LI, Feng; WANG, Rusong; PAULUSSEN, Juerguen, LIU, Xusheng (2004): Comprehensive concept planning of urban greening based on ecological principles: a case study in Beijing, China, Landscape and urban planning
326
Urbanization increases the distance between people and natural space.
Urban greenspaces are an important component of the complex urban ecosystem. Parks, forests and farmlands are three main types of urban greenspace, which have significant ecological, social and economic functions (Bradley, 1995; Shafer, 1999; Tyrv¨ainen, 2001; L¨utz and Bastian, 2002) (...) Greenspace has significant ecosystem services, which are defined as “the benefits human population
derives, directly or indirectly, from ecosystem functions” (Costanza et al., 1997). It can sequester carbon dioxide emissions and produce oxygen (Jo, 2002), purify air and water, regulate micro-climate, reduce noise (Bolund and Hunhammar 1999), protect soil and water (Pauleit and Duhme, 2000; Jim, 2001), maintain biodiversity (Attwell, 2000), and have recreational, cultural
and social values (Savard et al., 2000; Tarrant and Cordell, 2002).
The planning and management of urban greening is of significance to urban sustainable development
(Miller, 1988; Grey, 1996; Teal et al., 1998). In Canada and the US, as well as in Europe, there has been a growing recognition among community groups and environmental organizations that brownfields hold enormous potential for “greening” city environments (Sousa, 2003; K¨uhn, 2003). Some studies have shown how green or open space planning based on ecological principles can be implemented. Flores et al. (1998) proposed ecological content, context, dynamics, heterogeneity
and hierarchies as ecological principles for the development of a greenspace system for the New York City region. Leit˜ao and Ahern (2002) argued for a common framework that applies ecological
knowledge in landscape and urban planning. Jim and Chen (2003) applied landscape ecological principles to the greenspace planning of Nanjing City, China. Ong (2003) proposed an ecological indicator – the green plot ratio (the single-side leaf area per unit ground area) – as a suitable measure for the greening in architecture and urban planning. Herzele and Wiedemann (2003) developed an integrated indicator to assess the accessibility and attractiveness of urban greenspace in four Flemish cities. Pauleit et al. (2003) proposed a more flexible approach named Accessible Natural Greenspace Standards Model to promote the natural greenstructure of towns and cities and devised a decision-support framework for its implementation. Li and Wang (2003) proposed a method for the evaluation,
planning and prediction of ecosystem services of urban greenspace, applying landscape ecological
principles, taking Yangzhou City in China as the case.
In Autumn 2002, the Beijing Municipal Institute of City Planning and Design asked the Research Center for Eco-Environmental Science, Chinese Academy of Sciences and two other institutes for scientific support to revise the current Beijing Urban Master Plan. Our research team was commissioned to develop a plan for Beijing based on ecological principles. It provides basic
information, specific space-related objectives and a strategic conceptual framework for future eco-urban development of Beijing region. The study was finished by the end of July 2003.
This paper aims to outline the conceptual ecological framework developed in this study. It will then
show how an actionable urban greening plan at the regional, city and neighborhood levels to achieve longterm sustainability could be developed for Beijing City.
327
3. Problems of urban greening in Beijing
328
From 1992 to 2002, the Beijing settlement area increased by 25%, while the agriculture
land decreased by 32% (Fig. 3). Greenspace also decreased which will have a negative impact on the services provided by these ecosystems for people (Wang et al., 2001).
329
The most important reason for the encroachment of urban development on greenspace is that there are severe conflicts between real estate development and public interest. Compensation rules for
developing greenspace have been established and implemented by Beijing People’s Government. Compensation is calculated according to the area of greenspace and its location. Although compensation needs to be paid, this is much less than the economic benefits developers gain from real estate or other business activities.
330
Therefore, there is an urgent need for effective protection of greenspace and the development of a rational green and settlement system to counteract uncontrolled development. According to principles of landscape ecology, green wedges and green corridors may be a suitable green network system.
3.3. Problems of greenspace within the built-up area
Greenspaces within the built-up area also face problems. The most evident one is that greenspaces are unevenly distributed, and their design emphasizes aspects of beautification rather than ecological and recreational value. Therefore, the spatial pattern of the greenstructure needs to be improved. For instance, a natural forest structure, including a main tree canopy, underlayer shrubs and herbs should be promoted because of plant community stability and the potential for provision of more ecosystem services.
