Impacts of traffic noise on anuran and bird communities

Anurans and birds rely on sound for a number of social behaviors. Species that use roadside habitats are exposed to traffic noise that can mask important social signals and directly affect the community diversity and composition. We evaluate the impact of traffic noise on anuran and bird species richness, species occurrence, and composition in Puerto Rico, where there is a high density of highways and cars that generate high levels of noise pollution. We compared paired forest sites near (100 m, n = 20, dB > 60) and far (>300 m, n = 20, dB < 60) from highways, with similar vegetation structure, but different levels of noise. We found that the anuran community was not affected by traffic noise. In contrast, bird species richness and occurrence were significantly lower in sites near the highway, and bird species composition also varied significantly. Bird species with low-frequency songs were only detected in sites far from highways. The differences in the ecology and communication behavior between anurans and birds could explain these results. Anurans mainly call at night, when traffic activity was low. In contrast, bird singing activity occurs during the day and overlaps with the high levels of traffic noise. In addition, in natural habitats, Puerto Rican anurans occur at high densities and form noisy choruses (>80 dB), which may allow them to tolerate high levels of anthropogenic noise.     

Running on age in a 15-km road run: minor influence of age on performance

The importance of exercise in the elderly is widely recognized, but data on performances and drop-out in short running contests are lacking. This hinders stimulation and coaching of elderly persons in active aging. The aim of the study was to determine age-related changes in running performance in the most popular Dutch road run, and how this is influenced by gender, training, and increased participation rate over the last decade. This is a retrospective analysis of 194,560 participants of a 15-km run from 1995 to 2007. Multiple regression analysis of running time by age, gender, and training was performed. Trends in participation were examined by chi-square tests and ANOVA. Trends in running time and speed were examined by t tests. With aging, running time increased with 0.20% per year (P < 0.001). Running time was on average 13% (P < 0.001) shorter in men than in women and was 15.7% (P < 0.001) shorter in participants who trained on a regular basis. Decline in performance with age was 5.9% larger for men than women (P < 0.01) and 4.5% larger for trained than untrained participants (P < 0.01). Over the last decade, participation numbers increased most for elderly (≥60 years) and female participants, mean running performance declined with 9.9% (P < 0.001). Drop-out number was low at all ages (0.13–0.29%). It appears that aging has only minor negative influences on running performance, which can even be attenuated by training. Our data suggest that exercise by means of running is a safe and rewarding option for improvement of healthy and active aging.     

Nesting and foraging behavior of red-winged blackbirds in stormwater wetlands

Stormwater wetlands are a common part of urban and suburban landscapes. These constructed wetlands provide first-order treatment of effluent from roads, parking lots, lawns and other surfaces. They also provide habitat for wetland-associated birds. Thus, there is a concern that birds may be attracted to potentially toxic habitats. This study assesses nesting success and forging behavior of Red-winged Blackbirds (Agelaius phoeniceus) in retention stormwater wetlands based on drainage type. Drainage categories included residential, commercial, and highway sites. Commercial sites had the lowest nesting success and the lowest diversity of invertebrate foods. Mean nest success values for all three types of wetlands, especially for highway drainages, were comparable to published values from natural wetlands. Over two years of study highway ponds collectively served as source populations whereas residential and commercial sites were population sinks in one year and sources in the other. Red-wings using highway sites had the highest foraging efficiency as determined by the frequency and duration of forays. Residential sites had the greatest human disturbance and generally had intermediate-quality habitat and nesting success. We conclude that while stormwater wetlands collect run off and accompanying pollutants, they can still be valuable habitats for nesting birds in urban and suburban areas. We recommend a few management strategies that can increase avian use of these habitats.     

