City and Biodiversity
Transcript of City and Biodiversity
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Cities and
Biodiversity
Outlook
A Global Assessment of the Links between
Urbanization, Biodiversity, and Ecosystem ServicesAction and Policy
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Secretariat o the Convention on Biological Diversity.Cities
and Biodiversity Outlook (ISBN 92-9225-432-2 is an open access
publication, subject to the terms o the Creative Commons
Attribution License (http://creativecommons.org/licenses/by-nc/3.0/).
Copyright is retained by the Secretariat.
Cities and Biodiversity Outlook is reely available online:
www.cbd.int/authorities/cbo1.shtml.
An annotated version o the publication with complete reerences
is also available rom the website. Users may download, reuse,
reprint, modiy, distribute, and/or copy text, fgures, graphs
and photos rom Cities and Biodiversity Outlook, so long as the
original source is credited. The designations employed and the
presentation o material in Cities and Biodiversity Outlook do not
imply the expression o any opinion whatsoever on the part o the
Secretariat o the Convention on Biological Diversity concerning
the legal status o any country, territory, city or area or o its
authorities, or concerning the delimitation o its rontiers or
boundaries.
Citation: Secretariat o the Convention on Biological Diversity
(2012) Cities and Biodiversity Outlook. Montreal, 64 pages.
For urther inormation, please contact:
Secretariat of the Convention on Biological Diversity
World Trade Centre
413 St. Jacques Street, Suite 800
Montreal, Quebec, Canada H2Y 1N9
Phone: 1 (514) 288 2220
Fax: 1 (514) 288 6588
E-mail: [email protected]
Website: www.cbd.int
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1Cities and Biodiversity Outlook
Contents
Foreword by the UN Secretary-General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Message rom the Executive Director o UNEP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Preace by the Executive Secretary o the CBD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Overview oCities and Biodiversity Outlook Action and Policy 5
SECTION I
Summary o Global Urbanization, Biodiversity, and Ecosystem Services
Challenges and Opportunities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
SECTION IIKey Messages
1. Urbanization is both a challenge and an opportunity to manage ecosystem services globally . . . 20
2. Rich biodiversity can exist in cities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3. Biodiversity and ecosystem services are critical natural capital . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4. Maintaining unctioning urban ecosystems can signicantly enhance human health andwell-being . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5. Urban ecosystem services and biodiversity can help contribute to climate-changemitigation and adaptation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
6. Increasing the biodiversity o urban ood systems can enhance ood and nutrition security . . . . 36
7. Ecosystem services must be integrated in urban policy and planning . . . . . . . . . . . . . . . . . . . . . . . 39
8. Successul management o biodiversity and ecosystem services must be based on multi-scale, multi-sectoral, and multi-stakeholder involvement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
9. Cities oer unique opportunities or learning and education about a resilient andsustainable uture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
10.Cities have a large potential to generate innovations and governance tools and thereore
canand musttake the lead in sustainable development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
SECTION III
Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Evolution o the CBDs Cities and Biodiversity Initiative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Appendix 1: Aichi Biodiversity Targets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
CBO Inter-Agency Task-Force and Advisory Committee Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
List o Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Photo Credits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
The ull text oCities and Biodiversity Outlook is available online at www.cbd.int/en/subnational/partners-and-initiatives/cbo.
Cities and Biodiversity Outlook was supported by the Government o Japan through the Japan Biodiversity Fund, by the European
Union and several national research councils in Europe through BiodivERsA, and by SIDA through The Resilience and
Development ProgramSwedBio.
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2 Cities and Biodiversity Outlook
Foreword by the UN Secretary-GeneralBy 2050, an estimated 6.3 billion people will inhabit the worlds towns and
cities -- an increase o 3.5 billion rom 2010. Our planet will have undergone
the largest and astest period o urban expansion in human history. The area
directly transormed in the next our decades will be roughly the size o South
Arica, and the new demands o cities will reshape most landscapes, both builtand natural. Urban growth will have signicant impacts on biodiversity, natural
habitats and many ecosystem services that society relies on.
The challenges o urbanization are proound, but so too are the opportunities. The outcome o the Rio+20 UNConerence on Sustainable Development emphasizes that i they are well planned and developed, includingthrough integrated planning and management approaches, cities can promote economically, socially and
environmentally sustainable societies. Well-designed cities can sustainably accommodate large numbers
o people in a relatively small amount o space, oering improved quality o lie and allowing or greater
resource eciency and the preservation o larger intact natural areas.
The Cities and Biodiversity Outlook combines science and policy in a global assessment o the links betweenurbanization, biodiversity and ecosystem services. It showcases best practices and provides key adviceon the conservation and sustainable use o biodiversity. The principal message is that urban areas must
oer better stewardship o the ecosystems on which they rely, including by generating multiple ecosystem
services through design and restoration and reducing their environmental impact through improved e-ciency o material and energy use and by making productive use o waste. Cities can reconcile human
society and biodiversity by creating environments that are ecologically sustainable, economically produc-tive, socially just, politically participatory and culturally vibrant. I commend this study to policy-makers,
planners and all who have a stake in creating ecologically sustainable urbanization or the benet o
humanity and the planet.
Ban Ki-moon
Secretary-General, United Nations
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3Cities and Biodiversity Outlook
Message rom theExecutive Director o UNEPCities give rise to a diversity o views and emotions, rom places o pollution and
social divisions to centers o ancient and popular culture and crossroads o inno-
vation and new ideas. Today they are also increasingly recognized or their role inconserving biodiversity and are providing exciting opportunities or making the tran-
sition to an inclusive green economy in both the developing and developed world.
This is among the key points o this new report. Cities and Biodiversity Outlook (CBO) brings into sharp ocus
not only the extraordinary wealth o urban biodiversity but also its role in generating ecosystem services
upon which large and small urban populations and communities rely or their ood, water, and health. It
makes a strong argument or greater attention to be paid by urban planners and managers to the natural
or nature-based assets within their metropolitan boundaries as one way toward realizing a range o targets
established both pre- and post-Rio+20.
In partnering with cities, the CBD has also recognized their potential or assisting in meeting the 20 stra-
tegic Aichi Biodiversity Targets by 2020 that were agreed upon by governments at the 2010 meeting o the
Convention in Nagoya, Japan.
Among the many ascinating ndings here are the range o species ound in cities o all kinds and complexion.Brussels, or example, contains more than 50 percent o the foral species ound in Belgium. Cape Town ishost to 50 percent o South Aricas critically endangered vegetation types and approximately 3,000 indige-
nous vascular plant species.
CBO also underlines the health benets o urban biodiversity. Studies in the United States, or example, show thatcities with more trees have lower rates o asthma among young children. It also showcases how policymakingby local government can bring ood and health security to citizens, citing Kampala, Uganda, where regula-
tions have allowed close to 50 percent o households to produce sae, quality produce within the citys limits.
More than hal the global population already resides in cities. Cities represent major opportunities or deliv-ering a low-carbon, ar more resource-ecient world. This report brings to the ore their increasing relevancewith respect to biodiversity and the natural systems that underpin the wealth o all nations.
Achim Steiner
United Nations Under-Secretary General and Executive Director,
United Nations Environment Programme
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4 Cities and Biodiversity Outlook
Preace by the ExecutiveSecretary o the CBD
Cities and Biodiversity Outlook Action and Policy stems rom Decision X/22
requesting the Executive Secretary o the CBD to prepare an assessment othe links and opportunities between urbanization and biodiversity, based
on the concept o our fagship publication Global Biodiversity Outlook. Theprimary goals oCBO are to:
Serve as the rst comprehensive global synthesis
o researched scientic material on how urbaniza-tion aects biodiversity and ecosystem dynamics.
Provide an overview, analysis, and response to
knowledge gaps in our understanding o urbaniza-tion processes and their eects on social-ecologicalsystems.
Address how biodiversity and ecosystem services
can be managed and restored in innovative ways toreduce the vulnerability o cities to climate changeand other disturbances.
Serve as a reerence or decision- and policy-
makers on the complementary roles o national,
sub-national, and local authorities in preserving
biodiversity.
Ours is an increasingly urban world. The 20 ambitious Aichi Biodiversity Targets set by the CBD or 2020
cannot be achieved without coherent governance at global, regional, national, sub-national, and local levels.The habits o urban dwellers will largely determine the health o our ecosystems and the survival o biodi-
versity. As the pages that ollow make abundantly clear, sustainable urbanization is essential or maintaininghuman well-being. Citiestheir inhabitants and governmentscan, and must, take the lead in ostering a
more sustainable stewardship o our planets living resources. Many already are, in ways that are innovative,exciting, and inspiringbut so much more remains to be done. This publication isanew and valuable toolor steering urban development onto a sustainable path. I hope you will read it, share it, and together with
others, take action to save lie on Earth.
