Map the green space

Landscape and Urban Planning 998 (2003) 1–22

Comprehensive greenspace planning based on landscape
ecology principles in compact Nanjing city, China
C.Y. Jim a,∗ , Sophia S. Chen b
a

b

Department of Geography, University of Hong Kong, Pokfulam Road, Hong Kong, China
Institute of Geography and Limnology, Chinese Academy of Sciences, Beijing East Road, Nanjing, China
Received 12 July 2002; received in revised form 30 October 2002; accepted 3 November 2002

Abstract
Urban greenspaces are universally valued as amenity-recreation venues, wildlife refuges and essential livable-city ingredients. Western strategies of urban greenspace provision are difficult to implement or retrofit in most Asian cities, commonly
constrained by a high-density compact form. With recent rapid urbanization and associated brown and green field developments, ample opportunities arise to overhaul greenspace standards and patterns. The case study of the ancient city of Nanjing
in China permits planning for an integrated greenspace network, aiming at flexibility for future urban expansion, green field
acquisition, recreational functions, wildlife habitats and environmental benefits. It consists of green wedges, greenways and
green extensions that incorporate urban green areas at three landscape scales. At the metropolis scale, through normative
and substantive analyses of urban form and urban expansion, and assessment of suburban uplands, five green wedges are
demarcated to generate a star urban form. The green wedges link the extensive countryside to the central city, and define elongated finger-like spaces between them for urban expansion to avoid conflicts with green fields. At the city scale, three major
greenways, including city-wall circular greenway, Inner-Qinhuai River greenway, and canopy-road greenway, are designed
as a permeating framework to guide new greenspace location, configuration and continuity, and to link existing parks. These
greenways are equipped with a comprehensive trail system to foster pedestrian and cycling movements that are preferred
by the public and the government. At the neighborhood scale, a greenspace organization, consisting of residential public
open spaces, shaded sidewalks and riparian strips, conforms to the network geometry. As well-connected entities, these small
proximate enclaves provide opportunities for residents to have day-to-day contact with nature. They also serve to resist undue
urban influences and intrusions. Overall, the three-tiered greenspace system provides an alternative mode for urban development to the conventional transport-dominated one, to usher substantial improvement in landscape-environmental quality and
to augment the sustainable-city notion.
© 2003 Elsevier Science B.V. All rights reserved.
Keywords: Greenspace; Greenway; Green network; Compact city; Landscape ecology; Planning; Nanjing; China

1. Introduction

∗ Corresponding author. Tel.: +852-2859-2835;
fax: +852-2559-8994.
E-mail address: (C.Y. Jim).

0169-2046/03/$20.00 © 2003 Elsevier Science B.V. All rights reserved.
doi:10.1016/S0169-2046(02)00244-X

Greenspaces in cities exist mainly as semi-natural
areas, managed parks and gardens, supplemented by
scattered vegetated pockets associated with roads and
incidental locations. Embodying the garden city ideal
advocated by Ebenezer Howard (1898) and the large


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C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

urban park idea expounded by Frederick Law Olmsted in the US (Wilson, 1989), public greenspaces
have been increasingly designated in cities since the
1880s to counteract environmental impacts of urban
expansion and intensification. Plants, notably trees,
usher a wide range of environmental benefits and functions, and urban greenspaces often accommodate varied assemblages of flora and small animals, providing
readily accessible sites with natural ingredients or surrogates of nature for the enjoyment of inhabitants who
are otherwise detached from nature.
The compact city has been suggested as a sustainable urban form to contain the impacts of urbanization
on remnant natural areas (Beatley, 2000). Engulfing and fragmenting natural areas especially in the

peri-urban countryside are to be minimized (Swenson
and Franklin, 2000). The high-density development
mode, however, often lacks greenspaces (Jim, 2002a).
Similar to compact European cities, most Chinese
cities are intensively developed with a tight plan. Chinese planners have attempted to conserve and create
city greenspaces in response to rapid urbanization
since the 1980s. Most cities have augmented greening
programs since the 1990s, resulting in both congruence and conflicts between greenspace establishment
and urban development.
Landscape ecology offers insights on optimization
of space use vis-à-vis environmental conservation and
improvement (Forman and Godron, 1986; Dramstad
et al., 1996). It furnishes principles of greenspace
organization related to the theory of island biogeography (MacArthur and Wilson, 1967). In essence, large
patch, high connectivity and propinquity foster species
diversity and ecosystem functions. Such spatial concepts have been widely adopted in urban landscape architecture and landscape planning projects (Goldstein
et al., 1982/1983). Various studies have proposed a
landscape mosaic composed of linear elements to augment the connectedness of the otherwise isolated and
often small urban habitats (Ahern, 1991; Walmsley,
1995; Mazzotti and Morgenstern, 1997; Quayle and
Lieck, 1997; Flores et al., 1998; Schrijnen,
2000). In some American cities, greenways have been
designed as corridors for wildlife and human movement (Little, 1990; Flink and Searns, 1993). Similarly,
linkages for parks and community gardens at the
neighborhood scale have been realized in Singapore,
Canada and the United States (Francis et al., 1984;

McCormick, 1992; Pedersen, 1999; Meeus, 2000; Foo,
2001).
Scant research has been conducted on comprehensive greenspace planning in the context of

high-density development (Jim, 2002b). Introducing
greenspaces with connectivity into a heavily built-up
milieu demands detailed studies and dedicated solutions. Nanjing, an ancient city in east China, is
selected as a study case for its generous tree cover,
potential greenway sites within the urban fabric, and
extensive mature forests at its fringe. This research attempts to answer the following questions. (1) How to
protect urban fringe greenspaces from encroachment?
(2) How to effect the penetration of greenspaces into
the high-density inner-city? (3) How to establish adequate home-juxtaposed greenspaces for residents? (4)
How to establish an actionable greenspace plan at the
metropolis (built-up area and the near suburb), city
(built-up area) and neighborhood scales? (5) How to
devise an acceptable urban development within this
green framework?

2. Study area
Nanjing is located at 32◦ 03 N in the north-subtropical climatic zone with well-defined seasons and a
mean annual temperature of 15 ◦ C. The maximum
summer temperature exceeds 40 ◦ C, dropping to a
minimum of −14 ◦ C in winter. Rainfall averages
1033 mm per annum, occurring mainly in summer.
Typhoon may strike once or twice annually mostly in
August, but wind damage on trees or buildings is less
serious compared with coastal cities. The zonal natural
vegetation is a mixed broadleaf evergreen and deciduous forest. The authors’ sampling survey of urban trees
in 1998 yielded an evergreen:deciduous trees ratio of
about 1:3, and the top three species were Platanus acerifolia, Juniperus chinensis and Ligustrum lucidum.
The city’s varied topography comprises mountains,
low hills, low terraces, plains and rivers (Fig. 1). The
Yangtze River runs in the northwest, and the Qinhui

River runs southeast to the northwest through the city
to join Yangtze. Fringe mountains surround the city,
extending as low hills into built-up areas. The Purple
Mountain at its eastern fringe, rising to 448 m, has
the largest green cover of 29.7 km2 of semi-natural
forest.


