Search

Latinos, especially those who recently immigrated, face many obstacles in navigating the political and judicial environment in the United States. While prior scholarship suggests that racial minorities are more likely to be stopped by law enforcement for traffic violations and face harsher penalties for major crimes, little research has explored whether a defendant’s characteristics are influential in routine traffic court cases. Using an original database, this paper examines disparate treatment in speeding ticket reductions. The results indicate that Latino defendants are less likely to receive meaningful reductions to their charges. However, attorney representation greatly lessens the likelihood of disparate treatment for Latino drivers. As traffic court proceedings often represent the only interaction most people have with the judicial system, these findings have significant implications for racial equality, the administration of justice, attorney representation, and public opinion of the judiciary.

Urban forests are important components of societal interactions with nature. We focused on urban forest patches, a distinct and underexplored subset of the urban forest that spans land uses and ownerships, and requires silvicultural practices to address their unique biophysical characteristics and management regimes. Our goal was to elucidate multi-scalar urban forest patch governance arrangements as they translated to on-the-ground management in four urban areas (Chicago, New York City, Philadelphia, and Baltimore) within the eastern United States. A transdisciplinary knowledge co-production framework was used to guide identification of the prominent management challenge or dilemma motivating change to forest patch management in each location, and to describe the dynamic interplay of decision-making and governance processes across locations as they advanced toward desired forest conditions. A common management goal existed across all four locations: multi-age, structurally complex forests dominated by regionally native species. Ecological and social concerns affected by local context and city capacity served as starting points prompting management action and new collaborations. Disparate governance arrangements including top-down municipal resources, regional conservation facilitated by landowners, and grass-roots community-driven stewardship led to diverse support-building processes and innovative strategies that served as forces initiating and shaping new management actions. Science and iterative learning and adaptation influenced change in all locations, reinforcing new management arrangements and practices. Among the four study areas, the earliest management of urban forest patches started in the 1980 s, historically lacking embeddedness in urban forest management more broadly, and experiencing challenges with integration into existing governance infrastructure. Ultimately, new management and governance approaches to urban forest patches in all four study areas have evolved uniquely and organically, driven by place-based historical legacies and ongoing socio-ecological feedbacks. The generalization of findings for broader urban forest management guidelines, such as for trees and park, would lead to misguided outcomes.

The pretrial detention decision has critical implications for a defendant’s employment opportunities, family ties, likelihood of conviction, and length of prison sentence. While prior researchers h...

Within the politically charged immigration system in the United States, Congress mandates the entry of in absentia removal orders against immigrants who fail to appear for immigration court hearings. Statutory guidance similarly constrains the ability of appellate courts to overturn those in absentia orders. In this article, we examine how federal circuit court judges make decisions in the review of in absentia orders when faced with discretion-revoking congressional statutory language pitted against a highly politicized area of law where policy preferences sit at the forefront of judges’ minds. Using an original dataset of U.S. Courts of Appeals cases decided from 2001 to 2020, we find that pro-immigrant decisions are rare, as intended by the governing statute. We also find, however, that judicial policy preferences predict the degree to which federal judges support the petitioning immigrant through statutory factors related to the adequacy of government notice and the presence of exceptional circumstances to justify nonappearance.

The Earth's population will become more than 80% urban during this century. This threshold is often regarded as sufficient justification for pursuing urban ecology. However, pursuit has primarily focused on building empirical richness, and urban ecology theory is rarely discussed. The Baltimore Ecosystem Study (BES) has been grounded in theory since its inception and its two decades of data collection have stimulated progress toward comprehensive urban theory. Emerging urban ecology theory integrates biology, physical sciences, social sciences, and urban design, probes interdisciplinary frontiers while being founded on textbook disciplinary theories, and accommodates surprising empirical results. Theoretical growth in urban ecology has relied on refined frameworks, increased disciplinary scope, and longevity of interdisciplinary interactions. We describe the theories used by BES initially, and trace ongoing theoretical development that increasingly reflects the hybrid biological–physical–social nature of the Baltimore ecosystem. The specific mix of theories used in Baltimore likely will require modification when applied to other urban areas, but the developmental process, and the key results, will continue to benefit other urban social–ecological research projects.

Background The American Shoulder and Elbow Surgeons (ASES) shoulder score and the Single Assessment Numeric Evaluation (SANE) measure shoulder function. Relative to the ASES questionnaire, the SANE questionnaire is shorter and easier to score. We sought to determine (1) the correlation between ASES and SANE scores preoperatively and at 2 years postoperatively in patients undergoing rotator cuff repair (RCR) or shoulder arthroplasty and (2) the correlation between the change in ASES scores and change in SANE scores. Methods We reviewed the records of 107 patients who underwent RCR (n = 74) or shoulder arthroplasty (n = 33), which included patients undergoing total shoulder arthroplasty (n = 18) and reverse total shoulder arthroplasty (n = 15), at our institution from 2014 to 2015 and who completed the ASES and SANE questionnaires preoperatively and at least 2 years postoperatively. Pearson correlation coefficients were calculated to determine the relationship between SANE and ASES scores in RCR patients and arthroplasty patients (both total shoulder arthroplasty and reverse total shoulder arthroplasty) at each time point. Results In the RCR group, correlations between SANE and ASES scores were moderately positive preoperatively (r = 0.30) and strongly positive postoperatively (r = 0.86). In the arthroplasty group, correlations between SANE and ASES scores were moderately positive preoperatively (r = 0.46) and strongly positive postoperatively (r = 0.78). Conclusion SANE scores correlate positively with ASES scores postoperatively in patients undergoing RCR. Therefore, SANE scores, together with clinician-based and combination scores, can be used to assess postoperative shoulder function in these patients.

