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mChallenging Assumptions in Urban Restoration Ecology

Joshua Zeunert

ABSTRACT This paper presents a critical examina-tion of core assumptions of Restoration Ecology (RE) and Urban Restoration Ecology (URE) with a focus on reinstatement of native/indigenous vegetation in urban areas. RE’s widely utilized and imposed land use approach reconstructs questionable historic interpretations of natural landscapes. RE misappropriates various terms and ideologies central to its paradigm, thereby exclud-ing non- native biodiversity. Despite decades of theory, research, and practice, RE suffers a noteworthy risk of failure. RE applies rural conservation practices to urban environments, which often presents difficulties in terms of scale and suitability for fauna. RE is optimistic or mis-representative regarding economics, maintenance, and risk in urban environments. This paper briefly discusses an alternative focus, which includes a broader concept of restoration. More substantially, this paper explores multi-functional landscape techniques that: respond to novel states in urban environments; that address present and future needs and scenarios; deliver tailored ecosystem services; and provide resources and productivity specifi-cally relevant to urban contexts.

KEYWORDS Restoration ecology, urban, biodiversity, landscape architecture, indigenous, native, design, plan-ning, management.

INTRODUCTIONThis paper presents a critical examination of the

ideology and practice of Restoration Ecology (RE),

also known as ecological restoration/reconstruction/

reinstatement, in the landscape context of urbanized

Australia. While RE appears to be a reasonable and

positive endeavour, there are numerous core problems

with its ideology, approach, and eff ectiveness. This

paper does not seek to critique the practice of restoring

landscapes per se, but rather, questions the prevalence

of applying the dominant paradigm and narrow focus

in which RE is often conceived and conducted. The

critique focuses on RE that returns landscapes to past,

historical states (SER 2004; SER 2005; Handel 2011),

and the attempts to re- purpose urban and peri- urban

landscapes as reconstructed indigenous/native land-

scapes in urban areas where these have been altogether

destroyed and lost (herein referred to as urban restora-

tion ecology or URE).

While most RE is applied in rural environments

or at a regional scale, the majority of discourse does

not explicitly diff erentiate between urban and rural

contexts. Regardless of context, RE practitioners often

apply the same or similar methods in urban and rural

areas. While the RE movement provides accessible

material on implementation (SER 2005), very little is

provided or discussed to its relevance in urban sce-

narios. The need for RE in any given context is often

treated as a given (Clewell and Aronson 2006) and

therefore most literature does not closely examine the

context for RE, the “where” and “why.” Some RE dis-

course blurs the boundary between conservation and

restoration, and some misappropriates the term “bio-

diversity.” For the purposes of this paper, native and

indigenous are used to denote the plant and animal

species occurring in a nation/region before the arrival

of humans and/or signifi cant disturbance by humans.

232 Landscape Journal 32:2

Urban refers to an agglomeration of humans in towns,

cities, and megalopolises.

While this paper focuses on an Australian context,

it has many coincident themes and parallels with RE

in North America, the UK, and worldwide. Urban

disciplines aff ected by RE/URE ideology typically

include: ecology, urban and regional planning, urban

ecology, landscape architecture, urban design, natural

resource management, environmental management,

architecture, open space management, and horticul-

ture. Many of these disciplines have not disseminated

critique and debate of URE. As these disciplines often

aim to improve and increase natural resources and

capital, ecosystem services, and social engagement

with cultural and environmental issues and practices,

it is, thus, imperative to assess URE’s legitimacy in a

wider context.

This article provides a contextual background

for ecological restoration cast against a discussion

of fl awed assumptions, performance issues, and

a suggested paradigm shift to improve landscape

outcomes. Possibilities for further research on multi-

functional urban landscape approaches are pre-

sented, such as urban agriculture at the edges of its

scope of considerations.

BACKGROUNDEons of geological time on earth have given human-

ity—until recent decades—a seemingly endless abun-

dance of ecosystem services that have provided us with

the fresh water, food, and resources that fund our daily

activities. Human practices have always re- shaped

and impacted ecosystems, and until recent decades the

global human population has not been large enough to

cause widespread concern at the collective impacts of

human actions. In recent centuries and most markedly,

since the 20th century, humans have industrialized at

an accelerated pace fueled by extensive use of fossil

fuels, natural resources, and ecosystem services to the

detriment of biological diversity and native environ-

ments. A worldwide urban culture dependent on fossil

fuels has generated high pressure on global and na-

tional ecosystems, creating concern amongst ecologists,

scientists, and in some cases, the wider population.