C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

3

Fig. 1. Major landform features, main roads and old city-wall of Nanjing.

Nanjing has nearly 2000 years of development
history. The old core lies in the south near the
Inner-Qinhuai River. The Capital Plan implemented
in 1928 extended the city significantly to the north,
but expansion until the 1950s was confined mainly
within the 14th-century Ming Dynasty city-wall.
Thereafter, large factories were established along the
Yangtze River. They triggered additional population
and urban growth outside the wall towards north
and south. The Reform and Open Policy initiated in
the 1980s brought another phase of rapid urbanization and further encroachment into the surrounding
countryside. The built-up areas increased 60% from
1986 to 2000, covering 194 km2 and accommodating 2.47 million population with a density of 12,700
persons/km2 (State Statistics Bureau, 1987–2001). In
the last 5 years, areas outside the east and west sides
of the city-wall witnessed two large new residential

precincts. The Nanjing Planning Bureau has proposed
new towns around the main city in its 1991–2010
Masterplan (Nanjing Planning Bureau, 1998; Fig. 2;
hereinafter referred to as the Masterplan).

3. Study of green wedges at the
metropolis scale
3.1. Ideal city configuration in relation
to greenspace
Howard (1898) pioneered consideration of the green
dimension of urban forms, besides traditional functions such as employment, transport and housing. His
garden city concept included a compact group of cities
with intervening green areas. A rapid transit system
was to connect the ancillary cities with the central
one. The notion of greenspaces encircling a central
city has been translated into the planning instrument
of green belt to confine unbridled urban sprawl in England (Toft, 1995) and other places. It serves as a buffer
between city and countryside, limiting urban extension and safeguarding farmlands from encroachment,
whilst also providing open spaces with easy access.
It is, however, often difficult to sequester future city
development by a girdle. The somewhat rigid green
belt has been widely breached by leap-frog growth


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Fig. 2. The official Masterplan of Nanjing city for 1991–2010 (Nanjing Planning Bureau, 1998).

C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

(Frey, 2000) and sprawling into productive farmland
beyond it.
The idea of sustainable development, introduced in
the 1980s, ushered the adoption of ecological concepts in urban planning. Landscape ecology seeks to
explain landscape structure based on three fundamental spatial concepts, namely matrix, patch and corridor, with reference to flows of energy, materials and
organisms. The matrix is the most extensive and dominating landscape element. At the regional scale, the
ideal landscape configuration is city patches encompassed within a greenspace matrix with diversified
habitats to foster biodiversity. The greenspace–city interface should preferably be convoluted and curvilinear (Fig. 3) to facilitate nature’s penetration into urban areas (Forman and Godron, 1986). The resulting
green wedges serve as natural corridors linking the
inner-city with the extensive countryside matrix.
A city patch should have a high perimeter-to-area
ratio to maximize exchanges with the matrix environs. The edge effect can enhance habitat and species
diversity and population abundance. An elongated
patch with a longer border allows more interactions
with the surrounding matrix. Thus linear greenspaces
should be incorporated into urban areas to maximize
edge effects, such as line, ring, or star with radials

Fig. 3. A star-shaped configuration of the city–countryside interface
with a curvilinear and convoluted outline that provides a long
contact boundary and generous penetration of nature into urban
areas.

5

(Blumenfeld, 1949; Moughtin, 1996). An ideal city
form could have one dominant center with several

radial fingers. The compact center facilitates efficient land-use, and the fingers support flexible urban
growth based on public transport. The development
along the length of concentric rings, which interrupt
green wedges, is not encouraged.
3.2. Analysis of urban form and expansion
Three archetypal urban forms defined by geometric
shapes can be identified: linear, centralized and gridiron cities. The linear form has a major transport axis
linking key facilities. Linear cities could grow spontaneously in two directions along the axis. The highly
centralized city is dominated by a central public space,
with extensions along radial roads to form urban fingers connected by ring roads. This geometry leads to a
highly compact center, whereas away from the center
low-density development is possible with penetration
by green wedges. The gridiron form is common in
American and Asian cities. The chessboard layout
adopted since the Western Zhou Dynasty (1028-771
b.c.) has a lingering influence on city form in China
(Wu, 1993). Gridiron cities can comprise several rather
autonomous parts. Expansion occurs by adding parallel roads to the existing lattice to maintain a regular
growth pattern. If developed to a high-density, it tends
to exclude greenspaces. If developed at a low-density,
it caters mainly to private traffic and is ineffectual in fulfilling compact city objectives (Moughtin,
1996).
The real-world city form is often a hybrid of the
basic types, echoing imprints of physical and cultural
influences through time. For Nanjing, the inner-city
core enclosed within the Ming Dynasty (1368–1644)
city-wall has a gridiron system of four north–south
main roads intersecting four east–west ones. Outside
the wall, the regularity is interrupted by the surrounding hills. Several radial urban fingers with major transport lines have penetrated between the uplands. Thus
Nanjing blends three basic urban forms: gridiron of

the compact core, linear of urban fingers extending
radially from the core, and complex centralized form
as aggregate of both elements. The uplands between
the fingers constitute green wedges, suggesting that a
model of green wedges associated with urban fingers
is an appropriate green development pattern.


