THE UK NATIONAL ECOSYSTEM ASSESSMENT
Managing urban ecosystems for goods and services
Kevin J. Gaston1,*, Mar�ıa L. �Avila-Jim�enez1 and Jill L. Edmondson2
1Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9EZ, UK; and 2Department of
Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
Summary
1. Concomitant with the rise in the proportion of the global human population that resides
in urban areas has been growth in awareness of the importance of the provision of ecosystem
goods and services to those people. Urban areas are themselves of significance in this regard
because of their areal extent, and hence the quantity of services falling within their bounds,
and because of the need for local provision of services to urban residents.
2. Here, we review key challenges to the effective management of ecosystem goods and
services within urban areas.
3. These challenges include the structure of green space, its temporal dynamics, spatial con-
straint on ecosystem service flows, occurrence of novel forms of flows, large numbers of land
managers, conflicting management goals, possible differences between perceptions of urban
dwellers and the reality of the distribution and flow of ecosystem services, and the ‘wicked’
nature of the problem of ecosystem service management.
4. Synthesis and applications. Urban areas present very particular combinations of challenges
and opportunities for the management of ecosystem goods and services. The spatial and
temporal heterogeneity of green spaces greatly complicates the maintenance and improvement
in service provision as well as dramatically inflating costs. Spatial constraints on ecosystem
service flows mean that these can be highly dependent on the maintenance of particular areas
of connectivity, but also that provision of additional key points of connectivity may be
disproportionately beneficial to those flows. The existence of novel forms of flows of ecosys-
tem services in urban areas offers means of overcoming spatial constraints on more natural
flows, but will require the development of new kinds of ecosystem process models to inform
their design and management. The large numbers of land managers, conflicts between the best
approaches for managing for different goods and services, and frequent differences between
the perceptions of urban dwellers and the reality of urban landscapes create a complex
management context. The management of ecosystem goods and services is closely allied to
the challenges of conventional urban planning. However, applied ecology has a broad range
of tools available to assist in determining solutions, including the use of high-resolution
remote sensing techniques, landscape ecology principles and theory (e.g. patch and matrix
frameworks, meta-population models), and systematic conservation planning approaches.
Key-words: ecosystem services, ecosystems, flows, land-use change, planning, urban ecology,
urbanisation
Introduction
The individuals of a species are seldom randomly distrib-
uted in space (Gaston 2003). Rather, they tend to be
highly aggregated, with most individuals occurring in the
close proximity of many others. This is true of humans,
with the present centres of aggregation being the towns,
cities and conurbations in which the majority of us live
and work. Indeed, in much of the world, an increasing
proportion of people occur in such urban foci (United
Nations 2008).
Unlike the aggregated populations of the majority of
other species (with obvious exceptions such as seabird and
bat colonies), human urban populations typically obtain
most of their ecosystem resources from sources that are
distributed over a substantially larger area – although*Correspondence author. E-mail: [email protected]
© 2013 The Authors. Journal of Applied Ecology © 2013 British Ecological Society
Journal of Applied Ecology 2013 doi: 10.1111/1365-2664.12087
there is much variation, their ecological footprint is often
one to two orders of magnitude greater than the area
occupied by the population itself (Rees 1992, 1999;
Wackernagel et al. 2006). Acknowledging that urban
areas can make more efficient use of some resources than
more dispersed populations (Bettencourt et al. 2007), a
vital issue in limiting human impacts on the environment
at large is how those footprints can most effectively be
reduced (particularly as demand outstrips supply; e.g.
McDonald et al. 2011). Potential solutions include reduc-
ing the overall demand for resources (e.g. controlling pop-
ulation growth, promoting more sustainable resource use),
increasing their supply (e.g. increasing the flow of food
and energy from within parts of the existing footprint)
and increasing the intensity (decreasing the area require-
ment) of this supply (e.g. more intensive agriculture) (e.g.
Newman & Jennings 2008; Nelson et al. 2010; Phalan
et al. 2011; Sulston et al. 2012). However, a key challenge
to the second two approaches is that, to date, increases in
yield and intensity in modern agriculture have largely
been achieved by unsustainable means; there is a global
need to reduce the environmental impact of the agricul-
tural system (Godfray et al. 2010; Sulston et al. 2012).
Whilst approaches to increasing the supply and the inten-
sity of supply of resources focus on nonurban areas,
approaches to reducing the overall demand for resources
focus on the urban areas themselves. This has tended to
foster a belief that urban areas have little role to play in
the direct provision of ecosystem goods and services, and
such possibilities are commonly ignored both in discus-
sions of the distribution of those goods and services and
in global and regional accounting procedures for them
(e.g. Haines-Young 2009; Harrison et al. 2010). Instead,
attention is focussed on the influence of urban areas on
the destruction of potential regional provision and alter-
ation of natural regional patterns of flow.
Conversely, a growing body of research is demonstrat-
ing that urban areas can themselves be vitally important
for the provision of ecosystem goods and services. This
occurs in two ways. First, as urban areas increase in
extent, the ecosystem goods and services provided within
their bounds will inevitably constitute a growing propor-
tion of their regional and global provision. This is partic-
ularly so given that no such areas are entirely covered by
impermeable surfaces, indeed in many cities and towns
green spaces contribute a significant proportion of total
urban land cover (e.g. see Churkina, Brown & Keoleian
2010; Davies et al. 2011b). The global coverage of urban
areas remains relatively small, with a figure of 2–3% of
land (excluding permanent ice cover) commonly quoted
(e.g. Millennium Ecosystem Assessment 2005). However,
regional coverage may be substantially larger; figures for
165 countries vary from close to zero to 32% (World
Resources Institute 2007). At least for more temperate
zones, this means that urban areas can make substantial
contributions to ecosystem service stocks and flows,
particularly where these have been heavily depleted from
nonurban areas and where urban areas tend to be devel-
oped in zones that are rich in these resources (Nowak &
Crane 2002; Gaston 2005; Pataki et al. 2006; Pouyat,
Yesilonis & Nowak 2006; Davies et al. 2009, 2011a,a,b;
O’Neill & Abson 2009; Hutyra, Yoon & Alberti 2011). At
the very least, this may often be true to the point where it
is necessary to ensure the inclusion of urban areas when
determining regional baselines and conducting regional
accounting for ecosystem goods and services.
Second, and arguably much more significantly, urban
areas can themselves be key in the local provision of eco-
system goods and services to their occupants. Here, the
contribution to global stocks and flows of goods and ser-
vices is of far less importance than is their spatial and
temporal coincidence with these centres of human popula-
tion. Examples of such local provision arise amongst each
of the major groups of ecosystem goods and services: sup-
porting (e.g. soil formation and nutrient cycling), provi-
sioning (e.g. urban food production), regulating (e.g. local
climate and flood regulation) and cultural (e.g. aesthetic,
sense of place and health benefits of green space and wild-
life; Davies et al. 2011a). In most cases, the actual level
and pattern of provision remain to be well documented,
at least beyond a few exemplar case studies. However, it
is clear that existing local provision, and the improve-
ments that can be attained, makes urban areas both prac-
tically much more functional and more pleasant places to
live for their occupants. Indeed, a growing number of
papers have highlighted the significance of the levels of
provision and of the inequalities in their availability and/
or how they are accessed by different socioeconomic
groups (e.g. Jo & McPherson 2001; Hope et al. 2003;
Kinzig et al. 2005; Grove et al. 2006; Barbosa et al. 2007;
Tratalos et al. 2007; Alexandri & Jones 2008; Davies et al.
