**3. Landscape ecology and landscape planning**

conservation efforts [45]. In conjunction with the increased concerns for the nature and biodiversity, sustainability has become a central issue in urban areas, as a response to the growing concern for the quality of the natural environment as well as the social and econom‐

The concept of sustainable development is formally defined for the first time in the Brun‐ dtland Report (Our Common Future) as "development that meets the needs of the present without compromising the ability of future generations to meet their own needs" [48]. The concept of sustainable development seeks to achieve a dynamic and long-term balance between socioeconomic (e.g., well-being and equity of people) and environmental systems (e.g., protection and maintenance of the nature and biodiversity) [49]. As suggested by Selman [10], the landscape itself provides an arena in which this balance might be provided

With regard to sustainability in landscapes, it is claimed that a generally accepted definition of landscape sustainability is lacking or it is generally defined in different contexts [49, 50]. While some researchers used the Brundtland Report as the source of definition with an emphasis on the maintenance of ecological integrity and basic human needs [27, 51], some highlighted the importance of natural capital and ecosystem services [52, 53], while others considered the localisation and self-regenerative capacity as the essential property of sustain‐ ability in landscapes [54]. However, in broad terms, landscape sustainability is defined as "the capacity of a landscape to consistently provide long-term, landscape-specific ecosystem services essential for maintaining and improving human wellbeing in a regional context and

As with the three pillars of sustainability (environment, society and economy), landscape sustainability has been described on the basis of a variety of dimensions. Selman [50] draws attention to the five dimensions of landscape sustainability – i.e., environmental, economic, social, political and aesthetic sustainability. Likewise, Musacchio [55] describes six dimen‐ sions of landscape sustainability: environment, economy, equity, aesthetics, experience and

Selman [20] claims that environmental sustainability stems from landscape ecology as a response to the fragmentation of landscapes with an emphasis on the importance of land‐ scape multi-functionality, ecosystem services and/or resilience. First of all, a sustainable landscape should maintain and improve landscape connectivity to facilitate species' life cycles as well as sustaining healthy and viable populations through a biodiverse network of habitats [50, 55, 56]. It should also be able to support other functions, provide a variety of ecosystem services to people, biodiversity and nature, besides its ability to achieve a state of relative stability [50, 57]. Another dimension of a sustainable landscape, the economic sustainability, draws attention to the importance of a "virtuous circle" in which the endoge‐ nous economic vitality of a local landscape maintains and supports environmental produc‐ tion practices (i.e., tourism, recreation, and the production of food and timber) as well as promoting landscape quality and the quality of life [10, 55, 58]. The social sustainability of a landscape, on the other hand, refers to opportunities for public participation in decisionmaking processes, inclusivity and equity in access, equal right to benefit from the use of

ic life in the early nineteenth century [46, 47].

despite environmental and sociocultural changes" [49].

and maintained.

294 Sustainable Urbanization

ethics.

While a variety of definitions of landscape ecology have been proposed, one of the first people to use landscape ecology was Carl Troll [59], who integrated the different concepts of geography and ecology into a new inter-disciplinary research area [60, 61]. Defined as "the study of structure, function and change in a heterogeneous land area composed of interact‐ ing ecosystems" [62, 63], landscape ecology encompasses three main characteristics of landscapes: structure, function and change.

Landscape structure is the mosaic of different geographical units (ecosystems, etc.) and is characterised by the amount and occurrence of different units (composition) as well as their spatial distribution and arrangement in the landscape (configuration) [64–68]. Landscape function refers to the interaction between spatial components of landscapes (flow of matter, energy and organisms) and landscape change expresses alterations in the structure and functions of a landscape over time [27, 62, 69]. These three characteristics of landscapes are closely associated with each other and their relationships constitute the past, current and future landscapes [64, 70, 71].

Landscape ecology not only helps researchers to investigate the spatial structure and func‐ tions of changing landscapes, but it also can help to identify the origin of changes and the interactions between spatial structure, function and change of a landscape in order to find the most appropriate options for decision making [62, 63, 72–75]. Hence, it is clear that the science of landscape ecology provides valuable insights into how short and long term landscape planning processes can improve the quality of life and achieve sustainability in urban environments [74, 76].

