Landscape In Urban Areas Research Articles

Partitioning of turbulent flux reveals contrasting cooling potential for woody vegetation and grassland during heat waves

We compared the capacity of woody versus grassy vegetation covers to buffer high temperatures during heat waves by partitioning turbulent heat between latent (λE) and sensible (H) fluxes, and quantifying advection using the Priestley‐Taylor coefficient (α), for a16‐year old grassland and an adjoining 6‐year old plantation. We found that because λE dominated (>65%) the turbulent flux in the plantation and was at least twice as large as on the grassland (λE< 35% of the turbulent flux) during heat waves, the ambient temperature over the plantation was up to 5 °C lower in the afternoon, and averaged 1.2 °C lower for the whole day, compared with the grassland. Both vegetation covers emitted significant amounts of H when soil water availability was limited and also in winter when canopy cover was mostly inactive because of dormancy in the grassland and mutual shading in the plantation due to low solar angle. During the winter, advection of additional energy from surrounding vegetation suppressed λE and reduced α to <1.0 in both vegetation covers. Advection enhanced λE during periods of frequent rainfalls in summer, with mean α rising to 2.6 in the grassland and 3.4 in the plantation. Consistently low λE but high H made the grassland a source rather than a sink for advective energy, while the plantation was the opposite. The broadleaved evergreen woody vegetation consistently maintained a larger λE than the grassland in this mid‐latitude environment, contrary to the smaller λE observed over mostly coniferous forests at high (northern) latitudes (>35°). Annual evapotranspiration was 54% lower from the grassland (384 mm) than from the plantation (834 mm). Woody vegetation covers dominated by broadleaved species are therefore preferred for buffering extreme high temperatures during heat waves and recommended for rehabilitating degraded landscapes in urban areas. We also present functions for approximating α for soil water limited conditions.

Do natural areas in urban landscapes support successful reproduction by a group of conservation priority birds?

AbstractIf conservation priority birds are to persist in an increasingly anthropogenically altered world, suitable habitat must be created or preserved in potentially unsuitable landscapes. While natural areas in urban environments may provide habitat for declining groups of birds, little is known about effects of urbanization on the reproductive success of birds, such as grassland birds, that are typically thought to be associated with more rural landscapes. While typical conservation efforts have focused on conserving large patches of grassland in landscapes containing minimal amounts of woody vegetation and development, the assumption that habitat located in developed landscapes is of poor quality has not been tested and may wrongly devalue grasslands located in an urban matrix. To examine the influence of development on habitat quality for grassland birds, we studied grassland bird nest predation and brood parasitism in patches of varying size along an urbanization gradient in northeastern Illinois. Because nest predation is the primary cause of reproductive failure and a potentially limiting factor for grassland bird populations, we used miniature video cameras to identify predators at a subset of nests. From 2012 to 2013, we monitored 432 nests of 16 grassland bird species. Nest predation rates decreased with urbanization in the landscape as did probability of brood parasitism. We filmed 44 nests and documented 19 predation events. We found that coyotes Canis latrans, white‐tailed deer Odocoileus virginianus and thirteen‐lined ground squirrels Ictidomys tridecemlineatus were important nest predators in our study system. Contrary to prior assumptions, our results suggest that grasslands located in urban landscapes may provide habitat of equal or greater quality than many rural grasslands.

First Report of Vinca Blight Caused by Phytophthora nicotianae in Northwestern Mexico.

