No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Mapping private gardens in urban areas using object-oriented techniques and very high-resolution satellite imagery
Abstract
Gardens remain the least studied and least understood habitat in urban areas. With the recent exception of the URGENT funded urban domestic gardens project in the UK, there is a notable lack of research on the ecological character and contribution of gardens to the wider urban biodiversity. This is despite the fact that gardens usually comprise the largest vegetated component of the urban greenspace resource. In part this omission has been due to the difficulties inherent in obtaining ecological data on gardens and the lack of a methodology for classifying and analysing garden data. This paper presents data from a study undertaken in the city of Dunedin, New Zealand. The study developed a methodology using object-oriented classification techniques and very high-resolution multispectral Ikonos imagery to automatically map the extent, distribution and density of private gardens in the city. The focus was on the vegetated garden area which was calculated as comprising 46% of the residential area or 36% of the total urban area. Rigorous accuracy assessments were undertaken. When using the automated classification technique, a total of 90.7% of the private gardens were correctly identified. Discrimination of garden types (e.g. trees or grass dominated) was encouraging, but still requires improvement. Our results indicate the great potential that the methodology has in providing a quick method for obtaining good quality ecological data on garden habitats in urban areas.
... SPOT data has as another medium-resolution image source with 20m resolutions also been often used in this context (Quarmby andCushnie, 1989, Zhang andFoody, 1998;Furberg and Ban, 2013;Jebur et al., 2014. High-resolution optical data is an excellent data source for detailed urban land cover mapping as the studies of Myint et al. (2011), Mathieu et al. (2007aand 2007b and Qian et al. (2015a and2015b) have demonstrated. Such datasets are however not extensively used, most likely because of their commercial nature. ...
... Most ecosystem service studies that rely on remotely sensed data are performed at the landscape level, either determining actual values for a particular region, or investigating land use/land cover and the thus inherent ecosystem service value changes over time (Haas and Ban, 2013). Studies that derive detailed ecosystem service relevant information with remote sensing in and for urban areas are scarce (Mathieu et al., 2007a(Mathieu et al., , 2007bLakes and Kim, 2012;Haas et al., 2014) and generally lack the integration of spatio-temporal components or only target particular services or functions. ...
... The "Biotope Area Ratio" for assessment and management of urban ES is determined by classification of high-resolution multispectral data (IKONOS and Quickbird) by Lakes and Kim (2012). Mathieu et al. (2007b) use very high-resolution satellite imagery to map domestic gardens by applying image segmentation and an object-based classification strategy to IKONOS data. A similar strategy has also been successfully applied for mapping large-scale vegetation communities in urban areas (Mathieu et al., 2007a). ...
This thesis research focuses on the establishment of analytical frameworks for the detection of urban growth patterns based on spaceborne remote sensing data at multiple scales, spatial and temporal resolutions and on the evaluation of environmental impacts through the well-established concepts of landscape metrics and ecosystem services, their extension and combination.
... Introduction Mapping impervious surfaces is particularly problematic due to the mosaic of small features made up with different physical properties which dominates these urban environments (Mathieu et al., 2007). This problem gets even greater when using (very) high spatial resolution imagery for classification, as due to a smaller spatial resolution, the spectral response from these different small objects in an urban environment exhibits more and more complex patterns (Myint et al., 2011). ...
... To overcome this problem, the use of object based image analysis (OBIA) techniques (e.g. Mathieu et al., 2007Mathieu et al., , 2008Myint et al., 2011), and the fusion with LiDAR-derived data-sets have been reported to substantially improve impervious detection in an urban environment (Mathieu et al., 2007). Hence, this research aims to explore and combine the above methods for developing an accurate and state of the art methodology for mapping impervious surfaces in a pilot area of the Walloon region. ...
... To overcome this problem, the use of object based image analysis (OBIA) techniques (e.g. Mathieu et al., 2007Mathieu et al., , 2008Myint et al., 2011), and the fusion with LiDAR-derived data-sets have been reported to substantially improve impervious detection in an urban environment (Mathieu et al., 2007). Hence, this research aims to explore and combine the above methods for developing an accurate and state of the art methodology for mapping impervious surfaces in a pilot area of the Walloon region. ...
The problem of solid waste disposal and management is a serious concern across
the globe. It is one of the most serious environmental problems facing many Nigerian cities with Akure as no exception. In recent years, there has been an increase in the volume of waste generated across the nation, due to a number of factors which include; high population growth rate, increasing urbanization, and increase per capita income. However, the poor management of these increasing waste generated poses a serious threat to the environment and health quality. Secondary data sources were employed in the study, which include; Maps, Landsat imagery and a Digital Elevation Model, which were used in the selection of potential suitable site for solid waste disposal. Multi‐Criteria Decision Analysis (MCDA), an integration of Analytical Hierarchy Process (AHP) and Multi‐Criteria Evaluation was used for the study. Criteria considered were assigned a weighted value gotten from AHP analysis. Finally, a suitability map was produced which reveals that 158.274km2 of the study area is Highly suitable for landfill. These sites are located at 5000m to built‐up areas and 3500m to major and minor roads, which implies that economic costs of implementation are minimal. The selected region has a slope less than 15%, which is an infrastructural advantage as well as a means of minimizing environmental impacts. Geo‐spatial database of environmental and social information was created for Akure Local Government.
Keywords: Landfill, Multi‐Criteria Evaluation, Akure, Waste.
... Despite mounting evidence on the wellbeing benefits of gardening, particularly during the COVID-19 pandemic, the potential of gardening has been largely overlooked in public health policy (Cameron et al., 2012;Howarth et al., 2020aHowarth et al., , 2020bSpano et al., 2020;Theodorou et al., 2021). This is perhaps surprising given that private gardens occupy approximately 23% and 36% of the urban landscape in cities such as Sheffield, United Kingdom (UK), and Dunedin, New Zealand, respectively (Gaston et al., 2005;Mathieu et al., 2007). Similarly, private gardens constitute 35%-47% of urban greenspace in many cities in England, Scotland, and Wales (Loram et al., 2007). ...
... The present findings highlight that longer duration of gardening is associated with improved mental wellbeing and life satisfaction in middle-aged and older adults in Australia, with these relationships being stronger for older adults. Although the strengths of these associations were small, such effect sizes may nevertheless be consequential for public health, given the low costs associated with gardening (Buck, 2016) and widespread distribution of and engagement with garden settings worldwide (Buck, 2016;Dewaelheyns et al., 2014;Mathieu et al., 2007). In accordance with the WHO guidelines for moderate-intensity physical activity for adults (Bull et al., 2020), the present findings indicate that gardening for more than two and a half hours per week, as opposed to gardening for less, may suggest beneficial effects on mental wellbeing and life satisfaction, particularly for individuals aged 64 years and older. ...
... With the rapid development of technology, multiple data sources have become available for UGS research, including remote sensing data, aerial photography, mobile terrestrial sensors and LiDAR [12][13][14][15]. Using various data to extract and map vegetation has emerged as a fundamental research for related study [16][17][18][19]. The extraction mainly depends on the spectral, textural, geometric, contextual features and 3D features of vegetation [20][21][22][23], in which some features may require certain types of data to achieve accurate classification. ...
... For small sites or elongated sites, the parkland or sites with large numbers of green space densely distributed, or sites requiring fine design, the use of high-resolution data is more appropriate. For example, pocket parks and informal green space are important strategies in urban micro-regeneration, but the size and shape may be limited by the site, and thus, high-resolution data are needed in such studies [16,37,58]. If the site is larger and regular, or requires overall planning, the use of lower resolution data is more appropriate within the range of error permissibility. ...
The appropriate resolution has been confirmed to be crucial to the extraction of urban green space and the related research on ecosystem services. However, the factors affecting the differences between various resolutions of data in certain application scenarios are lacking in attention. To fill the gap, this paper made an attempt to analyze the differences of various resolutions of data in green space extraction and to explore where the differences are reflected in the actual land unit, as well as the factors affecting the differences. Further, suggestions for reducing errors and application scenarios of different resolutions of data in related research are proposed. Taking a typical area of Nanjing as an example, data taken by DJI drone (0.1 m), GaoFen-1 (2 m) and Sentinel-2A (10 m) were selected for analysis. The results show that: (1) There were minimal differences in the green space ratio of the study area calculated by different resolutions of data on the whole, but when subdivided into each land use type and block, the differences were obvious; (2) The function, area and shape of the block, as well as the patch density and aggregation degree of the internal green space, had a certain impact on the differences. However, the specific impact varied when the block area was different; and (3) For the selection of the data source, the research purpose and application scenarios need to be comprehensively considered, including the function and attributes of the block, the distribution characteristics of green space, the allowable error limits and the budget. The present study highlighted the reasons of differences and hopefully it can provide a reference for the data selection of urban green space in the practical planning and design.
... As a result, diverse pollinator communities can be found in gardens throughout the world Fetridge et al., 2008;Marín et al., 2020;Martins et al., 2017;Staab et al., 2020). Despite their small individual size, residential gardens collectively cover 16-36% of cities in different countries Colding et al., 2006;Loram et al., 2007;Mathieu et al., 2007;Ossola et al., 2021) and ...
... Currently, there is insufficient published pollen data to have included it in this study. Nevertheless, nectar sugar is a general energy source required by the vast majority of adult pollinators so it provides a common currency through which to compare the floral resource value of Mathieu et al., 2007). In addition, there was no significant difference in the nectar sugar production of urban land uses between Bristol and three other UK cities (see Chapter 2), but there is no equivalent data for non-UK cities to make comparisons. ...
... This study adopted the method of He Min et al. [16][17][18]: "Using the standard deviation within the object to express the heterogeneity within the object, and spatial correlation to express the heterogeneity between the objects". The standard deviation inside the object is used to represent the homogeneity inside the object. ...
... This study adopted the method of He Min et al. [16][17][18]: "Using the standard deviation within the object to express the heterogeneity within the object, and spatial correlation to express the heterogeneity between the objects". ...
In China, landslides are abundant, widespread, and regular, destroying villages and agriculture and sometimes posing a threat to people’s lives. The question of how to rapidly detect and attain landslide data is a significant topic of research, yet traditional measurement using medium-resolution remote sensing data is problematic. Object-oriented categorization is utilized in this research to extract landside data from high-resolution GF-1 and Sentinel-2 data. Data preprocessing begins with orthophoto correction, image matching, and data fusion, followed by band enhancement, which comprises band synthesis, principal component analysis, and filtering, and finally landside extraction using an object-oriented technique. The impact of geology, lithology, rainfall, and human activities on the occurrence of landslides in the study area is explored utilizing DEM data, visualization tools, remote sensing interpretation map, and other associated data. The studies are conducted in Shuicheng County, Guizhou Province, China, with a segmentation scale of 25 pixels and 14 classification feature parameters. Following that, the landslide mass is extracted and categorization findings of nearby characteristics are acquired. Finally, the destructiveness of the landslide is determined by comparing the results of object-oriented classification before and after the landslide. With a Kappa coefficient of 0.76 and a landslide extraction accuracy of 79.8%, the overall classification accuracy is 87%. Combined with the geological structure, rock lithology, spatial location, landslide occurrence process, elevation of the study area, precipitation and the impact of human activities, the causes of the landslide are discussed and analyzed. The early warning of other unknown landslides can be obtained by analyzing the features of the aforementioned components.
... As a result, diverse pollinator communities can be found in gardens throughout the world (Baldock et al., 2019;Fetridge et al., 2008;Marín et al., 2020;Martins et al., 2017;Staab et al., 2020). Despite their small individual size, residential gardens collectively cover 16%-36% of cities in different countries (Baldock et al., 2019;Colding et al., 2006;Loram et al., 2007;Mathieu et al., 2007;Ossola et al., 2021) and provide an estimated 85% of nectar in urban areas in the UK (Tew et al., 2021). Consequently, gardens offer a unique opportunity for pollinator conservation where the combined action of many individuals can have a major impact on foraging resources at a landscape scale (Goddard et al., 2010). ...
... Residential gardens cover 28% of Bristol by area (Baldock et al., 2019), putting it within the range seen for cities worldwide (e.g. 16% in Stockholm, Sweden; Colding et al., 2006 and 36% in Dunedin, New Zealand; Mathieu et al., 2007). In addition, there was no significant difference in the nectar sugar production of urban land uses between Bristol and three other UK cities (Tew et al., 2021), but there is no equivalent data for non-UK cities to make comparisons. ...