Use of urban marine habitats by foraging wading birds

Wading birds (i.e, Ardeidae: herons, egrets, and bitterns) are a guild of waterbirds that forage in coastal habitats which in the US and Europe are often located in close proximity to urban centers. However, the use of urban marine habitats may have consequences for bird populations, as birds can be subject to stress from increased levels of passive and active human disturbance. We examined the effects of human disturbance, available foraging habitat, and prey abundance on wading bird density and species richness at 17 urban coastal sites in Narragansett Bay, Rhode Island USA. The sites represented a gradient of immediately adjacent residential and commercial land use (e.g., 0.0–67.7% urban land use within a 30.5 m buffer of the sites) within an urban matrix (i.e., all sites were located within a suburban center with a population of about 85,000 people). Wading bird density (0.62 ± 0.12 birds ha⁻¹) and species richness (average 4.49 ± 0.37 species across all sites) were not influenced by passive human disturbance as measured by the extent of urban land surrounding a site. However, wading bird density and species richness both decreased significantly as active disturbance (i.e., number of boats moored or docked upstream of the site) increased (r = −0.56, F = 6.85, p = 0.019 and r = −0.73, F = 16.6, p = 0.001, respectively). In addition, both density (r = 0.72, F = 16.2, p = 0.001) and species richness (r = 0.72, F = 16.2, p = 0.001) increased concomitantly with a prey index that combines the density of fish and invertebrates on which the birds feed with the amount of available shallow water foraging habitat at a site. Our results suggest that wading birds i) may not be negatively affected by urban land surrounding estuarine foraging areas in and of itself; and ii) may be utilizing urban areas in the absence of high levels of active disturbance to take advantage of potentially enhanced prey resources. In the case where the benefits of foraging at a site outweigh the costs related to human disturbance, urban marine habitats may need to be considered for restoration or protection from further increases in active human disturbance.     

Gray squirrel density,habitat suitability,and behavior in urban parks

Increased density, increased intraspecific aggression, and a reduced fear of humans have been suggested as the more observable and frequently described characteristics of wildlife species undergoing synurbization, the process of becoming urbanized. The relationship among these variables and how they may be related to environmental variables that change with urbanization is poorly understood. In this paper we explore the relationship between density, intraspecific aggression, and reduced fear of humans in urban populations of gray squirrel. In the summer and fall of 2003 and 2004, we studied a park with a documented high density of gray squirrels, Lafayette Park, Washington, DC, and six urban parks in Baltimore, MD with unknown squirrel densities. We used linear regression (SAS Institute, SAS/STAT user’s guide. SAS Institute, Cary, NC, 2005) to determine if there was a relationship (P < 0.05) between squirrel density and intraspecific aggression, squirrel density and reduced fear of humans (wariness), and squirrel density and habitat suitability. We found a positive association between density and intraspecific aggression (R ² = 0.81, P < 0.00). A negative relationship between density and wariness (, P < 0.00). However, no relationship was evident between habitat suitability and squirrel density (, P = 0.437).     

Residential Instability,Family Support,and Parent–Child Relationships Among Ethnically Diverse Urban Families

From a social disorganization standpoint, neighborhood residential instability potentially brings negative consequences to parent–child relationship qualities, but family social support and racial/ethnic identity may modify this association. Using data (n = 3,116) from the Project on Human Development in Chicago Neighborhoods, this study examines associations between neighborhood residential instability and parent–child warmth and conflict, whether family social support moderates associations between residential instability and parent–child relationships, and variation by race/ethnicity. Multilevel models reveal that residential instability undermines parent–child relationship qualities, particularly for non‐White individuals. Family support is a protective factor for families in less stable neighborhoods and specifically buffers the association between neighborhood residential instability and reduced parent–child warmth. Among Hispanics, family support mitigates the association between residential instability and heightened parent–child conflict. Findings highlight residential instability as a detriment to parent–child relationships; families in unstable neighborhoods may benefit from family social support.     