Vinca (Catharantus roseus (L.) G. Don) is a common ornamental landscape plant. From July to September 2012, blighted and wilted vinca plants were found in retail stores, commercial nurseries, and urban landscape areas of Culiacan, Sinaloa, in northwestern Mexico. In several commercial nurseries and a retail store, incidence of the unknown disease on vinca plants ranged from 20 to 50%, resulting in significant economic losses. Symptoms of the disease started with a foliar blight, and if warm and wet conditions were present, the disease progressed, causing plant wilting and death. Surface-sterilized (0.5% NaOCl 1 min) diseased plant tissue was plated on V8 agar medium, and after 72 h of incubation at 25°C, white colonies of coenocytic mycelium were developed from the plated tissues. Isolates produced cottony colonies on V8 agar medium, grew well between 7 and 30°C (optimum of 25°C), and produced spherical, intercalary, and terminal chlamydospores (17 to 30 μm) and non caducous, papillate, spherical to ovoid sporangia of 30 to 39 × 21 to 31 μm. Based on these morphological characteristics, Phytophthora isolates were identified as Phytophthora nicotianae Breda de Haan (1,3). The identity of two representative isolates OV4 and OV11 was confirmed by sequence analysis of the rDNA internal transcribed spacers (ITS; GenBank Accession Nos. KC248202 and KC248201), and of the β-tubulin (β-tub; KC248404 and KC248403) and translation elongation factor 1-α (EF1-α; KC248206 and KC248205) genes. Comparative sequence analysis against the NCBI nucleotide database showed a high degree of identity with reference sequences of P. nicotianae (ITS, 99%; β-tub, 99%; EF1-α, 100%) (2). A pathogenicity test with a representative isolate of P. nicotianae was performed on 10-week-old healthy vinca seedlings (n = 10). An aliquot of 10 ml of a zoosporic suspension (104 zoospores/ml) was sprayed onto the seedlings' leaves. An equal number of non-inoculated control seedlings were sprayed with sterile distilled water. Seedlings were maintained in a moist chamber at 25°C with 80 to 90% relative humidity and watered as needed with sterile water. Inoculated plants showed initial symptoms of foliar blight after 4 days, whereas control plants remained healthy. Ten days after inoculation, inoculated plants showed severe wilting. P. nicotianae was reisolated only from inoculated plants, thus fulfilling Koch's postulates. To our knowledge, this is the first report of P. nicotianae attacking annual vinca in northwestern Mexico.

Built-up and vegetation extraction and density mapping using WorldView-II

This study demonstrates the use of high resolution WorldView-II satellite data in extraction of built-up land and vegetation using normalized index techniques. The PCA 1 and NIR 2 bands-based built-up index was proposed for extracting built-up land, which exhibit high accuracy. The normalized difference vegetation index based on Red Edge and NIR 2 bands of WorldView-II produced high accuracy inthe estimation of vegetation compared to the use of Red and NIR bands. The grid technique used in estimating built-up and vegetation density from precisely classified images provided better and accurate assessment of built-up and vegetation density in heterogeneous landscape of urban areas. This shows areas of very high to high built-up density are located in the central, western and southern parts, which are primarily devoid of vegetation. This study indicates possibilities of utilizing high resolution satellite data in urban landscape characterization using a grid-based technique.

A remote sensing approach for estimating the location and rate of urban irrigation in semi-arid climates