According to a definition provided by the Landscape Institute [77], landscape planning is "the development and application of strategies, policies and plans to create successful environments, in both urban and rural settings, for the benefit of current and future genera‐ tions". This definition refers to a formal process of decision making and technical/spatial planning activity built upon the assessment of physical, natural and cultural resources, where the main concern is the enhancement, restoration and/or creation of landscapes [10, 38, 78].

As mentioned earlier, urbanisation has been regarded as one of the main drivers of the change in landscape structure and function. As being one of the fundamental functions of a land‐ scape, connectivity enables the movement of organisms through landscapes as well as sustaining other functional processes in a landscape [10]. Therefore, the crucial role of landscape connectivity for the conservation of nature and biodiversity has been emphasised by researchers to reduce the adverse effects of urbanisation, in particular the fragmentation and isolation of habitats [4, 32, 34, 69, 79, 80].

While planning is regarded as a key tool to deliver sustainable development [10], the need for multi-disciplinary and more integrated approaches to nature conservation and landscape planning has been highlighted [6]. Within this context, in order to mitigate the effects of fragmentation and to conserve nature and biodiversity in urban areas, different spatial planning approaches and strategies have been integrated into landscape planning and ecology, i.e., habitat creation or preservation that produces more connected patches or networks [7, 23, 26].

The growing recognition of connected systems was reflected in planning strategies such as greenbelts and linked park systems since the early nineteenth century. Thereafter a variety of approaches have been developed throughout the world with regard to the connected systems of green spaces in urban areas (i.e., ecological/green networks) [1, 2, 6, 38, 81, 82].

Even though each of these network approaches shares a great deal of common ground in terms of their main idea and structural properties, they typically differ from each other in their intended aims and functions that the networks will deliver [6]. While there has been a consensus on the main benefits of different network approaches for nature, biodiversity and people [4, 5, 83–85], there is a degree of uncertainty around the terminology on these ap‐ proaches [3]. In this regard, it is necessary to clarify exactly what is meant by different network concepts and approaches in the literature. The next section therefore looks at the definition, the underlying rationale and the development of different networks being planned and managed in urban areas.

#### **3.1. Linked park systems, green belts and greenways**

The idea of greenways originates in the concept of parkways, the linear system of green and open spaces in urban areas, which was first developed by Frederick Law Olmsted in the nineteenth century [6, 86, 87]. Frederick Law Olmsted, the founder of the profession of landscape architecture in the USA, proposed two important plans for Brooklyn and Boston in order to connect urban parks and the surrounding areas as linear park systems. With a width between 65 and 150 m, these parkways aimed to deliver aesthetic and recreational functions for the benefit and use of people [6, 88, 89].

As the first greenway approach in the USA, the Boston Park System – or in other words the "Emerald Necklace" – was an attempt to integrate urban and suburban areas to increase the functioning of these areas [89–91]. On the other hand, in the same period in the UK, the concept of the "green belt" was first introduced by Ebenezer Howard, in his book *Garden Cities of To-Morrow* [92, 93]. Howard [94] claimed that if green and open spaces were located in close proximity to residential areas, they would contribute significantly to the physical and mental health of residents as well as their well-being.

As mentioned earlier, urbanisation has been regarded as one of the main drivers of the change in landscape structure and function. As being one of the fundamental functions of a land‐ scape, connectivity enables the movement of organisms through landscapes as well as sustaining other functional processes in a landscape [10]. Therefore, the crucial role of landscape connectivity for the conservation of nature and biodiversity has been emphasised by researchers to reduce the adverse effects of urbanisation, in particular the fragmentation

While planning is regarded as a key tool to deliver sustainable development [10], the need for multi-disciplinary and more integrated approaches to nature conservation and landscape planning has been highlighted [6]. Within this context, in order to mitigate the effects of fragmentation and to conserve nature and biodiversity in urban areas, different spatial planning approaches and strategies have been integrated into landscape planning and ecology, i.e., habitat creation or preservation that produces more connected patches or networks [7, 23,