There is an increasing global scientifi c consensus that

the Earth has entered a biodiversity extinction crisis

(UNEP 2007) due to the cumulative eff ects of human

(anthropogenic) impacts on the environment (ABCS

2010). A wide range of discourse on global and local

biodiversity loss has been published. Subsequent focus

on reducing further losses has encountered a range of

threats and impacts (ABCS 2010; Cocklin and Dibden

2009). In response, conservation of native and indige-

nous biodiversity has expanded to include the concepts

and practices of restoration ecology/ecosystem res-

toration (RE) (Lodwick 1994). Restoring ecosystems

and their services is intended as a measure to increase

resilience in the face of biodiversity loss and to restore

ecosystem services.

RE as practiced usually attempts to rebuild eco-

system services as “conservation for conservation’s

sake” (DeClerck and Salinas 2011) and/or reconstructs

historic landscapes that usually have lesser value to

humans. RE’s increasingly narrow focus on conserv-

ing and restoring ecosystems and their services creates

a mixed impact in practice. Though primarily based

on conservation motives rather than economic or

human ends (Redford and Adams 2009), the provision

of ecosystem services is an anthropocentric concept.

Evaluating the eff ectiveness of reconstructed ecosystem

services requires a similarly broad and anthropocen-

tric methodology. This article argues that as global

populations, ecological footprints, and human impacts

continue their unprecedented growth, it is imperative

that the landscapes we invest in are fl exible and multi-

functional as they:

1. maximize their benefits to future inhabitants; 2. maximize efficiency and performance; 3. are resilient to future pressures; 4. mitigate impacts of human activities, and5. provide useful resources, services, and benefits

(WCED 1987).

This paper does not seek to question the often

surprising evidence of native/indigenous biodiversity

located in urban areas, but rather to highlight the

challenges presented in maintaining or enhancing this

biodiversity, especially in areas growing in population,

density, and/or intensity of human activity.

What is Restoration Ecology/Urban Restoration Ecology? In their “foundational document” (Shackelford

et al. 2013, 297), the Society for Ecological Restora-

tion (SER) defi ne RE as “an intentional activity that

Zeunert 233

initiates or accelerates the recovery of an ecosystem

with respect to its health, integrity and sustainability”

(SER 2004, 1) and “the process of assisting the recov-

ery of an ecosystem that has been degraded, dam-

aged, or destroyed” (SER 2004, 3). SER’s Guidelines

for Developing and Managing Ecological Restoration

Projects elaborates:

Restoration attempts to return an ecosystem to its historic trajectory, i.e. to a state that resembles a known prior state or to another state that could be expected to develop naturally within the bounds of the historic trajectory (2005, 2).

Hobbs and Norton (1996) state that the goal of

ecosystem restoration is to re- transition an ecosystem

to its pre- disturbed structure, function, and composi-

tion. Initially, RE was primarily focused on rural and

regional environments; however, its application in

urban environments is increasing.

RE’s implementation has been aided by the

spatial estimation of indigenous landscape reference

ecosystems (low woodland, sedgeland, etc.). In Aus-

tralia, seminal works by Benson and Howell (1990)

and Kraehenbuehl (1996) mapped pre- European

reference ecosystems across the urban regions of Syd-

ney and Adelaide and provided detailed species lists,

historic photographs, drawings, and accounts. This

mapping has provided an understanding of historic

vegetation and landscapes in terms of spatial cover-

age and vegetation association structures, which has

aided RE’s implementation, especially where reference

ecosystems have been destroyed and lost. Assessment

of spatial areas, quality, and condition of reference

ecosystems is now commonplace and is often an

integral component of ecological studies and planning

processes. Yet this approach can also be questionable

as many of these assessments are highly subjective

and involve implicit value judgments (Parkes, Newell,

and Cheal 2003).

The SER guidelines list fi ve contexts for restora-

tion, three of which use urban examples where there

is no pre- existing indigenous landscape present (SER

2005) in the process of “return[ing] ecosystems to their

intended trajectory” (SER 2004, 1–2). RE’s value-

laden defi nitions and terms (Suding 2011) refl ect the

strong belief that historic, indigenous landscapes are

the rightful state.