Urban irrigation is an important component of the hydrologic cycle in many areas of the arid and semiarid western United States. This paper describes a new approach that uses readily available datasets to estimate the location and rate of urban irrigation. The approach provides a repeatable methodology at 1/3 km2 resolution across a large urbanized area (500 km2). For this study, Landsat Thematic Mapper satellite imagery, air photos, climatic records, and a land-use map were used to: (1) identify the fraction of irrigated landscaping in urban areas, and (2) estimate the monthly rate of irrigation being applied to those areas. The area chosen for this study was the San Fernando Valley in Southern California. Identifying irrigated areas involved the use of 29 satellite images, air photos, and a land-use map. The fraction of a pixel that consists of irrigated landscaping (Firr) was estimated using a linear-mixture model of two land-cover endmembers (selected pixels within a satellite image that represent a targeted land-cover). The two endmembers were impervious and fully-irrigated landscaping. In the San Fernando Valley, we used airport buildings, runways, and pavement to represent the impervious endmember; golf courses and parks were used to represent the fully irrigated endmember. The average Firr using all 29 satellite scenes was 44%. Firr calculated from hand-digitizing using air photos for 13 randomly selected single-family-residential neighborhoods showed similar results (42%). Estimating the rate of irrigation required identification of a third endmember: areas that consisted of urban vegetation but were not irrigated. This “nonirrigated” endmember was used to compute a Normalized Difference Vegetation Index (NDVI) surplus, defined as the difference between the NDVI signals of the irrigated and nonirrigated endmembers. The NDVI signals from irrigated areas remains relatively constant throughout the year, whereas the signal from nonirrigated areas rises and falls seasonally due to precipitation. The areas between airport runways were chosen to represent the nonirrigated endmember. Water-delivery records from 65 spatially-distributed single-family neighborhoods, consisting of nearly 1800 homes, were correlated with the NDVI surplus. The results show a strong exponential correlation (r2 = 0.94). In the absence of water-delivery records, which can be difficult to obtain, a surrogate was identified: the landscape evapotranspiration rate (ETL). ETL was used to scale NDVI surplus (which is dimensionless) to irrigation rates using an exponential scaling function. The monthly irrigation rates calculated from satellite and climatic data compared well with irrigation rates calculated from actual water-delivery data using a paired Wilcoxan signed-rank test (p = 0.0063). Identification of Firr at the pixel scale, along with identification of the irrigation rate for a fully-irrigated pixel, allows for mapping of urban irrigation over large areas. Maps showing the location and rate of monthly irrigation for the San Fernando study area were computed for January and August 1997.

The stag beetle: a collaborative conservation study across Europe

The stag beetle: a collaborative conservation study across Europe

USE OF ORNAMENTAL VEGETABLES, MEDICINAL AND AROMATIC PLANTS IN URBAN LANDSCAPE DESIGN

Ornamental vegetables, medicinal and aromatic plant species with their ground covering properties, various leaf forms, color and texture characteristics, and attractive fruit forms and colors contribute to the planting design through their aesthetic and functional quality. Urban landscape areas can be designed in order to produce, grow, and introduce endemic or endangered plant species, especially ornamental vegetables, medicinal and aromatic plants. These plants, planted either solitary or in groups, have a wide range of use in collection gardens, flower beds, villa gardens, plant boxes and roof gardens. In this study, after giving general information of the selected species, their uses, their aesthetic and functional purposes as well as economical contributions were defined.

Erratum to: Do protected areas in urban and rural landscapes differ in species diversity?

To compare species spatial turnover in urban and rural protected areas, we calculated turnover from presence-absence tables for each pair of protected areas (i) within the city of Halle, i.e. urban protected areas, (ii) within the district of Saalkreis that surrounds Halle, i.e. rural protected areas, and (iii) for each pair of urban and rural protected areas. We stated that we used the bsim similarity index as given in Lennon et al. (2001) and Koleff et al. (2003):

Simulating the water balance in an old non-engineered landfill for optimizing plant cover establishment in an arid environment

Landfills constitute extremely variable and heterogeneous environments and noxious landscapes in urban areas. The risk of a non-engineered landfill is relative to its hydrolologic behavior. Natural or planted vegetation on a landfill has an important role in its interior water balance, erosion control and removal of contaminants, besides imparting aesthetic value. Water deficit and heavy metal pollution are two of the most important factors limiting plant growth and establishment in landfills. The aim of this study was to investigate the colonization status, the ability to establish and the ecophysiological efficiency of different plant species grown on a waste landfill in the Mediterranean area in order to assess their potential for restoring waste landfills. For this purpose three grass species (Festuca arundinacea, Koeleria macrantha and Cynodon dactylon) were chosen for the restoration of a landfill in North Greece. Heavy metal concentration in both soil and plant tissues was determined. Plant density, cover and composition were measured after plant establishment. Assimilation and transpiration rate, stomatal conductance, and leaf water potential were seasonally measured and correlated with available soil water which was calculated using a commercial program for simulating the water balance in a landfill. The results indicate that C. dactylon appears to be ecophysiologically more efficient even though F. also seems able to participate in a forage plant cover at the landfill.