2011a,b, 2012; Fuller et al. 2012). The consequences of
compromising the provision of particular ecosystem ser-
vices in urban areas can in some cases be extreme, as evi-
denced for example by the rise in human mortality rates
associated with urban heat island effects (e.g. Goggins
et al. 2012).
Accepting that the provision of ecosystem goods and
services within urban areas is an important issue, then so
is their effective management; the term ‘management’ has
been used in a variety of ways in the context of urban
ecosystems (Jansson & Lindgren 2012), but here we
employ it broadly to refer to any change that positively
influences the availability and/or provision of an ecosys-
tem good or service (and ideally multiple goods and ser-
vices). Indeed, substantial public and private sums are
already spent annually in many urban areas on environ-
mental management actions, at a variety of spatial scales,
that intentionally or unintentionally have impacts on eco-
system goods and services. These include the creation of
green spaces (e.g. new public spaces, landscaping develop-
ments), hard and soft landscaping, managing vegetation
in existing or newly created green spaces (e.g. grazing,
mowing, tree planting and surgery, coppicing, growing
© 2013 The Authors. Journal of Applied Ecology © 2013 British Ecological Society, Journal of Applied Ecology
2 K. J. Gaston, M. L. Avila-Jim�enez & J. L. Edmondson
fruit and vegetables), managing green waste (e.g. compo-
sting, wood chipping), installation of green roofs and
walls, and ‘wildlife gardening’ (e.g. provision of nectar-
rich plants, bird feeders, nest boxes, bat boxes, ponds)
(Snep & Opdam 2010; Douglas & Ravetz 2011; Rowe
2011; Sadler et al. 2011; Hale & Sadler 2012).
There are several overarching challenges to the manage-
ment of ecosystem goods and services in urban areas,
including the structure of green space, its temporal
dynamics, the spatial constraint on service flows, the
occurrence of novel forms of flows, the large numbers of
land managers, conflicting management goals, the possible
differences between the perceptions of urban dwellers and
the reality of urban landscapes, and the ‘wicked’ nature of
the management problems. In this paper, we examine
each of these challenges in turn. We draw largely on
examples from the UK. In keeping with much of Europe,
many UK cities have a long history of human settlement
and a compact urban form, in contrast to the shorter his-
tory and sprawling urban form that typifies many cities
in, for example, the USA and Australia (Gaston 2010).
However, most of the key points generalise widely.
Green space structure
Although often not of itself sufficient, key to the provi-
sion of many, and perhaps the majority, of ecosystem
goods and services within urban areas is the provision of
green space (here used broadly to mean any area of land
not covered by impermeable surface, including remnant
vegetation, public parks, public and private landscaping,
domestic gardens, sports and playing fields, allotments,
cemeteries, nature reserves, and derelict lands). Such space
can vary greatly in its overall extent within any given
town, city or conurbation (Fuller & Gaston 2009; Gaston
2010). However, almost invariably this overall area is spa-
tially distributed in complex ways. Of particular relevance
to the provision of ecosystem goods and services are that
the majority of green spaces tend to be small (Fig. 1) and
that habitat heterogeneity is commonly high amongst
spaces. In some cases, the level of fragmentation is such
that cumulatively the smaller patches (albeit not the
smallest) comprise a large proportion of green space
(Fig. 2; Gaston et al. 2005; Fuller et al. 2010). The spatial
distribution of patches of different sizes tends to be highly
variable amongst different urban areas; however, large
green spaces are often more peripheral, whether these
urban areas are best described as monocentric or polycen-
tric in their built structure.
The habitat heterogeneity of green spaces is influenced
foremost by the different uses to which they are put (see
above). However, within these categories, there can
remain substantial additional heterogeneity, with fine-scale
patchworks of habitat types typifying some land uses,
such as public parks and domestic gardens (e.g. Smith
et al. 2005; Loram, Warren & Gaston 2008). This
heterogeneity is such that it may only become apparent
when urban green spaces are mapped at spatial resolu-
tions that are much finer than commonly employed when
studying rural landscapes, and necessitating high-resolution
remote sensing data (Fuller et al. 2010). A comparison
between two different areas of the city of Leicester, UK,
the first displaying nondomestically owned green space
dominated by a public park (Fig. 3a) and the second dis-
playing domestically owned or rented land within the
city’s suburbs (Fig. 3b), illustrates the heterogeneity of
green space within urban areas. For example, the cover of
trees within the area of the city dominated by park was
40% of total nondomestic green space, dropping to only
13% in the domestically owned or rented green space
within the city’s suburbs. However, the most stark
(a) (b)
(c) (d)
Fig. 1. Patch size frequency histogram, representing the number
of green spaces with a given areal extent (in km2), within New-
castle-upon-Tyne, UK, urban boundary: (a) histogram including
all green space patches; (b) histogram of green spaces patch size
excluding those with an area smaller than 0�001 km2; (c) histo-
gram of all green spaces with patch sizes exceeding 0�01 km2; and
(d) histogram of those green spaces exceeding 0�1 km2. Data
derived from MasterMap.
Fig. 2. Cumulative contribution of different-sized green space
patches to the overall areal extent of green space within Newcastle-
upon-Tyne, UK. The patches of green space are ranked in order of
size (smallest to largest), and the cumulative size (km2) is plotted
against the rank. Data derived from MasterMap.
© 2013 The Authors. Journal of Applied Ecology © 2013 British Ecological Society, Journal of Applied Ecology
Urban ecosystems for goods and services 3
contrast between these two areas of the city was the patch
size of the different vegetation land cover classes. In total,
the domestic green space within the suburban area was
comprised of over 6200 patches (Fig. 3b), dropping to
c. 2200 in the nondomestic green space (Fig. 3a). Mean
patch size ranged from 93 m2 for domestic green space to
204 m2 for nondomestic, with median values of 64 m2
and 81 m2, respectively.
This size and habitat structure of green spaces present a
major challenge to the management of the ecosystem
goods and services that they provide. First, they make
determining the levels of those goods and services diffi-
cult. Carefully structured survey programmes need to be
employed to ensure adequate coverage of the full breadth
of types and sizes of green spaces (e.g. Nowak et al.
2008a,b; Davies et al. 2011b). Complex techniques may
often also be required to extrapolate local observations
more widely. For example, whilst estimating the potential
impacts of individual trees on building energy use is
relatively straightforward, mapping these effects across an
entire city is not simple (Fahmy & Sharples 2009).
Second, the structure of green space is such that the
provision of many ecosystem goods and services scales,
typically positively, with patch size (e.g. Fuller et al. 2010;
Su et al. 2012). This makes an understanding of these
scaling relationships, many of which are markedly nonlin-
ear, and thus the potential consequences of increasing or
decreasing green space patch sizes, key to the manage-
ment of those goods and services. Third, the heterogeneity
of urban green spaces, with complex mosaics of habitats
(Davies et al. 2011b), means that management practices
are likely to have to be varied both within and between
them, which can render these practices costly, with econo-
mies of scale readily being lost. Fourth, the manner by
which ecosystem service provision is best maintained may
vary with green space size. For example, heavy manage-
ment may be most cost-effective for smaller (but probably
not the smallest) patches, but it may be better to rely
more fully on more natural processes in larger patches
both because these processes are themselves likely to be
more functional and because the scale of more interven-
tionist approaches may be impractical. Fifth, the cumula-
tive extent of smaller green spaces is significant because
strategic urban planning, and indeed much green space
planning per se, tends to focus almost exclusively on the
larger patches and typically ignores the smaller ones.