Two-dimensional unsteady hydraulic models can be attractive tools for characterizing the inundation dynamics relevant to floodplain forest ecosystems because of their ability to make dynamic, spatially continuous predictions. Such models are challenging to evaluate because they require spatially and temporally extensive datasets that are expensive or logistically difficult to collect. As a result, there are few examples of model evaluation methods intended for ecological applications in terrestrial or semi-terrestrial areas. Here, we demonstrated one evaluation approach using 3D arrays of low-cost temperature sensors to characterize wetted extent, depth and duration. Simulations of observed flood events in two geomorphically distinct river reach exhibited strong agreement with indirect measurements of wetted extent (>80%). Errors in depth prediction (average 24–29 cm) were similar to those of other ecological applications. Discrepancies in simulated flood durations were almost exclusively less than 24 h in length, which we interpreted as acceptable for the intended model applications. We found that unsteady 2D hydraulic models can capture a level of reality in wetted extent, depth and duration appropriate for characterizing key environmental gradients thought to drive forest composition. We also demonstrated a spatio-temporal model evaluation method that can be tailored to specific ecological research questions.

Forest patches in developed landscapes perform ecohydrological functions that can reduce urban stormwater flows. However, urban forest patch contributions to runoff mitigation are not well understood due to a lack of performance data. In this study, we focus on the potential of urban forest patch soils to infiltrate rainfall by characterizing rates of unsaturated hydraulic conductivity (K) in 21 forest patches in Baltimore, Maryland. Soil bulk density, organic matter, soil moisture, percent of coarse fragments (≥2 mm), and texture were evaluated at the same locations to assess drivers of K. The K was significantly higher in soils with high sand content and related positively with the percent of coarse fragment material in the soil. Forest patch size did not impact K. We estimate that 68 percent of historic rainfall could be infiltrated by urban forest patch soils at the measured K rates. Continuous monitoring at one forest patch also showed that K is dynamic in time and influenced by antecedent soil moisture conditions. We conservatively estimate that unsaturated urban forest patch soils alone are capable of infiltrating most rain events of low to moderate intensities that fell within these forest patches in the Baltimore region. Considering this ecohydrologic function, the protection and expansion of forest patches can make substantial contributions to stormwater mitigation.

The manuscript was written through contributions and approval of all authors. M. Baker and J. Sexton received support from Maryland Sea Grant R/UC‐1 under award NA10OAR4170072 from the National Oceanic and Atmospheric Administration, U.S. Department of Commerce.

International audience; We report the aeolian changes observed in situ by NASA's InSight lander during the first 400 sols of operations: Granule creep, saltation, dust removal, and the formation of dark surface tracks. Aeolian changes are infrequent and sporadic. However, on sols, when they do occur, they consistently appear between noon to 3 p.m., and are associated with the passage of convective vortices during periods of high vortex activity. Aeolian changes are more frequent at elevated locations, such as the top surfaces of rocks and lander footpads. InSight observed these changes using, for the first time, simultaneous insitu and orbital imaging and high-frequency meteorological, seismological, and magnetic measurements. Seismometer measurements of ground acceleration constrain the timing and trajectory of convective vortex encounters, linking surface changes to source vortices. Magnetometer measurements show perturbations in magnetic field strength during the passage of convective vortices consistent with chargedparticle motion. Detachment of sand-scale particles occurs when high background winds and vortexinduced turbulence provide a peak surface friction wind speed above the classic saltation fluid threshold. However, detachment of dust-and granule-scale particles also occurred when the surface friction wind speed remained below this threshold. This may be explained by local enhancement of the surface roughness and other effects described here and further studied in Part 2 (Baker et al., 2021). The lack of saltation and bright dust-coated surfaces at the InSight landing site implies surface stability and the onset of particle motion may be suppressed by dust "cushioning." This differentiates the InSight landing site from other areas on Mars that exhibit more aeolian activity. Plain Language Summary Aeolian activity, the movement of dust and sand by the wind, is common on Earth and has been observed on other planets, including Mars. A new Mars lander, InSight, has for the first time monitored aeolian changes by combining imaging with weather, seismic and CHARALAMBOUS ET AL.

Special collections of religious and theological materials have been part of the landscape of academic libraries in North America from their beginnings. This collection of ten articles treats several aspects of this rich history in three sections: the first deals with the history of specific collections at four libraries; the second treats current attempts to use special collections in teaching and the outreach mission of the library, including the development and use of digital technologies; and the third explores topics related to building library collections for the future, noting both pitfalls to be avoided and intriguing opportunities.

ForestGEO is a network of scientists and long-term forest dynamics plots (FDPs) spanning the Earth's major forest types. ForestGEO's mission is to advance understanding of the diversity and dynamics of forests and to strengthen global capacity for forest science research. ForestGEO is unique among forest plot networks in its large-scale plot dimensions, censusing of all stems ≥1 cm in diameter, inclusion of tropical, temperate and boreal forests, and investigation of additional biotic (e.g., arthropods) and abiotic (e.g., soils) drivers, which together provide a holistic view of forest functioning. The 71 FDPs in 27 countries include approximately 7.33 million living trees and about 12,000 species, representing 20% of the world's known tree diversity. With >1300 published papers, ForestGEO researchers have made significant contributions in two fundamental areas: species coexistence and diversity, and ecosystem functioning. Specifically, defining the major biotic and abiotic controls on the distribution and coexistence of species and functional types and on variation in species' demography has led to improved understanding of how the multiple dimensions of forest diversity are structured across space and time and how this diversity relates to the processes controlling the role of forests in the Earth system. Nevertheless, knowledge gaps remain that impede our ability to predict how forest diversity and function will respond to climate change and other stressors. Meeting these global research challenges requires major advances in standardizing taxonomy of tropical species, resolving the main drivers of forest dynamics, and integrating plot-based ground and remote sensing observations to scale up estimates of forest diversity and function, coupled with improved predictive models. However, they cannot be met without greater financial commitment to sustain the long-term research of ForestGEO and other forest plot networks, greatly expanded scientific capacity across the world's forested nations, and increased collaboration and integration among research networks and disciplines addressing forest science.