Do protected areas in urban and rural landscapes differ in species diversity?

Previous studies from Central Europe and North America showed that species richness is higher in urban than in rural landscapes. Do protected areas, which can be found in both city and countryside, reflect this species richness pattern? The impact of urban land-use might reduce conservation success and necessitate special management strategies. We compared species richness and species spatial turnover of selected animal and plant taxa (carabids, butterflies, snails, birds, lichens, mosses, vascular plants) in 30 protected areas in the city of Halle and 56 protected areas in the adjacent rural district of Saalkreis (Central Germany). Species were mapped by experienced biologists within a systematic species inventory. We corrected species numbers for the effects of landscape structure (e.g. size, shape and distance of habitats) which might influence species diversity beyond urbanisation effects. Butterflies, birds and lichens had significantly higher species numbers in the rural protected areas. Species spatial turnover was higher among urban areas than among rural areas or pairs of urban and rural areas for most taxa. Diversity in all taxa depended on the size of a protected area. We discussed these patterns in the context of the general urban-rural species diversity patterns. Our results indicate an increasing isolation of species assemblages with urbanisation and highlight that space for protected areas is even more limited in urban than rural areas. An effective conservation of urban species diversity should include both typical urban and semi-natural habitats to cover the full range of species living in cities.

Spatial Ecology of Bobcats and Gray Foxes in Urban and Rural Zones of a National Park

Urbanization threatens the persistence of many wildlife populations, particularly those of wide-ranging and low-density species such as mammalian carnivores. Effective conservation of carnivore populations requires an understanding of the impacts of adjacent urbanization on carnivores in reserves. I compared the spatial ecology of bobcats (Lynx rufus) and gray foxes (Urocyon cinereoargenteus) between urban and rural zones of a national park in northern California, USA. In the urban zone, gray foxes used the entire landscape from interior natural areas across the park edges and into the neighboring developed areas, although fox core areas were always within the park. Bobcats never entered development, and radiocollared adult female bobcats maintained home ranges in the interior of the park, far from the urban edge. Bobcats appeared to avoid crossing paved roads, while foxes crossed roads regularly. For adult female bobcats, home ranges were smaller in the urban zone, and core areas were both smaller and overlapped more. Home range size and overlap did not differ between zones for gray foxes. Bobcats seem to be more affected by the proximity of urbanization than foxes, perhaps because of differences in diet and social structure. The more flexible use of the landscape by foxes may give them access to increased resources and habitat, but also may expose them to more human-associated risks. If female bobcats are more sensitive to urbanization, this sensitivity could affect the long-term viability of bobcat populations in urban areas. Knowledge of how bobcats and gray foxes use the landscape in urban areas will allow more effective conservation and improved coexistence with these widespread carnivores by helping to predict where and why conservation or management issues may occur.

Attitudes of landscape professionals towards naturalistic versus formal urban landscapes in the UK

The last 30 years have seen a tide of interest sweeping across Europe in the development of nature in cities, and an increasing amount of landscape development in urban areas has involved the use of ‘naturalistic’ styles. This is an increasing attempt to find ways for urbanism and nature to co-exist. However, there have been considerable discussions among professionals regarding the advantages and disadvantages of ‘naturalistic’ styles in urban areas. This research examines professional attitudes to ‘naturalistic’ landscape styles in Britain, in contrast to more traditional, formal landscape styles, and aims to find out whether the interest in natural landscapes is really a fashion among landscape professionals. A self-administered postal survey was carried out using both quantitative and qualitative data collection techniques and analysis. The survey included 500 professionals from parks and recreation departments of local authorities, private landscape practices and conservation trusts, and resulted in a satisfactory response rate of 53%. The results of this study suggested that professionals recognise most of the values attached to naturalistic landscapes in urban areas. However, possible benefits that natural areas may have for urban people are not attached to naturalistic landscapes alone. The study also revealed that the naturalistic style is highly popular among conservation trusts but is less so among professionals from local authorities and private landscape practices who seem to appreciate both styles and believe that these styles are not separable from each other and should co-exist in an urban environment.