Residential gardens are a valuable habitat for insect pollinators worldwide, but differences in individual gardening practices substantially affect their floral composition. It is important to understand how the floral resource supply of gardens varies in both space and time so we can develop evidence‐based management recommendations to support pollinator conservation in towns and cities. We surveyed 59 residential gardens in the city of Bristol, UK, at monthly intervals from March to October. For each of 472 garden surveys, we combined floral abundances with nectar sugar data to quantify the nectar production of each garden, investigating the magnitude, temporal stability, and diversity and composition of garden nectar supplies. We found that individual gardens differ markedly in the quantity of nectar sugar they supply (from 2 to 1,662 g), and nectar production is higher in more affluent neighbourhoods, but not in larger gardens. Nectar supply peaks in July (mid‐summer), when more plant taxa are in flower, but temporal patterns vary among individual gardens. At larger spatial scales, temporal variability averages out through the portfolio effect, meaning insect pollinators foraging across many gardens in urban landscapes have access to a relatively stable and continuous supply of nectar through the year. Turnover in species composition among gardens leads to an extremely high overall plant richness, with 636 taxa recorded flowering. The nectar supply is dominated by non‐natives, which provide 91% of all nectar sugar, while shrubs are the main plant life form contributing to nectar production (58%). Two‐thirds of nectar sugar is only available to relatively specialised pollinators, leaving just one‐third that is accessible to all. Synthesis and applications. By measuring nectar supply in residential gardens, our study demonstrates that pollinator‐friendly management, affecting garden quality, is more important than the size of a garden, giving every gardener an opportunity to contribute to pollinator conservation in urban areas. For gardeners interested in increasing the value of their land to foraging pollinators, we recommend planting nectar‐rich shrubs with complementary flowering periods and prioritising flowers with an open structure in late summer and autumn. By measuring nectar supply in residential gardens, our study demonstrates that pollinator‐friendly management, affecting garden quality, is more important than the size of a garden, giving every gardener an opportunity to contribute to pollinator conservation in urban areas. For gardeners interested in increasing the value of their land to foraging pollinators, we recommend planting nectar‐rich shrubs with complementary flowering periods and prioritising flowers with an open structure in late summer and autumn.
... Such variations can manifest in antibioticproducing soil strains [2]. Urban gardens often constitute a significant proportion of green spaces in urbanized cities, with some cities having 23 to 36% of their areas dedicated to these gardens [3][4][5]. These gardens provide support for numerous local, landscape, and sociopolitical features that aid in the preservation of biodiversity. ...
Urban parks are a rich source of microbial diversity, as they are heavily used by city residents. In this study, we sampled a Mediterranean park and were able to isolate bacteria that have the ability to inhibit the growth of control microorganisms. Out of the 560 bacteria we tested, many displayed antibacterial activity, particularly against Salmonella sp. and K. pneumoniae. These results suggest that the microorganisms in the park are in close proximity to the human population. Additionally, the isolated bacteria demonstrated diverse enzymatic activities, possibly as a response to the environmental substances available to them, which could aid in the degradation of different compounds of interest. The study of the spatial distribution of soil parameters and the inhibition against relative-safe pathogens in an urban park in València (Spain) demonstrated a higher proportion of isolates in certain areas. These spatial data maps can help researchers understand the behaviors of bacterial populations on a regional level, which can assist in the creation of novel antimicrobial agents and promote advancements in public health.
... In [68], the amount of urban private green spaces in Leipzig (NE Germany), resulting from back-and front-yard green space, is around 40% (20 km 2 ) of the total amount of public green spaces, but in 25% of city districts, it prevails over public green areas. Other studies focused on quantifying private garden areas, for example, estimating between 22 and 36% of the total Dunedin urban area in New Zealand [69]. In line with these data, [35] found that about 23% (33 km 2 ) of the urban area in Sheffield (UK) is covered by home gardens. ...
Urban Green Spaces (UGS) contribute to the sustainable development of the urban ecosystem , positively impacting quality of life and providing ecosystem services and social benefits to inhabitants. For urban planning, mapping and quantification of UGS become crucial. So far, the contribution of private green spaces to ecosystem services in urban areas has yet to be studied. At the same time, in many Italian cities, they represent a considerable part of the urban green cover. This study utilises a methodological approach and provides insights into the contribution of urban public and private green spaces by the consideration of a case study area in Northeast Italy. To achieve this goal, the main steps were: (i) NDVI extraction from very high-resolution (20 cm) ortho-photos, (ii) classification of property status and (iii) analysis of the degree of the greenness of land cover units. From our results, the total amount of the green spaces is 5.70 km 2 , of which 72.1% (4.11 km 2) is private, and 28.9% (1.59 km 2) is public. As for the land cover, three NDVI classes were identified , highlighting different degrees of homogeneity in NDVI reflectance response within each urban land cover unit. These results will support the planning of new green areas in the post-epidemic National Recovery and Resilience Plan.
... In addition to the spectral features of the image, it also pays attention to the shape factors of the ground objects. In the existing research, the application of object-oriented methods to the extraction and classification of ground objects has been relatively successful [14][15][16][17], one of which is the lake extraction in the Kanas Lake area of Altay Mountain, Xinjiang, the accuracy of which is more than 95% under cloudless conditions using the object-oriented method [18]. However, the classification accuracy of the object-oriented method can be easily affected by the segmentation scale and the feature rule set, and the misclassification often occurs at the boundary of different ground objects. ...
The China–Pakistan Economic Corridor is the pilot area of the Belt and Road, where glaciers and lakes are widely distributed. Recent years, global warming has accelerated the expansion of glacier lakes, which increased the risk of natural disasters such as glacier lake outburst. It is important to monitor the glacier lakes in this region. In this paper, we propose a method combining the object-oriented image analysis with boundary recognition (OOBR) to extract lakes in several study areas of China–Pakistan Economic Corridor (CPEC). This method recognized the lake boundary with the symmetrical characteristic according to the principle of seed growth of watershed algorithm, which can correct the boundary extracted by the object-oriented method. The overall accuracy of the proposed method is up to 98.5% with Landsat series images. The experiments also show that the overall accuracy of our method is always higher than that of the object-oriented method with different segmentation scales mentioned in this paper. The proposed method improved the overall accuracy on the basis of the results obtained by the object-oriented method, and the results with the proposed method are more robust to the seeds than that with the boundary correction method of the watershed algorithm. Therefore, the proposed method can obtain a high extraction accuracy while reducing the complexity of the object-oriented extraction.
... This effect can be reflected in antibiotic-producing soil strains [2]. The area in urban gardens often determines the amount of green space in many urbanized cities, and in some cities, urban gardens cover between 23 and 36% of the city area [3][4][5]. Urban gardens support many local, landscape, and sociopolitical features that may contribute to conserving biodiversity. Understanding spatial connectivity can help predict species distribution, diversity, abundance, composition, and spatial distribution of bacterial resources. ...
The enzymatic activities of bacterial isolates have been widely studied, but a spatial distribution of this activity is rarely focused. New antibiotic-producing microorganisms can be discovered in a more efficient manner if spatial statistical techniques are applied to the distribution of the activity of bacterial isolates in different terrains. This study is focused to generate a series of maps illustrating the spatial distribution of different soil parameters and the inhibition against relative-safe pathogens (like Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Salmonella, Pseudomonas fluorencens and Enterobacter cloacae) in an urban park in València (Spain). This spatial data has demonstrated a higher proportion of isolates was specifically allocated. This routine of data presentation is valuable for understanding bacterial population dynamics at a local level.
... City greenery is crucial for providing ecosystem services and supporting societal well-being in heavily populated and pressured metropolitan areas. The Estimation of gardens areas in Stockholm has is more than16% (Colding et al., 2006), while in the UK it ranges between 22-27% (Loram et al., 2007), and in Dunedin, New Zealand it rises to 36% (Mathieu et al., 2007). ...
... Residential yards compose 25%-40% of land area in cities (Loram et al., 2007;Mathieu et al., 2007), and in the United States, they represent a homogeneous, continental-scale macrosystem with relatively similar biophysical properties compared to natural ecosystems (Groffman et al., 2017). However, individual management decisions made by residents (i.e., homeowners or renters who reside in a home) influence local-scale ecological outcomes, such as plant resources available to support wildlife. ...
Introduction
Integrated social and ecological processes shape urban plant communities, but the temporal dynamics and potential for change in these managed communities have rarely been explored. In residential yards, which cover about 40% of urban land area, individuals make decisions that control vegetation outcomes. These decisions may lead to relatively static plant composition and structure, as residents seek to expend little effort to maintain stable landscapes. Alternatively, residents may actively modify plant communities to meet their preferences or address perceived problems, or they may passively allow them to change. In this research, we ask, how and to what extent does residential yard vegetation change over time?
Methods
We conducted co-located ecological surveys of yards (in 2008, 2018, and 2019) and social surveys of residents (in 2018) in four diverse neighborhoods of Phoenix, Arizona.
Results
94% of residents had made some changes to their front or back yards since moving in. On average, about 60% of woody vegetation per yard changed between 2008 and 2018, though the number of species present did not differ significantly. In comparison, about 30% of woody vegetation changed in native Sonoran Desert reference areas over 10 years. In yards, about 15% of woody vegetation changed on average in a single year, with up to 90% change in some yards. Greater turnover was observed for homes that were sold, indicating a “pulse” of management. Additionally, we observed greater vegetation turnover in the two older, lawn-dominated neighborhoods surveyed despite differences in neighborhood socioeconomic factors.
Discussion
These results indicate that residential plant communities are dynamic over time. Neighborhood age and other characteristics may be important drivers of change, while socioeconomic status neither promotes nor inhibits change at the neighborhood scale. Our findings highlight an opportunity for management interventions, wherein residents may be open to making conservation-friendly changes if they are already altering the composition of their yards.
... With the vigorous development of remote sensing technology, high-resolution (HR) remote sensing images play an important role in many fields, such as object detection [1,2], urban planning [3], semantic labeling [4] and object detection [5]. However, most accessible public remote sensing datasets cannot maintain long-term coverage and high spatial resolution at the same time. ...
Nowadays, remote sensing datasets with long temporal coverage generally have a limited spatial resolution, most of the existing research uses the single image super-resolution (SISR) method to reconstruct high-resolution (HR) images. However, due to the lack of information in low-resolution (LR) images and the ill-posed nature of SISR, it is difficult to reconstruct the fine texture of HR images under large-scale magnification factors (e.g., four times). To address this problem, we propose a new reference-based super-resolution method called a Residual-Dense Hybrid Attention Network (R-DHAN), which uses the rich texture information in the reference image to make up for the deficiency of the original LR image. The proposed SR model employs Super-Resolution by Neural Texture Transfer (SRNTT) as a backbone. Based on this structure, we propose a dense hybrid attention block (DHAB) as a building block of R-DHAN. The DHAB fuses the input and its internal features of current block. While making full use of the feature information, it uses the interdependence between different channels and different spatial dimensions to model and obtains a strong representation ability. In addition, a hybrid channel-spatial attention mechanism is introduced to focus on important and useful regions to better reconstruct the final image. Experiments show that compared with SRNTT and some classical SR techniques, the proposed R-DHAN method performs well in quantitative evaluation and visual quality.
... The establishment of native Mediterranean plants in the Mediterranean biome for cultivation or landscaping of UGSs can significantly contribute to biodiversity conservation [199] and the restoration of ecological balance. Their proven tolerance to conditions of increased salinity and drought, renders them imperative for the success and sustainability of ecosystem restoration actions, and the exploitation of low-productivity or marginal land, now as well as under future climate induced stresses. ...
Abstract: Drought and salinity are two of the most urgent challenges faced in Mediterranean ecosystems, equally impacting natural systems, agricultural crops, and urban green. While many technical and soft approaches have been proposed to anticipate, mitigate, and remediate these impacts, a class of solutions has possibly been in front of us all along. Native Mediterranean fauna is well adapted, and when properly established still has unexploited conservation, restoration, and production diversification potential. Here, we outline the results of a long-term experiment taking place on the island
of Crete, Greece that started in 1996 and involves over 70 native Mediterranean plants planted and monitored in various green spaces (private, shared, public) and a university campus under a diversity of adverse topographies (e.g., coastal, steep slopes), soils (e.g., disturbed, nutrient-deficient), and microclimatic conditions, taking various plant formations and serving various functions. After plant establishment, drought and salinity resistance were evaluated by gradually exposing plants (n = 5249) to deficit irrigation and saline environmental conditions, and plants were followed up for at least 5 years to empirically assess their ability to cope with abiotic stress. From the Mediterranean plants
that were planted and tested, 52 were singled out because of their resistance and additional favorable traits. Motivated by this long-term assessment, a systematic literature review was conducted using the protocol Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) to validate empirical results, determine which were still unexplored, and bring to light additional uses. Results showed that 41 of the plants included in this research have significant medicinal properties, 26 have
nutritional uses, 17 industrial uses, and 18 have evidence of cosmetology uses. Additionally, the empirical assessment gave new evidence of at least 40 new species–trait combinations. By formally documenting the characteristics of these native Mediterranean plants, this work highlights their versatile traits, and the prospect of creating new uses and value chains enables, for the first time their inclusion in planting-decision support systems and aims to increase demand and facilitate the scaling
up of native greening in the context of sustainable land and water management within and beyond the Mediterranean basin.
