Exurban Areas Research Articles

Does Exurban Housing Development Affect the Physiological Condition of Forest-Breeding Songbirds? A Case Study of Ovenbirds (Seiurus aurocapillus) in the Largest Protected Area in the Contiguous United States.

Exurban development (low-density development in rural areas) can significantly alter wildlife community composition, but it is largely unknown whether it also affects wildlife at the individual level. We investigated individual-level impacts of exurban development in New York State's Adirondack Park by comparing the physiological condition of 62 male ovenbirds (Seiurus aurocapillus) breeding in forests with low-density housing development with those in contiguous forests. We used hematocrit (HCT) volume and plasma triglyceride (TRIG) levels to compare energetic condition, plasma uric acid (UA) and total plasma protein (TPP) levels to compare diet quality, and heterophil∶lymphocyte ratios (H∶L) to compare chronic stress. HCT was the only parameter to differ, with birds near houses exhibiting lower values. The comparable TRIG, UA, and TPP that we found between treatment types suggest that ovenbird food quality and availability are unaffected by exurban development in our study area. Similar H∶L suggests that homeowner activities do not significantly change chronic stressors faced by breeding male ovenbirds. We also found no difference in body mass, body size, or age ratio to indicate that habitats in either treatment type were in higher demand or more difficult to acquire. Although our results suggest that exurban development does not reduce habitat quality for male ovenbirds in a way that affects their condition, we caution that it may still ultimately reduce fitness by attracting synanthropic predators. Further work is needed to better understand the impacts of exurban development on wildlife at all levels and provide science-based information needed to meet conservation challenges in rapidly developing exurban areas.

Deer populations inhabiting urban areas in the south of Spain: habitat and conflicts

The presence of deer in urban environments is a recent phenomenon in the Iberian Peninsula. Deer are essentially forest species whose populations are currently expanding into many areas, and the newly exurban areas, between urban and forest habitats, seem to comprise very favourable habitat for them. For example, the existence of golf courses in new residential areas appears to offer important resources for deer species. The urban boom during recent years in the south of the Iberian Peninsula has promoted the rezoning of certain forest areas. Some of these were previously hunting estates and the existence of game species has not been taken into consideration when developing these new residential areas. We tested the hypothesis that these new exurban areas are favourable for red and fallow deer. Our study area was located in a luxury residential resort in southern Andalusia (Spain) with a low housing density and two golf courses. We found a significant increase in the density of both these deer species in the area following the rezoning, probably due to the creation of more favourable habitat for deer and the cessation of hunting activity. Deer preferred the urbanised areas and especially the golf courses. We also found a significant increase in deer-human conflicts in the area. We discuss the value of golf courses for deer; the importance of considering common wildlife, such as game species, in the planning regulations when land is rezoned in order to avoid future conflicts; and the management of these species in urban areas.

To what extent does urbanisation affect fragmented grassland functioning?

Urbanisation creates altered environments characterised by increased human habitation, impermeable surfaces, artificial structures, landscape fragmentation, habitat loss, resulting in different resource loss pathways. The vulnerable Rand Highveld Grassland vegetation unit in the Tlokwe Municipal area, South Africa, has been extensively affected and transformed by urbanisation, agriculture, and mining. Grassland fragments in urban areas are often considered to be less species rich and less functional than in the more untransformed or “natural” exurban environments, and are therefore seldom a priority for conservation. Furthermore, urban grassland fragments are often being more intensely managed than exurban areas, such as consistent mowing in open urban areas. Four urbanisation measures acting as indicators for patterns and processes associated with urban areas were calculated for matrix areas surrounding each selected grassland fragment to quantify the position of each grassland remnant along an urbanisation gradient. The grassland fragments were objectively classified into two classes of urbanisation, namely “exurban” and “urban” based on the urbanisation measure values. Grazing was recorded in some exurban grasslands and mowing in some urban grassland fragments. Unmanaged grassland fragments were present in both urban and exurban areas. Fine-scale biophysical landscape function was determined by executing the Landscape Function Analysis (LFA) method. LFA assesses fine-scale landscape patchiness (entailing resource conserving potential and erosion resistance) and 11 soil surface indicators to produce three main LFA parameters (stability, infiltration, and nutrient cycling), which indicates how well a system is functioning in terms of fine-scale biophysical soil processes and characteristics. The aim of this study was to determine the effects of urbanisation and associated management practices on fine-scale biophysical landscape function of urban and exurban grassland fragments, as well as to determine the potential for the use of LFA in decision-making involving the conservation of grassland fragments. The results indicated that the occurrence, size and characteristics of vegetated patches, and especially the presence of litter abundances, were the main factors determining differences in the LFA indices. Furthermore, mowing resulted in the overall fine-scale biophysical indices being higher for some of the urban grassland fragments. This implied that it is not necessarily the influence of urbanisation entailing high or low resource conserving patchiness and patch quality, but rather the management practices associated with urban and exurban areas. Therefore, from a conservation point of view, the grassland fragments in the City of Potchefstroom are just as conservable (on a biophysical function level involving soil processes) than the more “natural” exurban grassland fragments.