However, it is important to note that management to
maintain existing urban green spaces should be used pru-
dently as certain techniques may alter the ecosystem ser-
vice balance in these areas; for example, the use of fossil
fuel-powered machinery to prune urban trees will result in
a net reduction of carbon sequestration (Nowak et al.
2002; Davies et al. 2011b).
The consequences of differentially managing green
spaces of different sizes can be profound. In Table 1, in a
purely illustrative exercise which could be extended to
other ecosystem goods and services, we estimate the con-
sequences for above-ground carbon storage of managing
the green space stock of Newcastle-Upon-Tyne in the fol-
lowing ways – Model 1: all patches bigger than 0�1 km2
are converted into woodland, any smaller patch is man-
aged as a domestic garden; Model 2: all patches bigger
than 0�01 km2 are converted into woodland, any smaller
patch is managed as a domestic garden; Model 3: medium
size patches (>0�01 km2 and <0�1 km2) are converted into
woodland, smaller patches are managed as domestic gar-
dens, and larger patches are devoted to agriculture; and
Model 4: all patches managed similarly, with 50% wood-
land cover and 50% herbaceous cover. Carbon storage
potential can double from model 1 to model 3 and triple
from model 1 to model 2, whereas an intermediate
increase in storage could be achieved with model 4.
Temporal dynamics
Urban areas are typically very dynamic and responsive to
history, policy and other drivers, meaning that through
time a proportion of green spaces will turn over and
(a) (b)
Fig. 3. A comparison of the spatial heterogeneity of green space in the city of Leicester between; (a) nondomestically owned green space
in an area of the city dominated by a public park and (b) domestically owned or rented green space within a suburban area of the city.
Herbaceous vegetation (light green); shrubs, tall shrubs and trees (dark green); open water (blue); artificial surfaces (grey); buildings
(black). Within (a) white areas are domestically owned or rented green space, and (b) white areas are nondomestically owned green
space. Data derived from LandBase and MasterMap.
© 2013 The Authors. Journal of Applied Ecology © 2013 British Ecological Society, Journal of Applied Ecology
4 K. J. Gaston, M. L. Avila-Jim�enez & J. L. Edmondson
change in size and shape (e.g. Pauleit, Ennos & Golding
2005; Uy & Nakagoshi 2007; Kattwinkel, Biedermann &
Kleyer 2011; Zhou et al. 2011; Gillespie et al. 2012). For
example, Fuller et al. (2010) show how the proportion of
green space in 250 9 250 m grid cells across Sheffield,
UK, declines with the time (from 1860) since each cell
became predominantly urbanised; once urbanised, green
space in a cell has become progressively further eroded.
On a shorter time horizon, Dallimer et al. (2011) docu-
ment a net increase in the extent of green space in all but
one of 13 UK cities between 1991 and 2006. However,
this gain in the main occurred before 2001, since when
green space declined in nine of the cities, following policy
reforms towards greater housing densification in 2000.
Likewise, across the early years of the present century,
tree cover decreased significantly in 17 of 20 US cities
(Nowak & Greenfield 2012).
Particularly when combined with urban expansion, such
dynamics typically lead to mosaics of green space of
different ages, potentially including remnants of original
vegetation, heavily contaminated lands, well-established
stands of new vegetation, through to areas of fresh bare
ground and pioneer communities. The ages of green
spaces, or of the buildings with which they are associated,
can be correlated with their levels of vegetation cover (e.g.
Smith et al. 2005; Kendal, Williams & Williams 2012),
species richness and composition (e.g. Smith et al. 2006;
Luck & Smallbone 2010), and organic carbon storage
(e.g. Golubiewski 2006; Smetak, Johnson-Maynard &
Lloyd 2007). This dynamism of green spaces suggests that
the provision of ecosystem goods and services in urban
areas may need to be viewed in something akin to one of
the ‘patch’ frameworks of population ecology. By anal-
ogy, one can envisage a range of patterns of provision of
goods and services, spanning the equivalents of single
population, classical metapopulation, mainland-island
metapopulation, patchy population and non-equilibrium
metapopulation spatial structures (Harrison 1994). This
will be challenging, particularly because management
frameworks often do not match the spatial and temporal
scale of ecosystem processes (Borgstr€om et al. 2006).
Much of the implementation of management actions will
need to be resourced and conducted on the understanding
that its consequences will not be realised potentially for
many years or even decades.
Spatial constraint on flows
The spatial flows of ecosystem goods and services are
highly constrained (canalised) across urban landscapes.
That is, the built infrastructure (Fig. 4a and b) imposes
major limitations on how goods and services can pass
across these landscapes, whether those flows deliver the
benefits locally, regionally (e.g. to rural communities or
other urban ones) or beyond. It does so both at a gross
level in terms of the pattern of buildings and transport
networks (Fig. 4a and c) and at a finer resolution in terms
of the position of, for example, individual roads and
waterways (Fig. 4c and d). This constraint has perhaps
been best characterised for organismal movement
(Andrieu et al. 2009; Shanahan et al. 2011; Tremblay &
St. Clair 2011; Hale et al. 2012; Vergnes, Le Viol &
Clergeau 2012) and hence the services which wildlife provide
or to which they contribute. However, it generalises much
more widely. Indeed, it seems likely that the majority of
ecosystem goods and services show much more spatially
constrained flows than in many other environments.
From a management perspective, such spatial constraint
means that, on the one hand, flows of ecosystem goods
and services across urban landscapes may be especially
vulnerable to the severance of particular corridors of flow.
On the other hand, there may be considerable opportuni-
ties for disproportionately improving flows by the creation
of new corridors. Such concerns have been widely recog-
nised in plans to protect and develop the blue and green
infrastructures of many urban areas, with riverine corri-
dors having been a heavy focus of attention (e.g. Gledhill,
James & Davies 2008; Kazmierczak & Carter 2010; Kelly,
Luke & Lima 2011). A persistent issue, however, has been
that such planning tends also to concentrate, sometimes
exclusively, on the role of large unified ‘green/blue corri-
dors’ through urban landscapes, and to ignore the poten-
tial roles of the huge numbers of small patches of
vegetation (and perhaps water). This matrix within which
Table 1. Potential carbon stored above-ground within the urban
green space (87 km2) of Newcastle-upon-Tyne urban boundary
on different management scenarios, based on average above-
ground carbon quantifications by Davies et al. (2011a,b)
(0�76 kg C m�2 stored in domestic gardens, 0�14 kg C m�2 stored
in land covered by herbaceous vegetation, and 28�86 kg C m�2
associated with tree covered land): (i) potential amount of carbon
stored within the Newcastle-upon-Tyne urban boundary if all the
green spaces were covered by trees; (ii) if all the green spaces
were managed as domestic gardens; (iii) if all the green spaces
were covered by herbaceous vegetation; (iv) Model 1: if all the
large green spaces(area >0�1 km2) were tree covered and all the
smaller patches were managed as domestic gardens; (v) Model 2:
if all large and medium size green spaces (area >0�01 km2) are
tree covered and all the smaller patches were managed as domes-
tic gardens; (vi) Model 3: if all medium size green spaces
(<0�1 km2 to >0�01 km2 area) are tree covered, smaller patches
are managed as domestic gardens, and all large green spaces are
devoted to agriculture (with herbaceous cover); (vii) Model 4:
each greenspace is 50% tree cover and 50% herbaceous cover.