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4. Study of green network at the city scale

4.2. Physical landform assessment

4.1. Objectives and approach

In a mature compact city, usually few notable
landform features are spared from development,
such as rivers and hills which are ideal for greenway use. Nanjing incorporates diversified landform
features in the city. A series of hills (Fugui, Jiuhua, Beijige, and Gulou, Wutai, Qingliang) stretch
from east to west, forming the watershed between
Jinchuan River valley and Qinhuai River valley in
the urban area; Gupin and Shizi Hills run from
south to north inside and along the city-wall. On
these uplands, parks of 3–30 ha have been built,
conserving semi-natural to natural areas within the
city.
Two lakes and two rivers define the drainage system. Xuanwu Lake (3.7 km2 ) west of Purple Mountain

and Muchou Lake (0.37 km2 ) west of the city-wall
have been developed into municipal parks. Qinhuai
River runs through the city from southeast to northwest to join the Yangtze River. It bifurcates into a
cluster of tributaries that spread in the south city. The
main branch that runs along city-wall perimeter into
Yangtze River is labeled Outer-Qinhuai. In ancient
times it served as the city’s major transport route
(Nanjing Freeway Administration Department, 1988).
At present only a small section near Yangtze is navigated (Nanjing Gazetteer Editorial Office, 1994a).
The other stream, named Inner-Qinhuai, bifurcates
into two tributaries after flowing through the city-wall
at the Tongji Gate. In the north city, Jinchuan River
runs through the city from the south to the north into
Yangtze River, with a canal connecting to Xuanwu
Lake.
In Nanjing’s long history, many canals were constructed to connect the districts with water traffic. The
notable ones include Qingxi, Yundu and Chaogou
built in a.d. 240 (Nanjing Freeway Administration
Department, 1988). Also, moats were built at different locations to defend the city. In the last 1800 years,
most canals and moats were clogged or filled, leaving
intermittent sections. They have since lost their transport and military functions, but remain as stormwater
and sewage channels. As most sections juxtapose
present roads, some water-edges have been developed into roadside gardens (such as Zhenzhu Garden
along North Taiping Road). If the water quality could
be improved, the drainage system could allow linear

An ideal greenspace layout calls for a green network
embedded within urban areas (Forman and Godron,
1986). It separates urban areas, enhances landscape
impacts, and facilitates environmental and ecological

functions. The green network is materialized as a comprehensive greenway system which furnishes an alternative municipal green infrastructure. Endowed with
natural amenities and a path, a greenway serves multiple functions, such as protecting and enhancing natural
heritage and cultural relics, and providing open space
for passive recreation (Flink and Searns, 1993). It is
widely embraced by municipal governments, planners,
ecologists and the public. The greenway form could be
flexibly molded to connect parks, nature reserves, cultural features or historic relics, and often follows natural landform alignment such as riverbank, valley and
ridgeline. Each greenway could be uniquely designed
to match local conditions, rendering the approach quite
amenable for mature cities. It should be stressed that a
chlorophyll continuum alone does not imply a habitat
connection. For some sites, ecological attributes need
to be modified or created for habitat optimization to
enhance the natural functions of the greenways.
The network configuration furnishes a practical
framework for greenspace planning in Chinese cities.
Firstly, its linearity suits the compact urban form. In
China, urban land is limited and congested, at merely
70–100 m2 per capita, with scant greenspaces. The
greenway network could use derelict or unused lands
such as water-edges and slopes to minimize conflicts
with development. Secondly, new greenspaces can be
planned at greenway intersections and strategic locations to connect isolated green pockets. The linked
and integrated greenway system can act as a catalyst
to preserve existing greenspaces and generate new
ones. It reduces some common conflicts in Chinese
cities, such as road widening versus street trees, and
housing development versus green fields. The connections between the green enclaves can stem the
tendency to eliminate small and isolated greenspaces,
which are the most common form of greenspaces

in Chinese cities. Thirdly, the network can be designed to improve accessibility of greenspaces with
footpaths, footbridges and underpasses.


C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

greenspaces to penetrate into the congested urban
fabric.

Table 1
Major greenspace categories of Nanjinga
Area (ha)

4.3. Urban context analysis
Park

South Nanjing is more densely-populated than the
north, accommodating the original urban core with
dense packing of buildings separated by narrow streets
and scant open spaces. The three southern districts,
Qinhuai, Jianye and Baixia, have a built-up population
density reaching about 30,000 persons/km2 . The south
city, especially the old downtown along Inner-Qinhuai
River, urgently needs greenspaces to relieve the congestion. The north city has more institutional lands
such as government agencies and colleges. The residential neighborhoods there, mostly developed after
1949 in the closed-yard style (Wu, 1993), have a lower
built-up density with greenspaces interspersed between buildings (Nanjing Gazetteer Editorial Office,
1994b).
Urban planning could guide future land-use and
population distribution with influence on greenway

location. The Masterplan has earmarked farmlands
between Yangtze and Outer-Qinhuai Rivers for a
new residential district of over 100,000 inhabitants
(Nanjing Planning Bureau, 1998). A greenway system
could extend into this area to forestall excessive development and to preserve adequate recreational land.
The Masterplan includes redevelopment projects,
such as improving the old city core and rebuilding
poor-quality housing in the old downtown. These
schemes bring ample opportunities for greenways
through town-plan re-structuring. The relevant national ordinance stipulates 25% of urban land for
greening, furnishing a statutory basis for a comprehensive greenway system.
Upgrading the urban transport system could also
incorporate greenways. In Nanjing’s old city, the
gridiron urban form has bequeathed a lattice transport system. Greenways can be established along
selected roads equipped with widened amenity
strips and roadside trees. The criss-crossing primary
roads, however, break greenway continuity which
needs footbridges and underpasses for uninterrupted
pedestrian-movement. Such links could be planned
comprehensively in conjunction with the underground
railway system, which is under construction, to maximize accessibility and connectivity of the greenways.

7

Number Green
cover (%)

Notable features

100–3000 7

1–100
30

70–99
55–97

<1

3

50–70

0.1–7

34

40–100

Dominated by lawn
Scant woody
vegetation

Garden 0.2–2

22

40–90

Small enclaves
beside roads

<0.2

22

50–100

Plaza

Entry fee is charged
Active reactional
facilities

a This table is calculated from data of urban environment enhancement in Nanjing, edited by The Administrative Bureau of
Landscape and Gardening of Nanjing (1998).

4.4. Conservation elements assessment
The conservation elements include existing open
spaces, cultural relics, historic sites, rare species, and
valuable ecological habitats. They are scattered in the
city, separated by roads or buildings, and could be incorporated into the greenway system.
Existing open spaces in Nanjing mainly include traditional urban parks, recently built plazas and small
gardens beside streets. In 2000, 24 of the 40 parks
(Table 1) are located in the main city. Most parks
are associated with natural landform or historical features that can act as key nodes in the greenway system. Since 1996, nine new plazas each covering over
1 ha have been established in the main city. They are
largely situated at main-road intersections, dominated
by lawns and ornamental pavement, to serve transport, recreation and landscape functions. In addition,
small gardens each of 0.02–2 ha have been established
beside secondary roads, usually densely covered by

tree canopies for passive amenity. Some were included
in housing developments as residential greenspaces.
Others were developed from derelict edges of canals
and moats in tandem with road widening. As increase
in human density shifts habitat value from the urban
ground level to the overhead canopy, artificial cavities
and other measures could be created on trees to augment their habitat value to a variety of animals and
amenity value to humans.