... Most studies have focused on public urban green spaces (Dewaelheyns et al., 2018). Private green spaces deserve more attention because they can constitute a large proportion of urban green space in many cities, for example, >30% in Brisbane, Australia (Rupprecht and Byrne, 2014), >35% in the UK cities (Loram et al., 2007) and > 50% in Dunedin, New Zealand (Mathieu et al., 2007). Private greens spaces may be commercially owned and used by members of, or visitors to, that organisation; or they may small private residential green spaces used byindividuals of a household. ...
Backyards play important roles for individual households because they provide a private and safe green space for social and environmental interactions, relaxation, gardening and children's activities. The use of backyards is highly dependent on their thermal conditions. Turf is a common surface type in backyards but unirrigated turf can be as warm as pavement, bringing thermal discomfort and discouraging people from using them. Under certain conditions, turf irrigation provides an opportunity to reduce thermal stress by increasing evapotranspiration. This study aims to measure the impacts of turf irrigation on microclimate in a backyard environment in the warm season in Melbourne, Australia. The experiment consisted of four 6 m × 6 m turf-covered plots. Daily irrigation was applied at four amounts: 0, 2, 4 and 7 mm for six weeks. In Week 6, the 4-mm irrigation reduced daytime soil temperature, turf surface temperature, air temperature and universal thermal climate index by 1.7, 2.3, 0.6 and 0.4 °C, respectively. All daytime impacts were significant (p < 0.05, t-test). Irrigation has the potential to significantly improve the thermal conditions of backyards in combination with the use of tree shade.
... Residential gardens are uniquely situated to provide necessary habitat for pollinators in urban landscapes. Yards and gardens comprise about 25%-30% of all urban land (Mathieu et al., 2007), and recent surveys suggest that one in four adults base at least some of their gardening purchase decisions on a plant's purported benefits to wildlife (National Gardening Survey, 2020). Gardens managed for bees could provide habitat amid an otherwise resource-poor urban landscape (Quistberg et al., 2016). ...
Growing public awareness of pollinator declines has led to an increase in gardening for pollinators, particularly bees. In most regions of the United States a better understanding of the plants that support abundant and species rich bee communities will help urban pollinator conservation programs. To address this, we compared the relative attractiveness of 23 native Pacific Northwest plant species to bees. We performed timed bee counts and vacuum‐sampled bee communities, weekly, when plots were in peak bloom. Across three field seasons, we found that Douglas' aster (Symphyotrichum subspicatum), California poppy (Eschscholzia californica), varileaf phacelia (Phacelia heterophylla), Canada goldenrod (Solidago canadensis), farewell‐to‐spring (Clarkia amoena), globe gilia (Gilia capitata), and Oregon sunshine (Eriophyllum lanatum) consistently harbored high bee abundance and species richness, and show great potential for garden pollinator plantings. These findings can be applied to residential and community gardens, municipal parks and other plantings, as well as by restoration professionals and policy makers interested in creating and supporting pollinator habitat. Across three field seasons, we compared the relative attractiveness of 23 native Pacific Northwest plant species to bees including 4 non‐native garden comparator plants. Several native plants were consistently more attractive to bees than the exotic comparator species. The bee communities associated with the study plants were significantly different, suggesting that informed plant community design in a garden setting could maximize a garden's ability to support bees.
... Consequently, the demand for the construction of residential complexes and other building types has increased more than before (Karteris et al. 2016). The development of buildings and infrastructures due to the surge in urbanization demand has reduced the area allocated to urban green spaces (Mathieu et al. 2007;Wu 2014) so that more than 40% of the green spaces have vanished in the last 50 years (Kabir et al. 2018), while urban green spaces play a major role in environmental-friendly means of sustainability in city developments. According to the United Nations (2022), the world's cities account for about 75% of global greenhouse gas emissions, with transportation and buildings being major contributors. ...
Megacities recently are experiencing a shortage of green spaces basically due to the rapid growth of urbanization and increasing demand for different building types. Consideration of sustainable urban development is essential since the expansion of city facilities should be in line with social, economic, and environmental aspects. In this regard, green roof technology has been recommended as an effective solution for the growth of green spaces per capita and improving sustainability means of urban developments due to its diverse advantages. This study thus aimed at prioritizing sustainability indicators and relative sub-criteria of adopting green roof technology for residential and governmental buildings in the city of Mashhad, Iran, which has a dry climate. For this purpose, thirteen sub-criteria, which are extracted from the existing literature, are classified into three main sustainability indicators (environmental, economic, and social). Also, the best-worth method (BWM) as a multi-criteria decision-making technique was implemented to prioritize indicators and sub-criteria by analyzing the expert’s opinion. The results indicated that respective economic and environmental indicators attract the highest priority in residential and governmental buildings. Additionally, the most important sub-criteria in environmental, economic, and social groups are air quality, roof longevity, and public health in both building types, respectively. However, when all criteria were considered, the respective highest priorities belong to roof longevity and air quality in residential and governmental buildings, while biodiversity conservation is the least important one in both building types. The results of this research can be beneficial in other cities with similar economic and climate conditions.
... The conflict between urban expansion and biodiversity loss is an active area of research (Wang et al., 2021). However, details about the role of immediate private building surroundings (gardens, patios, etc.) as animal habitat remains incomplete and is the subject of ongoing research with modern technology potentially playing a key role in gathering more information (Mathieu et al., 2007). This is particularly important because the micro-cosmos that surrounds buildings, with fungi, bacteria and other often-unseen species is especially at risk. ...
The preservation of biodiversity is a rising global concern and will have a major impact on the design and management of buildings and their immediate surroundings. Thus far, the majority of work on biodiversity and the built environment appears to focus on urban planning, project development, and the niche area of designing buildings with living walls and green roofs. Knowledge on the specific interaction between individual buildings and animals is fragmented, preventing holistic efforts to better manage these interactions. This paper presents the findings from a scoping study which captures the state-of-the-art about relationships between individual buildings, building stakeholders, and animals. It reviews the current body of knowledge and points out three areas of interest that are crucial for future work on this area of study: (1) different stakeholder perspectives of building stakeholders on animals in and around buildings (2) positive and negative interactions between individual buildings and their immediate surroundings with animals and (3) management of interactions between animals in and around buildings. Findings show that literature in relation to these three aspects is fragmented and contains multiple gaps in relation to which species need to be considered and how, including a total absence of mathematical models able to represent animal-building interactions. It calls for better engagement between built environment researchers and their counterparts in biological sciences to collect appropriate data and extract relevant information from it, enhancing knowledge on complex biological processes towards producing shared understanding and developing integrated actions.
... Such a myriad of platforms has fundamentally improved our ability to inform sustainable urban development and smart city practices, which entail an understanding of fine-scale interactions between humans and the heterogeneous landscape (Angelidou et al., 2017;Zhang and Li, 2018). Land cover and land use (LCLU) of geographical entities and patterns identified from VHR data are becoming increasingly ubiquitous for various topics of urban studies, such as building energy consumption (Faroughi et al., 2020;Li et al., 2017), urban development and sprawl (e.g., Blaschke et al., 2014;Huang et al., 2017;Zhang and Li, 2018), biodiversity conservation (e.g., Chen et al., 2020;Dutta et al., 2020;Godwin et al., 2015;Turner et al., 2003), urban agriculture and gardening (Mathieu et al., 2007;Saha and Eckelman, 2017), social and environmental justice (e.g., Tapiador et al., 2011;Weigand et al., 2019), human thermal comfort and health (e.g., Myint et al., 2015b;Troyo et al., 2008;Whiteman et al., 2019), and humanitarian crisis or disaster response such as the impact of COVID-19 (e.g., Contreras et al., 2016;Giada et al., 2003;Venter et al., 2020). ...
Very-high-resolution (VHR) land cover and land use (LCLU) is an essential baseline data for understanding fine-scale interactions between humans and the heterogeneous landscapes of urban environments. In this study, we developed a Fine-resolution, Large-area Urban Thematic information Extraction (FLUTE) framework to address multiple challenges facing large-area, high-resolution urban mapping, including the view angle effect, high intraclass and low interclass variation, and multiscale land cover types. FLUTE builds upon a teacher-student deep learning architecture, and includes two new feature extraction modules-Scale-aware Parsing Module (SPM) and View-aware Embedding Module (VEM). Our model was trained with a new benchmark database containing 52.43 million labeled pixels (from 2014 to 2017 NAIP airborne Imagery) to capture diverse LCLU types and spatial patterns. We assessed the credibility of FLUTE by producing a 1-meter resolution database named UrbanWatch for 22 major cities across the conterminous United States. UrbanWatch contains nine LCLU classes-building, road, parking lot, tree canopy, grass/shrub, water, agriculture, barren, and others, with an overall accuracy of 91.52%. We have further made UrbanWatch freely accessible to support urban-related research, urban planning and management, and community outreach efforts: https://urbanwatch.charlotte.edu.
... Green spaces offer benefits in climate change mitigation and adaptation due to their carbon storage function, thermal comfort, reduced energy use, stormwater regulation, and drought management [4]. In particular, urban tree canopy cover and permeability areas are not considered [22][23][24]. Additionally, updating such maps requires considerable effort. ...
Urban green infrastructure (UGI) has a key role in improving human and environmental health in cities and contributes to several services related to climate adaptation. Accurate localization and quantification of pervious surfaces and canopy cover are envisaged to implement UGI, address sustainable spatial planning, and include adaptation and mitigation strategies in urban planning practices. This study aims to propose a simple and replicable process to map pervious surfaces and canopy cover and to investigate the reliability and the potential planning uses of UGI maps. The proposed method combines the normalized difference vegetation index (NDVI), extracted from high-resolution airborne imagery (0.20 m), with digital elevation models to map pervious surfaces and canopy cover. The approach is tested in the Municipality of Trento, Italy, and, according to a random sampling validation, has an accuracy exceeding 80%. The paper provides a detailed map of green spaces in the urban areas, describing quantity and distribution, and proposes a synthesis map expressed as a block-level degree of pervious surfaces and canopy cover to drive urban transformations. The proposed approach constitutes a useful tool to geovisualize critical areas and to compare levels of pervious surfaces and canopy cover in the municipal area. Acknowledging the role of green areas in the urban environment, the paper examines the potential applications of the maps in the policy cycle, such as land use management and monitoring, and in climate-related practices, and discusses their integration into the current planning tools to shift towards performative rather than prescriptive planning.
... The authors of [32] determined areas where changes in urban vegetation occurred based on satellite imagery and lidar data. The authors of [8] estimated economic well-being using high-resolution satellite imagery, while [33] mapped private gardens in urban areas using object-oriented techniques and very-high-resolution satellite imagery. The authors of [34] calculated the demarcation of prime farmland protection areas around metropolis areas based on high-resolution satellite imagery. ...
This paper aims to present possible areas to plant different vegetation types near traffic jams to reduce air pollution in the capital of Croatia, the city of Zagreb. Based on main traffic road and random forest machine learning using WorldView-2 European cities data, potential areas are established. It is seen that, based on a 10 m buffer, there is a possible planting area of more than 220,000 square meters, and based on 15 m buffer, there is a possible planting area of more than 410,000 square meters. The proposed plants are Viburnum lucidum, Photinia x fraseri, Euonymus japonicus, Tilia cordata, Aesculus hippocastanum, Pinus sp., Taxus baccata, Populus alba, Quercus robur, Betula pendula, which are characteristic for urban areas in Croatia. The planting of proposed trees may result in an increase of 3–5% in the total trees in the city of Zagreb. Although similar research has been published, this paper presents novelty findings from combined machine learning methods for defining green urban areas. Additionally, this paper presents original results for this region.
... Despite this scaling-up potential-and ever-evolving remote-sensing technologies (e.g., aerial photography, LIDAR, high-resolution sensors) to map the form and flows of the urban built environment (Gatrell & Jensen, 2008;Maktav et al., 2005;Weng et al., 2018)-documenting the spatial extent and composition of UA has proven challenging. This is, in part, due to its small-scale, ephemeral, and often heterogeneous nature and variety (Forster et al., 2009;Freire et al., 2009;Mathieu et al., 2007;McClintock et al., 2016). Notable efforts to map and characterize UA include those by McClintock et al. (2016) in Portland, and by Longcore et al. (2011) in Los Angeles. ...