Braulio Ferreira de Souza Dias
Assistant Secretary-General and
Executive Secretary Convention on Biological Diversity
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5Cities and Biodiversity Outlook
Overview o Bvy lk Ply
CBO Action and Policy provides the summary o a global assessment o the links between urbanization, biodi-versity, and ecosystem services. Drawing on contributions rom more than 120 scientists and policy-makers
rom around the world, it summarizes how urbanization aects biodiversity and ecosystem services and pres-
ents 10 key messages or strengthening conservation and sustainable use o natural resources in an urbancontext. It also showcases best practices and lessons learned, and provides inormation on how to incorpo-
rate the topics o biodiversity and ecosystem services into urban agendas and policies. CBO Action and Policy
emphasize challenges and opportunities in rapidly urbanizing developing countries. A workshop in Cape Townin February 2012 was specically organized to bring together urban planners, policymakers and scientists rommany dierent Arican countries to inorm about current and uture urban developments in Arica.The AichiBiodiversity Targets (see Appendix 1) highlighted throughout the key messages reinorce the mission o the
CBDs Strategic Plan to take eective and urgent action to halt the loss o biodiversity.
This volume was developed in parallel with and builds upon the more detailed scientic analysis and assessmenttitled Global Urbanization, Biodiversity, and Ecosystems Challenges and Opportunities, scheduled to be published in2013. Both publications are a collaborative eort o the CBD and the Stockholm Resilience Centre o StockholmUniversity, with signicant input rom ICLEI Local Governments or Sustainability.
The material reviewed here is evidence-based, tested, and in the public domain. For ease o readability, reer-
ences are limited. A more complete list o reerences along with a glossary will be ound in the scientic
analysis and assessment (core chapters available at www.cbd.int/en/subnational/partners-and-initiatives/cbo).
Modeled upon the CBDs fagship publication, Global Biodiversity Outlook, the production oCBO Action and
Policy has been highly inclusive. Two separate drats were widely circulated or review beore publication. An
Inter-Agency Task-Force and an Advisory Group (see p. 62), as well as the Global Partnership on Local and
Sub-National Action or Biodiversity, provided valuable oversight o the entire process.
CBO Action and Policy will be ocially launched at the Cities or Lie Summit parallel to the eleventh meetingo the Conerence o the Parties to the CBD in October 2012.
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7Cities and Biodiversity Outlook
SECTION I
y Global Urbanization, Biodiversity, andEcosystem Services Challenges and OpportunitiesThe ollowing is a summary o the CBO Gll Uz, Bvy, y v
llg , the scientifc assessment edited by Thomas Elmqvist, Michail Fragkias,
Burak Gneralp, Peter Marcotullio, Robert McDonald, Susan Parnell, Marte Sendstad, Karen Seto, andCathy Wilkinson. Chapter reerences below reer to the core chapters available online, with ull reerences,
at www.cbd.int/en/subnational/partners-and-initiatives/cbo.
Urban Expansion
The world is increasingly urban, interconnected, and changing. I current trends continue, by 2050 the globalurban population is estimated to be 6.3 billion, nearly doubling the 3.5 billion urban dwellers worldwide in 2010
(Chapter 7). More than 60 percent o the area projected to be urban in 2030 has yet to be built (Chapter 7). Mosto the growth is expected to happen in small and medium-sized cities, not in megacities (Chapter 7).
Five major trends in the urbanization process have
implications or biodiversity and ecosystem services:
The total urban area is expected to triple between2000 and 2030, while urban populations are
expected to nearly double, increasing rom 2.84
to 4.9 billion, during this period. In other words,
urban areas are expanding aster than urban popu-lations (see Figure 1) (Chapter 7).
This urban expansion will heavily draw on naturalresources, including water, on a global scale, and
will oten consume prime agricultural land, with
knock-on eects on biodiversity and ecosystem
services elsewhere.
Most uture urban expansion will occur in areas
o low economic and human capacity, which
will constrain the protection o biodiversity and
management o ecosystem services (Chapter 7).
Urban expansion is occurring ast in areas adjacentto biodiversity hotspot (see Figure 1) and aster inlow-elevation, biodiversity-rich coastal zones thanin other areas (Chapter 7).
Urbanization rates are highest in those regions
o the world where the capacity to inorm policy
is absent and where there are generally under-
resourced and poorly capacitated urban governance
arrangements (Chapter 10).
However, all projections have uncertainties, and severalactors or eventsor example, a deep and protractedworld economic crisis, accelerating ossil-uel prices,or a global pandemiccould considerably decrease
the projected rate o global urbanization.
Even under scenarios o considerably slower urbaniza-tion rates, urban areas all over the planet are currentlyacing severe challenges, among them (i) shortages o
natural resources (including water) and environmental
degradation; (ii) climate change, as maniested by risingsea level, higher temperatures, variation in precipita-tion, and more requent and severe foods, droughts,
storms, and heat waves; (iii) demographic and social
changes associated with urbanization and popula-tion growth, such as the contradictory tendencies o
increased wealth and the absolute increase in the
numbers o poor; and (iv) management o the transi-
tion to a more technologically sustainable uture thatwill reduce ecological impacts, including minimizing
carbon ootprints. Challenges related to climate changeare particularly complex, and despite the act that theworld is increasingly urban, the ways in which cities
infuence and are infuenced by climate change have
been considerably less explored than other areas o
research on global warming (Chapter 8). The situation isparticularly alarming or Arica, where greater temper-ature increases than the global average are expected.This will have adverse eects on human well-being,
particularly in cities, through dramatic changes in
areas such as water availability, health, and sanitation.
In Arica, China, and India, where the combined urbanpopulation is expected to grow by more than 1 billionpeople, the next two decades will be particularly chal-
lenging but will also present vast opportunities. Eventhough urban patterns o population growthand
social and economic activityvary, all cities rely on
and have a signicant impact on biodiversity. This
impact is likely to be greatest in Asia, where by 2030
nearly one-third o the worlds urban inhabitants willlive in China or India (Chapter 7). This is a massive
change in where humans live on the planet, both in
terms o the ruralurban shit o populations and in
the geographical locus o settlement, and there will beinevitable local and global ecological consequences.
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8 Cities and Biodiversity Outlook
There is thereore a particular need or enhanced ocuson governance capacity to deal with the challenges
related to urbanization both within and outside city
boundaries This will require action at multiple scales,rom the local to the international. Maximizing thebiodiversity potential through improved urban gover-nance globally will require more comprehensive localknowledge, especially o under-researched cities in
the Global South (Chapter 10).
Many o the worlds cities are located in biodiversity-rich areas such as foodplains, estuaries, and coastlines(Chapter 3). Urban expansion and habitat ragmen-
tation are rapidly transorming critical habitats that
are o value or the conservation o biodiversity acrossthe globe so-called biodiversity hotspotsamong
them the Atlantic Forest Region o Brazil, the Cape oSouth Arica, and coastal Central America. The directimpacts o urban growth will clearly aect biodiver-
sity in many biomes; about 10 percent o terrestrial
vertebrates are in ecoregions that are heavily aectedby urbanization (Chapter 2). I current trends in popu-lation density continue, by 2030 urban land cover willexpand between 800,000 and 3.3 million square kilo-meters, representing a two- to veold increase rom2000. This would result in considerable loss o habi-
tats in key biodiversity hotspots, including the Guineanorests o West Arica, tropical Andes, Western Ghats,
FIGURE 1. Global urbanization and biodiversity hotspots,
19502025. For explanation o biodiversity hotspots see p. 22.
URBANIZATION AND EFFECTS ON BIODIVERSITY
Urban biodiversityis the variety and richness o living organisms (including genetic variation) and habitat diversity ound in
and on th e edge o human settlements. This biodiversity ranges rom the rural ringe to the urban core. At the landscape and
habitat level it includes:
Remnants o natural landscapes (e.g. letovers o primeval orests).
Traditional agricultural landscapes (e.g. meadows, areas o arable land).
Urbanindustrial landscapes (e.g. city centers, residential areas, industrial parks, railway areas, ormal parks and gardens,
brownelds).
Diversity o plants and animals in the urban landscape shows some interesting patterns:
1. The number o plant species in urban areas oten correlates with human population sizemore so than it does with the size
o the city area.