Time is money: An empirical examination of the effects of regulatory delay on residential subdivision development

Variation in regulatory costs over time and across different types of investment projects creates risk for developers who hold land. These so-called implicit costs, which arise as a result of regulatory delay in the land development process, are hypothesized to be potentially large, but empirical evidence of their influence on development outcomes is limited. Using a unique micro-level data set on parcel-level subdivision development that includes data on the timing of subdivision approvals, we test the effects of implicit costs that arise as a result of increased subdivision approval times on the timing and pattern of residential subdivision development. Consistent with theory, we find that these regulation-induced implicit costs reduce the probability of subdivision development on any given parcel. In addition, we find that systematic variation in regulation-induced implicit costs across space has reduced development in more heavily regulated urbanized areas intended for development and intensified development in less regulated exurban areas located farther away. The results provide a new explanation of scattered, low-density urban development as the result of optimal land development with multiple development options and heterogeneous regulatory costs.

Received Signal Strength in a Macrocell in Lagos Environs Using Finite Element Method

This paper presents an analysis of received signal strength in a macrocell in Lagos environment using Finite Element Method (FEM). In this paper, six different site locations were covered and subdivided into peri-urban, open suburban, dense urban, open urban, suburban and exurban areas. It was deduced that the experimental values obtained was favourably with the FEM predicted values with the mean prediction error ranging between 6.66dB to 12.89dB while that of standard deviation error is 2.99dB to 8.09dB.

Logistics Spatial Patterns in Paris

The purpose of this study is to consider the spatial distribution of freight and logistics facilities in both the Paris region and the Paris megaregion (the Paris basin) between 2000 and 2012. A major rise in the number of warehousing and logistics facilities has been documented since the beginning of the 2000s in both areas. In terms of spatial characteristics, this growth illustrates both centrifugal processes, from the urban core to the suburban and exurban areas of the region, and centripetal processes, from the margins of the Paris basin to the edges of the Paris region. The logistics system is a global distribution process from international supply chains to urban supply chains. In this process, freight hubs serve as switches connecting these two scales of the logistics system. This role explains part of the locational patterns of logistics and warehousing facilities in Paris, both at the metropolitan scale of the Ile-de-France region and at the megaregional scale of the Paris basin. Areas of further research are provided; these could help establish and better specify the megaregional nature of the Paris basin as far as freight and logistics facilities are concerned.

Time is Money: An Empirical Examination of the Effects of Regulatory Delay on Residential Subdivision Development

Variation in regulatory costs over time and across different types of investment projects creates risk for developers who hold land. These so-called implicit costs, which arise as a result of regulatory delay in the land development process, are hypothesized to be potentially large, but empirical evidence of their influence on development outcomes is limited. Using a unique micro-level data set on parcel-level subdivision development that includes data on the timing of subdivision approvals, we test the effects of implicit costs that arise as a result of increased subdivision approval times on the timing and pattern of residential subdivision development. Consistent with theory, we find that these regulation-induced implicit costs reduce the probability of subdivision development on any given parcel. In addition, we find that systematic variation in regulation-induced implicit costs across space has reduced development in more heavily regulated urbanized areas intended for development and intensified development in less regulated exurban areas located farther away. The results provide a new explanation of scattered, low-density urban development as the result of optimal land development with multiple development options and heterogeneous regulatory costs.