Serum oxidizability potential is associated with age and exercise test results

The purpose of this paper is to find out whether serum oxidizability potential measured before an exercise test (EXT) correlates with age and ischemic heart disease severity. Oxidizability potential was determined in 3 age groups, in gr. I patients < 45 years, in gr. II age range = 45 - 70years {\hbox{range}} = {45} - {7}0{\hbox{years}} , and in gr. III patients > 70 years. Included subjects had chronic ischemic heart disease (IHD) and underwent a symptom-limited EXT upon initiation of a cardiac rehabilitation program. The thermo-chemiluminescence (TCL) assay was used to assess serum oxidizability potential. This assay is based on heat-induced oxidation of serum, leading to the formation of electronically excited species in the form of unstable carbonyls, which further decompose into stable carbonyls and light energy (low chemiluminescence). Measured photons emission is represented by a kinetic curve which is described by its amplitude and slope (=ratio). We assessed the correlations of TCL ratio with age, exercise duration, metabolic equivalents (METS), maximal heart rate (mHR), maximal systolic BP, >1 mm S-T depression, diabetes, hypertension, smoking, left ventricular ejection fraction (LVEF)> or <40%, previous myocardial infarction, and aorto-coronary bypass surgery. A high TCL ratio (%) correlated well with METS (r = 0.82), mHR (r = 0.77) and with exercise-induced S-T segment shift (r = 0.86, p < 0.05). A lower serum oxidizability potential, expressed as a low TCL ratio, thus suggestive of a previous high oxidative stress, was found in the two older age groups compared to gr. I (<45 years), p = 0.041, and in particular, in gr. III patients with low LVEF%. The TCL ratio (%) in gr. III was 188.7 ± 14.5, 192 ± 17 in gr. II, and 214 ± 13 in gr. I (p < 0.05), and was 166 ± 13.1 in gr. III with LVEF < 45% as compared to 271 ± 15.7 in gr. I patients with LVEF > 45% (p < 0.01). A trend for lower TCL ratio (%) was found in diabetic, hypertensive, and post-coronary bypass surgery patients. A paradoxically low TCL ratio (low oxidizability potential) was observed in patients without S-T depression compared to patients with S-T depression (189 ± 22 vs. 201 ± 15, p = NS), due to the fact these patients had a much lower LVEF% and a lower exercise capacity. Serum oxidizability potential is associated with age, EXT parameters, results, and IHD severity. TCL ratio is an “easy-to-measure marker” that might be incorporated into risk assessment and prediction in aged IHD patients.     

The roles of mosquito and bird communities on the prevalence of West Nile virus in urban wetland and residential habitats

This study investigated the impacts of urban wetlands and their adjacent residential environments on the transmission dynamics of West Nile virus (WNV) within the state of New Jersey (USA). A working hypothesis was that urban wetlands decrease the local prevalence of WNV through the dilution effect from increased bird diversity, and through relative reductions in the numbers of competent avian host and mosquito species commonly associated with WNV. Surveys of mosquito and bird communities were undertaken at six urban wetlands and their adjacent residential environments over two seasons (2009, 2010). The community compositions of both avian and mosquito species differed significantly across habitats, and over relatively short geographical distances. Residential areas contained significantly higher proportions of WNV-competent mosquito species (31.25?±?5.3?%; e.g. Culex pipiens and Culex restuans), and WNV-competent avian host species (62.8?±?2.3?%, e.g. House Sparrow and American Robin) when compared to adjacent urban wetlands (13.5?±?2.1?%; 35.4?±?2.1?% respectively). Correspondingly, WNV infection rates within local Culex spp. populations indicate that WNV was more prevalent within residential areas (28.53/1000) compared to wetlands (16.77/1000). Large urban wetlands (>100?ha) produced significantly lower weekly WNV infection rates in local Culex spp. (6.67?±?2.84/1000) compared to small (<15?ha) wetlands (22.57?±?6.23/1000). Avian species richness was also influenced by patch size. Large urban wetlands contained significantly more species than small wetland patches. These results confirm that the community compositions of mosquito and avian hosts are important drivers in WNV infections, and that the ecological conditions that favor transmission are more strongly associated with urban residential environments than with adjacent urban wetlands.     

Urban Poverty and Neighborhood Effects on Crime: Incorporating Spatial and Network Perspectives

Research on neighborhoods and crime is on a remarkable growth trajectory. In this article, we survey important recent developments in the scholarship on neighborhood effects and the spatial stratification of poverty and urban crime. We advance the case that, in understanding the impact of neighborhoods and poverty on crime, sociological and criminological research would benefit from expanding the analytical focus from residential neighborhoods to the network of neighborhoods that individuals are exposed to during their daily routine activities. This perspective is supported by re‐emerging scholarship on activity spaces and macro‐level research on inter‐neighborhood connections. We highlight work indicating that non‐residential contexts add variation in criminogenic exposure, which in turn influence offending behavior and victimization risk. Also, we draw on recent insights from research on gang violence, social and institutional connections, and spatial mismatch and call for advancements in the scholarship on urban poverty that investigates the salience of inter‐neighborhood connections in evaluating the spatial stratification of criminogenic risk for individuals and communities.     