2. The age o the city aects species richness; large, older cities have more plant species than large, younger cities.
3. Diversity may correlate with economic wealth. For example, in Phoenix, USA, plant and bird diversity in urban
neighborhoods and parks shows a signicant positive correlation with median amily income.
4. Twenty percent o the worlds bird species and 5 percent o the vascular plant species occur in cities.
5. On average, 70 percent o the plant species and 94 percent o the bird species ound in urban areas are native to the
surrounding region.
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9Cities and Biodiversity Outlook
and Sri Lanka (Chapter 7). Mediterranean habitat typesare particularly aected by urban growth because
they support a large concentration o cities as well
as many range-restricted endemic speciesspecies
that occur nowhere else in the world.
Urban expansion also aects reshwater biodiversity.Predictions o the eects o global urban demographicgrowth and climate change on water availability
suggest that reshwater biodiversity impacts would
be greatest in places with large urban water demandsrelative to water availability, as well as where there
is high reshwater endemism (Chapter 2). O partic-
ular conservation concern is the Western Ghats o
India, which is expected to have 81 million people
with insucient water by 2050 but which also has,among a high diversity o other taxa, 293 sh species,29 percent o which are endemic to this ecoregion
(Chapter 2).
Many cities contain sites o special importance or
conservation because they protect threatened speciesand habitats. Many are remnants o native vegeta-
tion that survived because their topography, soil, andother characteristics are unsuitable or residential,
industrial or commercial development. Other sites
remain protected because their ownership or their
use and management have remained unchanged ordecades (sometimes centuries), they are important
sites o cultural heritage, or have remained unusedor a long time (Chapter 3). Remarkable examples
o such remnants include the orests o the Mata
Atlantica in Rio de Janeiro, Brazil; the evergreen
orests o the Botanical Garden in Singapore; the
National Park El Avila with its rock aces in Caracas,Venezuela; remnants o bushland in Perth, Sydney,
and Brisbane, Australia; remnants o natural orestsin York, Canada, and in Portland, USA; Sonoran
desert parks in Tucson and Phoenix, USA; the RidgeForest in New Delhi and the semi-evergreen orest
o Sanjay Gandhi National Park in Mumbai, India;
and rock aces and outcrops in Edinburgh, Scotland(Chapter 3).
Urbanization increases the number and extent o
non-native invasive species by increasing the rate ointroduction events and creating areas o disturbedhabitat or non-native species to become established(Chapter 2). There is a suite o cosmopolitan species,skilled generalists that are present in most cities
around the world. At the same time, urbanizationoten leads to the loss o sensitive species depen-
dent on larger, more natural blocks o habitat or
survival. The net result is sometimes termed biotichomogenization. Nevertheless, it is remarkable thatthe number o native species in cities, especially
the Northern Hemisphere, is relatively high. Studies
across many taxonomic groups have shown that50 percent or more o the regional or even national
species assemblage is ound in cities. For instance,
more than 50 percent o the fora o Belgium can
be ound in Brussels, and 50 percent o vertebrates
and 65 percent o birds in Poland occur in Warsaw
(Chapter 3). While some cosmopolitan urban speciesare indeed ound worldwide, concerns about overallbiotic homogenization may be somewhat unounded.A recent global analysis o fora rom 112 cities and
birds rom 54 cities ound that on average two-thirds
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10 Cities and Biodiversity Outlook
o plant species occurring in urban areas tend to benative to the region o each city; the proportion o
native bird species is considerably higher (94 percent)than that o other taxa (Chapter 3). Clearly, many
cities continue to retain a signicant proportion o
native biodiversity.
Although some non-native species become invasive,
dominating entire ecosystems and causing signicanteconomic loss, other introduced species actually mayreplace unctions o lost species and enhance specicecosystem services in cities, such as soil mineraliza-
tion, climate-change adaptation and mitigation, andcultural/aesthetic benets.
Urbanization and Ecosystem Services
Ecosystem services are the direct and indirect contri-butions o ecosystems to human well-being (Chapter4). Cities depend on ecosystems both within and
beyond the urban environment or a wide variety o
goods and services that are essential or economic,
social, and environmental sustainability. Ecosystems
have the potential in cities to regulate climate, protectagainst hazards, meet energy needs, support agricul-ture, prevent soil erosion, and oer opportunities orrecreation and cultural inspiration. In many urban
areas, particularly in brownelds and other non-usedurban land, there are ample opportunities to create
novel unctioning ecosystems that generate servicesthat enhance the well-being o urban inhabitants.
Urban ecosystem services are treated in detail in KeyMessages 3 though 8; here we give a ew examples otheir role and value.
Examples o urban ecosystem services
The supply o water rom catchment areas, oten
located just beyond or even within city bound-
aries, is a good example o a localized service. The
conservation o wetlands (including rivers) and theirbiodiversity enables natural reservoirs or chan-
nels to store and provide water. The managemento habitats on Mount Kenya, or example, is esti-
mated to save the Kenyan economy more than US$20 million a year by protecting the water catch-
ment area o two o Kenyas main river systems andensuring a regular supply o water. Another exampleo a provisioning service is urban and peri-urban
agriculture, which can augment ood security and
generate income or vulnerable urban households
(see Key Message 6).
HOW URBANIZATION AFFECTS EVOLUTION AND ADAPTATION
Urbanization directly transorms the local biophysical environment and changes the conditions or organisms living there,
generating new selection pressures and adaptations. The main changes are:
1. Changes in abiotic factors: altered incident sunlight exposure, humidity, precipitation, wind speed and direction, noise
levels, water routing, and soil characteristics. In cities, the increase in ambient air temperature, which is oten 25C higher
than in surrounding rural areas, is known as the urban heat island (UHI) eect, currently exacerbated by climate change.
Elevations in atmospheric concentrations o carbon dioxide, methane, and ozone and in nitrogen deposition also occur. In
cities there is oten an accumulation o phosphorus, nitrogen, and metals, which can inltrate surace water and groundwater.
Urban runo containing nutrient pollution rom organic sewage, vehicle efuent, and plant ertilizer enters waterways and
leads to eutrophication.
2. Changes in biotic factors: the rate o succession is infuenced, and oten urban ecosystems are intentionally kept in early
to mid- successional stages and with greatly altered disturbance regimes. The trophic structure is oten changed, with a lack
o top predators and a dominance o generalists and omnivores.
Organisms that have survived such changed conditions in urban areas have been able to do so or at least two reasons: (1)
they evolved rapidly or (2) they were largely preadapted to this environment. There are several documented cases o rapid
evolution in urban areas, involving, or example, tolerance to toxic substances and heavy metals in plants, such as lead
tolerance in urban roadside narrowlea plantain (Plantago lanceolata). Among insects there are many cases o rapid evolution
in urban areas. One o the most notable is the case o industrial melanism among moths and butterfies (Lepidoptera) in
the UK, in which the insects became darker in color in response to heightened levels o air pollution. This phenomenon has
also been documented in the USA, Canada, and elsewhere in Europe. Parks and green spaces are oten highly ragmented,
leading to rapid genetic dierentiation among less mobile species, or example, white-ooted mice (Peromyscus leucopus)
in New York City. Urban low-requency noise has also been observed to induce changes at the population level o calls
o several species o birds and rogs, such as white-crowned sparrows (Zonotrichia leucophrys) in San Francisco. Also o
interest are the specic urban and rural types identied within well-studied Drosophila (ruit fy) species.
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11Cities and Biodiversity Outlook
Ecosystems regulate not only the supply but also thequality o water, air, and soil. Urban parks and vege-
tation reduce the urban heat island eect. There is
additional potential or lowering urban temperaturesthrough construction o green roos and green walls.Data rom Manchester, UK, show that a 10 percent
increase in tree canopy cover may result in a 34C
decrease in ambient temperature and save large
amounts o energy used in air conditioning. Urban
green spaces can contribute to climate regulation byrefecting and absorbing solar radiation, ltering dust,storing carbon, serving as windbreaks, improving air
quality (by oxygen emission and moistening), and
enhancing cooling by evaporation, shading, and the
generation o air convection (see Key Message 5).
Extensive areas o impermeable suraces in urban
areas result in large volumes o surace-water runoand increase urban vulnerability to climate-change
eects, such as increased requency and intensity ostorm events. Interception o rainall by trees, other
vegetation, and permeable soils in urban areas can
thereore be critical in promoting inltration and inter-ception, thereby reducing pressures on the drainage
system and lowering the risk o surace-water fooding.Urban landscapes with 5090 percent impervious
ground cover can lose 4083 percent o incoming rain-all to surace runo, whereas orested landscapes loseonly about 13 percent o rainall input rom similar
precipitation events. Urban mangroves and other
wetlands also serve as bioltration systems or treat-ment o sewage, storm water, and other water-vectoredwastes and help reduce downstream pollution.