The growing recognition of connected systems was reflected in planning strategies such as greenbelts and linked park systems since the early nineteenth century. Thereafter a variety of approaches have been developed throughout the world with regard to the connected systems

Even though each of these network approaches shares a great deal of common ground in terms of their main idea and structural properties, they typically differ from each other in their intended aims and functions that the networks will deliver [6]. While there has been a consensus on the main benefits of different network approaches for nature, biodiversity and people [4, 5, 83–85], there is a degree of uncertainty around the terminology on these ap‐ proaches [3]. In this regard, it is necessary to clarify exactly what is meant by different network concepts and approaches in the literature. The next section therefore looks at the definition, the underlying rationale and the development of different networks being planned and

The idea of greenways originates in the concept of parkways, the linear system of green and open spaces in urban areas, which was first developed by Frederick Law Olmsted in the nineteenth century [6, 86, 87]. Frederick Law Olmsted, the founder of the profession of landscape architecture in the USA, proposed two important plans for Brooklyn and Boston in order to connect urban parks and the surrounding areas as linear park systems. With a width between 65 and 150 m, these parkways aimed to deliver aesthetic and recreational functions

As the first greenway approach in the USA, the Boston Park System – or in other words the "Emerald Necklace" – was an attempt to integrate urban and suburban areas to increase the functioning of these areas [89–91]. On the other hand, in the same period in the UK, the concept of the "green belt" was first introduced by Ebenezer Howard, in his book *Garden Cities of To-Morrow* [92, 93]. Howard [94] claimed that if green and open spaces were located in close

of green spaces in urban areas (i.e., ecological/green networks) [1, 2, 6, 38, 81, 82].

and isolation of habitats [4, 32, 34, 69, 79, 80].

26].

296 Sustainable Urbanization

managed in urban areas.

**3.1. Linked park systems, green belts and greenways**

for the benefit and use of people [6, 88, 89].

The underlying idea of green belts was separating urban and rural environments from each other by designating some of the land around the inner cities as green to regulate urban sprawl and protect the countryside beyond the urban areas [6, 10, 93]. The fundamental difference between the traditional linked park systems and green belts is in their main functions. While the concept of parkways is built upon green corridors from and to the urban parks which are surrounded by trees (linking function), the concept of green belts is largely based on the idea of controlling urban growth by separating urban and rural areas with a buffer of undevel‐ oped land (separating function) [6, 92]. Conversely, according to Kühn [95], in the future, green belts might behave as complementary zones between different urban areas by linking them in a polycentric city region [95]. Within this framework, being located in the urban fringe, green belts have the potential of providing a multifunctional and dynamic environment where there is a wide variety of low-density economic activities and a diversity of wildlife [96, 97].

At that time, the town planner Patrick Abercrombie developed another pioneering approach to planning and implementing a park system for Sheffield: the Sheffield Civic Survey and Development Plan. In this comprehensive city plan, Abercrombie [98] proposed a park system where all the individual open spaces (e.g., existing and new parks, playgrounds, accessible moorlands and waterwork properties) were linked to each other with tree-planted avenues.

According to Abercrombie [98], the success of a systematic provision of open spaces in urban areas is dependent on the area, use and distribution of open spaces. Accordingly, the follow‐ ing planning principles underpinned the Abercrombie's city plan:


The underlying principle employed in Abercrombie's plan represented an emerging theoret‐ ical basis for the linked park systems, where it was suggested that all the green and open spaces should be located close to the centres of population it serves. Additionally, Winkler [99] claims that this strategic plan, grounded on an in-depth analysis process, has a crucial role in the development of Sheffield. Perhaps most importantly, Abercrombie's plan revealed the actual structure of Sheffield at that time, offering a complete framework for green and open spaces throughout the city and towards the Peak District National Park as well as making clear connections between green and open spaces and the centres of population [99].