Identifying common patterns in diverse systems: effects of exurban development on birds of the Adirondack Park and the Greater Yellowstone Ecosystem, USA.

We examined the impacts of exurban development on bird communities in Essex County, New York and Madison County, Montana by comparing differences in abundance of songbirds between subdivisions and control sites in both regions. We hypothesized that impacts to bird communities would be greater in the relatively homogeneous, closed canopy Adirondack forest of northern New York State than they would be in the more naturally heterogeneous grasslands interspersed with trees and shrubs of the Greater Yellowstone Ecosystem. We examined birds in five functional groups expected to be responsive to exurban development, and determined relative abundance within subdivisions and control sites across these two distinct regions. We found little support for our hypothesis. For birds in the area-sensitive, low nesting, and Neotropical migrant functional groups, relative abundance was lower in subdivisions in the Adirondacks and in Madison County, while relative abundance of edge specialists was greater in subdivisions in both regions. The direction and magnitude of change in the avian communities between subdivisions and controls was similar in both regions for all guilds except microhabitat specialists. These similarities across diverse ecosystems suggest that the ecological context of the encompassing region may be less important than other elements in shaping avian communities in exurban systems. This finding suggests that humans and their specific behaviors and activities in exurban areas may be underappreciated but potentially important drivers of change in these regions.

Conservation of fragmented grasslands as part of the urban green infrastructure: how important are species diversity, functional diversity and landscape functionality?

Natural remnants, such as fragmented grasslands form an integral part of the urban green infrastructure in the Grassland biome of South Africa. Nearly 30 % of natural grasslands are transformed with only 1 % formally conserved. Since grassland habitats are globally regarded as a biodiversity conservation priority, protection should be accorded outside formal conservation areas as well. However, urban grassland fragments are often regarded as highly transformed, and are therefore targeted for development rather than conservation. The aim of this study was to compare plant species composition, −diversity and -functional diversity, as well as the fine-scale biophysical landscape functionality of grassland fragments in urban and exurban areas in the vulnerable Rand Highveld Grassland vegetation type in the Tlokwe Municipal area of South Africa. Thirty selected grassland fragments were investigated along an urbanisation (urban-exurban) gradient that was quantified using several demographic- and physical variables as well as landscape metrics, each reflecting a pattern or process associated with urbanisation. Plant species composition, −diversity, and -life history traits were determined in randomly selected sample plots. Functional diversity indices were also calculated to describe the composition and distribution of plant functional traits in the selected grassland fragments. Additionally, landscape functionality, in terms of how effectively the landscape is functioning as a biophysical system, was determined using the Landscape Function Analysis (LFA) method. LFA provides information such as fine-scale resource conserving patchiness, soil surface stability, infiltration, and nutrient cycling. The fine-scale biophysical landscape function of urban and exurban landscapes are comparable, indicating that urban grassland fragments are worthy of conservation on a biophysical landscape function scale. However, differences in plant species diversity, functional trait composition, and plant functional diversity were evident.

Landscapes of Risk: The Geography of Fatal Traffic Collisions in Indiana, 2003 to 2011

Potential death from traffic collisions is a common hazard faced by nearly everyone. This analysis uses geographical approaches to examine fatal collision risk in the state of Indiana from 2003 to 2011. The state averaged 757 fatal collisions annually. About 60 percent occurred in urban or suburban areas. Risk was highest in low-density exurban and rural areas and on highways, county roads, and interstates. County sheriffs and state police were more likely to face fatal collisions than municipal police. Significant black spots existed around the Illinois and Kentucky state lines. Fatal collisions were less clustered than nonfatal collisions. Fatal collisions exhibited positive spatial autocorrelation but the global Moran's I for counties was close to random. Approximately 10 percent of ninety-two counties had significant local spatial autocorrelation in fatal collision rates. Police and emergency response resource distributions should be considered in light of fatal collision black spots in the state.