Fil: Macchi, Leandro. Universidad Nacional de Tucuman. Instituto de Ecologia Regional. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Tucuman. Instituto de Ecologia Regional; Argentina. Universitat zu Berlin; Alemania. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina

Measuring, monitoring, and managing biodiversity across agricultural regions depends on methods that can combine high-resolution mapping of landscape patterns with local biodiversity observations. This study explores the potential to monitor biodiversity in agricultural landscapes by linking high-resolution remote sensing with passive acoustic monitoring. Land cover maps produced using a small unmanned aerial system (UAS) and PlanetScope (PS) satellite imagery were used to investigate relationships between landscape patterns and an acoustically derived biodiversity index (vocalizing bird species richness) across 12 agricultural sample locations equipped with acoustic recorders in Iowa, USA during the 2018 growing season. Statistical assessment revealed a significant direct association between vocalizing bird richness and percent noncrop vegetation cover. High spatial resolution (1 m) UAS mapping produced stronger statistical associations than PS-based maps (3 m) for landscape composition metrics. Landscape configuration metrics (Shannon&rsquo, s diversity index, contagion, perimeter-area-ratio, and circumscribing circle index) were either cross-correlated with composition metrics or unusable owing to complete landscape homogeneity in some agricultural landscape samples. This study shows that high resolution mapping of noncrop vegetation cover can be linked with acoustic monitoring of unique bird vocalizations to provide a useful indicator of biodiversity in agricultural landscapes.

Collections documenting the history of Protestant missions are of great and ongoing interest to a wide range of researchers. Global in scope, they capture histories and perspectives often not otherwise available and support learning and scholarship in disciplines such as history, anthropology, and religious studies. This panel addressed librarians, students, and scholars working with theological, religious studies, or related collections and institutions, particularly where the documentation and study of colonial legacies is a primary concern for researchers, faculty, and students. It emphasized the need for critical engagement -- for instruction, management, outreach -- with complex and high-interest primary sources.

Gully development following agricultural land use change is well documented in many tropical developing countries. However, the impact of specific agricultural intensification practices on gully formation, such as the construction of unpaved roads and contour terracing, remains poorly understood. We studied gully formation in catchments with sugarcane agriculture to inform sustainable agricultural management in Brazil. Through field surveys in ten first-to second-order catchments, we mapped erosional features and described gullying along an incision gradient from rill, to ephemeral and permanent gullies. We documented formation of >130 erosional features that concentrated mainly (96%) on dirt roads along the outer margins of streamside vegetation and bordering transitions from hillslope to hollow. We further established a slope-contributing area threshold for gullying, highlighting high susceptibility to gully formation on dirt roads and contour terraces. Key implications of our findings include targeted enhancements of riparian buffers that extend beyond concave topographies as well as the use of topographic thresholds as a benchmark for gully formation along dirt roads in Brazilian sugarcane fields.

Tree cover is generally associated with cooler air temperatures in urban environments but the roles of canopy configuration, spatial context, and time of day are not well understood. The ability to examine spatiotemporal relationships between trees and urban climate has been hindered by lack of appropriate air temperature data and, perhaps, by overreliance on a single ‘tree canopy’ class, obscuring the mechanisms by which canopy cools. Here, we use >70 000 air temperature measurements collected by car throughout Washington, DC, USA in predawn (pd), afternoon (aft), and evening (eve) campaigns on a hot summer day. We subdivided tree canopy into ‘soft’ (over unpaved surfaces) and ‘hard’ (over paved surfaces) canopy classes and further partitioned soft canopy into distributed (narrow edges) and clumped patches (edges with interior cores). At each level of subdivision, we predicted air temperature anomalies using generalized additive models for each time of day. We found that the all-inclusive ‘tree canopy’ class cooled linearly at every time (pd = 0.5 °C ± 0.3 °C, aft = 1.8 °C ± 0.6 °C, eve = 1.7 °C ± 0.4 °C), but could be explained in the afternoon by aggregate effects of predominant hard and soft canopy cooling at low and high canopy cover, respectively. Soft canopy cooled nonlinearly in the afternoon with minimal effect until ∼40% cover but strongly (and linearly) across all cover fractions in the evening (pd = 0.7 °C ± 1.1 °C, aft = 2.0 °C ± 0.7 °C, eve = 2.9 °C ± 0.6 °C). Patches cooled at all times of day despite uneven allocation throughout the city, whereas more distributed canopy cooled in predawn and evening due to increased shading. This later finding is important for urban heat island mitigation planning since it is easier to find planting spaces for distributed trees rather than forest patches.