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C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

Greenspaces and cultural heritages serve synergistic
recreation functions, with the latter adding interesting
and knowledge-based ingredients. With a 2000-year
history and as the capital of ten dynasties, Nanjing
has 142 protected items of national, provincial or municipal cultural relics, including cemeteries, temples,
notable buildings and historical sites. Private, public or royal buildings and historical relics dominate
the inner-city sites, with potential to enrich the attraction of greenways. The Ming Dynasty city-wall is
the most prominent feature (with a 34 km perimeter,
over 14 m height, 14 m base width and 7 m top width;
Nanjing Freeway Administration Department, 1988).
A city-wall landscape belt has been incorporated in
the Masterplan. However, the existing gridiron road
system frustrates this green ribbon concept. Existing
or planned main roads going through the green rib-

bon should be reduced, and unavoidable intersections

should be treated sympathetically to facilitate continuity and accessibility of greenspaces.
Champion trees constitute a living cultural heritage of the city, and they are protected from felling
and transplanting by national ordinances. In Nanjing, 1132 trees, including many large ones over 70
years old, have been officially designated since 1982
(Nanjing Greening Committee, 2000). They are scattered in residential, government, industrial and park
lands, and many are potential landmark features for
greenways. Large trees grace parkways that link the
major commercial centers (such as Zhongshan, North
Zhongshan, South Zhongshan, East Zhongshan and
Hanzhong Roads; Fig. 4). Unfortunately, some have
been felled since 1993 to widen roads, and the remainder are threatened by rapid urbanization. Such

Fig. 4. Streets with existing large mature trees and roadside amenity strips in Nanjing.


C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

sylvan parkways need to be protected, and their
pedestrian-movement function reinforced in crowded
downtown areas.
5. Study of green extensions at
neighborhood scale
5.1. Social functions and design
requirements
Small greenspaces at the neighborhood scale cater
to daily needs for contact with nature. Burgess et al.
(1988) found that the most valued open areas are the
intimate and familiar ones that play a part in peoples’
daily lives, rather than the distant ones. The demand
for home-juxtaposed greenspaces calls for distance to

homes within 400 m or 10 min of walking. Quantitative criteria have been adopted in some countries to
foster penetration of greenspaces into crowded areas.
For instance, Singapore’s facility planning standards
for new towns suggest one local garden (at least
0.2 ha) for 3000 dwelling units (Foo, 2001). Similar
greenspace standards in China stipulate not less than
1 m2 per person for a neighborhood with 7000–15,000
people (State Technology Supervision Bureau and
Construction Ministry, 1994).
Detailed design of greenspaces could attend to the
need to attract patronage, such as easy accessibility
by most users and catering to neighborhood resident activities. Friendly entrances to the greenspaces
and comfortable connecting footpaths are suggested
(Taylor, 1978; Hough, 1989). Marcus et al. (1990)
proposed that certain park areas should be left for
spontaneous plant growth or to be designed by park
users, aiming to maximize the diversity of pleasurable experiences. Physical arrangement of facilities
for special user groups could meet the varied needs
of the neighborhood. Unsuitable design might result in low usage of neighborhood parks even in the
crowded metropolis. Joardar (1989) studied 14 local
parks in Calcutta, and found that poor visual quality and facility accounted for low popularity. Some
well-maintained public spaces might be shunned if
they ignore inhabitants’ needs.
As a public place, the neighborhood greenspaces
could encourage informal community meetings.
Comfortable seats at suitable locations could be de-

9

signed for people to meet, view and converse with

other residents. These places might become tangible
reminders of childhood and community life, with
plants playing a key role in forging the community
sense. Willeke (1989) observed that for most Americans, home is where the trees are. In China, trees
are also commonly related with the hometown. A
public place with vigorous trees of well-selected
species presents an attractive vista and serves as a
symbolic community image. Meeus (2000) suggested
that public gardens with unique designs could bestow
on each district a recognizable character and furnish
signature sites. Inhabitants have varied expectations
of neighborhood greenspaces, ranging from contact
with people to nature. Based on local physical and
cultural conditions, designers could provide a mixture of opportunities with varied environmental features and leisure facilities. A green connection with
greenspaces is a good measure to present users with
more choices. Connection increases habitat diversity
and capability to support flora and fauna, which in
turn enhance amenity value to humans. Such functions are increasingly valuable as human density
rises, accompanied by more isolation from functional
green.
5.2. Ecological benefits and design
implications
Plants especially trees in the city can improve
the environment by shading, intercepting pollutants,
attenuating noise, absorbing carbon dioxide and emitting oxygen. At the neighborhood scale, trees can
reduce building energy consumption due to cooling
and windbreak effects (Rudie and Dewers, 1984;
Davey Resource Group, 1993; Simpson and
McPherson, 1996). For air pollutant interception,
conifers are commonly suggested due to the high surface area, evergreen growth habit and effectiveness

(Dochinger, 1980; Mao et al., 1993). More vegetation
especially trees should be brought into urban areas
individually or in groups to maximize their ecological
benefits.
Abundance and diversity of wildlife indicate
ecosystem stability, which depends partly on habitat diversity. Within the urban fabric dominated by
artificial surfaces and structures, greenspaces act as
refuges for wildlife. They can also sustain some


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uncommon and rare plant species that are vanishing
in nature. Measures to enhance wildlife increase the
attraction of greenspace to humans. For the white
pine in the USA, Neuenschwander et al. (1999) suggested planting them on neighborhood streets, parks
and backyards to revive the declining species. In addition, more native species should be introduced into
urban forests to counter the domination by exotics
(Rowntree, 1984; Jim, 1991).
The remnant natural habitats in cities, with limited human interference, provide valuable sites for
diversified wildlife. They form unique urban communities that differ from the countryside ones. Anthropogenic and synanthropic species thriving under
semi-natural conditions have been reported by Gilbert
(1991) at a small discarded site in Sheffield, England.
Remnant natural habitats provide proximate ecological education opportunities compared to remote countryside locations. In addition, the edges of a river, lake,
stream, creek, canal or pond have particular value for
wildlife. Cook and Lier (1994) identified seven ecological zones at a canal cross-section to support different
life forms. The unmanaged vegetation at path verges
provide habitat for insects and food for seed-eating

birds. Some abandoned industrial sites or unused lands
within large factories have been commonly claimed
as semi-natural habitats by wildlife (Hough, 1989,
1994).
City birds and their habitats have been closely
examined. Davey Resource Group (1993) found
the highest bird density in areas with the largest
trees, greatest tree species richness and abundance
of ruderal growth. Tomialojc (1998) suggested that
high bird density might be related to the absence
of main predators and availability of natural food.
To maximize opportunities for wildlife, the communal greenspaces of neighborhoods could incorporate
some natural enclaves. The planting palette could emulate indigenous composition and biomass structure,
trigger successional changes, and create conditions
for spontaneous wildlife invasion. Landscape ecology
(Forman and Godron, 1986) and island biogeography theory (MacArthur and Wilson, 1967) provide
fundamental strategies for greenspace system design.
For small neighborhood greenspaces in Nanjing, a
network of greenways and green wedges is suggested
to link isolated green patches within and without
the city.