Distribution of green spaces derived from MasterMap
Scenario Potential C storage (tonnes)
All green spaces tree covered 2 508 301
All green spaces managed as
domestic gardens
66 054
All green spaces covered by
herbaceous species
12 168
Model 1 524 508
Model 2 1 477 882
Model 3 1 035 098
Model 4 1 260 234
© 2013 The Authors. Journal of Applied Ecology © 2013 British Ecological Society, Journal of Applied Ecology
Urban ecosystems for goods and services 5
the larger corridors are set will often in practice be of
great (and perhaps greater) significance to the flows of
ecosystem goods and services, which may exhibit patterns
of constraint across this matrix that need critically to be
identified and appropriately managed.
Key to planning for the management of urban ecosys-
tem services will be the use of spatial planning tools that
prioritise areas in terms of their realised or potential
importance for spatial flows and that can be used to
explore the consequences of different planning decisions.
Although the general principles have long been promoted
(McHarg 1992), lessons need to be learnt from those tools
that have been developed for biodiversity conservation,
which faces many closely related issues, and which can in
some cases be adapted to this end (e.g. Margules & Pressey
2000; Moilanen et al. 2012; Moilanen, Wilson & Poss-
ingham 2009; for application to ecosystem services see
Moilanen et al. 2011); the use of these tools for species
conservation in urban areas has already been highlighted
(e.g. Gordon et al. 2009).
Novel flows
As well as often being strongly spatially constrained, eco-
system goods and services can also flow across urban
landscapes in ways that do not occur, or are typically
much less significant, in other landscape types. In particu-
lar, humans directly move material around urban land-
scapes on a massive scale. This includes soil (e.g. for
landscaping), vegetation (e.g. through waste collection sys-
tems and urban horticulture) and water (e.g. through
drainage systems). For example, in a survey of 575
residents in the city of Leicester, UK (Living in Leicester;
Lomas et al. 2010), respondents reported annually remov-
ing in total the equivalent of nearly 6000 bin bags of
green waste from their gardens. Nearly 30% of this waste
was hedge and shrub clippings and tree prunings; this can
be converted to c. 630 kg organic carbon removed from
the urban green space (estimated using analysis of organic
carbon concentration and measurement of the dry weight
of full bin bags of seven common urban tree species and
11 common urban shrub species). To contextualise the
scale of movement of waste across the city, the total gar-
den area of survey respondents was c. 8 ha, which was
<1% of total garden area in Leicester. Removal from gar-
dens was greatly in excess of the flow of organic matter
into gardens, with respondents reporting annually adding
the equivalent of an estimated 1200 bin bags of material
to their gardens (including manure, commercial and own
produced compost, bark and tree chippings, straw and
topsoil). However, this represents an addition of organic
carbon to urban gardens above the natural inputs from
vegetation.
Such novel flows often remain rather poorly character-
ised and thus constitute major unknowns in documenting
the dynamics of ecosystem goods and services in urban
areas and formalising these in ecosystem models. None-
theless, they do offer potential avenues for managing
those goods and services that may be easier to alter than
might be the case with more natural patterns of flow.
Multiple managers
Urban ecosystems are unlike almost any others in the
exceedingly large numbers of land managers present.
Whilst substantial tracts of land may be under the control
(a) (b)
(c) (d) Fig. 4. Spatial structure of green spaces in
Newcastle-upon-Tyne, UK, and spatial
structure of identified barriers to and
channels for the flow of ecosystem ser-
vices. (a) Green spaces exceeding 0�1 km2
(in green) and built infrastructure (in
grey); (b) all green spaces within the urban
area (in green) and their physical bound-
aries (in grey); (c) transport infrastructure
(in grey: minor roads; in red: major roads;
in black: railway lines); (d) surface water
(rivers, streams, open canals, ponds and
lakes) (in blue). Data derived from
MasterMap.
© 2013 The Authors. Journal of Applied Ecology © 2013 British Ecological Society, Journal of Applied Ecology
6 K. J. Gaston, M. L. Avila-Jim�enez & J. L. Edmondson
of a few governmental or nongovernmental organisations
(private individuals, companies or charities), typically
much is divided amongst a vastly greater number of
individual homeowners or tenants, each of whom may be
responsible for an area of the order of tens to hundreds
of square metres. For example, in Leicester, green
space covers 56% of the urban area (73 km2), 80% of
which is privately managed. Green space associated
with c. 123 000 households, and therefore individual
managers, within the city constitutes 40% of the total,
with a further 40% of private land managed nondomesti-
cally (Fig. 5). A smaller proportion of the city’s green
space is owned and managed by the local authority
(20%); however, much of this land is held in larger
patches such as urban parks.
Most obviously, the large numbers of land owners and
tenants in urban areas make coordination of management
activities extremely difficult. Some level of control can be
exerted through legislation; however, this provides a
rather blunt instrument. The converse argument is that
because of the large numbers of land managers, only a
relatively small proportion may need to carry out a par-
ticular management action for a wide impact to result.
For example, the establishment of new ponds in just 10%
of the domestic gardens in the urban area of Sheffield
would result in the addition of 17 500 such habitat
patches (albeit typically small ones), at a density of c. 120
per km2 (Gaston et al. 2005). In Leicester, the urban
green space managed by 575 survey respondents (Living
in Leicester survey; Lomas et al. 2010) was c. 8 ha in
extent (<1% citywide garden area), of which nearly 50%
was covered by herbaceous vegetation. If 10% of this
herbaceous area was converted to land dedicated to
own-grown food, potential yield could exceed 10 tonnes
per annum (based on UK agricultural potato yields and
unpublished data from the Royal Horticultural Society
allotment yield trials in 1974; Tompkins 2006; Supit et al.
2010). A further 20% of the respondents’ gardens were
capped by artificial surfaces (e.g. driveways, patios and
footpaths; all common features of UK gardens; Loram,
Warren & Gaston 2008). Excavation of surface soil is rou-
tine during the construction of artificial surface; on aver-
age, the top 15 cm of soil is lost in domestic gardens and
consequently 6�7 kg m-2 organic carbon (Edmondson
et al. 2012). If 10% of the artificial surface in these
domestic gardens was removed and converted to lawn, soil
organic carbon storage, to 1 m depth, could increase by
13 tonnes, from 26 to 39 tonnes (data from Edmondson
et al. 2012). Only 20% of the same respondents used a
compost heap, with a smaller number adding household
fruit and vegetable waste, and any increase in the number
of people using this method could significantly reduce the
resource demand associated with waste management in
our urban areas (Gaston et al. 2005).
Other challenges that result from the large numbers of
managers include that (i) lots of managers are not manag-
ing for ecosystem service provision but for alternative,
and often conflicting, goals; (ii) different groups of man-
agers may have different perceptions as to what changes
are most desirable (e.g. Hofmann et al. 2012); (iii) there is
a loss of benefits of scale of management costs, both
financial and environmental (e.g. need for physical tools
for management, and the gas emissions that those tools
give rise to); and (iv) universal management actions to
target-specific environmental problems across whole urban
ecosystems, such as maximisation of green space flood
mitigation or organic carbon storage potential, are diffi-
cult to achieve.
Conflicting management goals
Inevitably, different ecosystem goods and services in
urban areas require different management approaches,
and in some cases, these will conflict. Thus, for example,
(i) increasing carbon sequestration and reducing summer
temperatures will often involve retaining or planting trees,
but this may result in an increase in emissions of biogenic
volatile organic compounds which are hazardous to
human health (Leung et al. 2010); and (ii) increasing
urban food production will reduce land available for
growing trees, and may involve use of chemicals that
impact on water quality. Given the large number and
small size of many green spaces, such conflicts are proba-
bly best handled by managing for different goods and ser-
vices in different patches, rather than in different parts of
the same patch. Unfortunately, this may sometimes be at
Fig. 5. The distribution of residential and nonresidential spaces
in Leicester, UK; nonresidential green space (light green), nonres-
idential artificial surface (pale grey), residential artificial surface
(dark grey), residential green space (dark green), buildings (white)
and inland water (blue). Distribution derived from the Master-
Map and LandBase GIS data sets.