The influence of riparian corridor width on ant and plant assemblages in northern Sydney,Australia

Protecting riparian corridors is a commonly applied environmental policy in urban landscapes. However, empirical data demonstrating their efficacy for biodiversity conservation outcomes is scarce. In this study we investigated whether riparian corridor width influences the diversity and community structure of ant (Hymenoptera: Formicidae) and vascular plant assemblages therein. Eighteen corridors of differing widths were selected from within the Ku-ring-gai Local Government Area, Sydney Australia. Ants were sampled using pitfall traps positioned within rectangular vegetation transects (30 × 10 m). Both ant and plant species richness, when standardised for sampling effort, were unrelated to riparian corridor width. However, significant compositional differences between sites were evident with increased width up to ~50 m. Narrow corridors contained greater abundances of opportunistic ant species and higher proportions of exotic plants. We interpret this to be the result of the greater disturbance/edge influence derived from adjacent upland urban environments. Site beta diversity did not increase with corridor width, suggesting that the exclusion of novel upslope habitats in narrow riparian corridors is not a significant cause of community assemblage modification at these sites. To minimise the impact of deleterious edge effects on ant fauna, environmental managers should seek to retain riparian corridors wider than ~50 m. However, we observed substantial between-site variability of biotic assemblages, irrespective of corridor width. Therefore we recommend that environmental management practice needs to take a catchment-wide approach and consider other parameters that may contribute to riparian health so as to optimise the protection of riparian biodiversity.     

Public Life in Gulfton: Multiple Publics and Models of Community Organization

Summary

Based on a case study of six community organizations in the Gulfton neighborhood in Houston, Texas, this paper proposes that community organization models need to consider that highly diverse and often contentious community efforts within a single community represent well the context of life in contemporary heterogeneous urban neighborhoods. Despite reservations, we find this diversity of organizational efforts and even the tensions among them generally positive, as they often reflect the most vibrant forms of public life in our otherwise privatizing world. Rethinking the diversity of community organizations as multiple publics in a privatizing context provides new openings for the importance and value of community organization within schools of social work and the larger society.     

Foster care,geographic neighborhood change,and the risk of delinquency

Background and purposePrevious studies report that foster care placement is associated with an increased risk of delinquency. Yet it remains unclear which aspects of the placement experience increase the risk of delinquency. The current study addresses this knowledge gap. This study investigates the relationship between geographic neighborhood change and the risk of delinquency for adolescents in foster care settings. Based on findings from the neighborhood effects literatures, we hypothesize that moving to a neighborhood characterized by concentrated disadvantage and residential instability is associated with increased risk of delinquency.MethodsThe design for the current study is longitudinal. The sample is comprised of 145 foster youth from two birth cohorts, one born in 1983 and one in 1984, in Chicago, Illinois. The sample was 92% African American and 52% male. Overall, 11% had an official juvenile arrest. We used data from multiple sources, including the 1990 census data and administrative data from the Illinois Department of Children and Family Services and the Cook County Juvenile Court. To measure neighborhood change, we calculated a difference between children's home and placement neighborhoods on ten census variables: percentages of households in a given neighborhood that were below the poverty line, neighborhood households on public assistance, female-headed households, unemployed population, and persons < 18 years old, African American, Latino, foreign-born, residents living in the same house as five years earlier, and owner-occupied homes, all of which are commonly used in neighborhood studies. We identified two factors within the neighborhood variables—concentrated disadvantage and residential instability,—and used the two-factor scores in the following analysis. We conducted a Cox regression to model time to first arrest.ResultsThe results indicate that moving to a neighborhood with high residential instability significantly increases an individual's risk of juvenile delinquency. In addition, two subgroups—male foster youth; and all foster youth with an experience of neglect—are significantly more likely to be associated with a formal delinquency petition.Conclusions and implicationsThe current study is unique and builds the knowledge base with regard to the placement of children and adolescents in substitute care settings. The findings indicate that the neighborhoods in which children are placed do matter in terms of their outcomes, and thus they should be considered in the placement decision process. This finding is consistent with the “person-in-environment” concept advanced by social work professionals.     