Ecosystems in urban areas also serve as habitatsor species and as storehouses or genetic diversity.
Nutrient cycling and soil ormation processes are
oten driven by non-iconic species, such as bacteria
or invertebrates; the contribution o biodiversity tothese vital ecosystem services oten goes unacknowl-edged or unprotected.
Biodiversity in cities exposes people to nature and
thereby acilitates an appreciation o nature. It also
provides opportunities or recreation, health and
relaxation, and community cohesion. Green-area
accessibility has been linked to reduced mortality
and improved perceived and actual general health.
It has been shown that the psychological benets
o green space increase with biodiversity, and that a
green view rom a window increases job satisac-
tion and reduces stress (see Key Message 4). This canhave a strongly positive eect on economic produc-
tivity and hence regional prosperity. The distribution
and accessibility o green space to dierent socioeco-nomic groups, however, oten reveals large inequitiesin cities, contributing to inequity in both physical andmental health among socioeconomic groups. Severalstudies have shown that property values (as measuredby hedonic pricing) increase with greater proximity
to green areas.
Many tools or monetary valuation o ecosystem
services are already available (Chapter 4), but these
need to be complemented with non-monetary valua-tion methods and with planning tools based on multiplecriteria that help to distinguish valuation tradeos. Thetotal value o multiple services generated by ecosys-
tems can be divided in dierent parts as illustrated inFigure 2, depending on whether there is a market andwhether the value can be expressed in monetary or
only in non-monetary terms. Ecosystem service sciencestill lacks a robust theoretical ramework that allows
or consideration o social and cultural values o urbanecosystems on an equal basis with monetary values indecision-making processes. Developing such a rame-work involves synthesizing the large but scattered bodyo literature that has dealt with non-monetary valueso the environment, and articulating this research into
ecosystem service concepts, methods, and classica-tions. Key Message 3 discusses several examples o
implementation at the local level.
Urban impacts on natural ecosystems can have
unoreseen eects on the health and well-being o
city-dwellers. Understanding how ecosystems deliverservices, who benets rom them, what happens whenan ecosystem changes, and how ecosystems may
contribute to greater resilience is thereore importantor developing sustainable cities (Chapter 4).
FIGURE 2. The value o ecosystem services can be
expressed as (1) recognized value, the bulk o which
includes cultural and aesthetical values that are oten
possible to express only in non-monetary terms; (2)
demonstrated value, where it is possible to calculate a
potential substitution cost in monetary terms (e.g. the
replacement cost o wild pollinators); and (3) captured
value, where there is a market that determines a value,
oten priced in monetary terms (water, ood, fber, etc).
(Modifed ater TEEB 2010.)
RECOGNIZED VALUE
DEMONSTRATED VALUE
CAPTURED
VALUE
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12 Cities and Biodiversity Outlook
Regional Analyses o Urbanization and Its Impacts on Biodiversity
The rate and ways in which the planet is urbanizing vary both across and within regions and countries. The
ollowing highlight some general trends or the main UN regions.
AfricaAlthough there is large spatial variation in rates o
change across the 55 nations o Arica, the combinedimpact o high natural population growth and rural-to-urban migration means that Arica is urbanizing
aster than any other continent (see Figure 3). Overallthe urban population is expected to more than doublerom 300 million in 2000 to 750 million in 2030.
Population expansion and a tradition o low-density
settlement mean that the rate o increase in urban
land cover in Arica is predicted to be the highest in
any region in the world: 700 percent over the period
20002030. Expansion is expected to be ocused in
ve main areas: the Nile River, the Guinean coast, thenorthern shores o Lakes Victoria and Tanganyika, the
Kano region in northern Nigeria, and greater AddisAbaba, Ethiopia. All except the latter are very sensi-
tive ecological zones.
For the most part, the urbanization in Arica is takingplace along the lines o past and current patterns
elsewhere in the world; however, it is also unolding
in ways that are distinctly Arican. Based on current
projections or 20102020, 74.2 percent o Aricas
total population growth will occur in cities o less
than 1 million. These are settlements with weak
governance structures, high levels o poverty, and lowscientic capacity regarding biodiversity. More than
43 percent o Aricas urban population lives below
the poverty line, higher than in any other continent,
making socioeconomic development a priority. The
generally weak state control, the presence o a eebleormal economic sectors, and the scarcity o local
proessional skills places constraints on handling thecomplex biodiversity challenges aced by rapid urban-ization. Because o the high level o inormality and
competing governance arrangements in Arica, espe-cially around land-use management, conventional
policy and regulatory measures used successully to
promote biodiversity in cities elsewhere in the worldmay not be very eective. However, the wide range o
custodians o the rich biophysical resources and therelatively undisturbed resource base o Arica, and thehigh level o inormality may also represent oppor-
tunities or local and rapid adaptation to changing
conditions in the urban landscape.
The eects o urbanization on land cover in Arica
appear to be unique. In the neotropics and SoutheastAsia, urbanization and agricultural export markets
are currently the strongest drivers o deoresta-
tion. In contrast, in much o sub-Saharan Arica old
FIGURE 3. Predicted urban growth rom 2010 to 2025 or cities that have a population o greater than 1 million in 2010.
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13Cities and Biodiversity Outlook
patterns o rural consumption o wood are still the
major drivers o orest loss. However, there are signi-icant variations within the continent. For example, inseveral West Arican cities, rapid population growth
has increased incentives or armers to convert
orests into elds or crops to sell in urban markets.
The recent land grab to secure Arican uel and oodproduction opportunities or urban citizens in other
parts o the world is a stark reminder that cities drawnot only on their immediate hinterlands or ecosystemresources.
It has been suggested that increased rates o rural
urban migration in Arica would relieve sources o
pressure on old-growth orests and allow marginal
agricultural lands to return to orest. However, given
the continued expansion o the rural population, albeitat a lower rate than urban growth, it has been ques-
tioned to what extent this is a general pattern. It is
likely that increased local and international demandor biouels and other cash crops may result in a new
export-driven mode o deorestation, just as in Asiaand the neotropics.
Arican cities are not readily dened. This is more thana classicatory and census issue, though there are realproblems in the lack o consistent and comparable
denitions and in the paucity o current and robust
gures on urban populations. Arica has generated
ambiguous settlement orms: as well as more conven-tional dense urban agglomerations, there is commonlya large peri-urban population and a cyclical pattern
o rural and urban migration. While a oothold in therural environment is retained, the shit to urban live-lihoods means that rural land-use patterns no longerretain the same degree o ocus on production, but
become instead landscapes inused with cultural andamilial signicance. Low levels o ormal employ-
ment in Arican cities put a high level o dependencyon the provision o ecosystem services, such as water,uel, and ood production, rom areas within cities aswell as nearby natural areas. In adjacent rural areas,biodiversity resource harvesting eeds into an exten-sive rural economy ocused on supplying cities, mainlywith ood and agricultural products.
Addressing urbanization and biodiversity challengesin Arica will require governance responses across thecontinent. In a Cities and Biodiversity Outlook work-
shop that brought together Arican researchers, localgovernment authorities, and planners in February 2012,participants discussed common governance challengesand identied eight key themes o specic relevance
to urban biodiversity concerns on the continent:
1. Many governments are still struggling with colo-nial legacy and the structures (or lack thereo) that
withdrawal and transition have let in the wake onew government.
2. High political instability oten exists, and maybe accompanied by varying levels o corruption.
This can result in high inormality o tenure and
economy. Particularly at the city level, lack o
nancial and human resources, and consequentlytechnical capacity, can prevent biodiversity and
environmental issues rom being recognized oraddressed.
3. In many instances, biodiversity concerns are seenas independent o and less important than other
urban pressures such as poverty, unemployment,and access to ood, energy, water, sanitation, and
housing. These pressures are principally the onesprioritized by politicians, who must act switly andexpediently to meet the demands o their constit-uencies and who are mindul to receive good pressto this end.
4. Where urban biodiversity interventions are imple-mented, they are generally undertaken with a
single ecosystem service in mind, and multiplebenets are oten neglected.
5. Even in governments where environmental-management issues receive recognition and
support, it may be dicult to generate continuedpolitical momentum and action.
6. Barriers to integrating the environment with otherissues may also be educational. Resources to inormthose in government may be inaccessible or nonex-istent, and academic terms and concepts that havebeen developed in other parts o the world may
be dicult to translate into other languages and
knowledge systems.