© 2013 The Authors. Journal of Applied Ecology © 2013 British Ecological Society, Journal of Applied Ecology
Urban ecosystems for goods and services 7
odds with the goals of the owners or tenants of individual
green space patches. For example, in the UK, urban gar-
dens are often managed so as to maintain high levels of
habitat heterogeneity, such that although the number of
habitat features increases with garden size, many features
are present in a high proportion of gardens with their
extent scaling strongly with garden size (Smith et al. 2005;
Loram, Warren & Gaston 2008).
Perception and reality
Throughout, we have focussed on the challenges for the
management of ecosystem goods and services in urban
areas posed by their actual distribution in space and time.
Under some circumstances, there may also be important
challenges that result from differences between their
actual distributions and flows, and those that urban dwell-
ers perceive to prevail. For example, Dallimer et al.
(2012) have shown that whilst there are no consistent rela-
tionships between the psychological well-being of urban
green space visitors and the species richness of various
groups of organisms, there are positive relationships
with the richness that those users perceive to be present.
This is potentially highly problematic, as management
for actual levels of biodiversity may well conflict with
management that would enhance perceived levels of
biodiversity.
Appreciation of the value of an ecosystem service may
also vary with the role and perception of the stakeholder
(i.e. beneficiary, manager, policymaker) and the ecosystem
service considered. For example, beneficiaries may place
high value on local resources (e.g. parks, allotments) that
in broader planning terms are insignificant. Furthermore,
the value of the ecosystem service can be expressed in dif-
ferent ways (e.g. economic, ecological or social value),
and these valuations are often not comparable (de Groot
et al. 2010).
Wicked problems
From a more over-arching perspective, The Royal Com-
mission on Environmental Pollution (2007) argues that
urban environmental management presents a classic case
of a ‘wicked problem’; ‘wicked’ in the sense of nasty or
vicious, rather than an ethical judgement. The mainte-
nance of and improvement in the provision of ecosystem
goods and services is increasingly seen as a substantive
component of this management, and the same conclusion
might justifiably be reached in this regard. The notion of
wicked problems derives from a treatise by Rittel & Webber
(1973), who observed that the kinds of societal problems
that planners deal with are ill-defined and cannot be
definitively solved and thus are intrinsically different from
archetypal problems in science. Their characterisation of
such problems, which derive in large part from ‘the inter-
dependencies and complexities of living together without
a shared set of values and views’ (Roberts 2000), is
rephrased here in the context of the management of eco-
system goods and services in urban systems:
1. There is no definitive formulation of an ecosystem ser-
vice management problem – The process of describing the
problem, say the need to improve urban food production,
and of solving it are essentially the same. This can serve
to fuel disagreement as to what the ‘problem’ actually is
and lead to a framing of the problem in a manner that
more readily connects it with the solution preferred by a
particular stakeholder (Roberts 2000).
2. Ecosystem management problems have no stopping
rule – Because there is no definitive formulation of the
problem, there is no point at which the solution has been
found. There is, for example, no point at which an
improvement in urban climate regulation would defini-
tively be sufficient.
3. Solutions to ecosystem service management problems
are not true-or-false, but good-or-bad – The nature of a
particular solution is likely to depend on who provides it,
with, for example, local residents and regional govern-
ment likely to manage a given green space in a different
way (the former tending to focus on their own needs, the
latter on standardising practices across a regional portfo-
lio of green spaces).
4. There is no immediate and no ultimate test of a solu-
tion to an ecosystem service management problem – A
given solution is likely to have many consequences, some
unintended and unexpected, and these may play out over
long periods. This highlights a particular need for multi-
ple studies of the outcomes of ecosystem service manage-
ment actions in urban areas.
5. Every solution to an ecosystem service management
problem is a ‘one-shot operation’; because there is no
opportunity to learn by trial-and-error, every attempt
counts significantly – This is because management actions
are seldom entirely reversible but have many conse-
quences. It is impossible, for example, accurately to pre-
dict all the ecosystem service consequences of establishing
a new green space in an urban area, and once established
it would be impossible simply to reverse some of those
consequences.
6. Ecosystem management problems do not have an enu-
merable (or an exhaustively describable) set of potential
solutions, nor is there a well-described set of permissible
operations that may be incorporated into the solutions –
The set of potential solutions and the extent to which they
are permissible will depend on who provides them. Some
have argued that in a complex world, what is required are
‘clumsy solutions’, which combine alternative (and some-
times conflicting) ways of perceiving and organising
answers (Verweij et al. 2006).
7. Every ecosystem service management problem is essen-
tially unique – There are always particularities to a prob-
lem that may override the commonalities with other
problems. Thus, for example, the detail of approaches to
improving the human–wildlife interactions that benefit
people’s well-being will vary amongst cities, amongst
© 2013 The Authors. Journal of Applied Ecology © 2013 British Ecological Society, Journal of Applied Ecology
8 K. J. Gaston, M. L. Avila-Jim�enez & J. L. Edmondson
communities within a city, and at different times for any
given community.
8. Each ecosystem service management problem can be
considered a symptom of another problem – For example,
poor local climate regulation might follow from a lack of
carbon storage and sequestration, as a consequence of
poor management of vegetation cover.
9. The existence of a discrepancy representing an ecosys-
tem service management problem can be explained in
numerous ways. The choice of explanation determines the
nature of the problem’s resolution.
10. The ecosystem service manager has no right to be
wrong – The objective is to improve a situation, and there
are plenty of tools available to assist a manager to that
end.
Roberts (2000) distinguishes three generic strategies for
identifying wicked problems and their solutions. If power
is concentrated amongst a small number of stakeholders,
or it is placed in their hands by consent, then authorita-
tive strategies can be employed. This can greatly reduce
the complexity of the process, but can also result in prob-
lems being too narrowly or incorrectly characterised, and
in other parties being ill-informed and unengaged. If
power is dispersed and contested, then competitive strate-
gies can be employed, encouraging different sets of stake-
holders to garner sufficient power to define the wicked
problem and its solution. This has the advantage of
encouraging innovation, but can result in protracted,
distracting and costly battles for that power, which in
the extreme can prevent any practical progress being
achieved. Finally, if power is dispersed but not contested,
then collaborative strategies can be used to define the
problem and solution. This can be efficient, in spreading
costs, and increasing ‘weight of numbers’ and the breadth
of ‘solution space’ that can be explored. However, effec-
tive collaboration can be challenging to achieve, and
costly in the effort required. Across the breadth of wicked
problems posed by ecosystem service management in
urban areas, no one of these three strategies will be ade-
quate in itself. For some issues, power is highly concen-
trated (e.g. water flows), for others it is highly dispersed
(e.g. vegetation management).