Chemistry of growth medium and leachate from green roof systems in south-central Texas

Installation of intensive and extensive green roofs is becoming popular for reducing runoff from impervious surfaces in many cities around the world. Most studies on runoff quality from green roofs have been conducted in cooler northern climates. We examined the losses and gains of nutrients, cations and selected anions in planted and unplanted growth medium and compared these to initial growth medium (IGM) typically used for green roof modules in south-central Texas. Water extracts of growth medium and leachate from three replicates of unplanted growth medium and three planted species (Sedum kamtschaticum, Delosperma cooperi and Talinum calycinum) were examined. During the first 6 months after establishment we observed high losses of nitrate (25 to 44 mg kg⁻¹), dissolved organic carbon (DOC: 155 to 190 mg kg⁻¹) and nitrogen (DON: 9.0 to 11.2 mg kg⁻¹) and orthophosphate-P (1 to 2 mg kg⁻¹). Average leachate concentrations based on four rain events 6 months after establishment ranged from 0.3 to 6.6 mg L⁻¹ in planted modules and 6.3 mg L⁻¹ in unplanted modules for nitrate-N, 38 to 42 mg L⁻¹ in planted modules and 32 mg L⁻¹ in unplanted modules for DOC, 2.1 to 3.1 mg L⁻¹ in planted modules and 2.1 mg L⁻¹ in unplanted modules for DON and 0.27 to 0.37 mg L⁻¹ in planted modules and 0.40 mg L⁻¹ in unplanted modules for orthophosphate-P. We suggest that after the establishment of green roofs, leachate losses may contribute some runoff concentrations of nitrogen, carbon and phosphorous in urban areas.     

The causal response of avian communities to suburban development: a quasi-experimental,longitudinal study

Correlations between urbanization and biodiversity are well known, but the causes driving such associations are lacking. We used a long-term, quasi-experimental approach to study the responses of avian communities to suburban and exurban development around Seattle, WA, USA. We measured indices of bird abundance, reproduction, and survival for 12 years at many locations, including 5 forest ‘reserves,’ 10 existing ‘developments,’ and 11 ‘changing’ sites where ongoing development converted forests to single-family residential neighborhoods. In the first few years of clearing, building, and occupation of new neighborhoods by humans avian communities shifted from those typical of second-growth forest to those more characteristic of developments. During this time avian diversity increased and numerical dominance by abundant birds declined. Species that adapted and exploited development reproduced more successfully there than did forest-dependent species that avoided development. Adults of species that thrived in developments attained equal annual survival across reserved to developed landscapes, while species that avoided neighborhoods tended to survive poorly outside of reserves. The humans living in our study areas frequently fed birds and provided nest boxes. These actions were positively correlated with increases in secondary cavity nesting and seed eating birds. Humans also maintained outdoor cats and 11 % of humans both fed birds and let their cats outside. These actions were negatively correlated with the abundance of birds regularly using feeders. We suggest that a key management goal in urban ecosystems is the maintenance of avian diversity because a diverse avifauna engages a diversity of humans.     

Neighborhood Qualification of the Association Between Parenting and Problem Behavior Trajectories Among Mexican‐Origin Father–Adolescent Dyads

To address the combined importance of fathers and neighborhoods for adolescent adjustment, we examined whether associations between fathers' parenting and adolescents' problem behaviors were qualified by neighborhood adversity. We captured both mainstream (e.g., authoritative) and alternative (e.g., no‐nonsense, reduced involvement) parenting styles and examined parenting and neighborhood effects on changes over time in problem behaviors among a sample of Mexican‐origin father–adolescent dyads (N = 462). Compared to their counterparts in low‐adversity neighborhoods, adolescents in high‐adversity neighborhoods experienced greater initial benefits from authoritative fathering, greater long‐term benefits from no‐nonsense fathering, and fewer costs associated with reduced involvement fathering. The combined influences of alternative paternal parenting styles and neighborhood adversity may set ethnic and racial minority adolescents on different developmental pathways to competence.     

The Roles of Instability and Housing in Low-Income Families’ Residential Mobility

Given the repercussions of residential mobility, increased understanding of correlates of mobility is important for efforts to support family well-being. Using survey data on low-income families from the Three City Study (N = 2393), multilevel mixed longitudinal analyses examined factors associated with family residential mobility across the domains of family instability, housing and neighborhood contexts, and family characteristics. Results revealed contributions of family instability and housing and neighborhood contexts to residential mobility, with a higher rate of residential moves associated with experiences of intimate partner violence, relationship transitions, and job transitions, as well as with living in private-market rentals, substandard housing, and disordered neighborhoods. However, owning a home and living in disadvantaged neighborhoods predicted a lower rate of residential moves.     