6. Patterns of green extensions at
neighborhood scale
6.1. Riparian linkage for the gridiron urban fabric
The riparian network provides a natural order for
public greenspaces at the neighborhood scale. Stream
banks, usually embedded in the urban fabric and often
ignored by people, are being rediscovered in Chinese
cities. They serve as the backbone of the greenspace

network, determining the location of new linear parks
and giving a skeleton to green connectors. The diversified wildlife habitats at water-edges can provide
various amenities for visitors. The pedestrian paths
along the riverbank can avoid conflicts with vehicular
traffic. As a natural indicator of unity and coherence,
the riparian network can be creatively used in urban
design to relieve the harshness of urban environment
and bring vitality to the downtown. Cases in point include the Royal Spring Park in Georgetown, Kentucky
and the Creek Front plan in Denver, Colorado (cover
story of Landscape Architecture, February, 1994), and
the Garrison Creek Linkage Plan in Toronto, Canada
(Pedersen, 1999).
6.2. Pedestrian route
Based on the belief that the whole is more than the
sum of the parts, the linkage system at the neighborhood scale aims at connecting existing isolated residential greenspaces with municipal parks and other
extensive greenspaces. A pedestrian way can act as a
substantive connector, through which inhabitants walk
from home directly to adjacent or more distant parks,
or even walk to the downtown. Definite destinations
and landmarks associated with the route can make the
linkages attractive. For example, the Creek Front plan
of Denver incorporated a series of pedestrian spaces
connecting the Denver Convention Center, Larimer
Square Historical District and with other destinations
to add vitality to the downtown.
6.3. Street and streetside system
Tree-lined streets can be enlisted as green corridors to provide continuity to the greenway network
where the drainage system cannot reach. Along the
route, crosswalks, signalized intersections and transit

C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

11

stops could be created or relocated to ensure the
convenience, comfort and safety of pedestrians. If
breaks in the green network are difficult to join due
to present structural and town-plan constraints, continuity should be proposed for the long-term. For instance, fences could replace concrete walls to expose
the greenery, and the streetscape quality of traffic islands, underpasses and medians could be upgraded to
soften concrete dominance. For high building-density
neighborhoods, the garden block strategy (Dekey,
1997) could be adopted. Several contiguous blocks
of greenspaces could serve as a green corridor with
residential blocks at two sides. Buildings can occupy
half of a block’s width, leaving the remainder for
greening (Fig. 5). Such linear garden blocks function
as residential greenspaces as well as green connectors for the overall green network. Where physical
constraints do not permit a better design, even alleys
could be converted into linear greenspaces.
6.4. New parks
New parks could be created at nodes of the drainage
or street systems. The intersections command a large
visitor catchment, and provide more route choices to
other destinations. Besides, the larger water area advocated for the new parks, with appropriate treatment
to optimize habitat conditions, considering the spatial
constraints, could attract more wildlife and provides
humans with more amenities for natural contacts.
Waterfront parks often have attractive natural endowments to attract patronage. In Denver’s Creek Front,
the drop structures to stabilize the channel act as dramatic water features. In Royal Spring Park, a dam is

designed to hold a pool of water stocked with trout
and a deck allows fishing in the stream. Both cases
are equipped with paved banks to facilitate visitors
touching the water.
6.5. Planting scheme
An indigenous-species planting scheme for the
green network could attend to species diversity, microclimatic moderation and aesthetic coherence. A
native vegetation composition is conducive to providing the right kind of food and shelter to native animals, the presence of which create a truly functional
green complex to augment amenity value to humans.

Fig. 5. Two patterns of green corridors that penetrate high building
density areas at the neighborhood scale are proposed for Nanjing.

Firstly, the existing vegetation should not be cleared
except for footpath construction. Natural treatment of
river edge could encompass a variety of plant species,
texture and color, and a low-maintenance landscape.
For most situations, a natural forest section could be
planned, including a main forest canopy, understory
trees, shrubs and herbs. Secondly, native species could
be given priority, supported by systematic identification of suitable candidates by form, texture, growth
rate, city tolerance and maintenance requirements
(Jim, 1999). Thirdly, certain species could be planted


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C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

throughout the project areas to provide coherence,

accompanied by varied species configuration, planting density and crown texture. Continuity, rhythm,
repetition and linkage could provide a quiet and pervasive order for urban landscape design in conjunction with its intimate partner, habitat design. Fourthly,
water-edge vegetation could be designed in relation to
the overall urban landscape. Formal tree planting usually reflects civic quality whereas naturalistic planting
indicates variety. For focal points with excellent vistas
or sections leading visitors to water, sparsely planted
trees in an extensive lawn could be adopted, and barrier planting discouraged. Associated civic projects
could be incorporated in the greening plan, including
improvement in lighting on streets and in parks, street
furniture, water quality and diversion of sewers.
6.6. Greenspace-oriented urban design for
high-density development
For most Asian cities, the acute conflicts between
urbanization and limited land produce crowded cities
with inadequate open spaces for humans and wildlife
(Jim, 2000). In Singapore, some new towns developed
under the Concept Plan provided a new high-density
pattern (Yuen et al., 1999; Foo, 2001) characterized by green connectors and strategically located
greenspaces with several key features: (1) a new town
is constituted of neighborhoods and precincts in a
three-tier hierarchical structure, with each basic-level
precinct holding 2500–5000 people in a few high-rise
apartment blocks; (2) the blocks are laid out in various orientations around a central precinct park of
about 0.2 ha; (3) all precinct parks are connected to
each other and to other public amenity places; (4)
the park connectors are located along drainage reserves and other non-built-up areas to optimize use
of the land resource and to provide green corridors.
The hierarchical-cum-connected greenspace system
permits easy accessibility to residents. Despite the
high-density and high-rise configuration, spatial congestion has been reduced by creative building design

and layout. The population and land area covered by a
Singapore new town are similar to some Nanjing districts. Compared with a standard Nanjing new town
and Jianye District (Table 2), the Singaporean model
provides residents with more high quality greenspaces
by patch number and total area.