Following these pioneering planning strategies, the concept of greenways has become a common landscape planning approach all over the world. Little [100] defined a greenway as the following:


Additionally, according to a definition provided by Ahern [3], greenways are the "networks of land that are planned, designed and managed for multiple purposes including ecological, recreational, cultural, aesthetic, or other purposes compatible with the concept of sustaina‐ ble land use". Thereafter, a further definition is given by Ahern [38] who describes green‐ ways as "the connected systems of protected lands that are managed for multiple uses including: nature protection, recreation, agriculture, and cultural landscape protection".

As shown in the abovementioned definitions, the focus of greenways has been moved from a single purpose planning approach to a multifunctional network approach, which is intend‐ ed to assist key ecological functions as well as supporting public enjoyment and movement in urban environments [101]. In this regard, Ahern [91] claimed that the term greenway is a generic description of various strategic landscape planning approaches and plans which embodies a multitude of concepts with the main aim of ensuring multifunctionality in urban areas.

#### **3.2. Ecological networks**

Historically, the term "ecological" was inserted into the network approaches in the Nether‐ lands with the ecological infrastructure concept [102]. As with greenways, the concept of ecological networks has been an attempt to integrate landscape ecology into landscape planning in order to protect nature and biodiversity, manage natural resources, and also to connect people with nature conservation [6]. Even though these terms have been used interchangeably, as pointed out by Ahern [91, 103], the term ecological networks is more common in Europe, whereas the term greenways is more common in the USA. Also, while greenways initially aimed to provide access to people between urban and rural green and open spaces in the USA, ecological networks in Europe stemmed from the need to conserve species and habitats [6].

Similar to greenways, a variety of definitions have been suggested for ecological networks in the literature. Bennett [104] defined ecological networks as "the coherent systems of natural or semi-natural landscape elements configured and managed with the objective of maintain‐ ing or restoring ecological functions as a means of conserving biodiversity, besides provid‐ ing appropriate opportunities for the sustainable use of natural resources". According to a definition provided by Jongman and Pungetti [6], ecological networks are "the systems of nature reserves and their interconnections that make a fragmented natural system coherent, so as to support more biological diversity than in its non-connected form".

Although differences of definitions exist, there appears to be some agreement that the concept of ecological networks is founded on the conservation of natural areas and biodiversity as well as the enhancement of the functioning of ecosystems [2, 105, 106]. In addition to these, Ignatieva et al. [107] claim that urban ecological networks are one of the most effective tools for providing physical, visual and ecological connectivity between urban areas and surrounding natural areas. Hence, the development and the integration of ecological networks into the planning system have been regarded as the spatial expression of the idea of landscape connectivity in planning activities [6].

**•** "A linear open space established along either a natural corridor, such as a riverfront, stream valley, or ridgeline, or overland along a railroad right-of way converted to recreational use,

**•** An open-space connector linking parks, nature reserves, cultural features, or historic sites

Additionally, according to a definition provided by Ahern [3], greenways are the "networks of land that are planned, designed and managed for multiple purposes including ecological, recreational, cultural, aesthetic, or other purposes compatible with the concept of sustaina‐ ble land use". Thereafter, a further definition is given by Ahern [38] who describes green‐ ways as "the connected systems of protected lands that are managed for multiple uses including: nature protection, recreation, agriculture, and cultural landscape protection".

As shown in the abovementioned definitions, the focus of greenways has been moved from a single purpose planning approach to a multifunctional network approach, which is intend‐ ed to assist key ecological functions as well as supporting public enjoyment and movement in urban environments [101]. In this regard, Ahern [91] claimed that the term greenway is a generic description of various strategic landscape planning approaches and plans which embodies a multitude of concepts with the main aim of ensuring multifunctionality in urban