The impact of urbanisation on avian species: The inextricable link between people and birds

This study investigates the impact of urbanisation on birdlife in a major city. Line transects and point counts were used to survey birds in three habitat types: parkland, residential areas and business/industrial areas. Abundance, richness and diversity of assemblages were determined for all bird species and for those birds native to the area. Behaviours of birds, and of human residents in relation to birds, in these urban areas were documented, including all instances of avian aggression. Bird species, including a subset of native bird species, have greater abundance and richness in parklands. Overall species diversity is greatest in residential habitat types, but native diversity is greatest in parklands. Introduced species are most abundant in business/industrial habitat types. The most frequent aggressive encounters were initiated by noisy miners Manorina melanocephalas, one of the four most common species throughout all habitat types (other common species include the rainbow lorikeet Trichoglossus haematodus, rock dove Columba livia and common myna Sturnus tristis). Other behaviours involved birds utilising food and roost resources and were classified as being caused by active and passive human behaviours. These outcomes indicate that local changes to the environment can impact the bird species by providing different food and roost resources. Human residents and local governments have a range of tools to modify the diversity of urban areas. Further research is needed to determine alternative definitions of modification, such as defining it as open space, and investigating the health of the avian populations in urban areas.     

Effects of off-road vehicles on reproductive success of pine snakes (<Emphasis Type="Italic">Pituophus melanoleucus</Emphasis>) in the New Jersey pinelands

Considerable attention has been devoted to the effects of people and their vehicles on birds and mammals, but possible effects on reptiles in populated areas have received less attention. Moreover, the effects of human activities on reptile reproductive success itself has been harder to demonstrate. This paper examines the effect of management of off-road vehicles in New Jersey’s pinelands on the reproductive success of pine snakes (Pituophus melanoleucus) from 1986 to 2005. We used the percentage of snakes in each hibernaculum that were young of the year (hatchlings) as an indicator of reproductive success, and compared this percent for five hibernacula that were in an area with varying degrees of off-road vehicle (ORV) disturbance, with 12 hibernacula in areas with no ORV disturbances (reference sites). This percent took into account differences in absolute numbers from one location to another, and over time due to hibernacula destruction (by people or predators) and natural variations (food supply). The ORV pressure in the pinelands is intense because it lies within the most densely populated urban area in the United States. Although the number of snakes in the reference hibernacula varied over the years from 46 to 63, the percent of young in these hibernacula did not vary significantly over the 20 year period (21–29%). In contrast, the percent-young in the disturbed sites differed significantly in years without ORV disturbance (28%) compared to those with ORV disturbance (15 and 16%, P < 0.01). Further, there were no differences between the percent of young in the reference sites and those in the disturbed site in years without ORV disturbance. ORV disturbance ceased only with the creation of large dirt berms coupled with fences that could not be easily broken. These data indicate the importance of having detailed population data on pine snakes in hibernacula, on ORV use (or indications of such use), and of managing ORV use to protect sensitive populations. Maintenance of healthy pine snake populations in urban areas may require continued adaptive management.     

Diversity in flowering plants and their characteristics: integrating humans as a driver of urban floral resources

Urban neighborhoods vary in development intensity and in the life style and demographics of their residents. Decisions made by urban residents affect plant communities, their functional characteristics, and the floral resources they provide. We recorded flowers in front-facing yards in 58 neighborhoods in Chicago, IL (USA) and examined patterns in community composition and species turnover between neighborhoods. We investigated how species richness and plant characteristics, including origin, cultivation intent, and life cycle, are affected by neighborhood socioeconomic factors. Urban plant species tended to be perennial, ornamental, and non-native. White clover had the broadest distribution and the highest floral abundance but was not present in several of the highest-income neighborhoods. Although we found 144 morpho-species across neighborhoods, most occurred infrequently. Species turnover was highest for ornamental species and lowest for weedy species, suggesting that intentional plantings are driving beta diversity across the landscape. We found the highest species richness in neighborhoods with intermediate numbers of Hispanic and white residents and with intermediate number of residential lots; neighborhoods with racially or ethnically homogenous populations had fewer plant species. The high frequency of weeds in low-income neighborhoods, the occurrence of certain ornamental plant species in whiter, wealthier communities, and high turnover of species from one neighborhood to another, all suggest a disparity in plant-related ecosystem services across cities. Complexity in urban plantings may be influenced by the suite of perspectives that residents bring towards habitat management. Cultivation sustains a diversity of plants and creates a disparity in plant traits by neighborhood socioeconomics.     

Determinants of urban tree canopy in residential neighborhoods: Household characteristics, urban form, and the geophysical landscape

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.