To What Extent is Restoration Ecology/Urban Restoration Ecology Utilized?

We are obviously past any point where strategies that focus on preservation of ‘‘pristine’’ habitats are sufficient for the job. Greater attention must be placed on human- dominated landscapes (Novacek and Cleland 2001).

The demand for restoration is rapidly increasing: RE

is in a signifi cant growth period and it is becoming a

primary focus of natural resource management with

thousands, if not millions of restoration projects occur-

ring annually across the globe (Suding 2011; Harris

2011). The SER have members and partners in over

sixty nations (Whisenant 2011). At a 2010 meeting of

the Convention on Biological Diversity, countries com-

mitted to a target of restoring 15 percent of degraded

ecosystems worldwide by 2020 (SCBD 2010). Growth

in RE is evident in the increasing volume of published

journal articles and academic programs and outputs.

Decisions that determine urban land use outcomes

involve planners, natural resource managers, landscape

architects, architect, environment offi cers, politicians,

and various consultants. RE is a prevailing and estab-

lished land- use methodology endorsed and imple-

mented by many of these professionals (Clewell and

Aronson 2006). URE is globally evident in the projects

of planners, landscape architects, and architects who

increasingly use intensive methods1 in highly urbanized

locations2 aimed at increasing indigenous biodiversity

(such as vertical green walls on high- density buildings

and large road- bridge wildlife crossings) (Francis and

Lorimer 2011; Blaustein 2013).

Why Question Urban Restoration Ecology?While URE appears to be a reasonable and positive

endeavour, there are numerous key problems with its

ideology, approach, and eff ectiveness. This is espe-

cially the case when it is applied with an assumption

that RE is an appropriate strategy in any given context.

Restoration eff orts frequently ignore the “why” of the

project and imply that restoration is needed, that this

is inherently obvious, and that restoration intentions

are noble (Clewell and Aronson 2006). The “how” of

restoration needs signifi cantly closer examination and

comparison with alternative approaches; a substantial


undertaking that is outside of the scope of this paper,

but briefl y explored in the fi nal section.

FLAWED ASSUMPTIONS EMPLOYED IN RESTORATION ECOLOGYRE’s core problem is that it is retrospective. It assumes

that the past provides the blueprint and best solution

to current and future issues. Restoring ecosystems to a

historical state by reinstating indigenous plant species

does not necessarily optimize or maximize outcomes nor

make them resilient in the face of pressures of present

and future scenarios. Faced with unprecedented changes

in climate, land use, and biodiversity, the goal of return-

ing to static, past points in time and restarting the eco-

logical clock is unrealistic (Moreira 2006; Suding 2011).

For example, Wade, Gurr, and Wratten claim

“ecological restoration of farmland can contribute to

sustainable agriculture by moving degraded ecosys-

tems closer to their former state and thereby restoring

ecosystem function” (2008, 831). Restoring ecosystem

function and historical integrity is a central goal of

most RE advocates; however, it is based on several

problematic assumptions:

1. Restoration can restore the lost historic state and/or native/indigenous ecosystem function of sites;

2. Historic states/ecosystems are optimum for current and future scenarios;

3. Nature is or was naturally “in- balance,” and this “balance” can be (re)constructed by humans;

4. Systems will recover in the desired way if they are reinstated;

5. Adaptation, use, or conservation of restored landscapes will be considered appropriate in the future;

6. RE is the most effective method for restoring “degraded” land;3 and

7. Degraded landscapes have less value4 than restored landscapes (accounting for the embodied energy and likelihood of success/failure of RE).

Lateral thinking may help to develop novel and

eff ective solutions to design, plan, and construct

relevant ecosystem services, rather than attempting

to replicate and reconstruct past landscapes. This is

especially relevant in urban contexts.

Restoration Differs from ConservationRE’s paradigm and practices are rooted in a rural

conservation ethic (Lodwick 1994; Dramstad, Olson,

and Forman 1996). While a logical evolution exists

between conservation and restoration, problems arise

when they are not clearly and explicitly diff erentiated

and many RE advocates and literature fall into this

misrepresentation. In simple terms, conservation pro-

tects areas of remnant native/indigenous biodiversity

already in place that have tangible conservation value.