Urban agriculture provides a range of ecosystem services (as well as potential disservices). This study examines the spatial extent, physical characteristics, and residents' perceptions of community and private gardens in Detroit, a city that has high potential for agricultural development given its abundant vacant and abandoned land. Despite popular narratives of Detroit as a mecca for urban agriculture, spatial analysis of the city's Lower Eastside (~15 sq. miles) reveals that gardens cover less than 1% of the vacant land and are often an ephemeral form of land use. Interviews indicate that residents plant gardens primarily for the cultural ecosystem services (e.g. social cohesion, community building) they provide and secondarily for provisioning services (i.e. food production). Uncertainty over land tenure, legacy environmental pollutants, unknowns regarding potential ecosystem disservices, and lack of government support and capital investment are the primary obstacles to scaling up urban agriculture in Detroit and other cities and will need to be addressed. To facilitate its expansion, we propose that urban agriculture be framed as a form of multifunctional green infrastructure. We conducted GIS-based analysis to identify suitable parcels for scaling up agriculture in the study area. To maximize the distribution of ecosystem service benefits, our modeling recommends dispersing rather than clustering gardens in the urban landscape. This strategy would provide more benefits to more people while countering the gentrification effects that may occur when cities expand green space.
... Gardens comprise an estimated 24-36% of the area of UK cities (Baldock et al. 2019) covering an area of 400,000 ha (The Wildlife Trust 2021). Similarly, gardens account for 36% of urban space in a New Zealand city (Mathieu et al. 2007), although this can vary greatly, with gardens accounting for just 16% of urban space in Stockholm, Sweden (Colding et al. 2006). Likewise, in developing countries, gardens also contribute essential green space to cities. Private garden patios in León, Nicaragua for example, account for 86% of the city's green space (González-García and Sal 2008). ...
Habitat loss and fragmentation are considered the foremost threats in pollinator decline, and in England and Wales, 97% of wildflower meadows were lost by 1984. The value of creating flower-rich margins in agricultural environments is established, yet there is growing potential to support pollinator populations in urban landscapes. We used citizen science to investigate the effectiveness of small 4m ² sown wildflower ‘mini-meadows’ in UK gardens and allotments in recruiting beneficial insects. Participants were allocated one of three treatment groups: Mix 1 (commercially available ‘meadow mix’); Mix 2 (formulated based on existing literature on pollinator foraging preferences); or Control (no additional wildflowers). All participants conducted insect sampling over two years using standardised pan and sticky trap methods May–August. Samples were returned for identification by trained specialists. Mini-meadows provided resource-rich habitats, increasing wild bee richness and supporting on average 111% more bumblebees, 87% more solitary bees and 85% more solitary wasps in the year following seed-sowing, compared to Control plots. The wildflower mixes were also taxon-specific in their attractiveness. Mix 1 attracted more solitary bees and bumblebees, whereas Mix 2 attracted more solitary wasps. There was no significant difference in the abundance of hoverflies between treatments. Higher abundance of solitary wasps and bees caught amongst the mini-meadow was perhaps due to shorter foraging ranges.
Implications for insect conservation
Domestic gardens and allotments provide huge potential habitat for pollinators, and small-scale floral enhancements can attract more beneficial insects in fragmented urban landscapes, supporting urban biodiversity, pollination services and biological control.
... The average greenspace coverage was 51.05% in statistical sectors, 31.48% in building blocks, and 70.98% in garden parcels ( Figure 13; Table 6). This variable coverage at different scales implies that the domestic gardens contribute the majority of urban greenspace [16,30]. At the broad scale of the Flemish region of Belgium, approximately 73% of houses have a domestic garden [58], which take up 8.3% of the total area. ...
Domestic gardens provide residents with immediate access to landscape amenities and numerous ecological provisions. These ecological provisions have been proven to be largely determined by greenspace composition and landscape, but the fragmentation and heterogeneity of garden environments present challenges to greenspace mapping. Here, we first developed a recognition method to create a garden parcel data set in the medieval Leuven city of Belgium, based on the land use layers and agricultural land parcels. Then, we applied multi-sourced satellite imagery to evaluate the added value of spatial resolution, plant phenology and 3D structure in identifying four vegetation types. Finally, we characterized the greenspace landscapes in garden parcels. Compared with single ALOS-2 imagery, SPOT-7 imagery and Pleiades-1A imagery increased the overall accuracy by 4% and 8%, respectively. The accuracy improvement (21%) produced from multi-temporal stereo Pleiades-1A imagery strongly verified the significance of plant phenology and 3D structure in garden mapping. The average greenspace cover in garden parcels was 71% but varied from 56% in urban gardens to 82% in rural gardens. The garden greenspace landscape is fragmented by the artificial structures in urban areas but has a more aggregated size and less complex shapes in rural areas. This study calls for greater attention to be paid to gardens, and for multi-disciplinary studies conducted in collaboration with urban ecologists and landscape designers to maximize the benefits to residents of both immediate landscape amenities and ecological provisions, in the face of global environmental changes and public health risks.
... Several studies suggest that the biodiversity of natural environments is an important driver of well-being (e. g., Carrus et al., 2015;Fuller et al., 2007) but the evidence is limited and somewhat inconsistent (Marselle et al., 2019). However, biodiversity of private gardens is of interest to urban researchers for another reason: private gardens have a substantial impact on urban biodiversity as they constitute a major green space in urban areas (Loram et al., 2008;Mathieu et al., 2007). ...
Private gardens have an enormous impact on urban biodiversity, making individual householder behavior critical to the conservation and enhancement of biodiversity in urban areas. Nature connectedness is considered to be a prerequisite for proenvironmental behavior, but how it manifests in private gardens is largely unexplored. Nature connectedness has also been found to be associated with several well-being dimensions. The present study investigates the associations between nature connectedness, biodiversity of private gardens, and mental well-being during the Covid-19 lockdown, a stressful period in many people’s lives. Hierarchical regression analyses were used to analyze data from an online survey of private gardeners in two cities, one in Germany and one in New Zealand, in May 2020, approximately two months after the beginning of the first Covid-19 lockdown. Garden characteristics explained a significant amount of variance in depression symptoms during the Covid- 19 lockdown. In light of rising pressures on urban green spaces, the findings point to the importance of private garden qualities for mental health and well-being. Nature connectedness emerged as a significant predictor of feature richness, a measure of the heterogeneity of habitats that support wildlife, and plant growth form richness in people’s gardens in both city samples. Nature connectedness was also a significant predictor of the extent to which people experienced positive emotions during the Covid-19 lockdown but not negative emotions and depression symptoms. Our results suggest that nature connectedness can provide benefits for both the environment and people through its positive association with private garden biodiversity and positive emotions.
... Capture-recapture trapping took place between 1 February and 15 April 2019 across three sites within the city of Dunedin, New Zealand (45°52′S, 170°30′E) (Fig. 1). The three sites represented three urban habitat types, as defined by a Dunedin habitat map shapefile (Freeman & Buck 2003;Mathieu et al. 2007): (1) "Forest fragment", a closed-canopy native and exotic tree stand surrounded by an urban landscape, (2) "Residential I", residential areas with greater than one third of the property comprised of mature, structurally complex gardens containing an assortment of lawns, hedges, shrubs, and large established trees, and (3) "Residential II", residential areas with greater than one third of the property comprised of less structurally complex gardens dominated by lawns. Green cover in Residential I totals about 70%, and in Residential II it ranges between 42% and 50% (Freeman & Buck 2003). ...
Invasive mammalian pests threaten biodiversity globally across a diverse range of habitats. The unique combination of resource subsidies and disturbance in cities can provide favourable conditions for invasion. Recent interest in urban biodiversity enhancement has increased the demand for effective urban pest control, but efforts are often hampered by a lack of understanding of the ecology of urban invasive mammals. The Australian common brushtail possum (Trichosurus vulpecula) has invaded most New Zealand landscapes, including urban areas, and is a nationally significant pest species. Recent shifts in national pest control and conservation priorities demand an assessment of the capacity for urban areas to harbour possum populations. We estimated the density of possums across three representative habitat types within the city of Dunedin, New Zealand: an urban forest fragment and two residential areas of varying vegetation quality. Possums were live-trapped and camera-trapped over eight days at each site in late summer to early autumn. Spatially explicit capture-recapture methods were used to estimate density at each site, and “minimum number alive” estimates were also calculated. Our estimate suggests that the forest fragment supported possums at a density (3.1 ha−1) capable of inflicting harm on resident native wildlife, but this density was low compared with non-urban estimates in the same forest type, suggesting a possible influence of disturbance from human activity in and around the fragment. Few possums were caught at the two residential sites (0.1 ha−1 at each), and behavioural avoidance may have reduced capture success there. Our estimates confirm that urban areas are an important habitat for possums, and our study provides the first rigorous estimates of urban possum density, which can be incorporated into predictive modelling and other methods of control planning.
... They are important patches of greenspace that can provide connectivity between larger areas of green spaces (parks, recreation grounds, etc.), therefore improving provision of urban ES. Whilst, individually, one domestic garden may appear insignificant, collectively domestic gardens can comprise over one third of a city's surface area (Mathieu et al. 2007), and become more important as a GI resource as urbanisation increases (Loram et al. 2011). Domestic gardens provide diverse ES, which benefit urban residents through both active and passive engagement (Lin et al. 2017). ...
Urban green infrastructure (GI) is a well-known solution to enhance resilience to climate hazards, particularly through the climate regulating functions of green spaces including cooling the city and moderating runoff, in addition to improving health and wellbeing. Domestic gardens provide a valuable contribution to the larger GI network in cities, however, there is less detailed knowledge about these areas and their role in urban climate regulation, in comparison to publicly accessible spaces such as parks. Environmental models require detailed information relating to GI type, structure, and height, since the functionality of different GI types (e.g. mown grass, rough grass, shrubs, trees) is variable in its influence upon urban microclimate. Whilst remote sensing classification techniques can distinguish broad vegetated and non-vegetated classes, they cannot identify the diverse range of surface types within gardens.
This chapter presents a novel approach to collecting fine-scale high quality information on urban domestic gardens to produce new climate information for planning healthy cities, within the case study city of Manchester, UK. The approach combines citizen science data with high resolution areal imagery and environmental modelling, to quantify and map cooling potential and runoff attenuation under different scenarios. This found that greening gardens could be the solution to reducing future risk of heat wave events and surface water flooding, particularly in neighbourhoods with a high proportion of gardens.
This new climate information was presented in an action plan, co-developed with project partner organisations, embedded within the existing policy framework. Engagement of citizens directly led to positive climate resilient actions within Manchester as residents pledged and implemented climate adaptation solutions within their gardens, such as replacing impervious surfaces with vegetation. This project demonstrates how cross-disciplinary collaboration among scientists, planners, government, non-governmental organizations, the private sector and the general public helps to address the challenges that lie ahead for cities as healthy environments.
... Access to green spaces is complex and determined by several factors, including distance from the home, perception of safety and individuals' demographic characteristics (Coombes et al., 2010;Dunton et al., 2014;Harrison et al., 1995). A large proportion of urban green space is often publicly inaccessible, existing as private land, especially as private household gardens (Mathieu et al., 2007). Access to a private garden varies with socioeconomic background and is generally higher for older individuals and those in higher income brackets (Judge & Rahman, 2020; Office for National Statistics, 2020). ...
In the United Kingdom, children are spending less time outdoors and are more disconnected from nature than previous generations. However, interaction with nature at a young age can benefit wellbeing and long‐term support for conservation. Green space accessibility in the United Kingdom varies between rural and urban areas and is lower for children than for adults. It is possible that COVID‐19 lockdown restrictions may have influenced these differences. In this study, we assessed parents' attitudes towards green space, as well as whether the COVID‐19 lockdown restrictions had affected their attitudes or the amount of time spent outside by their children, via an online survey for parents of primary school‐aged children in Cambridgeshire and North London, UK (n = 171). We assessed whether responses were affected by local environment (rural, suburban or urban), school type (state‐funded or fee‐paying) or garden access (with or without private garden access). Parents' attitudes towards green space were significantly different between local environments: 76.9% of rural parents reported being happy with the amount of green space to which their children had access, in contrast with only 40.5% of urban parents. COVID‐19 lockdown restrictions also affected parents' attitudes to the importance of green space, and this differed between local environments: 75.7% of urban parents said their views had changed during lockdown, in contrast with 35.9% of rural parents. The change in amount of time spent outside by children during lockdown was also significantly different between local environments: most urban children spent more time inside during lockdown, while most rural children spent more time outside. Neither parents' attitudes towards green space nor the amount of time spent outside by their children varied with school type or garden access. Our results suggest that lockdown restrictions exacerbated pre‐existing differences in access to nature between urban and rural children in our sampled population. We suggest that the current increased public and political awareness of the value of green space should be capitalised on to increase provision and access to green space and to reduce inequalities in accessibility and awareness of nature between children from different backgrounds. A free Plain Language Summary can be found within the Supporting Information of this article. A free plain language summary can be found within the Supporting Information of this article.
... Yet, the assemblage of everyday gardens -further called the garden complex (Dewaelheyns, Rogge, & Gulinck, 2014;Dewaelheyns, Kerselaers, & Rogge, 2016) -occupies between 22% and 36% of the urban ground (Colding, Lundberg, & Folke, 2006;Mathieu, Freeman, & Aryal, 2007). Research in the social and environmental sciences has shown that these everyday gardens can make a marked contribution to the social and environmental collective. ...