CONCLUSION
The local provision of ecosystem goods and services in
urban areas is essential to the populations that benefit
from them and will help reduce the regional and global
footprint of cities and towns. The management of these
goods and services poses a number of substantive chal-
lenges, including the structure of green space, its temporal
dynamics, the spatial constraint on ecosystem service
flows, the occurrence of novel forms of those flows, the
large numbers of land managers, conflicting management
goals, the possible differences between the perceptions of
urban dwellers as to the distribution and flow of ecosys-
tem services and the reality of that distribution and flow,
and the ‘wicked’ nature of ecosystem service management
in urban landscapes. However, there is also clearly a
broad range of tools available from applied ecology to
assist in their resolution. These include the use of high-
resolution remote sensing techniques, landscape ecology
principles and theory (e.g. patch and matrix frameworks,
meta-population models) and systematic conservation
planning approaches. These will need to be employed
within a broader transdisciplinary framework (Ervin et al.
2012) to address the interactions between natural and
human systems that are arguably at their most complex in
urban ecosystems.
Acknowledgements
This work was supported by EPSRC grant EP/I002154/1 SECURE: Self
conserving urban environments (a consortium of Loughborough Univ.,
Newcastle Univ., Univ. Exeter and Univ. Sheffield); EPSRC grant
EP/F007604/1 4M: Measurement, Modelling, Mapping and Management
(a consortium of Loughborough Univ., De Montfort Univ., Newcastle
Univ., Univ. Sheffield and Univ. Exeter); and NERC grant NE/J015237/1
Fragments, functions and flows (a consortium of British Trust for
Ornithology, Cranfield Univ., Univ. Exeter and Univ. Sheffield). Infoterra
provided access to LandBase; MasterMap data were supplied by Ordnance
Survey. We are grateful to S. Gaston, Z. Grabowski, J. Jones and an
anonymous reviewer for comments.
References
Alexandri, E. & Jones, P. (2008) Temperature decreases in an urban can-
yon due to green walls and green roofs in diverse climates. Building and
Environment, 43, 480–493.Andrieu, E., Dornier, A., Rouifed, S., Schatz, B. & Cheptou, P.-O. (2009)
The town Crepis and the country Crepis: how does fragmentation affect
a plant-pollinator interaction? Acta Oecologica, 35, 1–7.Barbosa, O., Tratalos, J.A., Armsworth, P.R., Davies, R.G., Fuller, R.A.,
Johnson, P. & Gaston, K.J. (2007) Who benefits from access to green
space? A case study from Sheffield, UK. Landscape and Urban Planning,
83, 187–195.Bettencourt, L.M.A., Lobo, J., Helbing, D., K€uhnert, C. & West, G.B.
(2007) Growth, innovation, scaling, and the pace of life in cities.
Proceedings of the National Academy of Sciences of the USA, 104,
7301–7306.Borgstr€om, S.T., Elmqvist, T., Angelstam, P. & Alfsen-Norodom, C.
(2006) Scale mismatches in management of urban landscapes. Ecology
and Society, 11, 16.
Churkina, G., Brown, D.G. & Keoleian, G. (2010) Carbon stored in
human settlements: the conterminous United States. Global Change
Biology, 16, 135–143.Dallimer, M., Tang, Z., Bibby, P.R., Brindley, P., Gaston, K.J. & Davies,
Z.G. (2011) Temporal changes in greenspace in a highly urbanised
region. Biology Letters, 7, 763–766.Dallimer, M., Irvine, K.N., Skinner, A.M.J., Davies, Z.G., Rouquette,
J.R., Armsworth, P.R., Maltby, L., Warren, P.H. & Gaston, K.J.
(2012) Biodiversity and the feel-good factor: understanding associations
between self-reported human well-being and species richness. BioScience,
62, 46–55.Davies, Z.G., Fuller, R.A., Loram, A., Irvine, K.N., Sims, V. &
Gaston, K.J. (2009) A national scale inventory of resource provision
for biodiversity within domestic gardens. Biological Conservation, 142,
761–771.Davies, L., Kwiatkowski, L., Gaston, K.J., Beck, H., Brett, H., Batty,
M., Scholes, L., Wade, R., Sheate, W.R., Sadler, J., Perino, G.,
Andrews, B., Kontoleon, A., Bateman, I. & Harris, J.A. (2011a)
Urban. UK National Ecosystem Assessment: Technical Report, pp.
361–410. UNEP-WCMC, Cambridge.
Davies, Z.G., Edmondson, J.L., Heinemeyer, A., Leake, J.R. & Gaston,
K.J. (2011b) Mapping an urban ecosystem service: quantifying above-
ground carbon storage at a city-wide scale. Journal of Applied Ecology,
48, 1125–1134.
© 2013 The Authors. Journal of Applied Ecology © 2013 British Ecological Society, Journal of Applied Ecology
Urban ecosystems for goods and services 9
Davies, Z.G., Fuller, R.A., Dallimer, M., Loram, A. & Gaston, K.J.
(2012) Household factors influencing participation in bird feeding activ-
ity: a national scale analysis. PLoS ONE, 7, e39692.
Douglas, I. & Ravetz, J. (2011) Urban ecology – the bigger picture. Urban
Ecology: Patterns, Processes, and Applications (ed. J. Niemel€a), pp. 246–262. Oxford University Press, Oxford.
Edmondson, J.L., Davies, Z.G., McHugh, N., Gaston, K.J. & Leake, J.R.
(2012) Organic carbon hidden in urban ecosystems. Scientific Reports, 2,
963.
Ervin, D., Brown, D., Chang, H., Dujon, V., Granek, E., Shandas, V. &
Yeakley, A. (2012) Growing cities depend on ecosystem services. Solu-
tions, 2, 74–86.Fahmy, M. & Sharples, S. (2009) On the development of an urban passive
thermal comfort system in Cairo, Egypt. Building and Environment, 44,
1907–1916.Fuller, R.A. & Gaston, K.J. (2009) The scaling of green space coverage in
European cities. Biology Letters, 5, 352–355.Fuller, R.A., Tratalos, J., Warren, P.H., Davies, R.G., Pezpkowska, A. &
Gaston, K.J. (2010) Environment and biodiversity. Dimensions of the
Sustainable City (eds M. Jenks & C. Jones), pp. 75–103. Springer
Science, Dordrecht.
Fuller, R.A., Irvine, K.N., Davies, Z.G., Armsworth, P.R. & Gaston, K.J.
(2012) Interactions between people and birds in urban landscapes.
Studies in Avian Biology, 45, 249–266.Gaston, K.J. (2003) The Structure and Dynamics of Geographic Ranges.
Oxford University Press, Oxford.
Gaston, K.J. (2005) Biodiversity and extinction: species and people.
Progress in Physical Geography, 29, 239–247.Gaston, K.J. (2010) Urbanisation. Urban Ecology (ed. K.J. Gaston),
pp. 10–34. Cambridge University Press, Cambridge.
Gaston, K.J., Warren, P.H., Thompson, K. & Smith, R.M. (2005) Urban
domestic gardens (IV): the extent of the resource and its associated fea-
tures. Biodiversity and Conservation, 14, 3327–3349.Gillespie, T.W., Pincetl, S., Brossard, S., Smith, J., Saatchi, S., Pataki, D.
& Saphores, J.D. (2012) A time series of urban forestry in Los Angeles.
Urban Ecosystems, 15, 233–246.Gledhill, D.G., James, P. & Davies, D.H. (2008) Pond density as a deter-
minant of aquatic species richness in an urban landscape. Landscape
Ecology, 23, 1219–1230.Godfray, H.J.C., Beddington, J.R., Crute, I.R., Haddad, L., Lawrence,
D., Muir, J.F., Pretty, J., Robinson, S., Thomas, S.M. & Toulman, C.