Dam removals with unmanaged sediment releases are good opportunities to learn about channel response to abruptly increased bed material supply. Understanding these events is important because they affect aquatic habitats and human uses of floodplains. A longstanding paradigm in geomorphology holds that response rates to landscape disturbance exponentially decay through time. However, a previous study of the Merrimack Village Dam (MVD) removal on the Souhegan River in New Hampshire, USA, showed that an exponential function poorly described the early geomorphic response. Erosion of impounded sediments there was two-phased. We had an opportunity to quantitatively test the two-phase response model proposed for MVD by extending the record there and comparing it with data from the Simkins Dam removal on the Patapsco River in Maryland, USA. The watershed sizes are the same order of magnitude (102 km2), and at both sites low-head dams were removed (~3–4 m) and ~65 000 m3 of sand-sized sediments were discharged to low-gradient reaches. Analyzing four years of repeat morphometry and sediment surveys at the Simkins site, as well as continuous discharge and turbidity data, we observed the two-phase erosion response described for MVD. In the early phase, approximately 50% of the impounded sediment at Simkins was eroded rapidly during modest flows. After incision to base level and widening, a second phase began when further erosion depended on floods large enough to go over bank and access impounded sediments more distant from the newly-formed channel. Fitting functional forms to the data for both sites, we found that two-phase exponential models with changing decay constants fit the erosion data better than single-phase models. Valley width influences the two-phase erosion responses upstream, but downstream responses appear more closely related to local gradient, sediment re-supply from the upstream impoundments, and base flows. Copyright © 2017 John Wiley & Sons, Ltd.

Recent emphasis on milldams as a cause of colonial-era floodplain sediment deposits and source for modern remobilization has ignited debate in scientific and environmental policy forums, especially in the mid-Atlantic USA. Although milldams are regionally ubiquitous and visually striking, no investigation has demonstrated that they are a dominant driver of regional floodplain sediment accumulation and remobilization. Long-term analysis in Baltimore County, Maryland found that milldams were sufficient, but not necessary for historical sediment accumulation. We compared erosion from streams upstream and downstream of confirmed milldam locations, in paired segment comparisons with and without the influence of historical milldams, and pooled across 37 study segments. We found the scale of inquiry produced different interpretations regarding the role of milldams in regional erosion and sedimentation. Although local milldam sediment remobilization rates were 15% greater than those immediately downstream, neither paired nor pooled segment comparisons provided evidence that milldam deposits are contemporary dominant sources of sediment. Further comparison across drainage areas demonstrated that milldam deposits could raise local remobilization rates by augmenting sediment availability along supply-limited channels. We introduce a unifying conceptual model that explains apparently contradictory findings in the literature where, rather than the sole cause of legacy sediment deposits, some milldams are nonetheless responsible for local increases in sediment remobilization rates along portions of the stream network.

Urbanization substantially changes the physicochemical and biological characteristics of streams. The trajectory of negative effect is broadly similar around the world, but the nature and magnitude of ecological responses to urban growth differ among locations. Some heterogeneity in response arises from differences in the level of urban development and attributes of urban water management. However, the heterogeneity also may arise from variation in hydrologic, biological, and physicochemical templates that shaped stream ecosystems before urban development. We present a framework to develop hypotheses that predict how natural watershed and channel attributes in the pre-urban-development state may confer ecological resistance to urbanization. We present 6 testable hypotheses that explore the expression of such attributes under our framework: 1) greater water storage capacity mitigates hydrologic regime shifts, 2) coarse substrates and a balance between erosive forces and sediment supply buffer morph...

Riparian buffers contribute to the mitigation of nutrient pollution in agricultural landscapes, but there is concern regarding their potential to be hot spots of greenhouse gas production. This study compared soil CO and CH fluxes in adjacent crop fields and riparian buffers (a flood-prone forest and a flood-protected grassland along an incised channel) and examined the impact of water table depth (WTD) and flood events on the variability of gas fluxes in riparian zones. Results showed significantly (0.001) higher CO emission in riparian areas than in adjoining croplands (6.8 ± 0.6 vs. 3.6 ± 0.5 Mg CO-C ha yr; mean ± SE). Daily flux of CO and soil temperature were significantly related (0.002), with Q values ranging between 1.75 and 2.53. Significant relationships (0.05) were found between CH daily flux and WTD. Flood events resulted in enhanced CH emission (up to +44.5 mg CH-C m d in a swale) under warm soil conditions (22°C), but the effect of flooding was less pronounced in early spring (emission1.06 mg CH-C m d), probably due to low soil temperature. Although CH flux direction alternated at all sites, overall the croplands and the flood-affected riparian forest were CH sources, with annual emission averaging +0.04 ± 0.17 and +0.92 ± 1.6 kg CH-C ha, respectively. In the riparian forest, a topographic depression (8% of the total area) accounted for 78% of the annual CH emission, underscoring the significance of landscape heterogeneity on CH dynamics in riparian buffers. The nonflooded riparian grassland, however, was a net CH sink (-1.08 ± 0.22 kg CH-C ha yr), probably due to the presence of subsurface tile drains and a dredged/incised channel at that study site. Although these hydrological alterations may have contributed to improvement in the CH sink strength of the riparian grassland, this must be weighed against the water quality maintenance functions and other ecological services provided by riparian buffers.