Historically, the term "ecological" was inserted into the network approaches in the Nether‐ lands with the ecological infrastructure concept [102]. As with greenways, the concept of ecological networks has been an attempt to integrate landscape ecology into landscape planning in order to protect nature and biodiversity, manage natural resources, and also to connect people with nature conservation [6]. Even though these terms have been used interchangeably, as pointed out by Ahern [91, 103], the term ecological networks is more common in Europe, whereas the term greenways is more common in the USA. Also, while greenways initially aimed to provide access to people between urban and rural green and open spaces in the USA, ecological networks in Europe stemmed from the need to conserve species

Similar to greenways, a variety of definitions have been suggested for ecological networks in the literature. Bennett [104] defined ecological networks as "the coherent systems of natural or semi-natural landscape elements configured and managed with the objective of maintain‐ ing or restoring ecological functions as a means of conserving biodiversity, besides provid‐ ing appropriate opportunities for the sustainable use of natural resources". According to a definition provided by Jongman and Pungetti [6], ecological networks are "the systems of nature reserves and their interconnections that make a fragmented natural system coherent,

so as to support more biological diversity than in its non-connected form".

**•** Any natural or landscaped course for pedestrian or bicycle passage,

**•** Locally, certain strips or linear parks designated as parkway or green belt".

a canal, scenic road, or other route,

298 Sustainable Urbanization

areas.

**3.2. Ecological networks**

and habitats [6].

with each other and with populated areas,

In general terms, spatially, the structural elements of ecological networks are composed of core areas, which are usually protected by surrounding buffer zones and are linked to each other with linear corridors [1, 78, 108, 109].

As claimed by Jongman [88], core areas are generally defined on the basis of traditional nature conservation practices as the natural and seminatural areas of conservation concern or the ecologically important areas with high nature value. Thus, the primary functions of core areas are thought to be the conservation of nature and biodiversity by meeting the ecological requirements of species or ecosystems [78].

The main purpose of corridors is to enable dispersal and migration of animal and plant species by providing functional connections between core areas (e.g., ecosystems or habitats for species) [1, 78, 108]. With regards to their intended ecological functions, Bouwma et al. [109] emphasised the crucial role of the spatial arrangement, internal structure and management of corridors, where the more complex corridors can provide multiple functions for different animal and plant species. Within ecological networks, three types of corridors are defined on the basis of their spatial structures and they are landscape, linear and stepping stone corri‐ dors [1, 78]. While landscape corridors can be in various forms of linked landscape matrices, linear corridors are composed of linear landscape elements such as rivers or forest strips. Conversely, stepping stone corridors are composed of a range of small habitat patches within the landscape matrix.

Buffer zones, on the other hand, prohibit the damaging effects from external influences and maintain landscape processes within core areas and corridors by creating environmental gradients around these [78, 88, 110]. Finally, another spatial element of ecological networks mentioned by Bouwma et al. [109] includes sustainable use areas which refer to the exploita‐ tion of opportunities within the landscape mosaic for the maintenance of ecosystem services and sustainable use of natural resources [1]. Also, more intensive human uses are allowed in buffer zones and sustainable use areas only if these activities support the maintenance of ecosystem services and sustainability [78, 110].

The common goals of ecological networks are to maintain the functioning of ecosystems and to promote the sustainable use of natural resources by assisting policy sectors [6, 81]. Within this framework, ecological networks have been considered one of the most important landscape planning approaches to address issues associated with human-induced habitat depletion. The concept of ecological networks has therefore attracted the attention of conser‐ vationists and planners in Europe [111, 112]. In Europe, many international initiatives and

strategies for ecological networks have been developed [105, 113]. For example, the Pan-European Ecological Network (PEEN) is thought to be one of the most ambitious internation‐ al ecological network programmes. The aims of the PEEN programme are to ensure the following:


Overall, the ecological network approach has been regarded as an important tool to main‐ tain some level of ecological structure and function in urban areas, since they are thought to provide habitats and ecological connectivity for species and to conserve the wildlife [6]. But, as indicated by Andrian [115], the emphasis of the wildlife and nature conservation has been a major driver for the development of urban ecological networks and there is still a need for integrating social and cultural values into ecological networks.