(2010) Food security: the challenge of feeding 9 billion people. Science,
327, 812–818.Goggins, W.B., Chan, E.Y.Y., Ng, E., Ren, C. & Chen, L. (2012) Effect
modification of the association between short-term meteorological fac-
tors and mortality by urban heat islands in Hong Kong. PLoS ONE, 7,
e38551.
Golubiewski, N.E. (2006) Urbanization increases grassland carbon pools:
effects of landscaping in Colorado’s Front Range. Ecological Applica-
tions, 16, 555–571.Gordon, A., Simondson, D., White, M., Moilanen, A. & Bekessy, S.A.
(2009) Integrating conservation planning and landuse planning in urban
landscapes. Landscape and Urban Planning, 91, 183–194.de Groot, R.S., Alkemade, R., Braat, L., Hein, L. & Willemen, L. (2010)
Challenges in integrating the concept of ecosystem services and values
in landscape planning, management and decision making. Ecological
Complexity, 7, 260–272.Grove, J.M., Troy, A.R., O’Neill-Dunne, J.P.M., Burch, W.R., Cadenas-
so, M.L. & Pickett, S.T.A. (2006) Characterization of households and
its implications for the vegetation of urban ecosystems. Ecosystems, 9,
578–597.Haines-Young, R. (2009) Land use and biodiversity relationships. Land
Use Policy, 26, S178–S186.Hale, J.D. & Sadler, J. (2012) Resilient ecological solutions for urban
regeneration. Proceedings of the ICE – Engineering Sustainability, 165,
59–68.Hale, J.D., Fairbrass, A.J., Matthews, T.J. & Sadler, J.P. (2012) Habitat
composition and connectivity predicts bat presence and activity at
foraging sites in a large UK conurbation. PLoS ONE, 7, e33300.
Harrison, S. (1994) Metapopulations and conservation. Large-scale Ecol-
ogy and Conservation Biology (eds P.J. Edwards, R.M. May & N.R.
Webb), pp. 111–128. Blackwell Scientific Publications, Oxford.
Harrison, P.A., Vandewalle, M., Sykes, M.T., Berry, P.M., Bugter, R.,
de Bello, F., Feld, C.K., Grandin, U., Harrington, R., Haslett, J.R.,
Jongman, R.H.G., Luck, G.W., da Silva, P.M., Moora, M., Settele, J.,
Sousa, J.P. & Zobel, M. (2010) Identifying and prioritising services in
European terrestrial and freshwater ecosystems. Biodiversity and Conser-
vation, 19, 2791–2821.Hofmann, M., Westermann, J.R., Kowarik, I. & van der Meer, E. (2012)
Perceptions of parks and urban derelict land by landscape planners and
residents. Urban Forestry and Urban Greening, 11, 303–312.Hope, D., Gries, C., Zhu, W., Fagan, W.F., Redman, C.L., Grimm, N.B.,
Nelson, A.L., Martin, C. & Kinzig, A. (2003) Socioeconomics drive
urban plant diversity. Proceedings of the National Academy of Sciences
of the USA, 100, 8788–8792.Hutyra, L.R., Yoon, B. & Alberti, M. (2011) Terrestrial carbon stocks
across a gradient of urbanization: a study of Seattle, WA region. Global
Change Biology, 17, 783–797.Jansson, M. & Lindgren, T. (2012) A review of the concept ‘management’
in relation to urban landscapes and green spaces: toward a holistic
understanding. Urban Forestry and Urban Greening, 11, 139–145.Jo, H.-K. & McPherson, E.G. (2001) Indirect carbon reduction by residen-
tial vegetation and planting strategies in Chicago, USA. Journal of
Environmental Management, 61, 165–177.Kattwinkel, M., Biedermann, R. & Kleyer, M. (2011) Temporary conser-
vation for urban biodiversity. Biological Conservation, 144, 2335–2343.Kazmierczak, A. & Carter, J. (2010) Adaptation to climate change using
green and blue infrastructure. A database of case studies. Interreg IVC
Green and blue space adaptation for urban areas and eco towns
(GRaBS). Manchester, UK. Available at: http://www.grabs-eu.org/
(accessed 5 July 2012).
Kelly, S., Luke, A. & Lima, M. (2011) Developing Urban Blue Corridors.
Scoping study. DEFRA, London Borough of Croydon, UK.
Kendal, D., Williams, N.S.G. & Williams, K.J.H. (2012) Drivers of diver-
sity and tree cover in gardens, parks and streetscapes in an Australian
city. Urban Forestry and Urban Greening, 11, 257–265.Kinzig, A.P., Warren, P., Martin, C., Hope, D. & Katti, M. (2005) The
effects of human socioeconomic status and cultural characteristics on
urban patterns of biodiversity. Ecology and Society, 10, 23.
Leung, D.Y., Wong, P., Cheung, B.K. & Guenther, A.B. (2010) Improved
land cover and emission factors for modeling biogenic volatile organic
compounds emissions from Hong Kong. Atmospheric Environment, 44,
1456–1468.Lomas, K.J., Bell, M., Firth, S.K., Gaston, K.J., Goodman, P., Leake,
J.R., Namdeo, A., Rylatt, M., Allinson, D., Davies, Z.G., Edmondson,
J.L., Galatioto, F., Guo, L., Hill, G., Irvine, K., Taylor, S.C. & Tiwary,
A. (2010) 4M: Measurement; modelling; mapping and management –the carbon footprint of UK cities. ISOCARP Low Carbon Cities.
Isocarp, The Hague, pp 168–191.Loram, A., Warren, P.H. & Gaston, K.J. (2008) Urban domestic gardens
(XIV): the characteristics of gardens in five cities. Environmental
Management, 42, 361–376.Luck, G.W. & Smallbone, L.T. (2010) Species diversity and urbanisation:
patterns, drivers and implications. Urban Ecology (ed K.J. Gaston),
pp. 88–119. Cambridge University Press, Cambridge.
Margules, C.R. & Pressey, R.L. (2000) Systematic conservation planning.
Nature, 405, 243–253.McDonald, R.I., Green, P., Balk, D., Fekete, B.M., Revenga, C., Todd,
M. & Montgomery, M. (2011) Urban growth, climate change, and
freshwater availability. Proceedings of the National Academy of Sciences
of the USA, 108, 6312–6317.McHarg, I.L. (1992) Design in Nature. Wiley, New York.
Millennium Ecosystem Assessment (2005) Ecosystems and Human Well-
Being: Current State and Trends. Vol. I. Island Press, Washington, DC.
Moilanen, A., Wilson, K.A. & Possingham, H. (eds.) (2009) Spatial Con-
servation Prioritization: Quantitative Methods and Computational Tools.
Oxford University Press, Oxford.
Moilanen, A., Anderson, B.J., Eigenbrod, F., Heinemeyer, A., Roy, D.B.,
Gillings, S., Armsworth, P.R., Gaston, K.J. & Thomas, C.D. (2011)
Balancing alternative land uses in conservation prioritization. Ecological
Applications, 21, 1419–1426.Moilanen, A., Meller, L., Leppanen, J., Montesino-Puzols, F., Arponen, A.
& Kujala, H. (2012) Spatial Conservation Planning Framework and Soft-
ware: Zonation User Manual (v 3.1). University of Helsinki, Helsinki.
Nelson, E., Sander, H., Hawthorne, P., Conte, M., Ennaanay, D., Wolny,
S., Manson, S. & Plasky, S. (2010) Projecting global land-use change
and its effect on ecosystem service provision and biodiversity with
simple models. PLoS ONE, 5, e14327.
Newman, P. & Jennings, I. (2008) Cities as Sustainable Ecosystems: Princi-
ples and Practices. Island Press, Washington, DC.