Summary Suitability of the local habitat (‘habitat filtering’) and dispersal between stream reaches determines the composition of insect communities, and urban land use may affect both processes. While urban streams are often poor habitats for insects and dispersal between them is often hindered, conservation and restoration activities generally focus solely on the local (in-stream) environment. We determined whether in-stream habitat filtering (a ‘local’ process) or dispersal between reaches (a ‘regional’ process) controlled assemblage composition in a landscape subject to ongoing urban development (‘urbanizing’). We compared models incorporating geographic distance between sites, environmental dissimilarity, and land-use/land-cover attributes of dispersal pathways in an attempt to explain the dissimilarity of stream insect assemblages. Distance and land-use/land-cover attributes were characterised along both overland (straight line) and corridor pathways. Both in-stream habitat filtering and dispersal affected assemblage composition, but habitat had a stronger influence. Overland distance was a better predictor of assemblage dissimilarity than corridor distance, implying stream insect dispersal occurs across catchment boundaries as well as along stream corridors. The best model incorporated land-use/land-cover attributes along dispersal pathways, which supported the idea that urban land-use in the terrestrial environment mediates dispersal. Conservation and restoration strategies for streams in urbanizing landscapes that focus on local habitat quality and ignore dispersal are missing a potentially important mechanism affecting insect assemblage composition. While the primary focus should be on maintaining or improving the local habitat, potential dispersal pathways should also be considered.

Remote sensing of the structural and spectral traits of vegetation is being transformed by structure from motion (SFM) algorithms that combine overlapping images to produce three-dimensional (3D) red-green-blue (RGB) point clouds. However, much remains unknown about how these point clouds are used to observe vegetation, limiting the understanding of the results and future applications. Here, we examine the content and quality of SFM point cloud 3D-RGB fusion observations. An SFM algorithm using the Scale Invariant Feature Transform (SIFT) feature detector was applied to create the 3D-RGB point clouds of a single tree and forest patches. The fusion quality was evaluated using targets placed within the tree and was compared to fusion measurements from terrestrial LIDAR (TLS). K-means clustering and manual classification were used to evaluate the semantic content of SIFT features. When targets were fully visible in the images, SFM assigned color in the correct place with a high accuracy (93%). The accuracy was lower when targets were shadowed or obscured (29%). Clustering and classification revealed that the SIFT features highlighted areas that were brighter or darker than their surroundings, showing little correspondence with canopy objects like leaves or branches, though the features showed some relationship to landscape context (e.g., canopy, pavement). Therefore, the results suggest that feature detectors play a critical role in determining how vegetation is sampled by SFM. Future research should consider developing feature detectors that are optimized for vegetation mapping, including extracting elements like leaves and flowers. Features should be considered the fundamental unit of SFM mapping, like the pixel in optical imaging and the laser pulse of LIDAR. Under optimal conditions, SFM fusion accuracy exceeded that of TLS, and the two systems produced similar representations of the overall tree shape. SFM is the lower-cost solution for obtaining accurate 3D-RGB fusion measurements of the outer surfaces of vegetation, the critical zone of interaction between vegetation, light, and the atmosphere from leaf to canopy scales.

Urban development practices redistribute surface materials through filling, grading, and terracing, causing drastic changes to the geomorphic organization of the landscape. Many studies document the hydrologic, biologic, or geomorphic consequences of urbanization using space-for-time comparisons of disparate urban and rural landscapes. However, no previous studies have documented geomorphic changes from development using multiple dates of high-resolution topographic data at the watershed scale. This study utilized a time series of five sequential light detection and ranging (LiDAR) derived digital elevation models (DEMs) to track watershed geomorphic changes within two watersheds throughout development (2002–2008) and across multiple spatial scales (0.01–1 km 2 ). Development-induced changes were compared against an undeveloped forested watershed during the same time period. Changes in elevations, slopes, hypsometry, and surface flow pathways were tracked throughout the development process to assess watershed geomorphic alterations. Results suggest that development produced an increase in sharp topographic breaks between relatively flat surfaces and steep slopes, replacing smoothly varying hillslopes and leading to greater variation in slopes. Examinations of flowpath distributions highlight systematic modifications that favor rapid convergence in unchanneled upland areas. Evidence of channel additions in the form of engineered surface conduits is apparent in comparisons of pre- and post-development stream maps. These results suggest that topographic modification, in addition to impervious surfaces, contributes to altered hydrologic dynamics observed in urban systems. This work highlights important considerations for the use of repeat LiDAR flights in analyzing watershed change through time. Novel methods introduced here may allow improved understanding and targeted mitigation of the processes driving geomorphic changes during development and help guide future research directions for development-based watershed studies.

Little is known about the impact of agricultural legacy on subsurface biogeochemical processes in the years following restoration of riparian wetlands (WLs). More knowledge is also needed on the relative importance of seasons, precipitation events, and inputs of water and nutrients driving nitrogen (N), phosphorus (P), sulfur (S), and greenhouse gas (GHG) (N2O, CO2, CH4) dynamics in these systems. This investigation of a riparian zone comprising a restored WL area and a nonrestored well-drained alluvium (AL) area in the United States Midwest revealed that despite successful hydrological restoration a decade earlier, biogeochemical conditions in the WL area remained less anoxic than in natural WLs, and not significantly different from those in the AL area. No significant differences in N, P, S, and C compound concentrations or fluxes were observed between the AL and WL areas. Over the duration of the study, nitrate (NO3−) and soluble reactive phosphorus appeared to be primarily driven by hillslope contributions. Ammonium (NH4+), sulfate (SO42−), and CO2 responded strongly to seasonal changes in biogeochemical conditions in the riparian zone, while N2O and CH4 fluxes were most influenced by large rewetting events. Overall, our results challenge overly simplistic assumptions derived from direct interpretation of redox thermodynamics, and show complex patterns of solutes and GHGs at the riparian zone scale.