#### **3.3. Green networks**

The green network concept has been inserted into urban planning practices, principally based on the idea of ecological networks [116]. Accordingly, the ecological and green network concepts have been used synonymously. However, the transition from ecological networks to green networks has created a noticeable shift in the spatial planning of nature and human dimensions. In other words, while the focus of the ecological network concept was on the conservation of species and habitats, the concept of green networks has brought the needs of species and humans together under the same roof [6, 82]. Moreover, the concept of green networks recognises the crucial role of green and open spaces and the linkages between them to support and improve sustainable development and also to enhance the functioning of urban environments [82]. Here, it is also important to note that the multiple benefits (social, eco‐ nomic, health and environmental) of urban green and open spaces have already been recognised by researchers, planners and decision-makers [84, 117–121].

Barker [122] defined green networks as "natural, or permanently vegetated, physically connected spaces situated in areas otherwise built-up or used for intensive agriculture, industrial purposes or other intrusive human activities". Additionally, the term green network was used by Bennett [104] to refer to a "spatial planning tool for the purpose of balancing and integrating land uses". Thus, the concept of green networks has been seen as a multifunction‐ al urban planning approach, in which the value and importance of natural, seminatural habitats and human-dominated habitats (e.g., urban green and open spaces) are appreciated to deliver benefits both for people and the environment.

Regarding the requirements of people in urban environments, a recent study by Scotland and Northern Ireland for Environmental Research claimed that green networks are capable of increasing the number of people visiting urban green spaces and the countryside by provid‐ ing a safe environment for people to move across [85, 123]. Furthermore, the green network approach goes beyond the limited vision of developing individual green spaces in urban areas just for recreational and visual purposes and focuses on the functionally connected systems of formal and informal green and open spaces [122, 124].

According to Forest Research [82], the concept of green networks takes into account multiple functions offered by green spaces as well as their ability to support the movement of people and species by the interconnections between them. Within this framework, the differences between individual green and open spaces and a green network have been explained according to their functions and spatial configurations. While green spaces refer to publicly accessible individual green areas in urban environments, green networks reflect a strategically identi‐ fied and functional system of green spaces for the benefit of people, habitats and biodiversi‐ ty [82, 125].

As well as these important features of green networks, Barker [122] suggested that one of the major benefits of green networks is their ability to provide connections between urban and rural landscapes. Therefore, green networks are said to be able to fulfil the requirements of wildlife, support ecological processes and meet the recreational, visual and social needs of people. In most countries, even though green networks have been primarily developed for their benefits to nature and biodiversity, they also serve multiple uses and functions such as meeting the ecological requirements of species and providing recreational facilities to people [122]. For example, in Sheffield, reasons for conserving and improving a green network for people and wildlife are defined as the following:


strategies for ecological networks have been developed [105, 113]. For example, the Pan-European Ecological Network (PEEN) is thought to be one of the most ambitious internation‐ al ecological network programmes. The aims of the PEEN programme are to ensure the

**•** the conservation of a full range of ecosystems, habitats, species and landscapes of European

**•** the maintenance of the habitats that are large enough to conserve animal and plant species,

Overall, the ecological network approach has been regarded as an important tool to main‐ tain some level of ecological structure and function in urban areas, since they are thought to provide habitats and ecological connectivity for species and to conserve the wildlife [6]. But, as indicated by Andrian [115], the emphasis of the wildlife and nature conservation has been a major driver for the development of urban ecological networks and there is still a need for

The green network concept has been inserted into urban planning practices, principally based on the idea of ecological networks [116]. Accordingly, the ecological and green network concepts have been used synonymously. However, the transition from ecological networks to green networks has created a noticeable shift in the spatial planning of nature and human dimensions. In other words, while the focus of the ecological network concept was on the conservation of species and habitats, the concept of green networks has brought the needs of species and humans together under the same roof [6, 82]. Moreover, the concept of green networks recognises the crucial role of green and open spaces and the linkages between them to support and improve sustainable development and also to enhance the functioning of urban environments [82]. Here, it is also important to note that the multiple benefits (social, eco‐ nomic, health and environmental) of urban green and open spaces have already been