© 2013 The Authors. Journal of Applied Ecology © 2013 British Ecological Society, Journal of Applied Ecology
10 K. J. Gaston, M. L. Avila-Jim�enez & J. L. Edmondson
Nowak, D.J. & Crane, D.E. (2002) Carbon storage and sequestration by
urban trees in the USA. Environmental Pollution, 116, 381–389.Nowak, D.J. & Greenfield, E.J. (2012) Tree and impervious cover change
in U.S. cities. Urban Forestry and Urban Greening, 11, 21–30.Nowak, D.J., Stevens, J.C., Sisinni, S.M. & Luley, C.J. (2002) Effects of
urban tree management and species selection on atmospheric carbon
dioxide. Journal of Arboriculture, 28, 113–122.Nowak, D.J., Walton, J.T., Stevens, J.C., Crane, D.E. & Hoehn, R.E.
(2008a) Effect of plot and sample size on timing and precision of urban
forest assessments. Aboriculture and Urban Forestry, 34, 386–390.Nowak, D.J., Crane, D.E., Stevens, J.C., Hoehn, R.E., Walton, J.T. &
Bond, J. (2008b) A ground-based method of assessing urban forest
structure and ecosystem services. Arboriculture and Urban Forestry, 34,
347–358.O’Neill, D.W. & Abson, D.J. (2009) To settle or protect? A global analysis
of net primary productivity in parks and urban areas. Ecological
Economics, 69, 319–327.Pataki, D.E., Alig, R.J., Fung, A.S., Golubiewski, N.E., Kennedy, C.A.,
McPherson, E.G., Nowak, D.J., Pouyat, R.V. & Lankao, P.R. (2006)
Urban ecosystems and the North American carbon cycle. Global Change
Biology, 12, 209–2102.Pauleit, S., Ennos, R. & Golding, Y. (2005) Modeling the environmental
impacts of urban land use and land cover change – a study in Mersey-
side, UK. Landscape and Urban Planning, 71, 295–310.Phalan, B., Onial, M., Balmford, A. & Green, R.E. (2011) Reconciling
food production and biodiversity conservation: land sharing and land
sparing compared. Science, 333, 1289–1291.Pouyat, R.V., Yesilonis, I.D. & Nowak, D.J. (2006) Carbon storage by
urban soils in the United States. Journal of Environmental Quality, 35,
1566–1575.Rees, W.E. (1992) Ecological footprints and appropriated carrying capac-
ity: what urban economics leaves out. Environment and Urbanization, 4,
121–130.Rees, W.E. (1999) The built environment and the ecosphere: a global
perspective. Building Research and Information, 27, 206–220.Rittel, H.W.J. & Webber, M.M. (1973) Dilemmas in a general theory of
planning. Policy Sciences, 4, 155–169.Roberts, N. (2000) Wicked problems and network approaches to resolu-
tion. International Public Management Review, 1, 1–19.Rowe, D.B. (2011) Green roofs as a means of pollution abatement.
Environmental Pollution, 159, 2100–2110.Sadler, J., Bates, A., Donovan, R. & Bodnar, S. (2011) Building for biodi-
versity: accommodating people and wildlife in cities. Urban Ecology:
Patterns, Processes, and Applications (ed. J. Niemel€a) pp. 286–297.Oxford University Press, Oxford.
Shanahan, D.F., Miller, C., Possingham, H.P. & Fuller, R.A. (2011) The
influence of patch area and connectivity on avian communities in urban
revegetation. Biological Conservation, 144, 722–729.Smetak, K.M., Johnson-Maynard, J.L. & Lloyd, J.E. (2007) Earthworm
population density and diversity in different-aged urban systems.
Applied Soil Ecology, 37, 161–168.Smith, R.M., Gaston, K.J., Warren, P.H. & Thompson, K. (2005) Urban
domestic gardens (V): relationships between landcover composition,
housing and landscape. Landscape Ecology, 20, 235–253.
Smith, R.M., Warren, P.H., Thompson, K. & Gaston, K.J. (2006) Urban
domestic gardens (VI): environmental correlates of invertebrate species
richness. Biodiversity and Conservation, 15, 2415–2438.Snep, R. & Opdam, P. (2010) Integrating nature values in urban planning
and design. Urban Ecology (ed K.J. Gaston), pp. 261–286. Cambridge
University Press, Cambridge.
Su, S., Xiao, R., Jiang, Z. & Zhang, Y. (2012) Characterizing landscape
pattern and ecosystem service value changes for urbanization impacts at
an eco-regional scale. Applied Geography, 34, 295–305.Sulston, J., Bateson, P., Biggar, N., Fang, C., Cavenaghi, S., Cleland, J.,
Cohen, J., Dasgupta, P., Eloundou-Enyegue, P.M., Fitter, A., Habte,
D., Harper, S., Jackson, T., Mace, G., Owens, S., Porritt, J., Potts, M.,
Pretty, J., Ram, F., Short, R., Spencer, S., Xiaoying, Z. & Zulu, E.
(2012) People and the Planet: The Royal Society Science Policy Centre
Report 01/12. The Royal Society, London.
Supit, I., van Diepen, C.A., de Wit, A.J.W., Kabat, P., Baruth, B. &
Ludwig, F. (2010) Recent changes in the climatic yield potential of
various crops in Europe. Agricultural Systems, 103, 683–694.The Royal Commission on Environmental Pollution (2007) The Urban
Environment. The Stationery Office, London.
Tompkins, M. (2006) The edible urban landscape. MSc thesis Available at:
http://www.cityfarmer.org/MikeyTomkins_UA_thesis.pdf (accessed July
2012).
Tratalos, J., Fuller, R.A., Warren, P.H., Davies, R.G. & Gaston, K.J.
(2007) Urban form, biodiversity potential and ecosystem services.
Landscape and Urban Planning, 83, 308–317.Tremblay, M.A. & St. Clair, C.C. (2011) Permeability of a heterogeneous
urban landscape to the movements of forest songbirds. Journal of
Applied Ecology, 48, 679–688.United Nations (2008) World Urbanization Prospects. The 2007 Revision.
United Nations, New York.
Uy, P.D. & Nakagoshi, N. (2007) Analyzing urban green space pattern
and eco-network in Hanoi, Vietnam. Landscape and Ecological
Engineering, 3, 143–157.Vergnes, A., Le Viol, I. & Clergeau, P. (2012) Green corridors in urban
landscapes affect the arthropod communities of domestic gardens.
Biological Conservation, 145, 171–178.Verweij, M., Douglas, M., Ellis, R., Engel, C., Hendriks, F., Lohmann, S.,
Ney, S., Rayner, S. & Thompson, M. (2006) Clumsy solutions for a
complex world: the case of climate change. Public Administration, 84,
817–843.Wackernagel, M., Kitzes, J., Moran, D., Goldfinger, S. & Thomas, M.
(2006) The ecological footprint of cities and regions: comparing resource
availability with resource demand. Environment and Urbanization, 18,
103–112.World Resources Institute (2007) Available at: http://earthtrends.wri.org/
index.php
Zhou, W., Huang, G., Pickett, S.T.A. & Cadenasso, M.L. (2011) 90 years
of forest cover change in an urbanizing watershed: spatial and temporal
dynamics. Landscape Ecology, 26, 645–659.
Received 29 November 2012; accepted 11 March 2013
Handling Editor: Julia Jones
© 2013 The Authors. Journal of Applied Ecology © 2013 British Ecological Society, Journal of Applied Ecology
Urban ecosystems for goods and services 11