Smart growth in two contrastive metropolitan areas: A comparison between Portland and Los Angeles

This study compares urban landscapes in the Portland and Los Angeles metropolitan areas at the neighbourhood level by operationalising six smart growth indices and mapping their spatial distribution patterns and time trends. Analysis results show that the two metropolitan areas have both strengths and weaknesses in different aspects of smart growth. Most neighbourhoods in both regions do not excel in all six smart growth measures: they are at the high ends of some smart growth indices but at the low ends of others. Some smart growth features such as mixed land use and mixed housing are already pervasive in suburban areas. Density in some mature suburban neighbourhoods is also relatively high. A large number of neighbourhoods in suburban and exurban areas exhibit high levels of socioeconomic diversity. Time trend analyses suggest that in both regions, older neighbourhoods tend to be ‘smarter’ than newer ones, except for racial/ethnic diversity.

Prevalence of open-angle glaucoma in southwestern China: the Yongchuan Glaucoma Study

This study examined the prevalence of primary open-angle glaucoma (POAG) among residents aged ≥50 years living in Yongchuan district of Chongqing. Stratified cluster sampling was employed in random selection to estimate the prevalence of glaucoma from April to June, 2005. Twenty-nine villages or neighborhood communities were randomly selected in urban area (Zhongshan Road), suburban area (Shanjiao Town) and exurban area (Zhutuo Town) of this district. All the respondents underwent detailed ophthalmic examinations. The examinations included questionnaire investigation, visual acuity test, naked-eye examination, measurement of peripheral anterior chamber depth (Van Herrick's technique), detection of intraocluar pressure (IOP) with a Perkins hand-held applanation tonometer (HA-2) and examination of the optic disc by using a 78 diopters (D) lens (including the cup-disc ratio, cup/disc ratio asymmetries, horizontal and vertical diameter, notching and optic disc hemorrhages). A total of 5938 residents were actually examined, and the response rate was 85.19%. The crude prevalence of POAG was 0.86% (n=51/5938, 95% CI 0.64%-1.11%). There were 24 males and 27 females in the glaucoma group. The glaucoma prevalence was not significant different in case number between the male and female subjects (P=0.4900). Furthermore, no association between age or schooling and POAG was noted (P=0.8030, 0.0734). Out of 51 subjects with POAG, unilateral glaucoma-related blindness occurred in 38 subjects (74.5%) and bilateral glaucoma-related blindness was found in 7 subjects (13.7%). This study exhibited that the prevalence of POAG was 0.86% among residents aged ≥50 years living in Yongchuan District of Chongqing. The vision loss caused by POAG in this population was obviously higher than that previously reported in other studies. Glaucoma management, detection of affected persons and handling of the burden of glaucoma should be the priorities of the agenda of local health authorities of Western China.

Synanthropic behavior of the Neotropical palm swift Tachornis squamata (Apodiformes: Apodidae) in the Brazilian Caatinga

The Neotropical palm swift, Tachornis squamata Cassin, 1853 (Apodidae), inhabits palm forests in the northern, northeastern and central regions of South America. At the Chapada do Apodi, Brazilian Caatinga, we investigated how the Neotropical palm swifts use palm trees to roost in two areas: urban and exurban. From May to November 2011 and from March to June 2012, out of the breeding season of the species, we compared the differences between the descriptive parameters of the palm-roosts and the activity levels of the swifts in urban and exurban roosting. We sampled 30 carnauba palm-roosts in exurban areas and 32 carnauba palm-roosts and 26 Chinese fan palm-roosts in urban areas for a period of 132 days, a total of 528 hours of sampling. The number of wasp nests was greater in carnauba palm-roosts in exurban areas than in palm-roosts in urban areas. However, there were greater numbers of swift nests and swifts in palm-roosts in urban areas than in exurban areas. Moreover, the activity levels (number of entry and exit events of swifts in the palm-roost) during sunrise (05:00-05:20 a.m.) and sunset (05:41-06:00 p.m.) were significantly lower in the exurban area than in the urban area. These results may contribute to establish better management practices for the coexistence between wildlife and humans in cities.

