**3. Tools for ecological retro-fitting of urban environment**

Ecological approach should accompany to planners, urban designers, architects, landscape architects, builders, from beginning of the planning process to production of the urban elements and building materials [5].

From ecological point of view, to retro-fit our settlements and urban environments in which we live, to reduce ecological footprints on the settlements, it is essential that ecological approach and ecological decision making systematic should be adopted. This systematic begins with ecological planning and contains ecological urban design for urban landscape and ecological architecture and eco-technologies for livable and sustainable cities.

**Figure 3** shows the hierarchic succession of the phases from planning to architecture and to the production technologies.

**Figure 3.** Tools for ecological retro-fitting of urban environment.

#### **3.1. Ecological planning**

**2.3. Urban ecology**

256 Sustainable Urbanization

with ecological structures and functions [16].

ecology continues to exist and evolve [18].

ban lands" [9].

Urban areas and ecology are contrary to each other theoretically and as to substance, urban ecology connects with them. Urban ecology was originally developed as a part of human ecology in the 1920s by a small but influential group of sociologists at University of Chicago and they identified urban ecology as "the study of the relation between people and their urban environment" [18]. Urban ecology is a scientific field on the issue of effects on organisms, the interactions among them, and the transformation and flux of energy and matter in urban and urbanizing systems [16]. Urban ecology is ecological research conducted in cities, towns, and urban areas [19]. To understand the structure and dynamics of urban systems, they must be recognized as social-ecological systems that integrate socioeconomic drivers and responses

Basically, "urban" is a term identifying the land use on a place. A common comprehension of "urban" a densely populated urban space characterized by multifunctional land uses. This comprehension seems to be more useful for researches on urban ecology; yet, it is difficult to determine ecological thresholds surrounding urban space. Although ecology is a natural science concerned with the distribution and abundance of organisms, the word has many other meanings as well [19]. Urban ecology is not only a view to urban land from the science of ecology but may include concerns from the social sciences. Urban ecology is a research subject forming a continuum from "pure" ecology in the urban space to an integration of ecology and social sciences to investigate urban systems [19]. Today, the sociological approach to urban

An explicit focus of researches about urban ecology is on sustainability, which includes bio‐ diversity and ecosystem services, energy consumption and carbon footprint for climate change studies [20]. Implementation of nature conservation in the cities will be possible by means of arrangements make harmonic natural–cultural and social environment with each other. Although the conflicting approach on ecology of urban areas focused on ecological footprints, and summaries of citywide species richness, contemporaneous ecosystem ap‐ proaches have begun to integrate physical environment of the nature, including urban cli‐ mate, hydrology, soils, and energetic issues, and to indicate the necessity for comprehension the social dimensions of urban ecology [9]. Urban ecology has increasingly played a signifi‐ cant leading role to overcome the conflicts faced by urban ecosystems. The major focus in many studies about application of urban ecology was on urban green network and its con‐ nection to citizens [20]. Three main goals based on ecology "in reference [9]", "may be ach‐ ieved in urban areas; Firstly, plant ecology can support to improved comprehension of the structure and function of urban ecosystems. Second, ecological function of urban areas must be increased. Third goal is to take advantages to humans of the vegetation elements of ur‐

As emphasized by many scientists and researchers, with an in-depth comprehension of ecology in cities, focusing on the ecology of cities is increasingly being more significant. A framework to put ecological information into practice in urban areas requires interdisciplina‐ ry approaches for enhancing social welfare and providing sustainability in urban areas.

Planning is a decision-making and spatial organization process connecting with human, nature, and life (**Figure 4**). In addition to this definition, planning also creates a system including connection and interaction among social, natural, and built environment. As the key issue of sustainable development, the principle of "using of the natural resources without exhausting them" was adopted nearly by the whole world and the space planning strategies gained a new dimension which considers natural resources [5, 21–23]. In the world, spatial planning strategies targeting sustainable development of cities gained ecological dimension guiding to both the regional and city planning process [21, 23]. Ecology should be the major theme to be considered from the beginning to the end of planning process [5]. Consideration of natural resources and ecological characteristics of an area is of great importance. In ecological land-use planning process, strategic environmental assessments, impact assess‐ ments, and ecological risk analysis are of great importance as basic phases [5, 21, 22].

**Figure 4.** Function of planning.

Land use involves the process of biologically and technically reshaping, converting and managing land for socio-economic benefits [24]. Built environment growing together with the economic development has taken a toll on the natural resources [22, 23]. Overexploitation and utility of resources due to extensive economic growth have now become the common causes of environmental degradation [24]. One the one hand, land-use decisions on the settlements impact economic actions, this also affect the physical environment, land surface, soil, and natural biotopes, on the other hand, negative impacts of these actions on ecological structure cause environmental problems [23]. Furthermore, the interconnectivity of ecosystems is increasingly jeopardized by the uncontrolled development, land-use conversion, tourism activities, and endless disturbances caused by anthropogenic agents [24]. There is a need also for cost-benefit analysis in planning process, so that it can bring ecological benefit, besides of economic development in growth process of the cities. While some of land-use decisions economically benefit in the short run, whereas they cause ecological costs in the long run [21, 23].

Therefore, the land-use decisions should be defined by environmentally sensitive/ecological planning process, during which natural characteristics and potentials of the lands must be examined by ecological threshold analysis [21–23]. The aim of ecological planning was to protect of natural resources and to create ecological cities and settlements. Ecological plan‐ ning is not only physical planning understanding, but also a planning process which aims sustainability of an integrative urban-nature development [23].

On the one hand, one of the most important approaches in the creation process of ecological cities is to utilize of natural resources efficiently and without consumption of them. On the other hand, one of the basic principles in ecological planning process is to create an integrat‐ ed green network in the cities. The management of urban lands, namely adding green components to open spaces is an increasingly important subject. Urban biodiversity is essential for residents as recreational areas, and their presence in the neighborhood unit is an appreci‐

ated characteristic reflected in property prices [25]. Open and green spaces, which were planned, applied, directed with the ecological, and recreational aims, play an important role for controlling urban growth and shaping urban form, in addition to being important for residents [26]. Open and green lands in the cities can perform their functions if the practices are suited development projects and ecological planning rules.

Geographical information systems (GIS) are majortools for planning in orderto make available to spatial outputs of land-use decisions. Thus, increasingly approaches using GIS for visual‐ izing the spatial dimension and extent of change are being employed to ensure these spatial aspects [27].