Restoration recreates past notions of native/indigenous

landscapes, with no guarantee of manifesting out-

comes of conservation value.

An example of a document that blurs conservation

and restoration/reconstruction is the national umbrella

plan, Australia’s Biodiversity Conservation Strategy

2010–2030. The document makes almost no specifi c

reference to the practice of “restoration” and what

it can achieve. Yet at least two of the 10 ambitious

national targets involve “re- establishing eco system

functions” (ABCS 2010, 9) through RE activities:

Item 5: “By 2015, 1,000 km2 of fragmented landscapes

and aquatic systems are being restored to improve

ecological connectivity,” and Item 6: “By 2015, four

collaborative continental- scale linkages are established

and managed to improve ecological connectivity”

(ABCS 2010, 10). There are countless other documents

worldwide that combine conservation/preservation

and restoration/reconstruction without diff erentiating

their ideology and approach. Clarifi cation between

these disciplines and practices would be benefi cial to

avoid confusion in ideology, technique, performance,

and outcomes.

Pre- European North America and Australia were Natural Landscapes? Proponents of RE usually do not regard pre- European

landscapes in North America and Australia as being

cultural landscapes—dynamic landscape systems that

were shaped by millennia of aboriginal practices such

as the use of fi re and hunting. A cultural landscape

is produced by the long- term interaction of humans

and nature (Moreira et al. 2006, 218) and defi ned as

“cultural properties . . . represent[ing] the combined

works of nature and of man” (UNESCO 2012, 14).

North American and Australian landscapes were only

natural before the arrival of humans (around 50,000

years prior to Europeans in Australia). For example,

Zeunert 235

Australian Aborigines skillfully managed their cultural

landscape systems and modifi ed these to suit their

purposes (actually reducing biodiversity and fertility

of landscapes) (Flannery 1994). These cultural land-

scapes supported an Aboriginal population estimated

at only 315,000–750,000 persons spread across the

sub- continent at the time of European settlement and

occupation of Australia in 1788 CE (Year Book Aus-

tralia 2002). This spatial coverage was refl ected in the

diverse range of Aboriginal tribes and language groups

(Horton 1996). Their populations were balanced from

a more culturally and environmentally sustainable car-

rying capacity of indigenous landscapes than the west-

ern cultures that followed: Australia’s biocapacity5 per

person fell by more than half between 1961 and 2007

(GFN 2011). RE’s pre- European, indigenous landscape

approach will not provide the biocapacity or ecosystem

services utilized by the contemporary Australian popu-

lation of 22 million people.6

Animistic and pantheistic Aboriginal culture

operated as an integrated and indivisible cultural and

environmental whole, whereas contemporary western

culture and RE have developed from a historic tradi-

tion of separation between nature and culture to form

an inherently dualistic opposition. We may question

whether RE practitioners (or indeed contemporary

Australians at large) are willing or even able to live in

accordance with pre- European Aboriginal cultural

practices.

Biodiversity That is Not Native is Not of ValueConservation organizations, Natural Resource

Management, biological nativists, and the RE move-

ment frequently use the term “biodiversity” with an

assumed reference to native and indigenous biodiver-

sity; its actual defi nition is biological diversity of all

life forms. These presume that native/indigenous bio-

diversity is the only biodiversity of importance. Non-

indigenous biodiversity is sometimes referred to and

regarded as “genetic pollution” (Barnett 2003) and is

underscored by a blanket rejection of exotic species,

which has been likened to xenophobia by some critics

(Peretti 1998; Hettinger 2001).

Species relationships are complex (Montalvo et al.

1997). Productivity, agroforestry, agricultural systems,

and home gardens can all be rich in wild biodiversity

(Scherr and McNeely 2008). There are hundreds of

examples of native animals that do not prefer their

original indigenous habitat to environments created by

humans (Low 1999, 2003).

Animals and plants do what they can to survive. If that means taking over a quarry or a dump, so be it. We should not judge this as ‘unnatural.’ If we are surprised, it only shows that our picture of nature is faulty. We need new ways to explain what we see. (Low 2003, 36).