4. Research approach
4.1. Landscape ecological concepts for greenspace planning
Landscape ecology is the study of interactions among landscape elements. It deals with the effects
of the spatial configuration of mosaics on a wide variety of ecological phenomena (Forman and Godron, 1986). Landscape ecology generates understanding of how spatial pattern affects ecological processes. It provides a theoretical basis for landscape and urban planning (Leit˜ao and Ahern, 2002). Forman and Godron (1986) proposed patches, corridors and the matrix as the three basic component types of any landscape.
Patches are relatively homogeneous non-linear areas. Landscape connectivity is the degree of spatial connectedness among landscape elements (Forman, 1995). It has ecological effects on flows of energy, materials and biological entities. It is dependent upon both the scale of observation and ecological processes under consideration. A network of patches and corridors can provide connectivity of natural elements and help to preserve linkage between different ecosystems (Wu
and Hobbs, 2002).
5. Ecological concept planning of urban
greening in Beijing
5.1. The temporal and spatial scale of greenspace
planning of Beijing
In greenspace planning of Beijing, three spatial
scales are to be considered:
• At the regional scale, the entire area of Beijing Province (16,807.8 km2) is considered. Even the relationship to the neighbor-city Tianjin is included in the plan.
• At the city scale, the urban area of Beijing (1040 km2) with its suburbs, and the surrounding
peri-urban zone is taken into account.
• At the neighborhood scale, some selected and typical areas within the fourth ringroad are considered.
The plan distinguishes between three time-scales for implementation:
• Until 2008: The “Green Olympic City”. Complete the Olympic Park and other greenings in relation to the Olympic Games 2008.
• Until 2020: The “Modern International City”. A modern international Beijing City with distinct characteristics will come into being.
• In the long term: The “Eco-City”. A green sustainable ecosystem connected with green wedges,
parks and green corridors will be established and improved.
332
The current greenspaces of Beijing are mainly the public parks, urban forests and agricultural land at the city scale. They are dispersed among the urban area (Fig. 6A). According to landscape ecological principles, and based on an assessment of the existing greenspaces, seven green wedges and some green corridors are proposed from the suburb to the urban center (Fig. 6B). The green wedges are composed of parks, gardens, forest patches, farmlands, rivers and wetlands. These green wedges and green corridors form an integrated ecological network by connecting the urban center, forest parks, mountains and the outer regional space (...)
In fact, there are already some residential areas within the proposed green wedges and green corridors. A countermeasure would be to remove some of the residential areas. In the case of old single-story suburban and rural houses, it is current practice to remove buildings and resettle the population in other places. In the case of new high-rise building areas, if they cannot be moved, greening within these areas must be improved to increase greenspace cover as a means of enhancing
ecosystem services and environmental quality.
The main practical difficulties to the implementation of the greenspace plans at the regional and city scales are as follows:
• Industry and relative service development policy. Industry development often invades the neighboring greenspace.
• Municipal infrastructure construction in existing greenspaces.
• Financing and revenue problems restrict the possibilities to create new greenspaces and manage existing ones.
334
The rivers, canals and lakes within the built-up area of Beijing are the natural greenways for linking the urban greenspace into an integrated unity. The riverside greenway can be used to create recreational open spaces for people with easy access and bring vitality to the downtown areas. Several inner urban rivers of Beijing with the banks built with concrete should be restored by creating natural waterfront. During the last decade, many single-story residential areas, which were located adjacent to rivers and canals, have been removed and substituted by riverside greening. The rivers in the built-up area of Beijing should be connected into a whole network. Riverside greening should encompass a variety of plant species, textures and colors, and be a low-maintenance landscape.
6. Discussion
335
In future, newecological indicators should be developed for urban planning for sustainable development (Diamantini and Zanon, 2000). The traditional indicator of greenspace coverage (the percentage of green land area on a site) does not reflect the quality of greenstructure, nor does it represent the variety of ecosystem services of greenspace. The ecological indicator of green plot ratio provides an effective method to assess the quality of greening in urban planning (Ong, 2003). It will be applied in the next step of greenspace design in Beijing.