Evaluation of ornamental plant resources to urban biodiversity and cultural changing: A case study of residential landscapes in Trabzon city (Turkey)

The residential vegetation features in urban landscapes play an important role as indicators regarding urban biodiversity potential and cultural changing. They also include ornamental resources in the context to landscape appreciation for human environment. Therefore, this paper provides quantitative information on the distribution of plant species in urban residential landscape areas of Trabzon city (Turkey). In a total of 218 sampled areas, 274 plants species belonging to 70 families were surveyed with respect to residential use types of the city. The study results showed that among the species recorded in five residential type (traditional housing, detached housing, villa, apartment blocks and sites, mass housing for employees), non-native taxa frequency of a total species are much and dominantly represent residential landscape structure. Additionally, the species richness and diversity is positively related to new urban development areas. But, it was clearly determined that the vegetation structure has tended to ornamental purposes different from traditional residential gardens including fruit and other benefiting species. Consequently, it can be evidence that the residential vegetation is ornamental plant resources to urban biodiversity and that the distribution of the species in urban landscapes follows necessities of city and human quality.

Public attitudes towards naturalistic versus designed landscapes in the city of Sheffield (UK)

The last few decades of the 20th century have seen a rapid change in attitudes towards nature in the urban environment, which reflects greater awareness of nature amongst the general public as well as landscape professionals. As a result, a fashion towards the production of more natural landscapes in urban areas emerged among landscape professionals, and an increasing amount of landscape practices in urban areas has involved the use of ‘naturalistic’ styles. At the same time, the possible benefits of contact with nature have been explored by environmental psychologists, and it has tended to be assumed that such contact is fundamental for human health and well-being and that this form of landscape represented ethical and aesthetic progress. However, there is also evidence that some people do not respond to natural landscapes in urban areas, and see them as unkempt, valueless or even frightening, and prefer the neat and tidy approach of formal, ornamental landscapes. This research examines the public attitudes towards urban naturalistic landscapes in contrast to more formal designs of urban green spaces. Attitudes of the general public were investigated using a site-based questionnaire survey in contrasting two public green spaces of Sheffield, UK. The results of this study led to the following conclusions. The public can distinguish between naturalistic and more obviously designed landscapes, appreciate both types, and derive some similar and some different benefits from the two. The general public perceive ‘nature’ or ‘natural’ in two ways in different contexts: as the opposite of formal in a parks context and as the opposite of the built-up environment in a town/city-wide context. The public prefer both types of natural areas in an urban setting for different reasons and design styles seem to have an influence on preferences.

Effects of urbanization on Neotropical wasp and bee assemblages in a Brazilian metropolis

The rapid growth of cities in many parts of the world has stimulated an increasing number of ecological studies of urban environments. Here, 12 study sites in the city of Belo Horizonte (MG), southeastern Brazil, were compared to analyze the effects of habitat changes related to urbanization on the species richness and abundance of native wasps and bees. Two spatial scales were considered: large portions of the urban landscape (entire sites) and small areas within these sites (public squares). Overall, the abundance of advanced eusocial bees (i.e. stingless bees), which were the dominant species, was directly affected by the loss of vegetation cover and the increase of buildings associated with urbanization. The magnitude of this effect varied according to the nesting habits of each species. The loss of vegetation cover associated with urbanization also had a negative effect on the abundance and species richness of advanced eusocial wasps. Generalist species of bees and wasps, such as Trigona spinipes and Polybia occidentalis, were very abundant and not sensitive to the habitat changes related to urbanization. Advanced eusocial bees also responded to small-scale habitat changes (size and vegetation cover of public squares). No relation was found between the solitary and the primitive eusocial wasps and bees and the habitat changes considered here. Conservation strategies in urban environments need to consider different spatial scales in order to maintain or enhance the local diversity of wasps and bees.