7. There is oten a disconnect between scales ogovernment, with lack o eective communicationbetween local and national levels, disenranchise-ment or mismanagement o local government by
higher levels o government, and ailure o nationalpolicy to be applied and implemented properly onthe local scale. Fiscal decentralization needs to
match political decentralization, municipal bound-aries may need to be extended or greater controlover land-use change in peri-urban areas, and
accompanying management tools must have area-wide (i.e., metropolitan or even regional) reach.
8. While international resources and unds exist,there is a lack o access and transparency o
process on how local governments procure these
opportunities.
Ultimately, how biodiversity is managed or integratedinto Arican cities will depend on whether it is posi-
tioned institutionally and topically as a priority in
governance agendas, and whether the co-benets
provided by ecosystems are integrally recognized
across general policy and action.
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14 Cities and Biodiversity Outlook
AsiaAsia is home to 60 percent o the worlds population,and there are large variations in the region with regardto urbanization levels and urban growth rates. Whilesome countries have populations that are predomi-
nantly urban (Singapore, 100 percent; Malaysia, 72
percent; Japan, 67 percent; Indonesia, 54 percent),
others have populations that are predominantly rural(Bangladesh, 28 percent; Vietnam, 29 percent; India, 30percent Lao Peoples Democratic Republic, 33 percent;Thailand, 34 percent). Despite these variations, threecharacteristics dene the region.
Many countries that are largely rural are undergoingmassive demographic and economic transitions,
resulting in a growing percentage o their popula-
tions living in urban areas. For example, the combinedpopulations o Kolkata and Dhaka in the Ganges
Brahmaputra Delta increased rom 4.9 million in 1950to more than 30 million in 2010. The changing demog-raphy o these mega-deltas is also changing their
economies, landscapes, and biodiversity.
Hal the increase in urban land across the world overthe next 20 years will occur in Asia, with the most
extensive patterns o change expected to take placein India and China (Chapter 7).
The infux o large-scale capital to many Asian deltas
has transormed the local economic base rom a
primarily agricultural one to a manuacturing and
processing economy, bringing about undamental
changes in landscapes and their ecologies. For example,the Irrawaddy Delta economy in Myanmar was tradi-
tionally intensive rice cultivation, shing, and orestry,supported by mangrove swamps. However, as Yangon,
the largest city in Myanmar and the economic, nan-cial, and trading hub o the country, increases in size
on the periphery o the delta, it is aecting the coastalmangrove ecosystems. Urbanization and associated landpracticesthe damming o rivers, seasonal food control,water diversions, agricultural practices, and construc-tion o the built environmenthave also transormedthe supply and routing o sediments and changed the
basic geomorphology and ecology o the delta.
IndiaIndias population (see Figure 4) is currently about 30percent urban and is expected to become 50 percenturban by about 2045. This will have signicant impli-cations or the countrys environment, ecology, and
sustainability. India already contains 3 o the worlds10 largest citiesDelhi, Mumbai, and Kolkataas
well as 3 o the worlds 10 astest growing cities
Ghaziabad, Surat, and Faridabad. Urbanization in Indiais unevenly distributed, with about hal the countrysurban population living in smaller urban agglomera-tions with populations under 100,000.
The rate o urban land expansion in India during thenext 20 years is expected to be high, in part because
the country is investing heavily in large-scale inra-structures such as roads, telecommunications,
water networks, and power and electricity grids.
Such development will put new pressures on ecosys-tems and biodiversity. At the same time, India has acultural tradition o respect or wildlie, as well as ordeliberative political processes, which in most citiesinclude civil society groups and non-governmentalorganizations. This may oer a window o oppor-
tunity or adjusting development to accommodate
biodiversity.
FIGURE 4. Urban population centers (red circles) and biodiversity hotspots in India, 19502025 (yellow circles reer to
population centers outside India). For explanation o biodiversity hotspots see p. 22.
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15Cities and Biodiversity Outlook
Until recently, rural development was a major ocusin India. This changed in 2005, when the launch o theJawaharlal Nehru National Urban Renewal Mission
shited the ocus to development o 63 urban centersthroughout the country. Reorms in India and nationalpolicies now treat urbanization as central to economicand industrial development, and there is an explicit
strategy to develop cities. One o the largest examplesis the developing MumbaiDelhi industrial corridor,
which is approximately 1,500 kilometers long and
connects two o the countrys megacities. The govern-ment is also establishing special economic zones,
industrial and technology parks, and ree-trade zonesthat will urther ocus urban expansion in specic
locations. These urban clusters are likely to transormentire regions, with signicant impacts on habitat
and biodiversity.
Urban expansion in India is accompanied by
complex eects on local and regional biodiversity,
ecosystem services, and orest cover because o a
combination o socio-demographic and liestyle
changes in urban areas. Urban growth, especially in
areas adjacent to orest land and protected areas,
increases pressures on these ecosystems through
habitat ragmentation, poorly regulated develop-ment and recreation, and spillover o air and water
pollution. At the same time, liestyle changes that
are due to urbanization may decrease pressures on
some orest resources such as uelwood and charcoal.Urbanization has promoted a transition in householdenergy use or cooking, rom uelwood to liqueed
petroleum gas. Between 1993 and 2005, urban uel-
wood demand in India declined rom 30 to 22 percento households, despite signicant population growthin urban areas; during this same time, rural uelwood
demand dropped only rom 78 to 75 percent. Overall,orest cover remained unchanged or increased slightlyin conjunction with this change in uel type in urbanhouseholds. While orest cover does decline with urbandevelopment, the eects are not homogeneous. For
example, relatively unregulated housing and industrialdevelopment has signicantly diminished mangroveorests in Mumbai. Yet just across the Thane Creek inNavi (New) Mumbai, where urban development was
a planned process starting in the 1980s, mangrove
orests have shown a remarkable recovery in the pasttwo decades.
Even the largest Indian cities retain a high proportiono native plants, birds, butterfies, and other taxa, espe-cially in parks and orest ragments that are protectedor still undeveloped. For instance, Kolkata, one o thelargest cities in the world, provides habitat or 273
bird species, all o them native to the region. As urbanregions expand, there is an increase in the incidenceo leopards, elephants, and other large mammals
encountering people in the expanding urban ringes.Traditional cultural and religious practices have otenencouraged wildlie such as primates to inhabit townsand cities, but changing liestyles are challenging
this coexistence. At the same time, highly adapt-able species such as the leopard show a remarkable
ability to persist in urbanizing habitats. Other, rarer
species continue to colonize habitats in urban areas,such as the sizeable population (10,00013,000) o
Lesser Flamingos that since the mid-1990s have beenwintering at Thane Creek in Mumbai. Finding ways
to minimize conficts with some species and improvehabitats or others is challenging, but it is also presentsopportunities to engage the public in understanding
and managing local biodiversity.
FIGURE 5. Urban population centers (red circles) and biodiversity hotspots in China, 19502025 (yellow circles reer to
population centers outside China). For explanation o biodiversity hotspots see p. 22.
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16 Cities and Biodiversity Outlook
Urbanization constitutes a process with great poten-tial but also signicant challenges or India. Inequalityhas increased in Indian cities over time, and challengessuch as climate change eects are aced dispropor-
tionately by the urban poor. Loss o agricultural landto urbanization, combined with insucient planningo inrastructure or supplying ood to cities, places asevere constraint on uture ood security or Indias
growing population. India is in a avorable positionto address its ormidable challenges o sustainable
urban development through innovative collaborationsamong municipal governments, civil society groups,
community groups, researchers, and other sectors osociety. Such collaborations are being tried in severallarge cities, including Bangalore, Delhi, and Chennai, aswell as in cities such as Surat and Indore. It is essentialand urgent that India nds ways to balance economicgrowth with reduction o pressure on ecosystems to
ensure a secure, equitable, and sustainable uture.
China
China is in the middle o its urbanization transition.Compared with the last three decades, the urbaniza-tion rate in the coming three decades will be slower,
with urban expansion moving rom the coastal areasto the interior. By 2030 Chinas urban population is
expected to exceed 900 million, an increase o more
than 300 million rom today. While there are uncer-
tainties around these projections, there is even greateruncertainty about the location and extent o uture
urban expansion. China has been urbanizing rapidlysince the early 1980s. This has been maniested by
large ruralurban population migrations and by the
expansion o the built environment. In particular,
urban expansion is predicted to create a 1,800-kilo-
meter coastal urban corridor rom Hangzhou to
Shenyang.