Such research challenges a prevalent assumption

of RE, that planting indigenous plant species will

provide optimum habitat and/or increase populations

of indigenous fauna. An article by 19 ecologists claims

that it is time to end the native versus non- native war:

It is impractical to try to restore ecosystems to some ‘rightful’ historical state . . . We must embrace the fact of ‘novel ecosystems’ and incorporate many alien species into management plans, rather than try to achieve the often impossible goal of eradicating them or drastically reducing their abundance (Davis et al. 2011, 154).

Can Biodiverse Indigenous Fauna Thrive in Urban Environments?A key aim of RE is establishing habitats for the

preservation of threatened and endangered native

fauna. This goal is often inappropriate in transport

infrastructure- dominated environments where fauna

face signifi cant challenges to movement (Selva et al.

2011) (Figure 1). Roadkill from vehicles is extensive7

and it aff ects all fauna types (Garriga et al. 2012) in

urban and rural locations (Ament et al. 2008). More-

over, fauna in urban environments are often regarded

as “pests” especially when populations achieve unman-

ageable levels. For example, large populations of bats

in Australian cities routinely create problems.8 The

City of Sydney Council redesigned their garbage bins

to prevent White Ibis from foraging and creating a

mess in public spaces. Indigenous Sulphur- crested

Cockatoos have damaged solar panels and hot water

systems at Adelaide’s Lochiel Park, where ironically,

they were attracted to the urban forest intentionally

planted to attract indigenous fauna! Urban habitats

can support large populations of species listed as

“vulnerable” in non- urban areas (such as Brush- tailed

Zeunert 237

Possums and the White Ibis) that can over- populate

urban areas and face population culls.

PERFORMANCE ISSUES RE/URE is not Effective, Efficient, Low- maintenance, Low- risk, or EconomicalThe challenges of realizing RE’s aspirations are well

understood by scientists and ecologists who exam-

ine its outcomes, even though published literature

favors successful projects (Zedler 2007). Enactment

and implementation of principles has lagged despite

decades of research and theory (O’Farrell and Ander-

son 2010). The majority of literature reviewing RE’s

results are focused on guided recovery and restoration

of pre- existing degraded ecosystems, rather than more

extensive restoration projects or complete restoration/

reconstruction on sites where it has been altogether

lost. Suding (2011, 465) states, “despite the multitude

of restoration projects and wide agreement that evalua-

tion is a key to future progress, comprehensive evalua-

tions are rare.” A review of 240 recovery studies found

that 35 percent were successful, 37 percent had mixed

outcomes, and 28 percent had no recovery (Jones and

Schmitz 2009). This survey indicates a relatively low

overall success rate in a highly favorable study context.

Palmer (2009, 1) highlights RE shortcomings, “promi-

nent examples of restoration methods or approaches

are commonly used despite little evidence to support

their effi cacy,” and “restoration ecology as a science

and ecological restoration as a practice are in need of

reform.”

The factors included in ecosystem restoration are

complex and variable. Zedler (2000, 402) lists that

“landscape setting, habitat type, hydrological regime,

soil properties, topography, nutrient supplies, dis-

turbance regimes, invasive species, seed banks, and

declining biodiversity can constrain the restoration

process.” She echoes challenges similar to Palmer’s,

“we have little ability to predict the path that sites will

follow when restored in alternative ways, and no insur-

ance that specifi c targets will be met.”

One of RE’s key goals of (re)attracting indig-

enous fauna is highly questionable as results

consistently show that “information is limited on

the extent to which plantings can provide habitat for

fauna and in what time frame” (Munro et al. 2009a,

150). An Australian article that reviewed 27 studies on

fauna in revegetated agricultural areas stated, “evi-

dence to date suggests that revegetation is not a good

replacement of remnant vegetation for many spe-

cies” (Munro, Lindenmayer, and Fischer 2007, 199).

Another study found that after 30 to 40 years, results

from RE plantings were hard to defi ne and inconclu-

sive (Munro et al. 2009b).

Many native/indigenous plantings are selected

to provide for the perceived outcome of lower main-

tenance and reduced water consumption. There is,

however, a common misconception that native and

indigenous plantings in urban landscapes require

little or no maintenance. The SER state that ongoing

ecosystem management is required to keep restora-

tion projects eff ective (SER 2005) and that “restora-

tion represents an indefi nitely long- term commitment

of land and resources” (SER 2004, 1). In urban areas,

“museum landscapes” are more common and may

require endless intervention (Moreira et al. 2006, 221)

yet interventions after the initial restoration can destroy

and disturb equilibrium (Clewell and Aronson 2006).