Table 2
Comparison of greenspaces between a Singapore new town and
the Jianye District of Nanjing
Singapore
new towna

Jianye District
of Nanjingb

Land area (ha)
Population (persons)
Population density
(persons/ha)

625
125000–250000
200–400

666
202100
303

Size (ha), number of
greenspace

0.2, 30–42
1–1.5, 5–6
5–10, 1

0.2–1.0, 10
1.0–5.0, 1
5–10, 0

Total area of
greenspace (ha)

16–27.4

6.5

a

Foo (2001).
Data on land area and population are adopted from Nanjing
Statistical Yearbook 1994; data on greenspaces are derived from
The Data Collection of Municipal Facilities Survey: Gardening
and Landscape (1995).
b

The Singaporean model has assured implementation by the public housing policy and clearly-defined
land-use patterns. It is difficult for the disparate private or semi-public developers in Chinese cities to
adopt a similar approach. An alternative and flexible
green framework can be tested in Nanjing’s new development areas, such as west of Outer-Qinhuai River
(Fig. 6). Based on existing stream and road systems,

several north–south and east–west green corridors can
be formed, with their intersections hinting potential
locations for new parks. This green framework departs
from the conventional passive approach in allocating greenspaces. It could coordinate the provision of
a greenspace network among neighborhoods that are
laid out as coordinated clusters of high-rise buildings.
More importantly, it can curtail the expansion of the
anachronistic chessboard urban form from the old city.
After defining the greenspace boundaries, the plan can
be implemented in phases. The conserved land meanwhile could continue to be covered by agriculture or
natural vegetation until development is triggered.
7. Applications of landscape ecology principles
7.1. Green wedges
The proposals for five green wedges in Nanjing are
closely related to landform; they have forest covers and
are connected to the countryside (Fig. 7). Two green


C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

13

Fig. 6. Six green corridors that link the current and planned clustered development areas at the city scale are proposed for Nanjing.

wedges of farmland, in the southeast and southwest,
can protect cultivated lands and break up the otherwise
monotonously contiguous urban developments. Mufu
Hill in the north is an elongated belt beside the Yangtze
River. It is almost engulfed by the urban fabric except
for the narrow riverbank which serves as a corridor

to the extensive countryside. The Hill is an important
scenic area of Nanjing and was highly appreciated
by ancient poets. About half of its forest canopy has
been destroyed since the 1970s due to quarrying. The
government intends to restore the damaged forest to
promote tourism. Connectivity with the greenspace
matrix should be conserved or rebuilt. Yuhua Hill
in the south provides extensive greenspaces for the
nearby densely-populated old downtown. It is physically segregated from the inner-city by the railway and
city-wall, hence suitable access should be provided.

Purple Mountain in the east is the largest wedge with
luxuriant vegetation cover. The extensive greenspace
penetrating into the city is significant for microclimatic
amelioration and recreation. The area was protected
from urban expansion except for some recreation facilities until the early 1990s when high-income housing developments intruded into the green fields. With
aggravating congestion in the city, the high-quality
greenspace attracts people for its fresh air, beautiful
scenery and easy access to the city. Also, recent advances in construction technology have permitted development on difficult terrain. Although intrusion into
green fields is officially forbidden, the developers enticed by high profit could often get permission.
In conserving the green wedges, two primary issues should be considered. Firstly, the boundary of
green wedge with the urban area should be clearly


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C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

Fig. 7. Five primary green wedges at the metropolis scale are proposed for Nanjing.

demarcated. It could be delineated with reference to
existing forest edges, contour lines (e.g. at 20 m), highways, or environmentally sensitive lands such as watershed protection areas and wetlands. Statutory designation as green belt or conservation areas can prevent encroachment, within which no construction is
permitted except for environmental improvement. A
buffer zone is needed in which limited developments
with little environmental impacts are permitted, such
as education or research institutes. The width of the
buffer zone should be equivalent to one to two city
blocks, about 500–1000 m. In selected localities of the
buffer zone, some low-density dwellings could be allowed after careful planning scrutiny. Secondly, the
connectivity of green wedges to the countryside matrix should be ascertained. Urban extension should be
confined to the fingers between the wedges, and development along ring roads that cut through the green
wedges must not occur. The tips of the green wedges
could be given special protection to avoid disruption
by urban sprawl.

7.2. Urban fingers
Urban fingers, in contrast to green wedges, originate from the central city and extend into the countryside. Four major urban fingers can be planned for
Nanjing, stretching respectively to the northeast, the
east, the southeast and the southwest (Fig. 8). They
are shaped by sympathetic accommodation of existing
greenspace layout, filling the space left by the planned
green wedges to avoid land-use conflicts. A major
public transport line should be planned for each finger to provide quick access to the center, along which
neighborhoods could be arranged in clusters for compact development (Moughtin, 1996). Besides this, ring
roads and circling railways around the city can provide
quick access between urban fingers. Most importantly,
development between fingers and along the ring roads
should be forbidden.
The Masterplan (Fig. 2) aims at conventional “fried
egg” urban development. A new urban center is plannedeast of the Purple Mountain, aiming to encompass

C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

15

Fig. 8. Four urban development fingers at the metropolis scale are proposed for Nanjing.

the big greenspace as a central park. However, this
design cuts off connectivity of the green wedge with
the broad countryside. It also fragments the Purple
Mountain area into a patch occluded within the urban
fabric. With this development mode, the green wedges
might finally be engulfed by urban expansion.
The urban fingers could also protect the Ming Dynasty city-wall. According to the Masterplan, the gridiron form would continue to spread west of Qinhuai
River, and many east–west roads connecting the central area would further breach the city-wall. As an
alternative, the western area should be treated as an
urban finger based on Jiangdong Road, and as the existing four east–west roads are enough, any additional
through-wall transport could be avoided.
7.3. Greenway network
Combining interpretation of landform, urban context, and conservation elements, the following major
greenways are proposed for Nanjing (Fig. 9).