We used statistical models to provide the first empirical estimates of riparian buffer effects on the cropland nitrate load to streams throughout the Chesapeake Bay watershed. For each of 1,964 subbasins, we quantified the 1990 prevalence of cropland and riparian buffers. Cropland was considered buffered if the topographic flow path connecting it to a stream traversed a streamside forest or wetland. We applied a model that predicts stream nitrate concentration based on physiographic province and the watershed proportions of unbuffered and buffered cropland. We used another model to predict annual streamflow based on precipitation and temperature, and then multiplied the predicted flows and concentrations to estimate 1990 annual nitrate loads. Across the entire Chesapeake watershed, croplands released 92.3 Gg of nitrate nitrogen, but 19.8 Gg of that was removed by riparian buffers. At most, 29.4 Gg more might have been removed if buffer gaps were restored so that all cropland was buffered. The other 43.1 Gg of cropland load cannot be addressed with riparian buffers. The Coastal Plain physiographic province provided 52% of the existing buffer reduction of Bay-wide nitrate loads and 36% of potential additional removal from buffer restoration in cropland buffer gaps. Existing and restorable nitrate removal in buffers were lower in the other three major provinces because of less cropland, lower buffer prevalence, and lower average buffer nitrate removal efficiency.

At the September 2014 United Nations Climate Summit, governments rallied around an international agreement—the New York Declaration on Forests—that underscored restoration of degraded ecosystems as an auspicious solution to climate change. Ethiopia committed to restore more than one-sixth of its land. Uganda, the Democratic Republic of Congo, Guatemala, and Colombia pledged to restore huge areas within their borders. In total, parties committed to restore a staggering 350 million hectares by 2030.

Riparian zones are an important strategy to mitigate N and P export to streams. However, their efficiency with respect to nitrate (NO3 −), ammonium (NH4 +), or soluble reactive phosphorus (SRP) in groundwater remains uncertain in the US Midwest. This study investigates water table fluctuations and NO3 −, NH4 +, and SRP concentration dynamics in two riparian zone types (outwash vs. glacial till) common in the upper US Midwest. During low water table periods, NO3 − removal was 93 % at WR (outwash site), and 75 % at LWD (glacial till site); but during high water table periods, NO3 − removal efficiencies dropped to 50 % at WR, and 14 % at LWD. Median seasonal mass fluxes of NO3 − removed at WR (9.4–21.7 mg N day−1 m−1 of stream length) and LWD (0.4–1.9 mg N day−1 m−1) were small compared to other riparian zones in glaciated landscapes. The WR site was a small SRP sink (0.114 and 0.118 mg day−1 m−1 during the dry period and wet period, respectively), while LWD acted as a small SRP source to the stream (0.004 mg day−1 m−1 during the dry period; 0.075 mg day−1 m−1 during the wet period). Both LWD and WR acted as sources of NH4 + to the stream with mass fluxes ranging from 0.17 to 7.75 mg N day−1 m−1. Although riparian zones in the US Midwest provide many ecosystem services, results suggest they are unlikely to efficiently mitigate N and P pollution in subsurface flow.

Riparian buffers are important nitrate (NO) sinks in agricultural watersheds, but limited information is available regarding the intensity and control of nitrous oxide (NO) emission from these buffers. This study monitored (December 2009-May 2011) NO fluxes at two agricultural riparian buffers in the White River watershed in Indiana to assess the impact of land use and hydrogeomorphologic (HGM) attributes on emission. The study sites included a riparian forest in a glacial outwash/alluvium setting (White River [WR]) and a grassed riparian buffer in tile-drained till plains (Leary Weber Ditch [LWD]). Adjacent corn ( L.) fields were monitored for land use assessment. Analysis of variance identified season, land use (riparian buffer vs. crop field), and site geomorphology as major drivers of NO fluxes. Strong relationships between N mineralization and NO fluxes were found at both sites, but relationships with other nutrient cycling indicators (C/N ratio, dissolved organic C, microbial biomass C) were detected only at LWD. Nitrous oxide emission showed strong seasonal variability; the largest NO peaks occurred in late spring/early summer as a result of flooding at the WR riparian buffer (up to 27.8 mg NO-N m d) and N fertilizer application to crop fields. Annual NO emission (kg NO-N ha) was higher in the crop fields (WR: 7.82; LWD: 6.37) than in the riparian areas. A significant difference ( < 0.02) in annual NO emission between the riparian buffers was detected (4.32 vs. 1.03 kg NO-N ha at WR and LWD, respectively), and this difference was attributed to site geomorphology and flooding (WR is flood prone; no flooding occurred at tile-drained LWD). The study results demonstrate the significance of landscape geomorphology and land-stream connection (i.e., flood potential) as drivers of NO emission in riparian buffers and therefore argue that an HGM-based approach should be especially suitable for determination of regional NO budget in riparian ecosystems.

Cuffney and Qian (2013) performed numerous simulations to demonstrate potential flaws in Threshold Indicator Taxa Analysis (TITAN), a method for interpreting taxon contributions to community change along novel environmental gradients. Based on their simulations, they concluded that: 1) TITAN is not an effective method for detecting different types of statistical thresholds in trend lines, 2) permutation results in highly significant p-values even for splits that are not thresholds, and 3) coincident change points may arise as an artifact of inaccuracies, imprecision, and systematic bias in both change-point estimation and TITAN’s bootstrap. The critique raises some important concerns, but because of significant misunderstanding, it is based on analyses that violate basic assumptions of both TITAN and indicator species analysis (IndVal), and thus, constitutes a straw man that cannot be used to evaluate their performance. We demonstrate that the critique: 1) fundamentally misrepresents TITAN’s prima...

When Neer introduced his proximal humerus prosthesis in the 1950s, there was renewed interest in shoulder arthroplasty. In his original paper describing hemiarthroplasty, five of 12 patients had good or excellent range of motion, and one of 12 had pain with use [1]. As the use of hemiarthroplasty and eventually total shoulder arthroplasty (TSA) increased, it became apparent that this procedure was not a panacea for all degenerative shoulder conditions.