Maintenance of indigenous species often requires

extensive “weeding” (usually conducted with herbi-

cides) and pruning. Replanting is often necessary to

meet safety requirements and avoid woody growth in

urban areas. Some species that require fi re to regenerate

or self- propagate, such as Xanthorrhoea and Banksia

species in Australia, have been planted in areas where

native plantings present a fi re threat—as many other

species are also highly fl ammable. Ongoing monitoring

and maintenance is required to fulfi l an “indigenous-

only” mantra. For example, at the award- winning

Banksia Street constructed wetland in Canberra, the

wetland was dredged and netted by ecologists to attempt

to remove a “feral” species of fi sh,9 requiring that “the

Directorate will work closely with members of the com-

munity to control these critters” (ACT ESD nd) This

is far from a novel ecosystem management approach

and a task that will likely prove impossible. There are

Figure 1A commonplace RE example (Top: Alstonville bypass, New South Wales ) aimed at increasing biodiversity and attracting indigenous fauna to a precarious environment. This approach is highly constructed.Bottom: the possibility of roadsides as productive landscapes for resources (for example, biofuels) and suitable crops for food production (e.g. pollution tolerant crops/livestock crops etc (Courtesy of Oxigen).


countless examples worldwide that mirror this example.

Volunteer workforces and conservation groups build

many “indigenous” landscapes, so the actual cost and

intensity of installation, establishment, and aftercare

can be skewed. RE’s return on investment, maintenance

intensity, and suitability to urban contexts are often less

ecological and low maintenance than intended.

RE Differs in Rural and Urban Contexts

As urban environments usually contain lower biodiversity that wildlands, species diversity in urban settings is a major challenge in ecology (Shochat et al. 2010, 199).

Most RE is conducted and documented in non- urban

environments. Does the introduction of regional and

remote indigenous conservation and restoration values

and practices into urban environments optimize urban

land management? There are increased complexities,

challenges, and pressures faced by RE and native/

indigenous vegetation in urban environments (Sten-

house 2004; Ingram 2008; Pavao- Zuckerman 2008;

Musacchio 2008; Francis et al. 2008). The considerable

time taken for RE’s outcomes undermine its appro-

priateness in many urban environments, which have

been characterized by rapid change in past centuries.

Assessment timeframes typically range from 10 to 50

years, with longer timeframes for terrestrial systems

(most common in urban scenarios).

Success of RE is often achieved through avail-

ability and local persistence of ecosystem storage

mechanisms (such as seed banks) and where soils and

natural landscape structures remain largely intact

(Suding 2011) and contiguous with other restoration

and conservation sites. In many urban areas these are

uncommon. Additionally, the success of RE is very low

at sites where changed species pools, impactful land-

use legacies, and species feedbacks are present (Suding

2011). These complications are all commonplace in

urban contexts (Stenhouse 2004). Thus, typical urban

conditions create signifi cant challenges and very low

odds for success of URE, or perhaps, present more

ideal opportunities for alternative land use.

Restoration Ecology Usually Requires Large and Undisturbed Scale for ViabilitySome RE proponents make clear that to have the

highest chance of being eff ective, RE should occur at

landscape and regional scales to combat continuous

decline in conservation values across the globe (Hobbs

and Norton 1996). Even in regional and rural environ-

ments, it is recommended that, “revegetation be con-

ducted in patches that are large, wide and structurally

complex to maximize the benefi ts to fauna” (Munro

2007, 199). These recommendations present challenges

for RE in space- constrained and human dominated

urban environments. Urban areas with existing or

potential landscape- scale corridors (Handel 2012) and

large ecological regions may be more suited to URE.

High land values can make building large extents of

URE diffi cult to implement, especially if areas ideally

exclude humans and/or human activities.

Outside of such large- scale areas and corridors,

URE’s eff ectiveness, resilience, and ongoing urban via-

bility is questionable. Maintaining viable populations

of biologically and genetically diverse fauna in most

urban areas is challenging or unrealistic. Regardless,

large extents of wild habitat in urban areas can prove

ineff ective due to predatory impacts from high numbers

of domesticated animals (cats, dogs, and their wild

descendants) (Stenhouse 2004). Fencing is an expensive,

management- intensive, and often impractical option to

exclude non- native species (Somers and Hayward 2012).