Barker [122] defined green networks as "natural, or permanently vegetated, physically connected spaces situated in areas otherwise built-up or used for intensive agriculture, industrial purposes or other intrusive human activities". Additionally, the term green network was used by Bennett [104] to refer to a "spatial planning tool for the purpose of balancing and integrating land uses". Thus, the concept of green networks has been seen as a multifunction‐ al urban planning approach, in which the value and importance of natural, seminatural habitats and human-dominated habitats (e.g., urban green and open spaces) are appreciated

**•** the promotion of sufficient opportunities for species to disperse and migrate,

**•** the restoration of the damaged parts of the key environmental systems, and

**•** the prevention of potential threats on key environmental systems [10–114].

integrating social and cultural values into ecological networks.

recognised by researchers, planners and decision-makers [84, 117–121].

to deliver benefits both for people and the environment.

following:

300 Sustainable Urbanization

importance,

**3.3. Green networks**


From a theoretical point of view, it is obvious that the intended functions of green networks are broadly compatible with the main functions of ecological networks, which aim to sup‐ port and enhance the movement of animal and plant species. Besides maintaining and enhancing urban biodiversity and nature, the green network approach also provides appro‐ priate opportunities for the sustainable use of natural resources, and so is regarded as one of the fundamental components of a more sustainable urban environment [82]. To conclude, the green network approach has been inserted into the planning and management strategies as a broad concept to achieve multifunctionality for biodiversity and people in urban areas.

#### **3.4. Green Infrastructure**

As a more recent approach, the GI concept takes its theoretical and conceptual background from the abovementioned network approaches to provide multiple benefits for biodiversity, nature and people within an urban environment [127, 128]. For this reason, we can claim that the GI concept is not a new idea in landscape planning and management [129]. Accordingly, it can be suggested that the concept of GI is grounded on the recognition of the crucial role of green networks in the wider landscape to provide essential services, functions and resources. In this context, Rouse and Bunster [130] claim that the previous plans of green and open spaces (e.g., greenways) have been increasingly adapted as GI plans to provide environmen‐ tal, economic and social benefits in urban environments.

GI is defined by Benedict and McMahon [127] as "an interconnected network of waterways, wetlands, woodlands, wildlife habitats, and other natural areas; greenways, parks and other conservation lands; working farms, ranches and forests; and wilderness and other open spaces that support native species, maintain natural ecological processes, sustain air and water resources and contribute to the health and quality of life for communities and people". In addition, according to Natural England [131], GI is "the network of multifunctional open spaces, waterways, trees and woodlands, parklands and open countryside within and between our cities, towns and villages". In an urban context, the Natural Environment White Paper defined GI as "the living network of green spaces, water and other environmental features in both urban and rural areas. It is often used in an urban context to cover benefits provided by trees, parks, gardens, road verges, allotments, cemeteries, woodlands, rivers and wetlands" [132]. Furthermore, Natural England [133] suggested that GI is "a strategically planned and delivered network comprising the broadest range of high quality green spaces and other environmental features".

The careful wording of these definitions includes three important ideas at the heart of the GI concept: connectivity in the form of networks, multifunctionality and green components [127, 129, 134]. In spite of the emphasis on the term "green", it is quite important to note that GI also includes the features of blue infrastructure, such as river systems, other water features and coastal environments [127, 131]. As mentioned earlier, connectivity refers to the functional linkages in a landscape for the movement of animals, plants and/or people as well as the flows of materials, nutrients and energy [30, 35, 41]. Accordingly, supporting and enhancing connectivity between (habitat) patches is an important issue for biodiversity and nature conservation, and also to support human well-being and health in GI planning [127, 134].

Moreover, taking into consideration the abovementioned definitions, it is obvious that the concept of multifunctionality is the core idea of the GI concept, since the ability of a land‐ scape to deliver multiple benefits and functions for wildlife, nature and people has been widely recognised by decision-makers, planners and managers. Multifunctionality refers to "the potential for GI to have a range of functions to deliver a broad range of ecosystem services" [135]. The key benefits of a GI approach are summarised by Forest Research [136] as the following:


green network approach has been inserted into the planning and management strategies as a broad concept to achieve multifunctionality for biodiversity and people in urban areas.