Cities and surrounding suburbs are Earth's fastest growing land use. Urban impervious surfaces affect hydrological and energy balances, as well as biological composition and functioning of ecosystems. Although datasets have been produced documenting urban growth at multiple time periods in coarse intervals, there remains an unmet need for observations spanning multiple decades at high frequency. We have developed an empirical method for retrieving annual, long-term continuous fields of impervious surface cover from the Landsat archive and applied it to the Washington, D.C.–Baltimore, MD megalopolis from 1984 to 2010. Fitting and applying a single regression model over time, the method relies on a multi-annual training sample of high-resolution impervious cover layers tied to coincident intra- and inter-annual Landsat image composites. These predictor images are composited and normalized to maximize discrimination of impervious surfaces from intermittently bare agricultural fields and minimize inter-annual variation due to phenology, solar illumination, and atmospheric noise. Excluding the year 2009 due to lack of data availability resulting from nearly continual winter snow cover, the resulting dataset is a continuous-field representation of impervious surface cover at 30-m horizontal and annual temporal resolution from 1984 to 2010. Average error was approximately ± 6% cover, with outliers due to shadows from large buildings in winter images. The region's impervious surface cover grew from 881 to 1176 ± 11 km2 over the 27-year span—an average annual gain of approximately 11 ± 2 km2/year—with great variability among local municipalities in terms of rate of development. Patterns including intensification (i.e., “infill”) and expansion (i.e., exurban or “sprawl”) of development, as well as fragmentation and isolation of natural areas were clearly visible in the data at various places and times. Neither impervious surface loss nor deceleration of growth were observed in any of the cities or counties over the study span. These findings show that empirical retrieval of impervious coverage at the spatial and temporal scale of the Landsat archive is possible using dense time-stacks of calibrated Landsat images, and that long-term records such as this can provide new opportunities for analyzing land-use patterns and their underlying causes to improve understanding of socio-economic processes and human–environment interactions.

The aesthetic, economic, and environmental benefits of urban trees are well recognized. Previous research has focused on understanding how a variety of social and environmental factors are related to urban vegetation. The aim is often to provide planners with information that will improve residential neighborhood design, or guide tree planting campaigns encouraging the cultivation of urban trees. In this paper we examine a broad range of factors we hypothesize are correlated to urban tree canopy heterogeneity in Salt Lake County, Utah. We use a multi-model inference approach to evaluate the relative contribution of these factors to observed heterogeneity in urban tree canopy cover, and discuss the implications of our analysis. An important contribution of this work is an explicit attempt to account for the confounding effect of neighborhood age in understanding the relationship between human and environmental factors, and urban tree canopy. We use regression analysis with interaction terms to assess the effects of 15 human and environmental variables on tree canopy abundance while holding neighborhood age constant. We demonstrate that neighborhood age is an influential covariate that affects how the human and environmental factors relate to the abundance of neighborhood tree canopy. For example, we demonstrate that in new neighborhoods a positive relationship exists between street density and residential tree canopy, but the relationship diminishes as the neighborhood ages. We conclude that to better understand the determinants of urban tree canopy in residential areas it is important to consider both human and environmental factors while accounting for neighborhood age.

Anthropogenic impairment of water bodies represents a global environmental concern, yet few attempts have successfully linked fish performance to thermal habitat suitability and fewer have distinguished co-varying water quality constraints. We interfaced fish bioenergetics, field measurements, and Thermal Remote Imaging to generate a spatially-explicit, high-resolution surface of fish growth potential, and next employed a structured hypothesis to detect relationships among measures of fish performance and co-varying water quality constraints. Our thermal surface of fish performance captured the amount and spatial-temporal arrangement of thermally-suitable habitat for three focal species in an extremely heterogeneous reservoir, but interpretation of this pattern was initially confounded by seasonal covariation of water residence time and water quality. Subsequent path analysis revealed that in terms of seasonal patterns in growth potential, catfish and walleye responded to temperature, positively and negatively, respectively; crappie and walleye responded to eutrophy (negatively). At the high eutrophy levels observed in this system, some desired fishes appear to suffer from excessive cultural eutrophication within the context of elevated temperatures whereas others appear to be largely unaffected or even enhanced. Our overall findings do not lead to the conclusion that this system is degraded by pollution; however, they do highlight the need to use a sensitive focal species in the process of determining allowable nutrient loading and as integrators of habitat suitability across multiple spatial and temporal scales. We provide an integrated approach useful for quantifying fish growth potential and identifying water quality constraints on fish performance at spatial scales appropriate for whole-system management.

The goal of this paper is to help managers better understand implications of using aggregate community metrics, such as taxon richness or Indices of Biotic Integrity (IBI), for detecting threshold responses to anthropogenic environmental gradients. To illustrate, we offer an alternative analytical approach, Threshold Indicator Taxa ANalysis (TITAN), geared toward identifying synchronous changes in the distribution of multiple taxa as evidence of an ecological community threshold. Our approach underscores the fundamental reality that which taxa are affected by stressors is important, both from a conservation standpoint and because taxon-specific life-history traits help us understand relevant mechanisms. First, we examine macroinvertebrate community response to an impervious cover gradient using a well-studied biomonitoring data set to show that representative community metrics are relatively insensitive to synchronous threshold declines of numerous individual taxa. We then reproduce these response relationships using a simulated community data set with similar properties to demonstrate that linear or wedge-shaped responses of community metrics to anthropogenic gradients can occur as an artifact of aggregating multiple taxa into a single value per sampling unit, despite strong nonlinearity in community response. Our findings do not repudiate the use of community metrics or multimetric indices, but they challenge assumptions that such metrics are capable of accurately reflecting community thresholds across a broad range of anthropogenic gradients. We recommend an alternative analysis framework that begins with characterization of the responses of individual taxa and uses aggregation only after distinguishing the magnitude, direction, and uncertainty in the responses of individual members of the community.