WHAT PARADIGM SHIFTS ARE REQUIRED?While RE has noble intentions and some signifi cant

achievements, its outcomes could be greater and its

achievements more relevant if it demonstrated more

fl exibility and willingness to collaborate with other

approaches and techniques (Nassauer and Opdam

2008). RE is often closed and prescriptive, infl exible,

and dogmatic. A core problem with RE is that it is

often applied as a “blanket approach” and universal

solution to site- specifi c issues. Imposing RE without

consideration of context and suitability, especially in

urban environments, does not optimize landscape

outcomes. Eff ective urban landscape management

should link culture and nature and provide services

for present and future society. While this may include

RE as part of a multifunctional landscape approach

(Rodenburg and Nijkamp 2004) the sole use of native

and indigenous vegetation based on past systems rather

Zeunert 239

than present and future systems is a retrospective and

restrictive imposition.

Restoring ecosystem services for utilization by

humanity is not optimized by RE’s focus on static

notions of historic native/indigenous landscapes and

species (Redford and Adams 2009). As literal interpre-

tations, these are often inappropriate to mitigate issues

such as excess pollutants, nutrients, runoff , waste water,

chemicals, salinity, acidifi cation, degradation, and

the range of unnatural physical conditions in urban

and peri- urban environments. RE frequently claims to

achieve such outcomes but often results in a cosmetic

application and pastiche of historic “nature” (Pierce

1994). Even if native/indigenous plants are capable

of mitigating these issues there is a high likelihood

that non- native plants will be more eff ective without

necessarily excluding native fauna (Low 1999, 2003).

Broadening restoration from the attempted reconstruc-

tion of historical states to focus on delivering ecosys-

tem services, resources, productivity, and resilience is

paramount to improving its urban compatibility and

eff ectiveness. This objective would be better achieved

without dogmatic bias to nativism and indigenous

plants, especially in areas where these no longer occur.

Flexible landscape techniques aimed at improving

ecosystem services relevant to current and future sys-

tems are emerging. These may achieve environmental,

social, and economic aims more directly and eff ec-

tively than RE’s often rigid and historic restoration

paradigm. It is logical to design and engineer effi cient,

multifunctional landscape systems that are resilient

in the face of human disturbance and to pressures

of concentrated high intensity human use. Emerging

techniques can be more eff ective at mitigating impacts

caused by human activity. It is important to focus on

urban strategies that improve environmental outcomes,

ecosystem services, resilience, adaptation to climate

change, future scenarios of resource scarcity, and peak

“everything” (Heinberg 2007).

CONCLUSION: ALTERNATIVES TO URBAN RESTORATION ECOLOGYAfter decades of implementation, RE fails to pro-

vide clear predictions or outcomes from restoration

scenarios in urban areas. Conversely, the increasing

emergence of urban agriculture, water sensitive urban

design (WSUD), productive landscapes, green infra-

structure, and phytoremediation in urban areas off er

the potential to address social and environmental

contexts and deliver effi cient and eff ective ecosystem

services for prevalent urban issues and concerns. Like-

for- like comparisons with URE would be useful to

quantify economic, social and environmental claims

(and warrant further framework- establishing research

that might point toward a more diversifi ed approach to

resource conservation).

Urban contexts usually provide many exploitable

conditions that are well- suited to urban agriculture,

WSUD, productive landscapes, and green infrastruc-

ture. These include excess nutrients such as phos-

phorus and nitrogen (unsuitable for most Australian

native plants), pollutant and chemical runoff (prob-

lematic for natural hydrology), resource hungry citi-

zens and their domesticated animals (problematic for

native biodiversity), demand for employment; desire

for social participation; and desire for economic

benefi ts. Garnett estimated that urban agriculture in

London, if deployed at an overall rate of 20 percent of

green open space, could supply London with 18 per-

cent of their annual fruit and vegetable intake (1999).

In cities with longer growing seasons or larger emp-

tied tracts of land, this fi gure would be considerably

higher. Victory Gardens in the USA accounted for

44 percent of fresh vegetable production during World

War II (Birnbaum 2013).