Belonging to the small-scale and private sphere, gardens are usually omitted from urban and regional landscape plans. Yet, we argue that the assemblage of everyday gardens-the garden complex-is an inherent component of the landscape metropolis that holds the potential to become a powerful landscape agency. This potential is enclosed, among others, within three particular qualities: hybridity, scalar paradoxes, and complex dynamics. Practicing these qualities as concepts for landscape design and analysis helps to expand the imaginaries of everyday gardens to more purposefully reflect and negotiate the condition of the landscape metropolis. By means of two case studies-two domestic gardens-we demonstrate that designing with hybridity entails versatility, simultaneity, and multiplicity, thereby engendering a richness of meaning and experiences. This pluralism is also inherent in the scalar paradoxes we observed. Cross-scalar interactions evoke design implications that transcend the confines of the private plot, surpassing individual, human gain, and making individual gardens enter into dialogue with each other and with their surroundings. Lastly, by working with an enlarged set of complex dynamics, the two case studies prove that a garden can be a driver of change and innovation, and thereby a valuable source of resilience.
... Capture-recapture trapping took place between 1 February and 15 April 2019 across three sites within the city of Dunedin, New Zealand (45°52′S, 170°30′E) (Fig. 1). The three sites represented three urban habitat types, as defined by a Dunedin habitat map shapefile (Freeman & Buck 2003;Mathieu et al. 2007): (1) "Forest fragment", a closed-canopy native and exotic tree stand surrounded by an urban landscape, (2) "Residential I", residential areas with greater than one third of the property comprised of mature, structurally complex gardens containing an assortment of lawns, hedges, shrubs, and large established trees, and (3) "Residential II", residential areas with greater than one third of the property comprised of less structurally complex gardens dominated by lawns. Green cover in Residential I totals about 70%, and in Residential II it ranges between 42% and 50% (Freeman & Buck 2003). ...
Invasive mammalian pests threaten biodiversity globally across a diverse range of habitats. The unique combination of resource subsidies and disturbance in cities can provide favourable conditions for invasion. Recent interest in urban biodiversity enhancement has increased the demand for effective urban pest control, but efforts are often hampered by a lack of understanding of the ecology of urban invasive mammals. The Australian common brushtail possum (Trichosurus vulpecula) has invaded most New Zealand landscapes, including urban areas, and is a nationally significant pest species. Recent shifts in national pest control and conservation priorities demand an assessment of the capacity for urban areas to harbour possum populations. We estimated the density of possums across three representative habitat types within the city of Dunedin, New Zealand: an urban forest fragment and two residential areas of varying vegetation quality. Possums were live-trapped and camera-trapped over eight days at each site in late summer to early autumn. Spatially explicit capture-recapture methods were used to estimate density at each site, and "minimum number alive" estimates were also calculated. Our estimate suggests that the forest fragment supported possums at a density (3.1 ha −1) capable of inflicting harm on resident native wildlife, but this density was low compared with non-urban estimates in the same forest type, suggesting a possible influence of disturbance from human activity in and around the fragment. Few possums were caught at the two residential sites (0.1 ha −1 at each), and behavioural avoidance may have reduced capture success there. Our estimates confirm that urban areas are an important habitat for possums, and our study provides the first rigorous estimates of urban possum density, which can be incorporated into predictive modelling and other methods of control planning.
... Individually, gardens might be small but combined they cover around 20%-30% of the areas within settlements (Dewaelheyns et al., 2014;Gaston et al., 2005;Loram et al., 2007;Mathieu et al., 2007). Gardens are created by the gardeners and consist of different components, which interact with each other. ...
Gardens are culturally shaped environments in which natural processes can be experienced. Thus, they offer insights into the relation people have with these processes and the biophysical domain. This includes soils and plants, as these are the natural materials gardeners work with regularly. A cultural ecosystem service (CES) perspective might help to understand interactions between the gardeners and the environment, for example, soils. This could provide insights for scientists, public stakeholders and non‐governmental organizations to raise awareness for ecosystem services (ES) of soils. Understanding how gardens are created and used, requires studies from the natural sciences but also from the humanities and social sciences. The natural sciences provide insights into soil properties, biodiversity, plant requirements and the water cycle, while the humanities and social sciences are needed to understand identity formation, social and cultural practices, belief systems and psychological aspects connected to gardening. Inter‐ and transdisciplinary research can then inform scientists, gardeners, policy makers and educators as well as the general public about CES. This can be used to develop educational programs and measures to protect these valuable CES as well as the general ES of gardens and soils. A free Plain Language Summary can be found within the Supporting Information of this article.
... al. [45] applied a mixed method of RapidEye imagery and GIS-data combined with random forest models to detect private front and backyard green spaces within the city of Leipzig, Germany. Mathieu et al. [57] used object-oriented classification techniques and very high-resolution multispectral Ikonos imagery to automatically map the extent of >90% of private urban gardens within the city of Dunedin, New Zealand. Nevertheless, the manual mapping operation performed in the present study has been preferred since: (1) a sufficiently detailed cartography was not available (1:2000); (2) it determined a better definition of the UGS perimeter, allowing us to perform a detailed morphological analysis. ...
A loss of natural capital within cities and their surrounding areas has been noticed over the last decades. Increasing development associated with higher sealing rates has caused a general loss of Urban Green Spaces (UGS) within the urban environment, whereas urban sprawl and the improvement of road networks have deeply fragmented the surrounding landscape and jeopardized ecosystems connectivity. UGS are an essential component of the urban system, and their loss has a greater impact on, e.g., ecological and hydrological processes, threatening human well-being. Different types and spatial configurations of UGS may affect their own ability to provide ecosystem services, such as biodiversity support and water regulation. Nevertheless, the study of UGS spatial patterns is a research branch poorly addressed. Moreover, UGS analyses are mainly focused on public and vast green spaces, but seldom on informal, private, and interstitial ones, returning a myopic representation of urban green areas. Therefore, this study investigates the UGS spatial patterns within six Southern European cities, using the urban morphology analysis to assess all urban vegetated lands. Results revealed three main Urban Green Spatial Patterns (UGSPs): Fragmented, Compact, and Linear Distributions. UGSPs taxonomy represents a novelty in the urban morphology field and may have important implications for the ability to provide ecosystem services and, thus, human well-being.
... In relation to the land area occupied by home gardens, Gaston et al. (2005) estimated that in Sheffield (UK), domestic gardens covered 23% of the urbanised area. A study in Dunedin, New Zealand found domestic gardens comprised 36% of urban land cover (Mathieu, et. al., 2007) while in Brisbane, private gardens accounted for 20.7% land cover, based on statistical sampling (Rupprecht and Byrne, 2014). ...
Purpose
This paper aims to examine the planning policy and legal framework governing the creation and operation of urban agriculture in Sydney, Australia’s global city. All levels of urban agriculture are considered – from domestic and small community gardens to large agribusiness – as all make an important contribution to agricultural production in an urban context.
Design/methodology/approach
Using the Australian State of New South Wales and its capital Sydney, as a focus, the study examines the recent trend of the recognition and re-establishment of agriculture as a desired land use in cities. Three examples are selected for closer scrutiny – Horsley Park Urban Agriculture Precinct, located in the Western Sydney Parklands; City of Sydney’s City Farm, located in the inner suburb of St Peters; and the Western Sydney Aerotropolis Agribusiness Precinct, located at a new airport on the fringe of Sydney.
Findings
As more city-dwellers embrace urban food production and as city authorities seek to encourage and facilitate farming activities, it is clear that regulatory structures which allow it to happen should be incorporated into urban planning legislation at (in the Australian context) state government level. If cities want to encourage urban agriculture, planning legislation needs to be part of the broader legal framework for enabling it to germinate and thrive.
Originality/value
This paper explores the emergence of two new types of urban agriculture: first, the multi-functional, small-scale urban farming operation, situated conceptually between a community garden and a full-scale commercial agricultural enterprise, and located spatially in the midst of built-up urban form; and second, the intensive, high tech export-oriented model exemplified by the Aerotropolis Agribusiness Precinct.
... Este tipo de arborización a manera de zonas verdes o jardines domésticos viene cobrando importancia dentro de las áreas urbanas ocupando notables superficies incluso en zonas residenciales dispersas (Gaston et al., 2005;Loram et al., 2007;Mathieu et al., 2007), en el cual el área de estudio en mención no es la excepción, evidenciando la importancia de este tipo de cubiertas vegetales dentro del uso del suelo urbano ligados no solamente a aspectos y factores de orden natural sino también socioeconómico (Padullés et al, 2015). Sin desconocer además la importancia que vienen teniendo las coberturas arbóreas sobre procesos de planeación e infraestructura urbano regional (Howes y Herbert, 2005). ...
Entorno Geográfico | N° 21 | enero-junio 2021 | pp. 77-105 | ISSN (en línea): 2382-3518 / ISSN impreso: 1692-0074 | Universidad del Valle Esta obra está bajo licencia internacional Creative Commons Reconocimiento-NoComercial-CompartirIgual 4.0.
This paper makes an inventory and the floristic composition vegetationornamental use most representative of the urban sites of Peque townat thesilvicultural level, Gardening and landscaping beautification, since withinits urban and semi-urban perimeter it preserves, combines, manages and maintains and integrates its vegetation cover in its land use planning processes. It started with quantitative research techniques based on the calculation of absolute and relative abundance, diversity indices at the Shannon level, Berger-Parker index and Mixing ratio, which were complemented with qualitative techniques at the sounding level. fast and participatory rural activities, workshops, audiovisual recordings (photography and video), semi-structured interviews, direct and participant observation; In addition, sampling was carried out to take botanical samples, formats, notes and a field trip for subsequent taxonomic identification; where 56families, 97 genera and 107 species are reported, of which 39 botanical families that form part of the Angiospermae group subclass Magnoliopsidae(Dicotiledoneae) stand out in greater quantity, with 78 species, followed by the subclass Liliopsidae(Monocotiledoneae) with 13botanical families and 24 species, in descending order appear the Gymosperms (coniferous and related) with 3 botanical families and 4 species and finally the group of Pteridophytes (Ferns) with 1 family and 1 species respectively,in order to become a contribution to knowledge and valuation of a part of the local flora and as a reference point in decision-making and planning regarding its management.
... OBIA's main characteristic is that it uses multi-scale image segmentation to combine a variety of spatial, spectral, and textural data in the classification process, which greatly improves accuracy [16]. In the processing of VHR images, OBIA categorization approaches have been thoroughly explored, and numerous approaches have been developed to classify objects [17][18][19]. However, during the OBIA process, two important issues remain: selecting appropriate features for image classification and determining the right scale for image segmentation [20]. ...
Urban vegetation mapping is critical in many applications, i.e., preserving biodiversity, maintaining ecological balance, and minimizing the urban heat island effect. It is still challenging to extract accurate vegetation covers from aerial imagery using traditional classification approaches, because urban vegetation categories have complex spatial structures and similar spectral properties. Deep neural networks (DNNs) have shown a significant improvement in remote sensing image classification outcomes during the last few years. These methods are promising in this domain, yet unreliable for various reasons, such as the use of irrelevant descriptor features in the building of the models and lack of quality in the labeled image. Explainable AI (XAI) can help us gain insight into these limits and, as a result, adjust the training dataset and model as needed. Thus, in this work, we explain how an explanation model called Shapley additive explanations (SHAP) can be utilized for interpreting the output of the DNN model that is designed for classifying vegetation covers. We want to not only produce high-quality vegetation maps, but also rank the input parameters and select appropriate features for classification. Therefore, we test our method on vegetation mapping from aerial imagery based on spectral and textural features. Texture features can help overcome the limitations of poor spectral resolution in aerial imagery for vegetation mapping. The model was capable of obtaining an overall accuracy (OA) of 94.44% for vegetation cover mapping. The conclusions derived from SHAP plots demonstrate the high contribution of features, such as Hue, Brightness, GLCM_Dissimilarity, GLCM_Homogeneity, and GLCM_Mean to the output of the proposed model for vegetation mapping. Therefore, the study indicates that existing vegetation mapping strategies based only on spectral characteristics are insufficient to appropriately classify vegetation covers.
Private domestic gardens have immense potential to contribute to urban biodiversity conservation. However, they are divided into small private plots and managed individually by garden owners. Therefore, engagement in wildlife-friendly gardening (WFG), which entails alternative management and design choices, relies on the individual willingness of each garden owner. Using an online survey and qualitative walking interviews with garden owners, our study explores individual internal and external factors underlying engagement in WFG. We interpret and reflect on our findings in the context of gardening as a relational practice between people and nature. Our findings suggest that motivations for gardening play a central role in how internal and external factors promote or impede WFG. For example, motivations towards organic gardening and learning from nature promote WFG, whereas personal and family care and well-being motivations seem to impede it. The perceived and actual garden area, as well as self-reported insufficient knowledge and social norms, covary the most with engagement in WFG. Engagement in WFG relates to people's relationships with nature, as embodied in social norms of community acceptance and cohesion, and care and respect for nature and others. Future research into pro-environmental behaviours in gardens should adopt more relational approaches that go beyond the individual self and take better account of feedback between individual actions and social relations. Read the free Plain Language Summary for this article on the Journal blog. © 2023 The Authors. People and Nature published by John Wiley & Sons Ltd on behalf of British Ecological Society.