Housing Density and Ecosystem Function: Comparing the Impacts of Rural, Exurban, and Suburban Densities on Fire Hazard, Water Availability, and House and Road Distance Effects

Many amenity-rich regions are experiencing rapid land-use change through low-density residential development or exurbanization. Those same natural-resource amenities that attracted migration are often degraded by housing growth and associated development. This study examines the impacts of exurbanization on three ecosystem indicators (fire hazard, water availability, and generalized distance effects of houses and roads) and compares them to areas with rural and suburban housing densities in the Sonoita Plain, southeastern Arizona. We found that although they support significantly lower population densities, exurban areas have impacts on ecosystem function comparable to suburban areas. Exurban areas had the highest potential for fire, suggesting that it is the presence of people rather than the density that increases fire hazard. The increase in the number of wells in exurban areas far exceeded suburban areas and matched increases for agricultural use in rural areas. When the impacts of houses and roads on ecosystem function were considered, 98% of exurban areas were “highly” or “very highly” impacted, compared to 100% for suburban areas and 35% for rural areas. Since development in the area is not readily visible, assessing the spatial extent of impacts is important for understanding the vulnerability of systems and guiding decisions about development.

Analysis of land use/land cover change, population shift, and their effects on spatiotemporal patterns of urban heat islands in metropolitan Shanghai, China

Using time series Landsat TM/ETM+ imagery and demographic data of Shanghai for 1997 and 2008, the relationship between land use/land cover (LULC) change and population shift and their effects on the spatiotemporal patterns of urban heat islands (UHIs) were quantitatively examined using an integrated approach of remote sensing, geographical information systems (GIS), and statistical analysis. The results showed that this city has experienced unprecedented urban growth and sprawl during the study period. The developed land increased by 219.50%, approximately 72.52% of which was converted from former cropland (24.79%), fallow land (21.21%), forest and shrub (18.97%), bare land (6.62%), and water (0.93%). Furthermore, in combination with the detection of LULC change, an analysis of the spatially differential growth rates for developed land area and population size revealed an urban–suburban–exurban gradient pattern of population shifting, as evidenced by a sharp increase in developed land area within the middle sub-zones at the urban fringe and the exurban sub-zones beyond the outer traffic ring. Consequently, changes in LULC and population shifts resulted in significant variation in the spatiotemporal patterns of the UHIs due to the loss of water bodies and vegetated surfaces. In the foreseeable future, substantial population growth and urban expansion will continue, especially in the rapidly urbanizing suburban and exurban areas, and thus, the extent and magnitude of UHI effects will continue expanding as well. The relationships between land use, the UHI effect, and regional climate change require that the underlying mechanisms, patterns, and processes of land conversion as well as the response of urban climate should be addressed throughout official decision-making processes. Thus, the planners and decision-makers could fully evaluate the environmental consequences of different land development scenarios and therefore improve the scientific basis of future planning and regulations.

Threshold Responses of Forest Birds to Landscape Changes around Exurban Development

Low-density residential development (i.e., exurban development) is often embedded within a matrix of protected areas and natural amenities, raising concern about its ecological consequences. Forest-dependent species are particularly susceptible to human settlement even at low housing densities typical of exurban areas. However, few studies have examined the response of forest birds to this increasingly common form of land conversion. The aim of this study was to assess whether, how, and at what scale forest birds respond to changes in habitat due to exurban growth. We evaluated changes in habitat composition (amount) and configuration (arrangement) for forest and forest-edge species around North America Breeding Bird Survey (BBS) stops between 1986 and 2009. We used Threshold Indicator Taxa Analysis to detect change points in species occurrence at two spatial extents (400-m and 1-km radius buffer). Our results show that exurban development reduced forest cover and increased habitat fragmentation around BBS stops. Forest birds responded nonlinearly to most measures of habitat loss and fragmentation at both the local and landscape extents. However, the strength and even direction of the response changed with the extent for several of the metrics. The majority of forest birds’ responses could be predicted by their habitat preferences indicating that management practices in exurban areas might target the maintenance of forested habitats, for example through easements or more focused management for birds within existing or new protected areas.