Benefi ts of agriculture in many urban contexts

include:

1. efficient water use (1/5 to 1/10 usage rates compared to commercial agriculture) (Moar 2010; Brookman 2011),

2. supplying fresh produce to urban areas via low food miles (Gaballa 2008),

3. utilizing urban wastewater and nutrients (reducing pollutant loads on freshwater and aquatic ecosystems),

4. utilizing food/green waste and compostable material from urban regions,

5. using ecologically degraded urban and peri- urban land, and

6. generating ongoing employment and income; and increasing biodiversity (Garnett 1999).

WSUD mitigates urban pollutants and can pro-

vide space effi cient and non- chemical water fi ltration

in urban areas. Biofi ltration is signifi cantly more


space- effi cient than natural wetlands at removing

pollutants. More research is required to assess poten-

tial application and food or resource yields and

productivity of WSUD plantings. Productive landscape

approaches eschew cosmetic, ornamental species

(exotic or native) in favor of useful, performance, and

resource- focused landscapes (which need not preclude

aesthetic or biodiversity concerns) (McLain et al 2012).

In urban futures, conventional aesthetic priori-

ties may lose their focus as performance of open space

becomes progressively more important. Society is

becoming increasingly critical of manicured façades

of green space (Hough 1995) and the false natural-

ness and pastiche of RE (Moreira et al. 2006), and has

come to value a more rigorous assessment of the per-

formance and embodied eff ects of open space (Melosi

2009). Increased use of landscape performance tools

may raise viability of emerging performance- based

landscape movements (O’Farrell and Anderson 2010).

Context is a more relevant concern in landscape mea-

surement compared to architectural performance tools

that often treat the building as an “object in space.”

The embodiment of biases in performance and rating

tools requires caution, as these tools can be prescrip-

tive of values and objectives while passing as impartial,

quantitative, and empirical. Arguably, urban land-

scapes should address and provide for their context

rather than impose a global or blanket agenda such as

is manifested in many RE motivated projects.

NOTES1. Green roofs and green walls entail technical complexity

for installation and ongoing operation, and are an energy intensive way of reinstating pre- European vegetation.

2. Architect Ken Yeang attempts to attract biodiversity to his skyscrapers, which are usually located in Asian megalopo-lises and highly urbanized areas.

3. It is likely that there are site issues (such as soil salinity from land clearance or acidic soil from synthetic nitrogen used in agriculture) for which the past, historic reference landscapes never faced, nor are necessarily capable of effectively addressing (Suding 2011).

4. Various authors have documented and advocated for the value of degraded landscapes (such as Low 1999, 2003; Hough 1995)

5. Biocapacity refers to the capacity of a given biologically productive area to generate an ongoing supply of renew-able resources and to absorb its wastes. Unsustainability

occurs if the area’s ecological footprint exceeds its bio-capacity. Biologically productive areas include croplands, pastures, forests, and fisheries.

6. Australia’s population growth rate at around 2 percent is the highest of industrialized nations and means that its population will double somewhere midway through the 21st century.

7. WIRES, a New South Wales based organization relying largely on volunteers rescued 75,000 animals in 2009.

8. Indigenous Artist Lin Onus’s installation Fruit Bats (1991) explored this conflict. Some bats carry the Hendra virus.

9. Like many “pest” species, the small fish Gambusia were introduced to control mosquitoes but they prey on native fish, tadpoles, and macroinvertebrates.

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ACKNOWLEDGEMENTS The author would like to thank Lance Neckar and David Pitt for their editorial assistance. The author would also like to thank Tim Waterman, Dr Janis Lander, Dr Jo Russell- Clarke, Alys Daroy, and the peer reviewers for their feedback and assistance with editing.

AUTHOR Joshua Zeunert is a Lecturer at Writtle College in the UK. Formerly an AILA Registered Land-scape Architect in Australia, Josh practiced with leading landscape architecture design practices in Sydney and Adelaide while working as a casual academic at UNSW and UniSA, before becoming a lecturer at the University of Adelaide. Josh also holds a degree in architecture and has a background in environmental studies. His current research involves design thinking and practice in urban agriculture, productive landscapes, and environmental design.

challenging assumptions in urban restoration ecology

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