326
Urbanization increases the distance between people and natural space.
Urban greenspaces are an important component of the complex urban ecosystem. Parks, forests and farmlands are three main types of urban greenspace, which have significant ecological, social and economic functions (Bradley, 1995; Shafer, 1999; Tyrv¨ainen, 2001; L¨utz and Bastian, 2002) (...) Greenspace has significant ecosystem services, which are defined as “the benefits human population
derives, directly or indirectly, from ecosystem functions” (Costanza et al., 1997). It can sequester carbon dioxide emissions and produce oxygen (Jo, 2002), purify air and water, regulate micro-climate, reduce noise (Bolund and Hunhammar 1999), protect soil and water (Pauleit and Duhme, 2000; Jim, 2001), maintain biodiversity (Attwell, 2000), and have recreational, cultural
and social values (Savard et al., 2000; Tarrant and Cordell, 2002).
The planning and management of urban greening is of significance to urban sustainable development
(Miller, 1988; Grey, 1996; Teal et al., 1998). In Canada and the US, as well as in Europe, there has been a growing recognition among community groups and environmental organizations that brownfields hold enormous potential for “greening” city environments (Sousa, 2003; K¨uhn, 2003). Some studies have shown how green or open space planning based on ecological principles can be implemented. Flores et al. (1998) proposed ecological content, context, dynamics, heterogeneity
and hierarchies as ecological principles for the development of a greenspace system for the New York City region. Leit˜ao and Ahern (2002) argued for a common framework that applies ecological
knowledge in landscape and urban planning. Jim and Chen (2003) applied landscape ecological principles to the greenspace planning of Nanjing City, China. Ong (2003) proposed an ecological indicator – the green plot ratio (the single-side leaf area per unit ground area) – as a suitable measure for the greening in architecture and urban planning. Herzele and Wiedemann (2003) developed an integrated indicator to assess the accessibility and attractiveness of urban greenspace in four Flemish cities. Pauleit et al. (2003) proposed a more flexible approach named Accessible Natural Greenspace Standards Model to promote the natural greenstructure of towns and cities and devised a decision-support framework for its implementation. Li and Wang (2003) proposed a method for the evaluation,
planning and prediction of ecosystem services of urban greenspace, applying landscape ecological
principles, taking Yangzhou City in China as the case.
In Autumn 2002, the Beijing Municipal Institute of City Planning and Design asked the Research Center for Eco-Environmental Science, Chinese Academy of Sciences and two other institutes for scientific support to revise the current Beijing Urban Master Plan. Our research team was commissioned to develop a plan for Beijing based on ecological principles. It provides basic
information, specific space-related objectives and a strategic conceptual framework for future eco-urban development of Beijing region. The study was finished by the end of July 2003.
This paper aims to outline the conceptual ecological framework developed in this study. It will then
show how an actionable urban greening plan at the regional, city and neighborhood levels to achieve longterm sustainability could be developed for Beijing City.
327
3. Problems of urban greening in Beijing
328
From 1992 to 2002, the Beijing settlement area increased by 25%, while the agriculture
land decreased by 32% (Fig. 3). Greenspace also decreased which will have a negative impact on the services provided by these ecosystems for people (Wang et al., 2001).
329
The most important reason for the encroachment of urban development on greenspace is that there are severe conflicts between real estate development and public interest. Compensation rules for
developing greenspace have been established and implemented by Beijing People’s Government. Compensation is calculated according to the area of greenspace and its location. Although compensation needs to be paid, this is much less than the economic benefits developers gain from real estate or other business activities.
330
Therefore, there is an urgent need for effective protection of greenspace and the development of a rational green and settlement system to counteract uncontrolled development. According to principles of landscape ecology, green wedges and green corridors may be a suitable green network system.
3.3. Problems of greenspace within the built-up area
Greenspaces within the built-up area also face problems. The most evident one is that greenspaces are unevenly distributed, and their design emphasizes aspects of beautification rather than ecological and recreational value. Therefore, the spatial pattern of the greenstructure needs to be improved. For instance, a natural forest structure, including a main tree canopy, underlayer shrubs and herbs should be promoted because of plant community stability and the potential for provision of more ecosystem services.