Domestic gardens constitute important refuges for biodiversity. However, their typical small size mismatches with the larger scales at which species procure resources from urban areas. Consequently, they lack the capacity to enhance biodiversity at these scales. This could be addressed by aggregating garden resources (e.g. vegetation) and increasing garden connectivity. Specifically, this could involve neighbouring householders removing brick walls and fences that segregate gardens and collectively planting vegetation across garden boundaries. Nevertheless, insufficient research has explored 1) how hard surfacing gardens influences native/non-native vegetation presence, which could influence this action’s effectiveness 2) the number of householders willing to undertake such action 3) reasons for unwillingness and how this could be resolved. These research gaps were addressed using an online householder questionnaire distributed weekly to the UK ‘followers’ of four Facebook pages from January to December 2014. From a total of 276 respondents, 220 (84%) had gardens with hard surface and this had a significant negative association with native vegetation presence. Only 7 (3%) presently collectively planted vegetation, but 152 (58%) expressed future willingness. Desires to retain garden control and privacy predominantly underpinned unwillingness. In order to increase the effectiveness and prevalence of collectively planted vegetation, more stringent planning policy is required to restrict hard surfaced gardens. Moreover, desires for garden control and privacy need to be accommodated. This could be principally achieved by 1) communicating that little control would be lost as a result of this action 2) segregating gardens with hedges, which benefit biodiversity and simultaneously provide privacy.
There is a need for better understanding of urban land systems as cities around the world are confronting environmental change. One urban land system that has large implications for biophysical systems, but is especially difficult to manage are private residential neighborhoods. This perspective essay draws together previously disconnected scholarship on housing and land systems to define residential land tenure: the formal and informal rules, rights, and obligations to access, use, and transfer a land parcel by virtue of those assigned to the dwelling it contains. The environmental consequences of residential land tenure are illustrated using the example of compulsory collective governance, a housing tenure arrangement that has become part and parcel with single family detached residential subdivisions across the Anglosphere. Under this regime, land holders forfeit control in exchange for wealth building potential centered on aesthetics. The consequences for the environment are largest where statutory law is weak and pro-environmental action does not align with aesthetics-driven wealth building goals. Broadly, the example illustrates how urban land institutions operating primarily in the social realm can also be understood as de facto land managers in urban contexts.
Native bees are declining in many regions, often associated with loss of natural habitat. Urbanisation replaces natural vegetation with a highly-modified landscape, where residential gardens are a major component of urban greenspace. While many cities retain native vegetation remnants within the urban matrix, these are often small, isolated and degraded. However, there is little empirical evidence on the capacity of residential gardens to provide equivalent or beneficial habitat for native bees, and which local and landscape factors influence bee assemblages. We surveyed bee assemblages in the southwest Australian biodiversity hotspot at seven residential gardens and seven bushland remnants over two years. We recorded 153 species/morphospecies of native bees. Native bees were more abundant in bushland remnants than residential gardens. Abundance of the introduced honeybee Apis mellifera was generally high, and did not differ between habitats. Bushland remnants hosted more species, and rare and unique species, than did residential gardens. Native bee body-size and nesting guilds varied in their response to habitat type. Native bee abundance and richness increased with abundance of native plant species, but decreased with total flower species richness. Native bee species richness was negatively impacted by urbanisation (built space and isolation from bushland reserves). There were no significant relationships between honeybee abundance and local and landscape factors. Our study demonstrates that while residential gardens can host native bees, urban bushland remnants harbour a more comprehensive suite of species and are key for the conservation of native bee populations.
Understanding the drivers of biodiversity in cities is a central goal of urban ecology. There is currently intense scientific and public interest in the factors that influence pollinator diversity in cities and their surroundings. Existing studies point to a variety of landscape and local factors as potentially important, including urbanization (often defined as impervious surface cover in the surrounding lands), tree canopy cover and the diversity and abundance of locally flowering plants. However, few studies have sought to weigh the relative importance of these predictors of bee community metrics. Using a set of 27 residential yards chosen to represent a gradient of both urbanization and tree canopy cover at a landscape scale, we used pan trapping and netting to assess the abundance and diversity of local bee communities across the City of Ottawa, Ontario, Canada. Surprisingly, the landscape factors (urbanization and tree cover) described only a tiny fraction (<1%) of the total variance in bee abundance and diversity across sites. This was true regardless of the scale of analysis at which the landscape factors were measured. Instead, a yard's floral richness, and, to a somewhat lesser extent, its floral abundance, emerged as the most important predictors of a yard's bee community abundance and diversity. Our study offers an important counterpoint to a growing body of work emphasizing the impacts of landscape factors on bee communities. Instead, our research suggests that improving bee floral resources by increasing the plant species richness and abundance locally is a powerful tool to support bee conservation, regardless of the level of urbanization or tree cover in the surrounding landscape. Our work highlights that the practice of promoting ‘bee-friendly’ plantings in private yards, currently being undertaken by a number of non-profits around the world, can play an important role in restoring and maintaining urban pollinator communities.
To effectively manage urban environmental systems, interventions on private lands may sometimes be necessary. This is illustrated in many water districts where water agencies run programs that provide incentives to landholders to change their landscaping to meet the water agency’s management goals. It is difficult to monitor, track, and evaluate landscape change programs on private land, however. To most efficiently do so, very high-resolution, time-series measurements of urban landcover would be useful, but such data is often unavailable. This study evaluates how private urban landscape change is represented in the highest resolution, publicly available, multispectral data product distributed in the United States. The study focuses on residential parcels that participated in a lawn replacement rebate program run by the East Bay Municipal Utility District, a water agency in California. Each parcel has a known quantity of turfgrass converted to drought-tolerant landscaping. The study asks if Normalized Differential Vegetation Index (NDVI) values derived from National Agriculture Imagery Program (NAIP) data can be used to detect participation in a lawn replacement program at the parcel-level. While the NAIP data product has substantial error in a time-series and urban context, this study finds that approaching change detection using a fixed effect panel data model accommodates error, making it possible to identify NDVI change. With control groups defined by matching and weighing with Covariate Balancing Propensity Scores, results indicate that observed browning at the parcel-level can be causally attributed to participating in the lawn replacement program. This ability to detect small, causal changes in a heterogenous environment opens possibilities for monitoring and evaluating programs acting on private urban landscapes, contributing to more effective and efficient design, pricing and implementation.
In the recent years, convolutional neural networks (CNN)-based super resolution (SR) methods are widely used in the field of remote sensing. However, complicated remote sensing images contain abundant high-frequency details, which are difficult to capture and reconstruct effectively. To address this problem, we propose a dense channel attention network (DCAN) to reconstruct high-resolution (HR) remote sensing images. The proposed method learns multi-level feature information and pays more attention to the important and useful regions in order to better reconstruct the final image. Specifically, we construct a dense channel attention mechanism (DCAM), which densely uses the feature maps from the channel attention block via skip connection. This mechanism makes better use of multi-level feature maps which contain abundant high-frequency information. Further, we add a spatial attention block, which makes the network have more flexible discriminative ability. Experimental results demonstrate that the proposed DCAN method outperforms several state-of-the-art methods in both quantitative evaluation and visual quality.
Urban agriculture in home gardens builds resilience, improves health and food security, provides ecological and environmental benefits and connects people back to nature. This research estimated total available productive land and urban agriculture potential of home gardens in ‘general residential’ and ‘low-density residential’ land use zones using a case study of a regional City of Dubbo in Australia. All the plots in six selected categories ranging from 300 m² to 1200 m² were spatially analysed using Census and ortho-imagery data and spatial analysis (GIS and remote sensing) methods. 601–750 m² and 751–900 m² subdivision categories cover nearly 40% of all residential land use zones in the City of Dubbo. Four productive land utilisation scenarios (90%, 75%, 50% and 25%) were modelled to evaluate the extent to which urban agriculture in home gardens could supply the share of resident households' annual dietary energy demand. The high utilisation scenario could support 84.3%, while the lowest utilisation scenario could meet 23.4% of the residents’ annual dietary vegetable demand. The plots in the 751–900 m² category, with the highest productive land cover, could produce up to 1443 metric tons of vegetables annually under the lowest utilisation scenario. The potential of home gardens to grow food depends on plot sizes and configuration, onsite land cover patterns and available productive land, morphologies urban/suburban forms, and related social, cultural and economic factors. Appropriate planning policy support and considering a long term planning horizon, grants and incentives, horticulture training and skill development could immensely help in the uptake of urban agriculture in residential land uses. If productive land in millions of residential gardens put to urban agricultural uses, it could work cumulatively as an alternative local food production network.
Urban Ecology is an increasingly important field as we look to preserve biodiversity and ecosystem services in urban spaces. In this thesis, I review the literature on diversity, abundance and species composition of ants in urban areas and through ant surveys examine questions of ant species richness and composition in the urban landscape. This study examines the effects of various urban matrix features at the habitat, local, and landscape levels on ant species richness and community composition. I surveyed ant richness at both the landscape and local scales by baiting and searching at twenty-seven equidistant sites within Ann Arbor city limits (landscape scale), and thirty sites within six city blocks northeast of Ann Arbor’s urban core (local scale). Ant species richness and ant species community composition were compared to landscape features (site proximity to rivers, parks, or urban core), local features (site proportion of vegetation, streets, or buildings) and habitat features (observed substrate or street direction). Local and landscape features were identified with various tools in ARC Geographic Information Systems Desktop and habitat feature were identified on site. A positive relationship was found between canopy cover and ant species richness. The composition of ant species within a sample site was more highly related to local habitat factors (such as bark or trash) than overall site composition, or proximity to urban or natural features. Furthermore, at the local scale species richness was associated with the nearest street city block. Our data suggest that small local changes in the habitat and block scale in urban landscapes are likely to alter ant species community composition. Specifically, changes in vegetation may increase species richness of ants and mediate the interaction between arboreal species and tramp species in the urban environments.
The study sets out the benefits of the new IKONOS satellite image data for urban planning and for urban information tasks in general. Following a brief delineation of the reference modalities, the quality of the data is assessed and the problems for georeferencing are pointed up. Diverse fields of application of the data in urban planning and administration are then enumerated. Classification of IKONOS satellite data using, respectively, a pixel and a segment-based approach is described. To this end, classifiers arrived at using the ExpertClassifier (ERDAS) and eCognition (Definiens) classification programs are introduced and their respective recognize and classification qualities compared. ExpertClassifier draws on a pixel-based classification strategy which has performance limitations where high-resolution images are concerned but is ideal in implementation terms. In the case of eCognition, pixels of homogeneous areas are collected into segments. Besides the spectral signature, it is also possible to use form, size and neighbourhood and hierarchy relations as means of classifying segments. Such classification properties grow in importance as the image resolution increases.
Airborne laser scanners and multi‐spectral scanners provide information on height and spectra that offer exciting possibilities for extracting features in complicated urban areas. We apply an object‐based approach to building extraction from image data in an approach that differs from conventional per‐pixel approaches. Since image objects are extracted based on the thematic and geometric components of objects, quality assessments will have to be made object‐based with respect to these components. The known per‐pixel‐based methods for assessing quality have been examined in the new situation as well as their limitations. A new framework for carrying out quality assessments by measuring the similarity between the results of feature extraction and reference data is proposed in this paper. The proposed framework consists of both per‐object and per‐pixel measures of quality, thus providing measures pertaining to qualitative and quantitative measurements of object quality from thematic and geometric aspects. The proposed framework and measures of quality have been applied to an assessment of the results of object‐based building extraction using high‐resolution laser data and multi‐spectral data in two test cases. The results show that the per‐object‐based method of assessing quality gives additional information to conventional per‐pixel, attribute‐only assessment methods.
Fragmented developed areas usually support source-sink patches for invasive organisms in urban landscapes. Invasive plants that have a different origin than the spreading source have an important role in artificial landscape restoration in degraded areas. However, many alien plant species have invaded the original habitat or ecosystem of native plants; sequentially their fast growing populations colonize neighboring ecosystems easily. Biological contamination sometimes occurs, unbalancing biodiversity in the natural landscape system. Therefore, long-term monitoring for dynamic communities after restoration in urban areas is indispensable for establishing a strategy for sustainable urban management. Under this principle we have examined the spreading of representative naturalized plant species according to recent land use changes. In this study, we have selected two representative invasive plants, Robinia pseudoacacia and Eupatorium rugosum. Their distribution pattern and patch characteristics of population were identified by the data of Seoul Biotope Map and a field survey. As a result of GIS-aided analysis of landscape patches, these two species often occurred in the same place. Concentration patterns of population distribution were found in forest edges disturbed by development of roads and human settlement. Especially, Eupatorium rugosum had extended to inner forest patches although the individuals were scattered. Distribution patterns of those species were partly related to landscape indices such as patch size and shape of the forest edge.