7.3.1. City-wall circular greenway
The Ming Dynasty city-wall, built on a series of
hills and water-edges, has witnessed six centuries of
history and is associated with many historical events
and anecdotes. As a key cultural heritage element of
Nanjing, it deserves more attention and protection. It
has been broken into eight sections due to rapid and

poorly-planned urban expansion since the 1960s. It
was not designated as a provincial cultural relic until the 1980s. The remnant segments are collectively
21 km long, about 60% of the original length. They are
largely hidden behind juxtaposed buildings and spontaneous vegetation, and are hardly visible without a
careful search. Few walls are easily accessible to the
public, with only two short sections around Zhongshan and Zhonghua Gates restored as tourism spots.
This proposed greenway follows the city-wall alignment. The project incurs modest cost and could return
the wall to the people. The wall and its environs could
be equipped with easy access, simple facilities and a
trail lined by ruderal vegetation. A linear woodland


16

C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

Fig. 9. Major greenways are proposed for Nanjing: (A) city-wall circular greenway; (B) canopy-road greenway exemplified by the Zhongshan
Road parkway; (C) the Zhongshan Road parkway before it was degraded by recent tree removal; (D) Inner-Qinghuai-River greenway.

corridor to connect them and to screen the associated
trail from vehicular traffic could fill the gaps between
wall segments. Ten existing parks situated along the
wall perimeter are associated with high-caliber natural or cultural endowments. The new greenway will
link these disparate venues to forge a greenspace system, enhancing access, visitorship and recreational
choices. New parks can be installed at strategic greenway nodes. At the intersection of West Beijing Road
and the greenway, a new park could be installed to
extend northwards to Gulin Park and southwards to
Shitoucheng Park, thus constituting an extensive waterfront landscape corridor. Another large park could
be established around the confluence of the Outer- and
Inner-Qinhuai Rivers to provide extensive greenspaces

for an enlarged visitor catchment that is within walking distance of the old downtown, and to promote
amenity use of the urban fringe.
Beyond the wall, an almost continuous network of
rivers, moats and lakes skirts the wall environs ex-

cept the Purple Mountain section. Between the watercourses and the wall, a narrow strip of no more than
15 m lies either vacant or is occupied by poor-quality
houses and roads. This 34 km perimeter with relatively
few road junctions could be cleared and converted into
a water-edge cycling-hiking trail (Fig. 9A) to run adjacent to the wall alignment. At the wall breaches, new
accesses could link the wall, trail and parks. Spontaneous mural vegetation should be preserved, to be supplemented by new planting. The water-edges opposite
the planned trail could be developed into riverbank
parks in conjunction with nearby housing developments to create a walkable neighborhood (Walmsley,
1995). Flink and Searns (1993) suggested that a natural rough channel edge is more suited for aquatic
wildlife than a smooth one free of debris and vegetation. However, most urban river edges of Nanjing have
been covered by concrete associated with flood control
projects (Nanjing Gazetteer Editorial Office, 1994a).
The ecological functions of the remainder should be


C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

conserved or restored to a natural state along the proposed riverbank parks as part of the habitat creation
and management process.
7.3.2. Canopy-road greenway
This greenway enlists the 12 km Zhongshan Road,
which links the major commercial centers of Nanjing.
Since it was built in 1929 to lead to Dr. Sun Yat-sen’s
(founding father of modern China) mausoleum, the
road has served as a transport trunk and a symbolic

city axis. Influenced by early 20th century American parkway fashion (Wilson, 1989), the road was
designed to be 40 m wide, including dual-three carriageways lined by six rows of plane trees (Platanus
acerifolia; Fig. 9B and C). Other avenues in the same
tree-lined style were proposed in the National Capital Plan of the 1920s, such as Baixia, Hanzhong and
Changjiang Roads (Wu, 1993; Cody, 1996). The parkway system links urban parks and neighborhoods into
a city-wide greenspace system. Impacts of the massive tree-planting program have become conspicuous
after some decades. Many trees have reached huge
dimensions, providing significant cooling effect and
noise attenuation (Mao et al., 1993). The spreading
limbs form arboreal arches above carriageways, imprinting an outstanding signature landscape and bestowing pride on its citizenry. Unfortunately, like other
roadside greeneries, these magnificent trees could not
escape losses under urbanization pressure. The four
rows in the medians were felled to widen roads in
1994. The remnants are threatened with further destruction from increasing traffic demands and conflicts
between trees and adjacent buildings.
The greenway plan aims to restore the landscape
quality of the degraded parkway. Firstly, carriageways
could be reduced to provide growing space (Fig. 9B).
The remnant tree strip could be widened to at least
4 m, where trees, shrubs and grasses could jointly establish a native and naturalistic plant community. A
minimum distance of 6 m between tree trunk and adjacent building could be instituted to reduce conflicts.
The design and footprint of buildings and subway stations could be sympathetic to existing and future needs
of trees. The reversion to the original carriageway
width may reduce traffic capacity, but improvement
in transport management that hitherto has been sparingly used could offset the effect of the reduction. Secondly, a pedestrian–bicycle path system parallel to but

17

separate from the carriageway could be incorporated,
with provision of footbridges and underpasses. In the

commercial center, such as Xinjiekou area, pedestrianized streets generously planted with trees are suggested. At some intersections, the footpath could be
diverted to nearby roads to avoid conflicts with vehicular traffic. Based on the former parkway network,
the proposed greenway could form a backbone for an
integrated city-wide footpath framework. Successful
cases have been implemented elsewhere, such as Portland (Oregon) where a major highway was rerouted
and replaced with a Park (Langdon, 1992), and San
Francisco where a freeway was converted to a boulevard plus a light-rail line (Thompson, 1993).
With multiple functions and potential benefits, the
greenway plan should be acceptable to the public and
the government. Firstly, the roads lined with graceful Platanus acerifolia connote cultural and natural
significance as the city’s icon. Secondly, tree-lined
boulevards traversing commercial–residential districts
are welcome by residents as surrogate urban parks
in the congested inner-city, allowing leisurely strolls
or cycling under green canopies. They attract heavy
pedestrian flow and improve business for the shops.
Such streetscape improvement could obtain financial
support from the business sector, as exemplified by
Dongfang Road in Shanghai (Zhou, 1999). The Masterplan has set city-center enhancement as a priority
objective, a feasible project backed by successful cases
elsewhere, such as Kansas (Missouri) and New York
(Little, 1990; Walmsley, 1995).
7.3.3. Inner-Qinhuai River greenway
This greenway targets the south branch of InnerQinhuai River from Tongji Gate to Shuixi Gate. It
is 4069 m long and 12–30 m wide, running through
the old urban center. In ancient times, the flourishing district accommodated fine houses of rich
people and high officials. Some houses built in the
Ming (1368–1644) or Qing (1644–1911) Dynasties
have been preserved (Jiang, 1980; Nanjing Gazetteer
Editorial Office, 1996). Like many ancient cities

originally rooted in the river, modern Nanjing shuns
its geographical and historical provenance, neglects
the old downtown, and shifts the center north to the
present Xinjiekou. In the city core, old buildings are
decaying, open spaces are encroached upon, and the
river is polluted by sewage. With dense population,


18

C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

Fig. 10. A proposed pilot landscape improvement project for linear greenspaces along old canals in Nanjing: (A) location of the target
area; (B) layout of the six green corridors (labeled 1–6); (C) landscape design and recommended tree species for the green corridors.