One consequence o urban expansion has been the
loss o ertile agricultural land. Another, less noticed,has been the urban expansion within biodiversity
hotspots. Throughout China, and especially along thecoast, urban areas are increasingly encroaching on
protected areas. As urbanization progresses towardthe western regions o the country, biodiversity-rich
areas such as Himalaya, Indo-Burma, Mountains o
Central Asia, and Mountains o Southwest China (seeFigure 5) are likely to be aected by development
and land conversion. Urban development policies in
the uture thus need to ocus on biodiversity: how toconserve the places that are most biologically diverseand yet relatively unaltered by humans and how to
bring back biodiversity into the cities that are alreadybuilt. Chinas development has had, and is expected
to increasingly have, an impact on ecosystems well
beyond its national boundaries.
In addition to the preliminary orecasts reported here,a recent literature review identied China as having
2,541 nature reserves, covering more than 15 percento the countrys territory. The proximity o urban areasto these reserves will increase dramatically by 2030.
Thereore there is a critical window o opportunity inthe next ew decades or China to implement more
proactive approaches to guiding urban expansion in
ways that have the ewest negative eects on biodi-versity and ecosystem services.
Minimizing habitat and biodiversity loss and limiting
degradation o ecosystem services will require appro-priate urban planning and reormation o the currentland market system. Urban planning activities in
China are carried out under three central governmentagencies as well as under provincial and municipal
governments. Overlapping authorities among the agen-cies is an opportunity or strong action and directed
urban development, but it also puts a high demand oncoordination. In a simultaneous process, as the country
becomes increasingly market-oriented, the planningproession needs to evolve, as planners roles are rapidlyevolving into those o brokers and creative designers.
Latin America and theCaribbeanMore than 80 percent o the population in Latin
America lives in cities, and by 2050 it is expected to
reach 90 percent, thus making it the most urbanizedo all world regions. The region includes megalop-
olises such as Mexico City, So Paulo, and Buenos
Aires, whose populations exhibit signicant social
and economic dierences. The number o cities in theregion has grown sixold in the past 50 years (althoughgrowth rates have been slowing), while rural areas arebeing abandoned. Today, the deorestation rontier
is advancing, along with cities ounded less than 20
years ago, the Amazon basin rom the Southeast in
Brazil, and along major roads and rivers.
In the Caribbean, the percentage o the popula-
tion living in cities is somewhat smaller (around 65
percent), with signicant sub-regional dierences
(rom 21 to 90 percent). Historically, urban areas in theCaribbean have been predominantly characterized by
capital port cities, many o which were ounded duringthe sixteenth and seventeenth centuries. However, it isonly since the Second World War that this region hasexperienced rapid rates o urban growth. The biggestcapital cities (such as Havana, Santo Domingo and
Port-au-Prince) are still below 3 million, but urban-
ization growth rates overall are steeper than in the
rest o Latin America (with Haiti and Trinidad and
Tobago exhibiting the highest annual urbanization
rates). Capital cities oten house a signicant part o
the entire population.
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17Cities and Biodiversity Outlook
With ew exceptions (such as Curitiba, Brazil, and
Bogota, Colombia), management o and planning orbiodiversity and ecosystem services in Latin Americancities are uncommon. More urgent considerations,
such as providing housing or rural immigrants, are
prioritized over environmental and biodiversity values.Urban sprawl caused by housing or low-income
inhabitants oten occurs in areas that are mistakenlyconsidered to be o marginal value, such as foodplainsand wetlands. In much o Latin America, the urban-
ization pattern is dened by inecient land use, poorplanning, and land prices that do not refect the biolog-ical value o the land. Many areas that are considered
to be o marginal value have important conservationvalues or ecosystem services and biodiversity.
Research on the rapid urbanization o Latin Americaand the Caribbean is poorly developed. More detailedinormation is needed about the eects o rapidly
increasing housing density on ecosystem unctions,
how ecosystem services are linked to the availability odierent types o urban green spaces, and how socio-economics, urban morphology, and natural as well asanthropogenic hazards aect ecosystem provisioning
over time. Such inormation would be enormously
valuable in helping Latin American and Caribbean
cities guide their urban planning and conservation
biology policies.
EuropeIn Europe, the current urbanization level is 7080
percent, and urban growth in recent decades has beenmostly in the orm o urban land expansion rather
than population growth. Indeed, in some areas in
Eastern Europe, many cities are shrinking in popula-tion, creating new opportunities or innovative use oormer residential and industrial areas.
Most o the areas occupied by present cities were
settled already by people in Neolithic times, when
Europe was colonized by agriculturalists (9500 B.C.).
From the point o view o biodiversity, it is importantto recognize that the recolonization o European plantsand animals ater the last Ice Agewhich covered largeareas o Europewas not completed beore human
infuence began to cause local disturbances, so that theevolution o native biodiversity overlapped with humaninfuence. The long history o urban development in
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18 Cities and Biodiversity Outlook
Europe is one reason why its cities oten are character-ized by higher species richness o plants and animalsthan the surrounding rural areas are. This long historymay also be one actor explaining why European plantsand animals worldwide tend to successully establishin areas with dense human population.
The long-lasting urban expansion combined with alter-
ation o the natural environment may also explain whysevere environmental changes caused by urbaniza-
tion were recognized or the rst time in Europe. Thusthe roots o urban ecology, environmental protection,and sustainable urban development can be ound inEurope.
Researchers in Berlin started to investigate extensivelyits biodiversity (plants, animals, and habitats) and touse this data or urban planning in the 1970s. Berlin
was one o the rst cities in the world to do this in a
systematic way. Beginning in 1980, this example o
biotope mapping was ollowed by many European
cities, and today many large cities have long-termdata on vascular plants, dierent animal groups, andhabitats that are used or city planning and nature
conservation. Many cities have a long tradition o
designating areas or nature conservation within theirborders because o the numerous ecological servicesthey provide or dwellers. Today the European Unionrequires its member states to allocate at least 10
percent o their area or nature conservation. Most
o the bigger European cities have a higher percentageo nature reserves, which contain species and habi-
tats o national importance.
North AmericaCities in the USA and Canada share a complex
pattern o shrinking and/or shiting patterns o
population in central parts o the cities coupled
with sprawl in outer suburbs and exurban areas.
This pattern creates unique challenges or biodi-
versity conservation. Metropolitan areas in both
countries oten include signiicant amounts o
natural and semi-natural remnant habitats that
are under threat o development or impaired by
habitat changes tied to changes in land manage-
ment practices; vacant lands in inner cities and
older suburbs that are awaiting redevelopment orthat will remain vacant because o economic poli-
cies and planning decisions; and a diverse range o
habitats created and managed by home owners, prop-erty managers, and local governments. Biodiversityconservation programs in North American cities areenhanced by a long tradition o urban wildlie and
urban orestry programs run by state/provincial andlocal governments. These programs have resulted inhabitat conservation and restoration projects, tree
planting and urban greening eorts, and eorts to
involve local residents in conservation projects nearwhere they live. Non-governmental organizations
have also been involved in biodiversity conserva-
tion programs in North American cities. Their eortsinclude volunteer-led monitoring and restoration
projects, programs promoting conservation practicesin yards and gardens, and education and advocacy
programs. In the USA, extension programs run by
state universities provide inormation on conser-vation practices to urban residents and to local
governments.
Even though more than 90 percent o all urban ecolog-ical studies so ar have been conducted in cities inEurope or North America, there is still a lack o exper-imental approaches, and most studies have ocused
on either birds or plants. There is also a lack o long-term data, but two Long-Term Ecological Research
(LTER) sites in North America, Baltimore and Phoenix,are generating valuable inormation on the dynamicso the urban landscape rom an ecological and biodi-
versity perspective.
OceaniaOceania is dened by the United Nations as the islandswithin Polynesia, Micronesia and Melanesia, Australiaand New Zealand. Urbanization came late to the
islands in the Pacic Ocean, typically ollowing inde-pendence, but has increased rapidly since the 1970s.
Excluding the population o Papua New Guinea, morethan hal o all Pacic Islanders now live in urban
areas. In some atoll states, urban growth has producedvery high population densities, comparable to those
in densely populated Asian cities.
Both Australia and New Zealand have highly urbanizedpopulations, where 85 percent o their populations livein urban areas, but at relatively low densities. Australiais one o the worlds least densely populated countries,with ewer than three people per square kilometer.
Presently 10,450 square kilometers o Oceania is urbanarea. By 2030, it is predicted with high likelihood thatthe urban area will double in Oceania, concentrated
around existing urban centers. This expansion will
signicantly aect biodiversity, particularly in New
Zealand, Micronesia, Melanesia, and Polynesia, as theirentire land area is comprised o biodiversity hotspots.