Summary 1. Existing methods for identifying ecological community thresholds are designed for univariate indicators or multivariate dimension-reduction of community structure. Most are insensitive to responses of individual taxa with low occurrence frequencies or highly variable abundances, properties of the vast majority of taxa in community data sets. We introduce Threshold Indicator Taxa ANalysis (TITAN) to detect changes in taxa distributions along an environmental gradient over space or time, and assess synchrony among taxa change points as evidence for community thresholds. 2. TITAN uses indicator species scores to integrate occurrence, abundance and directionality of taxa responses. It identifies the optimum value of a continuous variable, x, that partitions sample units while maximizing taxon-specific scores. Indicator z scores standardize original scores relative to the mean and SD of permuted samples along x, thereby emphasizing the relative magnitude of change and increasing the contributions of taxa with low occurrence frequencies but high sensitivity to the gradient. TITAN distinguishes negative (z−) and positive (z+) taxa responses and tracks cumulative responses of declining [sum(z−)] and increasing [sum(z+)] taxa in the community. Bootstrapping is used to estimate indicator reliability and purity as well as uncertainty around the location of individual taxa and community change points. 3. Using two simulated data sets, TITAN correctly identified taxon and community thresholds in more than 99% of 500 unique versions of each simulation. In contrast, multivariate change-point analysis did not distinguish directional taxa responses, resulting in much wider confidence intervals that in one instance failed to capture thresholds in 38% of the iterations. 4. Retrospective analysis of macroinvertebrate community response to a phosphorus gradient supported previous threshold estimates, although TITAN produced narrower confidence limits and revealed that several taxa declined at lower levels of phosphorus. Re-analysis of macroinvertebrate responses to an urbanization gradient illustrated disparate change points for declining (0·81–3·3% urban land) and increasing (6·8–26·6%) taxa, whereas the published threshold estimate (20–30%) missed the declining-taxa threshold because it could not distinguish their synchronous decline from the gradual increase in ubiquitous taxa. 5.Synthesis and applications. By deconstructing communities to assess synchrony of taxon-specific change points, TITAN provides a sensitive and precise alternative to existing methods for assessing community thresholds. TITAN has tremendous potential to inform conservation of rare or threatened species, develop species sensitivity models, identify reference conditions and to support development of numerical regulatory criteria.

This study evaluated the capability of four spatial hydrologic models to estimate summer low-flow stream discharge, as a surrogate for baseflow, and assessed the influence of land cover/land use on these flows, in small streams across the Oak Ridges Moraine. Low-flow discharge varied predictably with area of the upstream catchment, but also with reach slope and a measure of land cover disturbance (LDI). Low-flow volumes were lowest in streams with moderate agricultural and/or urban development (LDI of eight to 12%), and high over a range of development intensities. Each of Baseflow Index (BFI×Area), Darcy Index (DI), MODFLOW (MF) and a finer resolution MODFLOW model (FMF) were about equal in their capability to estimate low-flow discharge, with MF and FMF having a somewhat stronger relationship and Darcy Index having a somewhat poorer relationship, particularly in smaller catchments. Each of the models generally predicted low-flow discharge volumes to within about 400 L/s of the actual observed low-flow d...

Events such as volcanic eruptions may act as disturbance agents modifying the landscape spatial diversity and increasing environmental instability. On June 4, 2011 the Puyehue-Cordon Caulle volcanic complex located on Chile (2236 m.a.s.l., 40° 02' 24? S- 70° 14' 26? W) experience a rift zone eruption ejecting during the first day 950 million metric tons into the atmosphere. Due to the westerly winds predominance, ash fell differentially upon 24 million ha of Patagonia Argentinean, been thicker deposits accumulated towards the West. In order to analyze changes on stream fish assemblages we studied seven streams 8, 19 and 30 months after the eruption along the ash deposition gradient, and compare those data to pre eruption ones. Habitat features and structure of the benthic macroinvertebrate food base of fish was studied. After the eruption, substantial environmental changes were observed in association with the large amount of ash fallout. In western sites, habitat loss due to ash accumulation, changes in the riparian zone and morphology of the main channels were observed. Turbidity was the water quality variable which reflected the most changes throughout time, with NTU values decreasing sharply from West to East sites. In west sites, increased Chironomid densities were recorded 8 months after the initial eruption aswell as lowEPT index values. These relationships were reversed in the less affected streams farther away from the volcano. Fish assemblages were greatly influenced both by habitat and macroinvertebrate changes. The eruption brought about an initial sharp decline in fish densities and the almost total loss of young of the year in themostwestern streams affecting recruitment. This effect diminished rapidly with distance fromthe emission center. Thirty months after the eruption, environmental changes are still occurring as a consequence of basin wide ash remobilization and transport. Fil: Lallement, Mailén Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina Fil: Macchi, Patricio Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina Fil: Vigliano, Pablo Horacio. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina Fil: Juárez, Santiago Martín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina Fil: Rechencq, Magali. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina Fil: Baker, Matthew. University of Maryland Baltimore County; Estados Unidos Fil: Bouwes, Nicolaas. Eco Logical Research; Estados Unidos Fil: Crowl, Todd. State University of Utah; Estados Unidos