C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

heterogeneous land-use and the need to protect cultural heritage, urban redevelopment has confronted
difficulties. The greenway plan could shed light on the
old downtown. For the two strands of Inner-Qinhuai
River, a linear park, a waterfront esplanade, and a
tree-lined ‘promenade’ are suggested (Fig. 9D). The
footpath running through the linear park near the rehabilitated riverbank affords unobstructed sight of the
river. Valuable old buildings could be incorporated
in the park as interesting heritage features. A street
could serve as a separator between the park and the
adjacent built-up areas.
A new park could be planned based on the existing
Zhonghua Gate Park at the tip of the v-shaped river

course. It could serve as a node linking the riverbank
greenway to the city-wall greenway, to present an
alternative route for walking through the commercial center. The park could be abundantly filled with
trees to create an urban forest to envelop the ancient
city gate. For the old downtown community, these
greenspaces could enhance the quality of life, the
health of citizens and natural areas, and residents’
pride (Shafer et al., 2000). Moreover, the improved
community ambience could attract new businesses
and developments which are earnestly sought by the
government.
7.3.4. Greenway extensions
The above three greenways constitute the primary
framework of Nanjing’s greenway system. Others
can be inserted to interweave with or extend from
them to connect to green wedges in the urban fabric.
For instance, a east–west greenway across the city
could link the Purple Mountain and Yangtze River
along East Beijing Road, West Beijing Road and
Caochangmeng Street. It can string together several
small parks and many large institutional grounds, including Jiangsu Provincial Government, Nanjing Municipal Government, colleges and research institutes,
in which abundant greenspaces and outstanding trees
have been identified in the 1998 field survey. The
existing large roadside trees can shade the pedestrian
and cycling paths. In adjacent institutional grounds,
see-through fences could replace concrete walls to
improve path-side landscape. Moreover, the enclosed
green enclaves could be open to the public on holidays. Along the greenway, new greenspaces are
proposed as rest gardens and connectors. In the north

19

city, a greenway based on an abandoned railway line
linking an obsolete mine in Mufu Hill is proposed,
in conjunction with the government’s rehabilitation
of degraded hills with afforestation. This rail-trail
project with improved and diversified public access
could be incorporated in the city’s greening program.
Furthermore, the greenways can sprout branches
extending into neighborhoods along streets, rivers,
miscellaneous open spaces within or around residential areas, factories, and institutions. Such green extensions could cater to residents’ day-to-day demand
for nature and amenity, and provide essential connectors in the urban fabric, through greenways and green
wedges, to the extensive peri-urban green matrix.
Historical canals are pervasive within the urban fabric, providing a ready framework for green extensions
into crowded residential neighborhoods. Based on the
canal system in an inner-city block with scant public
open areas, a greenspace system is proposed to include three parks and six green corridors (Fig. 10).
The three new parks are small linear entities located
at road junctions adjacent to the canal. They are either new venues or extension of existing ones with
additional recreational facilities and access. Based on
habitat conditions along the six green corridors, trails
and tree sites are designed as shaded walkways, forest
strips, or water-edge parks with lawn and sparse trees.

8. Conclusion
Interviews with some government greenspace planners of Nanjing suggested a lack of a theoretical basis
or a holistic framework to guide greenspace distribution at different scales. This ad hoc approach has resulted in a piecemeal greenspace plan which is dictated
by urban development, with scant consideration of location vis-à-vis other features, connectivity between
venues, habitat and species diversities, and incorporation of environmental improvements. Such shortcomings have prompted this study for a comprehensive
greenspace planning framework that involves practical

applications of ecological and landscape-ecological
principles.
The proposed comprehensive greenspace framework aims at fulfilling some fundamental landscape
ecology requirements. It is composed of green wedges,
greenways and green extensions to be implemented at


20

C.Y. Jim, S.S. Chen / Landscape and Urban Planning 998 (2003) 1–22

three scales. At the metropolis scale, the green wedges
are preserved as wildlife corridors linking the urban
fabric with the extensive countryside. They are filled
with forests as moderator of urban microclimate, as
air-sheds to supply fresh air and to flush away polluted
air, and as open areas situated at a convenient distance
for the enjoyment of nature in the countryside setting.
At the city scale, the greenways constitute a comprehensive and well-connected network within the urban
fabric. They satisfy recreational demands and serve as
habitats and migration routes for wildlife tolerant of
urban stresses. At the neighborhood scale, the green
extensions permeate deep into the urban fabric to provide intimate nature-contacts and recreational venues
that are important for residents’ daily life. The three
hierarchical green elements are substantively linked
to form a green matrix that enmeshes built-up areas,
defines the urban landscape and maximizes environmental benefits. The choice of species, landscape
design and habitat creation and management should
aim at an ecological approach marked by natural
successional changes, self-maintenance, high degree

of stability and biodiversity, and most importantly,
long-term sustainability.
The contribution of the greenspace network could
be established from different perspectives. Multiple
socio-economic functions are served by the lower hierarchy greenway and green extension designs, including frequent use, social integration, life enrichment
and neighborhood regeneration, which are recognized
as pertinent ingredients of a livable-city (Department
for Transport Local Governments and the Regions,
2001). Suitable locations for greenspaces are identified, such as remnant hilly patches geotechnically not
desirable for urban development, and other natural features and cultural relics that dovetail with greenspaces.
The drainage system consisting of Yangtze River, Qinhuai River and many canals thus have been enlisted
as the primary framework for greenspace permeation.
Their linearity and connectedness are pre-adapted to
the greenway notion.
Challenges from rapid urbanization on greenspaces
have been evaluated together with conservation measures. Five primary green wedges have been designated to guard greenspaces from encroachment, with
intervening spaces allowing for urban growth. Three
major greenways have been planned which link existing parks to provide high-quality open spaces that

could mold and frame new urban development or redevelopment. Based on an analysis of present neighborhood greenspaces, the green extension pattern has
been configured to comprise a combination of footpaths, streets, existing and new parks, planting areas
and associated amenity projects. These green extensions of various forms and functions, are intimately
intermixed with the compact city and serve to relieve
the harshness of the crowded gridiron urban fabric.
Above all, both the ecological framework and the flexible patterns are important measures for greenspaces to
penetrate into the city matrix. Further research on ecological benefits will shed more light on this greenspace
plan, especially by clarifying the ecological criteria to
determine green patch size, shape, interface with adjacent land-uses, and area coverage in urban areas.

Acknowledgements

The research grant support kindly provided by the
Committee on Research and Conference Grants of The
University of Hong Kong is gratefully acknowledged.
Thanks are also due to the Nanjing Municipal Government for information on urban planning and development, and to Mr. T.B. Wong for drawing the maps.

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