Effect of High Gasoline Prices on Low-Density Housing Development

Real estate development in suburban and exurban fringe areas defined the latest housing boom in the United States. The development of vast subdivisions of greenfield parcels in counties distant from urban cores and employment centers led to an upward trend in driving distances. A gradually developing and then dramatic run-up in the price of oil from 2003 to 2008 precipitated a gasoline price shock. The convergence of rising gasoline prices and a glut of newly constructed, low-density tract housing led to an equally dramatic decline in new housing starts in areas far from center cities and the older suburbs. Whereas the gasoline price shock affected the number of housing starts, the recession is responsible for the decline in housing prices; the two concepts act independently of one another. By correlating gasoline prices, housing starts in rural counties as compared to urban centers, vehicle efficiency, and vehicle miles traveled data, I have determined that the demand for sprawl development declines substantially as the price of gasoline rises over time. Households not seeking to move are not likely to move purely because of changes in gasoline prices; however, people who have plans to change residence take gasoline prices into account when choosing a new neighborhood. The recent global peak oil production milestone acknowledged by the International Energy Agency (IEA) has significant implications for transportation costs and, therefore, the future efficacy of auto-oriented suburban housing development. Whether these emerging trends continue into the future remains to be seen.

America's Racially Diverse Suburbs: Opportunities and Challenges

This article examines increasing racial diversity of suburban areas in the 50 largest metropolitan areas of the United States, analyzes the stability of racially diverse areas, and proposes a variety of policies designed to promote stably integrated neighborhoods, municipalities, and schools. The more than 6,500 suburban communities and 22,000 census tracts in the 50 largest metropolitan areas are divided into four types based on their racial composition and urbanization, and data for the period 1980–2010 are used to examine racial change and to evaluate the stability of different types of communities. By 2010, just 39% of suburban residents in these metropolitan areas lived in “traditional” suburbs—predominantly white communities or developing exurban areas. This is much lower than in 2000 when 51% of suburban residents lived in these types of suburbs. At the same time, the percentage of suburban residents living in racially diverse suburbs increased from 38% to 44%, and another 17% lived in predominantly nonwhite suburbs by 2010. Racially diverse suburbs exhibit many strengths, but resegregation and economic decline represent very serious challenges. Many currently integrated areas are actually in the midst of social and economic change, and many communities that were once integrated have now resegregated. Fifty-six percent of the neighborhoods that were integrated in 1980 had become predominantly nonwhite by 2010, and only 40% of neighborhoods that were integrated in the 1980 remained in that category in 2010. A variety of housing, legal, and school policies are available to promote stable integration in these areas.

Master-planned in exurbia: Examining the drivers and impacts of master-planned communities at the urban fringe

Smart growth strategies of infill and compact growth in existing suburban cities will most likely not be sufficient to absorb a new US household growth in the future. To meet housing demands and preferences, master-planned communities will continue to be built in outlying exurban areas. However, little is known about the impacts these communities may have on the surrounding physical, built and social environment in the exurban landscape. In this paper, we provide a review of the literature of what is known about the drivers behind the development of master-planned communities and the physical, built and social impacts of these developments on the surrounding exurban landscape. We then provide a case study of an exurban area outside of Seattle, Washington containing a large master-planned community. Through focus group interviews, we explore residential motivations to move to the area, and the benefits and challenges of living in an exurban landscape with a newly built master-planned community. Using qualitative data analyses, we find that residents are drawn to this exurban area for the abundance of natural amenities and outdoor recreation opportunities. However, the new master-planned community development presents many benefits and challenges for those living in the area; particularly the residential perceptions of impacts that the development has had on the surrounding natural and built environment. These real and perceived impacts of the master-planned community development has compounded and magnified the impacts to the social environment throughout the entire exurban community. Implications for planners and suggestions for future research are given.

Geographic Distribution of E-Shopping

The proliferation of Internet shopping has imposed enormous pressure on traditional stores. Few studies have examined the geographic distribution of online buyers and its implications on retail development and transportation. Using 585 Internet users in the Minneapolis and Saint Paul, Minnesota, metropolitan area, this study develops structural equation models to test two competing hypotheses regarding the connections between spatial attributes and e-shopping: diffusion of innovation and efficiency. The results demonstrate that the influence of shopping accessibility on e-shopping is not uniform and depends on the locations in metropolitan areas. Specifically, Internet users living in urban areas, areas with greater shopping accessibility, or both tend to purchase online more often than their counterparts in other areas because the former are better educated and use the Internet more than the latter. However, low shopping accessibility in exurban areas does promote the use of e-shopping as compared with exurban areas with relatively high shopping accessibility.