The main topic of this paper is high-resolution image fusion. The techniques used to merge high spatial resolution panchromatic images with high spectral resolution multispectral images are described. The most commonly used image fusion methods that work on the principle of component substitution (intensity-hue-saturation method (IHS), Brovey transform (BT), and multiplicative method (MULTI)) have been applied to Ikonos, QuickBird, Landsat, and aerial orthophoto images. Visual comparison, histogram analyses, correlation coefficients, and difference images were used in order to analyze the spectral and spatial qualities of the fused images. It was discovered that for preserving spectral characteristics, one needs a high level of similarity between the panchromatic image and the respective multispectral intensity. In order to achieve this, spectral sensitivity of multispectral and panchromatic data was performed, and digital values in individual bands have been modified before fusion. It has also been determined that spatial resolution is best preserved in the event of an unchanged input panchromatic image.
This paper addresses information extraction from IKONOS imagery over the Lukole refugee camp in Tanzania. More specific, it describes automatic image analysis procedures for a rapid and reliable identification of refugee tents as well as their spatial extent. From the identified tents, the number of refugees can be derived and a map of the camp can be generated, which can be used for improving refugee camp management. Four information extraction methods have been tested and compared: supervised classification, unsupervised classification, multi-resolution segmentation and mathematical morphology analysis. The latter two procedures based on object-oriented classifiers perform best with a spatial accuracy above 85% and a statistical accuracy above 97%. These methods could be used for refugee camp information extraction in other geographical settings and on imagery with different spatial and spectral resolutions.
This paper compares different image processing routines to identify suitable remote sensing variables for urban classifi- cation in the Marion County, Indiana, USA, using a Landsat 7 Enhanced Thematic Mapper Plus (ETM� ) image. The ETMmultispectral, panchromatic, and thermal images are used. Incorporation of spectral signature, texture, and surface temperature is examined, as well as data fusion techniques for combining a higher spatial resolution image with lower spatial resolution multispectral images. Results indicate that incorporation of texture from lower spatial resolution images or of a temperature image cannot improve classification accuracies. However, incorporation of textures derived from a higher spatial resolution panchromatic image improves the classification accuracy. In particular, use of data fusion result and texture image yields the best classifi- cation accuracy with an overall accuracy of 78 percent and a kappa index of 0.73 for eleven land use and land cover classes.
Fire suppression associated with decades of cattle grazing can result in bush encroachment in savannas. Textural analyses of historical, high resolution images was used to characterize bush densities across a South African study landscape. A control site, where vegetation was assumed to have changed minim-ally for the duration of the image record (1955-1996), was used to standardize textural values between multidate images. Standardized textural values were then converted to estimates of percent woody canopy cover using a simple linear regression model. Results indicate a 30% relative increase in percent woody cover between 1955 and 1996.
An increasing need exists to update older transportation infrastructure, land use/land cover, environmental impact assessment and road network layer maps. Planning and development rely on accurate data layers for new construction and changes in existing routes. Recent developments in commercial satellite products have resulted in a broader range of high quality image data, enabling detailed analysis. This information differs in its characteristic features (e.g. spatial resolution and geolocational accuracy) as well as utility for particular tasks. Transportation features have historically been difficult to accurately identify and structure into coherent networks; prior analyses have demonstrated problems in locating smaller features. Roadways in urban environments are often partly obscured by proximity to land cover or impervious objects. Recent research has focused on object-based methods for classification and different segmentation techniques key to this approach. Software packages such as eCognition have shown encouraging results in assessing spatial and spectral patterns at varied scales in intelligent classification of aerial and satellite imagery. In this study we examine 2.44m QuickBird and 4m Ikonos multispectral imagery for a 7.5' quad (Dead Tiger Creek) near the Mississippi Gulf Coast. Both spectral and object-based approaches are implemented for pre-classification, after which road features are extracted using various techniques. Results are compared based on a raster completeness model developed. Challenges include intricate networks of smaller roads in residential zones and regions of tall/dense tree cover. Observations for these sites will assist in developing a larger-scale analysis plan for the CSX railroad corridor relocation project.
As part of a larger survey of biodiversity in private gardens in Sheffield, UK, we examined the composition and diversity of the soil seed banks in each of 56 gardens. Six soil cores from each garden revealed 2759 seedlings of 119 taxa, although the real species richness is likely to be much higher than this. By far the most abundant species were weedy natives, while the most common alien was Buddleja davidii. Seeds of perennial herbs were more abundant than hundreds of all other life forms combined. More frequent species were also more abundant, but the relationship was weak. Numbers of species in the seed bank and in the garden flora were positively but very weakly related. Seeds were quite evenly distributed between 0 –5 cm and 5 –10 cm soil layers, and most seeds were of species known to have persistent seed banks. Seeds of some species were largely confined to gardens in which the plant was growing, but others were not.
The urbanization of agricultural lands is currently one of the dominant pat-terns of land use change in developed countries. In the United States and parts of Europe, this has led to the implementation of agricultural land preservation programs and riparian protection and replanting efforts along urban streams. The ecological benefits of such programs for the conservation of freshwater biodiversity have yet to be fully explored. We designed a study to investigate the patterns of stream macroinvertebrate community structure along a gradient of agriculture to urban development, and the patterns among urban streams that vary in the amount of intact riparian buffer. In 2001 and 2002, we sampled the 29 small headwater streams comprising the outlying tributaries of four watersheds just north of Washington, D.C., in Montgomery County, Maryland, USA. This region has had dramatic urban development over the last 50 years, yet significant efforts have been made to maintain riparian buffers and promote preservation of agricultural land. Macroinvertebrate richness was strongly related to land use, with agricultural streams exhibiting the highest macroinvertebrate diversity. Taxa richness was related negatively and linearly (no statistical threshold) to the amount of impervious surface cover. For the urban streams, there was a strong positive relationship between invertebrate diversity and riparian forest cover. Urban streams with high amounts of intact riparian forest exhibited biodiversity levels more comparable to less urban areas despite high amounts of impervious cover in their catchments. The agricultural headwater streams in this study were not only more diverse than the urban headwaters, but their levels of macroinvertebrate diversity were high compared to other published estimates for agricultural streams. These higher richness values may be due to widespread use of ''best management practices'' (BMPs), including no-till farming and the implementation of woody and herbaceous riparian buffers, which may alleviate many acute stressors caused by cultivation. These findings suggest that, if managed properly, the preservation of agricultural land from development may help conserve stream invertebrate biodiversity, and that maintenance of riparian forests even in highly urbanized watersheds may help alleviate ecological disturbances that might otherwise limit macroinvertebrate survival.
The extent and continued expansion of urbanisation has focused attention on the significance for native biodiversity of those green spaces remaining within such areas and the most appropriate methods of managing them. In the UK, a high proportion of urban space is comprised of the private or domestic gardens associated with residential dwellings, and many recommendations have been made for simple changes to improve their value for biodiversity (wildlife gardening). Here, we report the results of replicated experimental tests of five such common recommendations, involving the introduction to gardens of (i) artificial nest sites for solitary bees and wasps; (ii) artificial nest sites for bumblebees; (iii) small ponds; (iv) dead wood for fungi and other saproxylic organisms; and (v) patches of nettles Urtica dioica L. for butterfly larvae. The broad conclusion is that whilst some methods for increasing the biodiversity of garden environments may be very effective, others have a low probability of success on the timescales and spatial scales likely to be acceptable to many garden owners. If one of the functions of small scale biodiversity enhancement is to develop and encourage awareness of biodiversity and its conservation, then encouragement to conduct particular activities must be balanced with a realistic appraisal of their likely success.
Domestic (‘private’) gardens constitute a substantial proportion of ‘green space’ in urban areas and hence are of potential
significance for the maintenance of biodiversity in such areas. However, the size and nature of this resource and its associated
features are poorly known. In this study, we provide the first detailed audit, using domestic gardens in the city of Sheffield
as a model study system. Domestic gardens, the mean area of which was 151m2, cover approximately 33km2 or 23% of the predominantly urban area of the city. The smaller gardens contribute disproportionately to this total because,
although individually they add little, they are large in number. Conversely, the regions of the city with proportionately
more garden area contribute most to the total garden area of the city, although such regions are limited in number. Based
on the findings of a telephone based survey, 14.4% of dwellings with gardens were estimated to have ponds, 26% to have nest-boxes,
29% to have compost heaps, 48% to hold trees more than 3m tall, and 14% of dwellings were estimated to be home to one or
more cats. Whilst the absolute frequency of these features is low to moderate, by extrapolation they nonetheless yield estimates
for domestic gardens in Sheffield of a total of 25,200 ponds, 45,500 nest boxes, 50,750 compost heaps, 360,000 trees, and
a population of 52,000 domestic cats. These results are considered in the context of the role of gardens in urban areas as
habitats for wildlife and the implications for housing policy.
Shrub encroachment into arid and semi-arid grasslands in the southwestern United States is of concern because increased shrub cover leads to declines in species diversity, water availability, grazing capacity, and soil organic matter. Although it is well known that shrubs have increased over time, we have little quantitative information related to the non-linear nature of this vegetation change over a particular period. On the Jornada Experimental Range (JER; USDA-ARS) and the adjacent Chihuahuan Desert Rangeland Research Center (CDRRC; New Mexico State University) in southern New Mexico, shrub increase has been measured with various ground survey techniques extending back to 1858. For this study, we used 11 aerial photos taken between 1937 and 1996 that covered a 150-ha study area and had sufficient resolution for shrub detection. A QuickBird satellite image provided coverage for 2003. We used image segmentation and object-based classification to monitor vegetation changes over time. Shrub cover increased from 0.9% in 1937 to 13.1% in 2003, while grass cover declined from 18.5% to 1.9%. Vegetation dynamics reflected changes in precipitation patterns, in particular, effects of the 1951–1956 drought. Accuracy assessment showed that shrub and grass cover was underestimated due to the constraint of the pixel size. About 87% of all shrubs >2 m2 were detected. The use of object-based classification has advantages over pixel based classification for the extraction of shrubs from panchromatic aerial and high-resolution satellite imagery. Incorporating both spectral and spatial image information approximates the way humans interpret information visually from aerial photos, but has the benefit of an automated classification routine. Combining several scales of analysis in a hierarchical segmentation method is appropriate in an ecological sense and allows for determining shrub density in coarser level classes. Despite encountering difficulties in analyzing a greatly varying aerial photo data set, including variability in spectral and spatial resolutions, moisture conditions, time of year of observation, and appearance of grass cover, aerial photos provide an invaluable historic record for monitoring shrub encroachment into a desert grassland.
Domestic (ȁ8privateȁ9) gardens constitute a substantial proportion of ȁ8green spaceȁ9 in urban areas and hence are of potential significance for the maintenance of biodiversity in such areas. However, the size and nature of this resource and its associated features are poorly known. In this study, we provide the first detailed audit, using domestic gardens in the city of Sheffield as a model study system. Domestic gardens, the mean area of which was 151 m2, cover approximately 33 km2 or 23% of the predominantly urban area of the city. The smaller gardens contribute disproportionately to this total because, although individually they add little, they are large in number. Conversely, the regions of the city with proportionately more garden area contribute most to the total garden area of the city, although such regions are limited in number. Based on the findings of a telephone based survey, 14.4% of dwellings with gardens were estimated to have ponds, 26% to have nest-boxes, 29% to have compost heaps, 48% to hold trees more than 3 m tall, and 14% of dwellings were estimated to be home to one or more cats. Whilst the absolute frequency of these features is low to moderate, by extrapolation they nonetheless yield estimates for domestic gardens in Sheffield of a total of 25,200 ponds, 45,500 nest boxes, 50,750 compost heaps, 360,000 trees, and a population of 52,000 domestic cats. These results are considered in the context of the role of gardens in urban areas as habitats for wildlife and the implications for housing policy.
Using high resolution imagery such as IKONOS data should make it possible to detect man-made-features such as buildings and roads more easily than with conventional satellite image data. However, due to the higher spatial resolution of IKONOS data, an automatic or semi-automatic detection of such features based only on their spectral characteristics can become difficult, especially in heterogeneous areas such as dense urban areas (see Bauer, T. & Steinnocher, K. in this issue). A typical problem in urban remote sensing is the handling of shadows. Using a DEM and additional semantic information can help to detect such cases and to manage them adequately. Furthermore, when using an additional DEM, significant elevation information of questionable objects can be used to identify their shape. As eCognition is able to use an arbitrary number of channels for the image segmentation and classification, the DEM was used for the initial segmentation and for the subsequent object classification. Thereby, the influence of the DEM on the object generation can be controlled by adjusting the channels' weights. Based upon the underlying concepts of eCognition to generate and classify image objects, different strategies have been developed.
