**2. Urbanisation and sustainability**

### **2.1. Urbanisation, fragmentation and connectivity**

Urbanisation can be defined as a dynamic process, where the land is mainly modified with an extension of the urbanised area and/or increased population [12–14]. While different social processes are regarded as the main drivers of urbanisation (i.e., population growth and employment opportunities), the process of urbanisation itself affects social, economic and political life [14, 15].

In general, urbanisation is thought to have adverse effects on the nature, biodiversity, the quality of life of people as well as the functioning of local and global ecosystems [16]. Since the built-up areas cover a large proportion of the land surface in urban environments, they are generally thought to be more disturbed and degraded compared to rural areas [16, 17].

However, it has been claimed that the process of urbanisation may also provide favourable conditions for biodiversity as it creates and supports a variety of species because of the diversity of habitats included in urban environments [12, 18, 19]. This is exemplified in the work undertaken by Gaston et al. [20] who demonstrated that domestic gardens in Sheffield

contain a large amount of biodiversity. Also, Savard et al. [21] drew our attention to some other benefits of urban ecosystems to people, species and the other aspects of biodiversity (e.g., population structure and genetic diversity). This is evident in the case of the cultivation of rare plants in urban areas, which may attract species that are dependent on those plants.

On the other hand, changes in the existing land uses/covers and fragmentation have as‐ sumed to be the most important environmental issues associated with the process of urbani‐ sation [7, 22–24]. The term fragmentation reflects both a status and process. As a status, fragmentation can be defined as the degree of isolation of previously connected landscape components [25, 26]. As a process, it implies a dynamic process of structural and functional changes in a landscape where a continuous habitat type is split into separated patches with different sizes, shapes and functions [9, 10, 27].

Bennett [23, 24] summarises the major effects of fragmentation under structural changes in the landscapes and adverse effects on wildlife. With regard to its effects on landscape structure, fragmentation causes the loss and/or degradation of valuable habitats with an increasing isolation – or in other words the loss of connectivity [9, 23, 24, 28–30]. Recent evidence suggests that larger habitats can support a wide diversity of animal and plant species [31–33]. Accordingly, the loss or reduction of habitats also means a dramatic reduction in biodiversi‐ ty, where some species become rare or extinct depending on their habitat requirements [9, 10, 32]. Therefore, the maintenance of connectivity has been regarded as a worldwide concern to mitigate the detrimental effects of fragmentation as well as the conservation of the nature and biodiversity.

The concept of connectivity stems from the relationships between the spatial structure and functioning of landscape and means "the degree to which a landscape facilitates or impedes movement of organisms among habitat patches" [4, 35, 36]. As one of the fundamental properties of landscapes, connectivity has been considered as "a measure of the ability of organisms to move among suitable habitat patches" [4, 30, 37].

According to another definition provided by Ahern [38], connectivity is "a spatial character‐ istic of systems which enables and supports the occurrence of specific processes and func‐ tions, through adjacency, proximity or functional linkage and connection". In this regard, the concept of connectivity encompasses the structural and functional aspects of a landscape. While structural connectivity refers to the degree to which habitat patches are physically/ structurally linked to each other [23, 24, 39], functional connectivity denotes the measure of species' ability to move between habitat patches and does not necessarily require physical connections between habitat patches [19, 40, 41]. Functional connectivity, therefore, depends on the behavioural responses of organisms to the spatial structure of landscapes [39, 42, 43].

#### **2.2. Urbanisation and sustainability**

These approaches have their own planning aims and strategies, in particular in the early stages of their development. But they have become closer with regard to their common concerns and the underlying concept of landscape connectivity to identify their spatial configuration. In the context of this chapter, the theoretical and scientific background of different network ap‐

The scope of early landscape planning approaches to networks was limited by their foci, where the spatial planning of nature and human dimensions has been treated as separate sectors. However, nature conservation and landscape planning practices have started to evolve into more integrated and multidisciplinary approaches, which are centered on the concepts of

A more recent planning approach is GI and it is thought to be able to ensure the multifunc‐ tionality of different land uses and provide sustainable benefits to nature, biodiversity and people from available land in and around urban environments. However, there is still need for a more robust decision-making structure and feasible planning approach as well as a

This chapter reviews and discusses the literature on landscape ecology applications in landscape planning with an emphasis on sustainability in urban environments. The chapter starts with urbanisation as an issue and explains how it leads to fragmentation and the loss of connectivity. After giving a brief overview of issues related to fragmentation, it moves on to the relationship between urbanisation and sustainability. Thereafter, it introduces different ways in which networks have been developed in ecology and planning to mitigate the adverse

Urbanisation can be defined as a dynamic process, where the land is mainly modified with an extension of the urbanised area and/or increased population [12–14]. While different social processes are regarded as the main drivers of urbanisation (i.e., population growth and employment opportunities), the process of urbanisation itself affects social, economic and

In general, urbanisation is thought to have adverse effects on the nature, biodiversity, the quality of life of people as well as the functioning of local and global ecosystems [16]. Since the built-up areas cover a large proportion of the land surface in urban environments, they are generally thought to be more disturbed and degraded compared to rural areas [16, 17].

However, it has been claimed that the process of urbanisation may also provide favourable conditions for biodiversity as it creates and supports a variety of species because of the diversity of habitats included in urban environments [12, 18, 19]. This is exemplified in the work undertaken by Gaston et al. [20] who demonstrated that domestic gardens in Sheffield

measurable and traceable tool to planning GI in order to achieve these goals.

effects of fragmentation by enhancing landscape connectivity.

**2. Urbanisation and sustainability**

political life [14, 15].

**2.1. Urbanisation, fragmentation and connectivity**

proaches has been reviewed.

292 Sustainable Urbanization

sustainability and multifunctionality [6, 10, 11].

The relationship between urbanisation and sustainability largely depends on their dynamic interactions and interdependencies with environmental, societal and economic processes [44]. In urban areas, natural habitats and biodiversity have been subjected to intense human disturbances, and so urban environments and their surroundings have been the focus of

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

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 and maintained.

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 despite environmental and sociocultural changes" [49].

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 ethics.

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

resources, social inclusion and community cohesion [50, 58]. The political aspect of land‐ scape sustainability focuses on an effective governance structure, where the planning, protection and management of different landscape elements are put in place on common grounds for both the public and private sectors [50]. Finally, the aesthetic sustainability of a landscape relates to the visual amenity and healthy functioning of the landscape [50, 55].

In view of all that has been mentioned so far, we can clearly see that a sustainable landscape is a multidimensional and dynamic system in which every component is crucial for provid‐ ing multi-functionality, supporting the essential ecosystem services, benefiting the health and well-being of people as well as meeting the different needs of people in urban environments.