4. Research approach
4.1. Landscape ecological concepts for greenspace planning
Landscape ecology is the study of interactions among landscape elements. It deals with the effects
of the spatial configuration of mosaics on a wide variety of ecological phenomena (Forman and Godron, 1986). Landscape ecology generates understanding of how spatial pattern affects ecological processes. It provides a theoretical basis for landscape and urban planning (Leit˜ao and Ahern, 2002). Forman and Godron (1986) proposed patches, corridors and the matrix as the three basic component types of any landscape.
Patches are relatively homogeneous non-linear areas. Landscape connectivity is the degree of spatial connectedness among landscape elements (Forman, 1995). It has ecological effects on flows of energy, materials and biological entities. It is dependent upon both the scale of observation and ecological processes under consideration. A network of patches and corridors can provide connectivity of natural elements and help to preserve linkage between different ecosystems (Wu
and Hobbs, 2002).
5. Ecological concept planning of urban
greening in Beijing
5.1. The temporal and spatial scale of greenspace
planning of Beijing
In greenspace planning of Beijing, three spatial
scales are to be considered:
• At the regional scale, the entire area of Beijing Province (16,807.8 km2) is considered. Even the relationship to the neighbor-city Tianjin is included in the plan.
• At the city scale, the urban area of Beijing (1040 km2) with its suburbs, and the surrounding
peri-urban zone is taken into account.
• At the neighborhood scale, some selected and typical areas within the fourth ringroad are considered.
The plan distinguishes between three time-scales for implementation:
• Until 2008: The “Green Olympic City”. Complete the Olympic Park and other greenings in relation to the Olympic Games 2008.
• Until 2020: The “Modern International City”. A modern international Beijing City with distinct characteristics will come into being.
• In the long term: The “Eco-City”. A green sustainable ecosystem connected with green wedges,
parks and green corridors will be established and improved.
332
The current greenspaces of Beijing are mainly the public parks, urban forests and agricultural land at the city scale. They are dispersed among the urban area (Fig. 6A). According to landscape ecological principles, and based on an assessment of the existing greenspaces, seven green wedges and some green corridors are proposed from the suburb to the urban center (Fig. 6B). The green wedges are composed of parks, gardens, forest patches, farmlands, rivers and wetlands. These green wedges and green corridors form an integrated ecological network by connecting the urban center, forest parks, mountains and the outer regional space (...)
In fact, there are already some residential areas within the proposed green wedges and green corridors. A countermeasure would be to remove some of the residential areas. In the case of old single-story suburban and rural houses, it is current practice to remove buildings and resettle the population in other places. In the case of new high-rise building areas, if they cannot be moved, greening within these areas must be improved to increase greenspace cover as a means of enhancing
ecosystem services and environmental quality.
The main practical difficulties to the implementation of the greenspace plans at the regional and city scales are as follows:
• Industry and relative service development policy. Industry development often invades the neighboring greenspace.
• Municipal infrastructure construction in existing greenspaces.
• Financing and revenue problems restrict the possibilities to create new greenspaces and manage existing ones.
334
The rivers, canals and lakes within the built-up area of Beijing are the natural greenways for linking the urban greenspace into an integrated unity. The riverside greenway can be used to create recreational open spaces for people with easy access and bring vitality to the downtown areas. Several inner urban rivers of Beijing with the banks built with concrete should be restored by creating natural waterfront. During the last decade, many single-story residential areas, which were located adjacent to rivers and canals, have been removed and substituted by riverside greening. The rivers in the built-up area of Beijing should be connected into a whole network. Riverside greening should encompass a variety of plant species, textures and colors, and be a low-maintenance landscape.
6. Discussion
335
In future, newecological indicators should be developed for urban planning for sustainable development (Diamantini and Zanon, 2000). The traditional indicator of greenspace coverage (the percentage of green land area on a site) does not reflect the quality of greenstructure, nor does it represent the variety of ecosystem services of greenspace. The ecological indicator of green plot ratio provides an effective method to assess the quality of greening in urban planning (Ong, 2003). It will be applied in the next step of greenspace design in Beijing.
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