Cities and Natural Process is a book for all concerned with the future of our cities, their design and sustainability, and our quality of life within them. Michael Hough describes how economic and technological values have squeezed any real sense of nature out of the modern city, the ways in which this has led to a divisive separation of countryside and city, wasted much of the city's resources, and shaped an urban aesthetic which is sharply at odds with both natural and social processes. Against this is set an alternative history of ecological values informing proven approaches to urban design which work with nature in the city.
Region-based approaches are suitable for the analysis of high-resolution remotely sensed data. In this context, special emphasis has to be laid on the segmentation of multi-sensoral and multi-scale input data with respect to the geometrical and semantical robustness of the achieved results, but also on the grade of automatization and transparency of the algorithms.
Remote sensing data relative to vegetation canopies can only be interpreted if the mechanisms of interaction of electromagnetic radiation with plants and the underlying soil are known. The optical properties of vegetation canopies are not static. They not only vary with time as a function of plant status but also as a function of external (solar elevation, orientation and inclination of the view axis, atmospheric conditions ...) and internal factors (soil colour, row orientation, canopy geometry). -from Author
Temporal and spatial resolution requirements for extracting urban/suburban infrastructure and socio-economic attributes from remote sensor data are presented. The goal is to relate the user information requirements with the current and proposed remote sensing systems to determine if there are substantive gaps in capability. Several remote sensing systems currently provide some of the desired urban/suburban infrastructure and socio-economic information when the required spatial resolution is poorer than 4 by 4 m and the temporal resolution is between 1 and 55 days (e.g., Landsat MSS and Thematic Mapper, SPOT1-4, Bussian TK-350, BADABSAT, Indian IRS-1CD, NOAA A VHBB, GOES, Meteosat). Current high spatial resolution sensor systems such as the Russian SPIN-2 KVR-1000 (2- by 2-m panchromatic; when in orbit) and proposed sensor systems (EOSAT Space Imaging IKONOS 1- by 1-m panchromatic; Earth Watch Quickbird 0.82 by 0.82 m; OrbView-3 1 by 1 m) may provide additional capability. Large-scale metric aerial photography or digital camera imagery with spatial resolutions ranging from ≤ 0.25 to 1 m will still be required to satisfy several important urban/suburban information requirements.
As part of a larger survey of biodiversity in gardens in Sheffield, UK, we examined the composition and diversity of the flora in two 1‐m2 quadrats in each of 60 gardens, and compared this with floristic data from semi‐natural habitats in central England and derelict urban land in Birmingham, UK. Garden quadrats contained more than twice as many taxa as those from any other habitat type. Ca. 33 % of garden plants were natives and 67 % aliens, mainly from Europe and Asia. A higher proportion of garden aliens originated from Asia and New Zealand than in the UK alien flora as a whole; 18 of the 20 most frequent plants in garden quadrats were natives, mostly common weeds. Garden quadrats showed no evidence of ‘nestedness’, i.e. a tendency for scarce species to be confined to the highest diversity quadrats. Conversely, species in all semi‐natural and derelict land data sets were significantly nested. Compared to a range of semi‐natural habitats, species richness of garden quadrats was intermediate, and strikingly similar to the richness of derelict land quadrats. Although species accumulation curves for all other habitats showed signs of saturation at 120 quadrats, gardens did not. Correlations between Sørensen similarity index and physical distance were insignificant for all habitat types, i.e. there was little evidence that physical distance played any part in structuring the composition of the quadrats in any of the data sets. However, garden quadrats were much less similar to each other than quadrats from semi‐natural habitats or derelict land.
The present study explains a quick method for the assessment of the importance of open spaces in towns as habitat for plants and animals; the assessment criteria include the period of development, area, rarity and variety of habitat conditions.
As part of a larger survey of biodiversity in gardens in Sheffield, UK, we examined the composition and diversity of the flora in two 1-m 2 quadrats in each of 60 gardens, and compared this with floristic data from semi-natural habitats in central England and derelict urban land in Birmingham, UK. Garden quadrats contained more than twice as many taxa as those from any other habitat type. Ca. 33 % of garden plants were natives and 67 % aliens, mainly from Europe and Asia. A higher proportion of garden aliens originated from Asia and New Zealand than in the UK alien flora as a whole; 18 of the 20 most frequent plants in garden quadrats were natives, mostly common weeds. Garden quadrats showed no evidence of 'nestedness', i.e. a tendency for scarce species to be confined to the highest diversity quadrats. Conversely, species in all semi-natural and derelict land data sets were significantly nested. Compared to a range of semi-natural habitats, species richness of garden quadrats was intermediate, and strikingly similar to the richness of derelict land quadrats. Although species accumulation curves for all other habitats showed signs of saturation at 120 quadrats, gardens did not. Correlations between Sørensen similarity index and physical distance were insignificant for all habitat types, i.e. there was little evidence that physical distance played any part in structuring the composition of the quadrats in any of the data sets. However, garden quadrats were much less similar to each other than quadrats from semi-natural habitats or derelict land.
Historical background, fundamental concepts, statistical considerations and a case study emphasize the need for absolute precision in applying remotely sensed data. This book is a complete guide to assessing the accuracy of maps generated from remotely sensed data.
This book provides an overview of the structure and function of urban ecosystems as well as a summary of existing information on specific urban habitats. The introduction and first four chapters of the book review characteristics of urban flora and fauna, urban climate and air pollution, soils and vegetation dynamics. The remaining 11 chapters cover the ecology and management of specific urban habitat types, with case studies included.
Planners in urban areas face a dilemma when deciding the future of sites with both conservation and development value. This paper examines the development of a simple geographic information system in Leeds, England, to enable planners to record and assess the ecological value of sites proposed for development. It goes on to explore the potential for developing similar local level data bases for use in the New Zealand urban context.
The analysis of landscape pattern through remote sensing data is relatively widespread in landscape ecology and landscape planning. However, the lack of comparability of results between different image‐processing methods and across spatial resolutions limits the potential usefulness of landscape pattern indices. In this study, 96 sampling plots in Switzerland were investigated covering land‐use intensities ranging from old‐growth forest to intensive agricultural landscapes. The sampling plots were captured using fused Landsat ETM–IRS, Quickbird and aerial photograph data. In order to quantify landscape patterns, seven patch indices (derived by object‐oriented classification) and six grey‐value indices were extracted from the sampling plots. Principal component analysis was applied to the datasets, with the amount of variance in the first four axes compared among the sampling plots. Biplots of indices and sampling plots derived from all datasets were investigated with respect to land‐use intensity patterns. PCA results indicated that increasing spatial resolution corresponded to a slight increase in explained variance. Moreover, image grey‐values explained more variance between the sampling plots than segmented patch indices. Furthermore, biplots of grey‐value indices were capable of grouping sampling plots according to the land‐use intensity gradient, while segmented patch indices failed to adequately represent these.
There are a number of challenges in applying high-spatial resolution satellite image data for analysis of larger urban areas. This paper explores the use of object-oriented image analysis approaches in mapping urban land cover and land use. The study is based on seven IKONOS images covering the Santa Barbara, CA region. Image processing included geometric and atmospheric correction and image segmentation and classification using spectral and spatial information to separate 9 land cover classes 79 % overall accuracy was achieved with this approach. Specific problems are identified due the spectral and spatial complexity of urban areas, causing confusion between different roof types, roads and bare soil and NPV. Further analysis and refinement of the land cover mapping product (in particular buildings) applied two spatial metrics urban land use and socioeconomic information. The results show the importance, capabilities and challenges of object-oriented approaches in providing detailed and accurate information about the physical structure of urban areas and their relationship to urban land use and socioeconomic characteristics that should be further investigated in related studies.
1Wild birds are commonly observed in private residential gardens in Great Britain. However, little is known about how their use of this significant and increasingly important habitat is changing and how such changes relate to their population status.2Trends in the use of private residential gardens by wild birds in Great Britain were investigated using weekly bird records from 18 300 gardens over 8 years.3We showed that the use of this habitat is seasonal and cyclic, with the timing and regularity of its periodicity variable between species.4We evaluated the significance of the underlying trends in the cyclic reporting rates. Eighteen species showed clear trends, the three with the most negative year term parameter estimates being ‘red-listed’ as high conservation concern.5Examining correlations with national scale survey data suggested that garden reporting rates are related to general population trends in a number of species, including several of conservation importance. Other species exhibit important differences between national and garden trends.6Synthesis and applications. Our analysis demonstrates ecologically meaningful trends and provides novel insights into seasonal cycles of habitat exploitation, using relatively simple and cost-effectively collected data. This will lead to greater understanding of the relationships between gardens and general bird populations and of the times of year at which garden habitats are most important for birds. We have demonstrated the practicality and productivity of ‘citizen science’ in this context, and provided new information on the status of some birds of conservation concern.
Abstract The absence of small birds from many suburban areas may be due to adverse garden characteristics, interspecific aggression or human behaviour such as supplementary food provisioning that encourages predators. We investigated the relationship between these factors and the presence of seven small bird species in Sydney through a community-based survey. The survey was conducted by participants over a 7-day period between 7 am and 10 am in November and early December 2000. Three dominant species, the noisy miner (Manorina melanocephala), pied currawong (Strepera graculina) and common myna (Acridotheres tristis) were each present in over 59% of gardens. Each small bird species was present in less than 40% of gardens. All small birds were negatively associated with noisy miners, but only the silvereye (Zosterops lateralis) was negatively associated with pied currawongs. None of the species of small birds was negatively associated with common mynas. Four species of small birds were associated with at least one habitat variable, notably the proportion of native vegetation. Although more birds were recorded in gardens in which meat was provided, there were significantly fewer small birds in these gardens. There were also more birds recorded in gardens where seed was provided, with red-browed finches (Neochmia temporalis) positively associated with seed provisioning in most regions of Sydney. The presence of dogs and cats was not related to the total abundance of birds overall or small birds in gardens. While garden characteristics may influence the presence of small birds to some degree, the presence of noisy miners, a species that are thought to aggressively exclude other species from their territories, is likely to be an important influence on these species in suburban areas. Furthermore, supplementary feeding by people is likely to negatively influence some small birds. The presence of carnivorous pets does not seem to influence the presence of small birds at the scale of the individual garden.
Connectivity has been an accepted goal in ecological restoration of wilderness areas for some time, but it is a relatively new approach in urban areas. The connectivity analysis presented here explores the numbers and patterns of corridors required to connect urban green spaces as part of an overall biodiversity conservation strategy. Green spaces in this study were weighted based on size and a habitat requirement of 0.5 ha for a hypothetical indicator species. Thirteen potential networks were evaluated using Gamma, Beta, and Cost Ratio indices. The study zone contained 54 green spaces (habitat nodes) with a combined area of 636.5 ha in a total urban area of approximately 2,600 ha. Several models (Travelling Salesman, Paul Revere, and Least Cost to User) were used to evaluate possible connections. These results indicated that at least 325 linkages are necessary to connect half of the nodes. Such large numbers of linkages are only feasible by enhancing the matrix of backyard habitat, planted boulevards, and utility rights-of way found in a city. Strengthening such networks should work well to support the biota protected in urban parks and wildlife refuges and the seasonal migrants that sometimes depend on urban habitats for their survival.
Question: How do lawn floras compare with those of semi-natural grasslands? Are the compositions of lawn floras determined by local, within-garden factors (e.g. lawn management and size) or by regional factors (e.g. climate and location)? Are lawn floras nested (like semi-natural grasslands) or not (like cultivated parts of gardens)? Are there gradients of species composition within lawns?
Location: Sheffield, UK.
Methods: We examined the composition of the floras of entire lawns and of two 1-m2 lawn quadrats in 52 gardens.
Results: A total of 159 species of vascular plants was recorded, 60 of them only once. Most lawn species were forbs, but most lawn cover consisted of grasses. Lawn species were predominantly natives. Bigger lawns had more species, but richness was not closely linked to other environmental or management variables. Composition of lawn floras varied with altitude, with woodland and wetland plants more common in the higher west of the city, and weeds of waste ground in the east. The species-area curve derived from 1-m2 lawn quadrats was very similar to that of semi-natural grasslands. Lawn quadrats were significantly nested, with rarer species mostly confined to more species-rich quadrats. Trampling-tolerant Poa annua was more abundant in the part of the lawn nearer the house.
Conclusions: In most respects, lawns behaved much more like semi-natural grasslands than like cultivated flower beds and borders. Species composition of lawns is strongly influenced by local climate. Most lawns show an internal gradient of composition, linked to a gradient of intensity of use.