The importance o managing the ecosystem serviceso this biodiversity, and o mitigating the impact ourban growth and associated agricultural expansion,is increasingly recognized. Much o the research in
Australia and New Zealand on ecosystem services
has an agroecosystem ocus, with the goal o changingagricultural practices to enhance rather than erode
ecosystem services.
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19Cities and Biodiversity Outlook
The Way Forward
The broad picture presented in this section demon-
strates that patterns o urbanization have signicantglobal implications or biodiversity and ecosystem
services. In particular, urbanization is one o the majordrivers o habitat conversion, especially in coastal andisland systems, and is an important driver o biodi-
versity loss in reshwater systems.
Since urbanization is undamentally changing the
nature o our planet, preserving biodiversity on this newurban world requires going well beyond the traditionalconservation approaches o protecting and restoring
what we think o as natural ecosystems, and trying toinuse or mimic such elements in the design o urbanspaces. Cities already represent a new class o ecosys-tems shaped by the dynamic interactions between
ecological and social systems. As we project the spreado these ecosystems across the globe, we must becomemore proactive in trying not only to preserve compo-
nents o earlier ecosystems and services that theydisplace, but in imagining and building entirely new
kinds o ecosystems that allow or a reconciliation
between human development and biodiversity.
While urbanization displaces many species, we
also know that other species have evolved adaptive
responses in behavior and physiology to not only
survive but thrive under urban selection pressures.
Novel plant and animal communities have evolved
in urban areas, oten with active management by
human society, and some o these now provide impor-tant services extending beyond urban boundaries.
Residential gardens and parks, or example, have
become important reservoirs or populations o beesand other pollinators that provide valuable ecosystemservices or agriculture, but that nd it dicult to
survive under the conditions o modern intensive agri-culture. Even some endangered species nd suitable
habitat in urban ecosystems when their original habi-tats have disappeared. Innovations such as rootop
gardens and vertical orests, and human interventionssuch as supplementary eeding and watering, have
the potential to oer novel habitats and niches or
species that may be quite dierent rom those in more
natural ecosystems. Novel species and their assem-blages that evolve under urban conditions may well
represent what the uture holds or much o Earths
terrestrial biodiversity.
We emphasize that addressing urbanization and biodi-versity challenges will require improved governance
responses across multiple scales. Particularly at the
city level, a lack o nancial and human resources, aswell as technical capacity, can prevent issues on biodi-versity and environmental rom being recognized or
addressed. In many instances, biodiversity concerns
are seen as independent o and less important than
other pressures such as poverty, unemployment, andaccess to ood, water, sanitation, and housing. This
perception needs to change, because biodiversity inter-acts with and oten underlies urban development
directly as well as indirectly. Thereore, more ecolog-ically sensitive approaches may lead to innovative
solutions or many o the perceived ills o urbanization.
Governance o biodiversity and ecosystem services isintertwined with several other management agendas,and like all sustainability aspirations requires local
knowledge and governance capacity. The implica-
tions o urban expansion are both local and global, asecosystems do not ollow municipal or national bound-aries. The displaced ecological impact o increased
urban consumption highlights the importance o
moving away rom narrow place-based solutions to
more broadly addressing concerns on ecological degra-dation and urban biodiversity concerns. It is time to
recognize the overarching impact o an increasingly
urbanized world and to design appropriate gover-
nance responses. Coordination is essential to avoid themismatch between governance systems and ecosystemunctioning. Not all interventions or institutional initia-tives are going to be ormal or ormally recognized;
local inormal initiatives can also have important
benets and should be not ignored (see Chapter 10
and Key Messages 7, 8, and 9).
Finally, as emphasized in several places throughout
this document, rapid urbanization provides multipleopportunities to ensure basic human welare and a
viable global environment. The opportunities lie in
that urban landscapes are also the very places whereknowledge, innovations, and human and nancial
resources or development o solutions to current
and uture challenges o sustainability are likely to beound. More than 60 percent o the area projected to beurban in 2030 has yet to be built (Chapter 7). This pres-ents unprecedented opportunities to vastly improve
global sustainability through designing systems or
increased resource and water eciency, as well as
or exploring how cities can be responsible stewardso biodiversity and ecosystem services within and
outside city boundaries.
There are no global panaceas to urban biodiversity andecosystem management, or to sustainability. However,there is much to be gained rom questioning currenttrajectories and values while learning rom others,
producing better evidence and sharing inormation
and experiences. No city can solve the current chal-
lenges alone.
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20 Cities and Biodiversity Outlook
section ii
Key MessagesThe 10 key messages in this section highlight how planners, engineers, architects, policy-makers, politicians,scientists, and citizens alike can take on the challenges o reducing the loss o biodiversity and thus contribute
to the implementation o the Aichi Biodiversity Targets o the CBD (see p. 60). Although many o the actionsdescribed are local and will have local eects, cities are embedded in the biosphere and increasingly inuence
sustainability on the planetary scale, ar beyond the limits o individual cities. These key messages are meantto inspire. As readers will quickly discover, there are vast opportunities or people and organizations all over
the world to acilitate sustainable growth patterns while managing native biodiversity and saeguardingecosystem services.
With increasing globalization, materials and energy
are drawn in great quantities rom all over the world
oten rom large distancesto the primarily urbanlocus o consumption and waste generation. The
connection o urban regions to globally dispersed
areas o production is illustrated by the global, spatialanalysis o the link between plant production required
or ood, eed, ber, and bioenergy supply and the loca-
tion o the consumption o these products.
Insights are provided by analyses o the global reach
o resource use by highly urbanized countries such asThe Netherlands. To supply the ood and ber needs
o its population, this small country requires an area
our times its own size. This emphasizes the depen-
dence that many populations have on rural land and
communities in other countries. The distal fows and
connections between urban and non-urban regions are
important drivers o land-use change. Some countriesand corporations are now even attempting to ensure
their ood and energy security via land-lease arrange-ments in other countries (e.g. in several countries in
Arica). This has impacts on land use, biodiversity, andecosystem services, and potentially negative implica-tions or local investments, inrastructure, development,
and livelihoods.
Recent studies suggest that the global ood supply willneed to roughly double by 2050 to meet the dietary
needs o the primarily (approximately 70 percent)urban global population. A doubling o the global ood
supply without extensive additional environmental
degradation to non-urban areas will present major
challenges. However, there are also untapped oppor-
tunities in cities that may contribute to achievingthis goal. For example, cities can use a combina-
tion o measures to decrease waste and reduce meatconsumption while at the same time they invest
in protecting biodiversity, water quality, local ood
production and key carbon-sequestering ecosystems.
Ecosystem management requires amulti-scale approachSince the ecosystem services that benet urban popu-
lations are generated at multiple scales, it is necessary
to take a comprehensive, integrated, and multi-scale
approach to their management. It is not just the builtcapital o cities that we need to considerit is theull spectrum o assets, including social and natural
capital at local, regional, national, and global scales.
This also means that institutions responsible or the
stewardship o our assets need to extend their reachto these more distant scales.
One tool or analyzing complex urbanrural rela-
tionships is the Ecological Footprint Analysis. Theecological ootprint is the amount o land necessary
to sustain each citizens liestyle, considering not onlyood but also materials, energy, and water and other
natural resources. It compares per capita ootprint(the equivalent, in hectares, o the area needed toproduce all the resources consumed per capita) and
biological capacity (the average equivalent produc-
tive area available per capita). The method began at
the national level and has recently been explored
or analysis by economic sector, demand category,and sub-national area or socioeconomic group. Todate, more than 100 cities or regions (see Figure 1.1)
have used the Ecological Footprint Analysis to help
develop policies. In 1995 Londons ootprint was 125
times the size o the cityrequiring an area the size
o the UKs entire productive land surace to provide
needed resources. In 2000 the city commissioned a
report on Londons ootprint and later engaged in a
project called Toward Sustainable London: Reducingthe Capitals Ecological Footprint.
KEY MESSAGE 1: Urbanization is both a challenge and anopportunity to manage ecosystem services globally.
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21Cities and Biodiversity Outlook
The application o the concept and the management
o ootprints remain intensely challenging. How do
the various sectors involved assign responsibilitiesand share costs? What are the specic contributions
and roles o each player (private sector, government
agencies, NGOs and major groups, international orga-nizations, and multilateral agreements)? It is relativelyeasy to measure ootprints at the local level, but it is
very dicult to address and manage them unless actors
are involved at the landscape level whose mandate goes
beyond the city boundaries. An interesting emerging
area is the attempt to develop the ecological ootprintconcept as a component o the planetary boundary
concept and make it possible, at least or some o thevariables, to identiy regional boundaries.
