coarse-textured soils providing a possible mechanism for expansion of xerophytic tree species.

New York↗

USGS2021

Coastal Tree-Ring Records for Paleoclimate and Paleoenvironmental Applications in North America

For more than a century, tree-ring research has identified relationships between climatic and ecological conditions and tree growth to describe past environments and constrain future ecosystem vulnerabilities. Tree-ring records are frequently used as environmental proxies that extend knowledge of past climate and ecology on millennial scales. Many of the most pressing global change questions facing North America concern the rate of climate change and vulnerability of ecosystems and society along the coast. The opportunities and applications in dendrochronology continue to grow with advancing methodologies, faster computational ability, and the cost-reduction of many chemical and anatomical analyses. Here, we propose that many pressing global change questions that affect coastal communities can be addressed using dendrochronological techniques. We review coastal tree-ring studies that demonstrate the utility and potential for future tree-ring studies in the northeastern, southeastern, northwestern, and southwestern North American coasts. Additionally, we show that tree-ring chronologies along the coast give insight into local and regional climate phenomena that are distinct from nearby, inland tree-ring chronologies of the same species. Lastly, we identify opportunities for coastal dendrochronology and encourage the collection of more tree-ring records that are directly impacted by coastal phenomena.

Quaternary Science Reviews↗

USGS2019

Linking fire and the United Nations Sustainable Development Goals

Fire is a ubiquitous natural disturbance that affects 3–4% of the Earth's surface each year. It is a tool used by humans for land clearing and burning of agricultural wastes. The United Nations Sustainable Development Goals (SDGs) do not explicitly mention fire, though many of the Goals are affected by the beneficial and adverse consequences of fires on ecosystem services. There are at least three compelling reasons to include a fire perspective in the implementation of the United Nations Sustainable Development Goals. The first reason relates to the stated vision of the United Nations 2030 Agenda to protect the environment. In order to achieve environmental protection during sustainable development activities, it is necessary to understand and plan for the effects of disturbances, in this case fire, on ecosystem services. The second reason is that fires produce emissions with regional and global impacts on air quality and rainfall patterns. Fires contribute to global warming though the release greenhouse gases, primarily CO 2 , and black carbon, identified as a SLCP (short-lived climate pollutant). The third reason is that fire is one of several complex processes that lead to land degradation across the globe. Opportunities exist to incorporate a fire perspective into sustainable development projects or approaches. Two examples are highlighted here. Transdisciplinary communication and collaboration are needed to address the complex issues related to fire, and to climate and land use change.

Science of the Total Environment↗

USGS2017

International Watershed Technology: Improving Water Quality and Quantity at the Local, Basin, and Regional Scales

This article introduces the five papers in the “International Watershed Technology” collection. These papers were selected from 60 technical presentations at the fifth biennial ASABE 21st Century Watershed Technology Conference and Workshop: Improving the Quality of Water Resources at Local, Basin, and Regional Scales, held in Quito, Ecuador, on 3-9 December 2016. The conference focused on solving spatial and temporal water quality and quantity problems and addressed topics such as watershed management in developing countries, aquatic ecology and ecohydrology, ecosystem services, climate change mitigation strategies, flood forecasting, remote sensing, and water resource policy and management. While diverse, the presentation topics reflected the continuing evolution of the “data mining” and “big data” themes of past conferences related to geospatial data applications, with increasing emphasis on practical solutions. The papers selected for this collection represent applications of spatial data analyses toward practical ends with a theme of “tools and techniques for sustainability.” The papers address a range of topics, including the matching of crops with water availability, and assessing the environmental impacts of agricultural production. The papers identify some of the latest tools and techniques for improving sustainability in watershed resource management that are relevant to both developing and developed countries.

Transactions of the ASABE↗