As a more recent approach, the GI concept takes its theoretical and conceptual background from the abovementioned network approaches to provide multiple benefits for biodiversity, nature and people within an urban environment [127, 128]. For this reason, we can claim that the GI concept is not a new idea in landscape planning and management [129]. Accordingly, it can be suggested that the concept of GI is grounded on the recognition of the crucial role of green networks in the wider landscape to provide essential services, functions and resources. In this context, Rouse and Bunster [130] claim that the previous plans of green and open spaces (e.g., greenways) have been increasingly adapted as GI plans to provide environmen‐

GI is defined by Benedict and McMahon [127] as "an interconnected network of waterways, wetlands, woodlands, wildlife habitats, and other natural areas; greenways, parks and other conservation lands; working farms, ranches and forests; and wilderness and other open spaces that support native species, maintain natural ecological processes, sustain air and water resources and contribute to the health and quality of life for communities and people". In addition, according to Natural England [131], GI is "the network of multifunctional open spaces, waterways, trees and woodlands, parklands and open countryside within and between our cities, towns and villages". In an urban context, the Natural Environment White Paper defined GI as "the living network of green spaces, water and other environmental features in both urban and rural areas. It is often used in an urban context to cover benefits provided by trees, parks, gardens, road verges, allotments, cemeteries, woodlands, rivers and wetlands" [132]. Furthermore, Natural England [133] suggested that GI is "a strategically planned and delivered network comprising the broadest range of high quality green spaces and other

The careful wording of these definitions includes three important ideas at the heart of the GI concept: connectivity in the form of networks, multifunctionality and green components [127, 129, 134]. In spite of the emphasis on the term "green", it is quite important to note that GI also includes the features of blue infrastructure, such as river systems, other water features and coastal environments [127, 131]. As mentioned earlier, connectivity refers to the functional linkages in a landscape for the movement of animals, plants and/or people as well as the flows of materials, nutrients and energy [30, 35, 41]. Accordingly, supporting and enhancing connectivity between (habitat) patches is an important issue for biodiversity and nature conservation, and also to support human well-being and health in GI planning [127, 134].

Moreover, taking into consideration the abovementioned definitions, it is obvious that the concept of multifunctionality is the core idea of the GI concept, since the ability of a land‐ scape to deliver multiple benefits and functions for wildlife, nature and people has been widely recognised by decision-makers, planners and managers. Multifunctionality refers to "the potential for GI to have a range of functions to deliver a broad range of ecosystem services"

**3.4. Green Infrastructure**

302 Sustainable Urbanization

environmental features".

tal, economic and social benefits in urban environments.


The Landscape Institute [137] claims that a strategically planned and managed GI approach may provide enhanced multifunctions in comparison with the sum of individual green and open spaces in an urban area. The concept of multifunctionality can be fitted into the plan‐ ning of individual green and open spaces as well as routes but we can achieve a fully multi‐ functional GI network when these individual sites and their connections are taken together [10]. In this respect, it is important to note that multifunctionality in a landscape is character‐ ised by a high level of complexity, where different functions occur at the same time and interact with each other [138].

Consisting of natural, seminatural and man-made ecological systems altogether in a system, a GI forms a multifunctional network within and around urban areas [139]. Hence, the planning and management of a GI approach should take into account its capacity to deliver multiple ecological services, address the requirements of people and enhance the spatial character and quality of landscapes in urban environments [96, 131, 133]. Accordingly, a GI approach also requires involvement of a variety of stakeholders (e.g., planning authorities, policy makers, conservationists and the general public) in order to meet its intended func‐ tions and benefits that we expect them to provide [5, 140, 141].

In brief, the GI is a more promising and comprehensive planning approach to develop a coherent system of green and open spaces which serve multiple purposes and provide multifunctionality in urban areas [142].