Cities have a vital role to play in managing
planetary resourcesIt is important to point out that while actions at the
city level capture important opportunities and resultin contributions towards the reduction o ootprints,
actions by a consortium o municipalities or stategovernments operating at larger scales are likely to
accomplish even more. Cities are already engagingin cooperative partnerships and beginning to takean active role in the management o resources and
impacts on the regional or even global scale. Additional
cooperative partnerships among urban and non-urban
places are needed, and these must extend to multipleglobal environmental issues, and address their inter-connections and impacts on our planet. A global
system o cities must also operate within a rame-work o other actors such as national, regional, and
local governments, multinational corporations, and
civil society. Each o these actors has important rolesto play in managing planetary resources.
Eective stewardship must consider the multi-scale,
interconnected resource chains and their diverse ac-
tors. Urban regions must take increased responsibilityor motivating and implementing solutions that takeinto account their proound connections with andimpacts on the rest o the planet. This responsibility
includes implementing the ecosystem approach o the
Convention on Biological Diversity in the urban land-
scape and encouraging local governments to start aprocess or addressing the Aichi Biodiversity Targets
(see p. 60). How this can be done is exemplied in theremaining key messages.
Select ReerencesFolke, C, Jansson, A, Larsson, J, and Costanza, R, (1997) Ecosystem
Appropriation o Cities Ambio Vol. 26, no.3, pp 167172.
Rockstrm, J., et al. 2009. Planetary Boundaries: Exploring the SaeOperating Space or Humanity. Ecology and Society 14(2): 32.Online at www.ecologyandsociety.org/vol14/iss2/art32/.
Figure 1.1. Photo o Montserrat
Mountain in Catalonia, Spain, In
2009 the autonomous community
o Catalonia, commissioned an
extensive report on its ootprint in
preparation or its own biodiversity
law. The report is ramed within the
Convention on Biological Diversity
and its related European Union
directives. It speaks not only o
ootprints but o international anti-
cooperation and ecological debt, th
negative consequences o trade, an
exchanges with its partners. The rep
estimates the eects o overseas dir
investment o Catalonian companies
on biodiversity and considers
the landscape impacts o resort
development by Catalonian hospital
groups in the region and elsewhere.
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22 Cities and Biodiversity Outlook
It is commonly assumed that cities and rich biodiver-sity are incompatible, but the act is that many citieshave high species richness and several are even located
within globally recognized biodiversity hotspots.
Some notable examples o cities with rich biodiversityare ound on nearly all continents and latitudesBerlin, Bonn, Brussels, Cape Town, Chicago, Curitiba,
Edmonton, Frankurt, Freiburg, Helsinki, Kolkata,Mexico City (see Figure 2.1), Montreal, Mumbai,
Nagoya, New York City, So Paulo, Seattle, Singapore,Stockholm, and Vienna, to name but a ew. This otenhas historical roots; areas with rich and diverse ecosys-
tems are also rich in natural resources and thereorehave long been magnets or human settlement and
commerce.
Urban habitats can be surprisingly diverse. Forests,
mountains, grasslands and shrublands, savannas,peat swamps, mangroves, rivers, lakes, rocky shores,
coastal habitats, dunes, seagrass meadows, intertidal
mudfats, and coral rees are examples o habitatsound in cities. Such richness o habitats also results in
the generation o multiple ecosystem services, which
can contribute signicantly to human well-being (seealso Key Messages 4 and 6).
While intact natural ecosystems harbor the richest
biodiversity, remnants o pristine natural landscapes(e.g. relicts o primeval orests), traditional agricultural
landscapes (e.g. meadows and satoyama), restored
landscapes, and managed and industrial landscapes(e.g. industrial parks, railway tracks, residential and
city centers, parks, gardens, and brownelds) areincreasingly becoming reugia or biodiversity in cities.
Several actors inluence urban biodiversityUrban biodiversity is infuenced by the status o the
original surrounding ecosystems and by the planning,design, and management o the built environment,
which in turn are infuenced by the economic, social,
and cultural values and dynamics o human popula-tions. Conserving native ecosystems in urban areas isincreasingly important, especially given the current
rate o urbanization. Brussels, or example, containsmore than 50 percent o the foral species ound in
Belgium. Berlin has 22 habitats o global importance.
As natural areas previously outside urban bound-aries are incorporated into cites and developed, the
displacement o biodiversity and ecosystem servicesbecomes increasingly problematic worldwide.
Biodiversity HotspotsConservation International denes a biodiversity hotspot as having at least 1,500 endemic plant species and having lost at least
70 percent o its original habitat area. O the 34 biodiversity hotspots identied globally, all contain urban areasmany o them
signicant in size and population. Cities in biodiversity hotspots have a vital role to play in the conservation o these critically
threatened ecosystems. ICLEI and several partners recently established the Cities in the Hotspot program (see p. 53), to secure
ecosystem services in such areas.
KEY MESSAGE 2: Rich biodiversity can exist in cities.
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23Cities and Biodiversity Outlook
Many cities contain protected areas within or justoutside their borders that provide important contri-
butions to biodiversity. In Cape Town, Table Mountain
National Park, an iconic landmark extraordinarily richin endemic plants and animals, is entirely surroundedby the municipality. In Mumbai, Sanjay Gandhi National
Parkknown or its dense semi-evergreen orests,280-plus species o birds, 150 species o butterfies, and
40 species o mammals, including a small populationo leopardsprotects 104 square kilometers entirely
within a megacity. In Stockholm, the National Urban
Park comprises 2,700 hectares with high biodiversity,
right in the city center. In Kenya, Nairobi National
Park (see Figure 2.2), just 7 kilometers rom the centero Nairobi, is home to lions, giraes, cheetah, rhinos,
bualo, and more than 400 species o birds. In thewestern USA, Saguaro National Park lies just outside
the City o Tucson and protects about 40,000 hectareso the unique Sonoran Desert ecosystem.
These examples show that with proper planning andmanagement, cities can retain substantial compo-nents o native biodiversity.
Biodiversity includes common species too
Biodiversity does not have to be rare to be valu-ableit reers to common and widespread speciestoo. Monitoring the status o common species isimportant because luctuations in their popula-
tions can indicate environmental problems. A casein point is the quintessentially urban House Sparrow(Passer domesticus) whose populations have recently
declined drastically in Eurasian cities throughoutits native range, or reasons that are not yet entirely
clear. Understanding the ecology o common speciesmay help us improve habitats or them as well as or
rarer species. Furthermore, ecosystem services may
be delivered even by ecosystems that are degraded orthat contain low biodiversity. While pristine ecosys-
tems typically provide a greater number o ecosystemservices than those that are degraded or altered,many ecosystems that are signicantly altered rom
their pristine state can still provide useul goods andservices (e.g. carbon storage, clean air and water).
Connecting ragmented ecosystems is likely to increase
ecological unctionality as a whole and thereore tomaximize the ecosystem services oered. There arediverse and innovative ways to connect natural ecosys-tems. Planting trees with overarching canopies can
help small mammals, birds, and insects cross roadsand highways (see Figure 2.3). Roadside planting that
mimics the multilayering o orestsor example, acomposite o tall trees, medium-sized trees, shrubs,
and understory vegetationcan cater to a diversity oanimal users. Ecolinks such as underground tunnels and
vegetated overhead bridges can help connect natural
areas. All o these eorts can complement the impor-
tant roles played by protected areas in cities. O course,
Figure 2.1. Photo o the Mexican jaguar (Panthera onca hernandesii).
One o the worlds largest cities, Mexico City has 8.8 million inhabitants
in the city proper and about 22 million in the metropolitan area. The
city supports about 2 percent o all the known species in the world,
including 3,000 species o plants, 350 species o mammals, 316
species o birds, and many species o aquatic plants and animals.
URBAN NATURE FACTS
Even backyard gardens can harbor signifcant biodiversity: a studyo 61 gardens in the city o Shefeld, UK, ound 4,000 species oinvertebrates, 80 species o lichen, and more than 1,000 species oplants.
Cities can be important habitats or a diverse bee auna. Bees in urbanand suburban settings have a richer, healthier diet than bees in modernintensive armland settings.
Medium-sized carnivores such as the red ox, coyote, Eurasian badger,
and raccoon living in or around urban areas may achieve higherpopulation densities than they do under natural conditions.