A study on the information entropy and fractal dimension of land use structure and form in Shanghai

Land use change is an important component of global environmental change, and a representation of the impact of human activities on physical environment. Study on regional and urban land use change is the newest trend now. This paper studied land use structure and form changes of the central area in Shanghai from 1947 to 1996 and revealed all the driving factors leading to such changes based on the system ideas and the fractal theories. The paper calculated and compared the information entropy and equilibrium degree of land use structure on different condition. The results showed that the information entropy and equilibrium degree of land use structure were increasing gradually based on study area, but were decreasing from 1947 to 1958 and start to increase since 1958 based on urbanized area. The differences in areas of each land use type are reducing and the land use structures are approaching to equilibrium state in Shanghai. In recent 50 years, the boundary dimensions of urban industrial area, farmland, village small town construction area and reserved land for construction purpose have an ascending trend, their boundary forms are even more complicated, but residential area and other urban landscapes change little. The radius dimensions of residential area, industrial area, other urban landscape and village small town construction area were increasing gradually, those of agricultural area and reserved land for construction purpose had an ascending trend before 1979 and started to descend since 1979. In recent 50 years, all the land use types have been expanding from city center to peripheries with different speeds and degrees.The radius dimension of farmland is maximal and that of residential area is minimal, which forms an annular spatial pattern from residential area to industrial area and to agricultural area according to distance away from city center. All these spatial-temporal feature changes are impacted by the local environment, traffic condition, economic development and government conduct, while economic development and government conduct are the most important driving factors leading to urban form changes.

The city is my canvas

Contemporary trompe l'oeil artist Richard Haas transforms the drab exteriors of neglected buildings into breath-taking facades. The City is My Canvas documents his most important projects of the last two decades in double-page spreads which illustrate the before and after phases of each site. From Italian Quadrata paintings to Baroque and Rococo interiors, trompe l'oeil murals have a long tradition as decoration and didactic illustration. Muralist Richard Haas brings this tradition into the 21st century as he revitalizes forgotten buildings in eroding city centres by creating new false facades that seamlessly blend into the existing environment. The world is constantly changing, and the needs of the city change with it, says Haas. Even if blank urban walls at key locations of the city are now primarily seen as opportunities for computer-generated advertizements, whole segments of the mid-range urban American landscape and large areas of our edge cities remain in drastic need of refinement, softening and improvement.

Emergy evaluation of food production in urban residential landscapes

To transform cities from heterotrophic into sustainable ecosystems many authors have called for increased food production, including home gardening, in urban areas. We conducted an emergy analysis of four model backyard landscape plots—a conventional ornamental landscape, an intensive organic garden, an edible landscape, and a forest garden—to assess the yield and sustainability of these systems. Data were collected during the 2001 growing season and extrapolated to make a five year projection. In the 2001 season, all plots had low Emergy Yield Ratios (EYR) of between 0.0003 and 0.17 and extremely low Emergy Sustainability Indices (SI). In the five year projection, all plots still had low EYRs of between 0.0008 and 0.33 and very low SIs. These low indices are due primarily to the high levels of economic inputs required for the installation and maintenance of these plots in an urban context. Analyses performed on larger systems (households, neighborhoods and cities) containing productive landscapes such as those studied here may produce different results. Installing food-producing landscapes in urban areas without altering the networks by which such landscapes are supplied, however, may not substantially alter the heterotrophic nature of cities.

The role of building inspection systems in map and database maintenance

Changes to the landscape in urban areas, and capturing information on such changes, are considered in relation to three revision models used by mapping agencies. The municipality as the locus of de...