Forests and Sustainable Cities © Bluejayphoto Bluejayphoto

250ISSN 0041-6436

An international journal of forestry and forest industries Vol. 69 2018/1

FORESTS AND SUSTAINABLE CITIES © BLUEJAYPHOTO BLUEJAYPHOTO

Mantova, Italy, will host the first World Forum on Urban Forests in November/December 2018

World Forum on Urban Forests Mantova, Italy, 28 November–1 December 2018 2018

The first World Forum on Urban Forests will showcase cities worldwide that are using urban forestry to provide economic benefits and ecosystem services and to strengthen social cohesion and public involvement. The Forum will bring together actors from around the world and across sectors to explore urban forestry strategies towards a greener, healthier and happier future.

An initiative of FAO, the City of Mantova, the Italian Society of Silviculture and Forest Ecology, and Politecnico di Milano

More information: www.wfuf2018.com 250ISSN 0041-6436

An international journal of forestry and forest industries Vol. 69 2018/1

Editor: A. Sarre Editorial Advisory Board: I. Buttoud, P. Csoka, D. Reeb, S. Rose Contents Emeritus Advisers: J. Ball, I.J. Bourke, C. Palmberg-Lerche, L. Russo Editorial 2 Regional Advisers: T. Hofer, A.A. Hamid, J. Meza S. Borelli, M. Conigliaro and F. Pineda Urban forests in the global context 3 Unasylva is published in English, French and Spanish. Subscriptions can be obtained P. Calaza, P. Cariñanos, F.J. Escobedo, J. Schwab and G. Tovar by sending an e-mail to [email protected]. Building green infrastructure and urban landscapes 11 Subscription requests from institutions (e.g. libraries, companies, organizations C. Dobbs, A.A. Eleuterio, J.D. Amaya, J. Montoya and D. Kendal and universities) rather than individuals The benefits of urban and peri-urban forestry 22 are preferred in order to make the journal accessible to more readers. D.J. Nowak All issues of Unasylva are available online Improving city forests through assessment, modelling free of charge at www.fao.org/forestry/ and monitoring 30 unasylva. Comments and queries are welcome at [email protected]. C.C. Konijnendijk, P. Rodbell, F. Salbitano, K. Sayers, FAO encourages the use, reproduction and S. Jiménez Villarpando and M. Yokohari dissemination of material in this information product. Except where otherwise indicated, The changing governance of urban forests 37 material may be copied, downloaded and N. Nagabhatla, E. Springgay and N. Dudley printed for private study, research and teaching purposes, or for use in non-commercial Forests as nature-based solutions for ensuring urban products or services, provided that appropriate water security 43 acknowledgement of FAO as the source and copyright holder is given and that FAO’s P. Cariñanos, P. Calaza, J. Hiemstra, D. Pearlmutter and U. Vilhar endorsement of users’ views, products or The role of urban and peri-urban forests in reducing risks services is not implied in any way. and managing disasters 53 The designations employed and the presentation of material in this information J. Castro, S. Krajter Ostoić, P. Cariñanos, A. Fini and T. Sitzia product do not imply the expression of any “Edible” urban forests as part of inclusive, sustainable cities 59 opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations C.Y. Jim (FAO) concerning the legal or development Protecting heritage trees in urban and peri-urban environments 66 status of any country, territory, city or area or of its authorities, or concerning the delimitation FAO Forestry 75 of its frontiers or boundaries. The mention of specific companies or products of manufacturers, World of Forestry 77 whether or not these have been patented, does not imply that these have been endorsed or Books 79 recommended by FAO in preference to others of a similar nature that are not mentioned. The FAO publications reviewed in Unasylva are available on the FAO website (www.fao.org/ publications) and can be purchased through [email protected].

Cover: The Cheonggyecheon promenade, Seoul, Republic of Korea. The area has been restored in a major urban-renewal project to improve the downtown environment. Cities need forests © Nicolas McComber EDITORIAL

ore than half the world’s population now lives in towns are needed. According to Konijnendijk and co-authors, diverse and cities, and that proportion will continue to grow in models of urban forest governance are emerging in which local coming decades. If planned and managed well, cities communities, not-for-profit organizations, municipal authorities Mcan be great places to live, but many urban developments cause and the private sector all have roles to play in ensuring that the environmental havoc – ultimately leading to problems such as benefits and costs of UPF are shared equitably. urban “heat islands”, flooding, and air pollution. The cost for Nagabhatla and co-authors point out that ensuring a sustainable citizens is borne in deteriorating well-being; the costs for the water supply in cities looms as a major global challenge. They planet include increased greenhouse gas emissions and other advocate nature-based solutions, which are actions to protect waste and the degradation of soils and waterways. and manage ecosystems that both address societal challenges Cities need forests. The network of woodlands, groups of trees and provide benefits for human well-being and biodiversity. and individual trees in a city and on its fringes performs a huge Forests increase soil infiltration, soil water-holding capacity and range of functions – such as regulating climate; storing carbon; groundwater recharge; regulate flows; reduce soil erosion and removing air pollutants; reducing the risk of flooding; assisting sedimentation; and contribute to cloud cover and precipitation in food, energy and water security; and improving the physical through evapotranspiration. UPF, say the authors, will increas- and mental health of citizens. Forests enhance the look of cities ingly be deployed as a cost-effective, nature-based solution for and play important roles in social cohesion; they may even reduce managing water in cities. crime. This, the 250th edition of Unasylva, takes a close look Cariñanos and co-authors examine the role of UPF in reduc- at urban and peri-urban forestry (UPF) – its benefits, pitfalls, ing risks and coping with disasters. Poorly managed urban and governance and challenges. peri-urban forests can also create hazards, however, and the In the opening article, Borelli and co-authors describe the essen- article looks at how these can be handled with the overall aim tial role that urban and peri-urban forests must play in meeting of increasing urban resilience to shocks. global commitments on sustainable development. The United The article by Castro and co-authors takes a somewhat different Nations and other bodies have long recognized that unplanned tack, looking at the role of “food forests” in city sustainability. urban growth can drive poverty and inequality and cause social It concludes that more work is needed to maximize the potential and environmental problems on a global scale. Most recently, the of such forests as part of the green infrastructure of cities. Sustainable Development Goals explicitly address the need for Finally, the article by Jim looks at the cultural role, management sustainable urban development, aiming to “make cities and human and mismanagement of heritage trees, which are “outstanding” settlements inclusive, safe, resilient and sustainable”. Forests are trees to which societies attach special value. If a city can take increasingly seen as essential elements of this, and many inter- excellent care of its heritage trees, argues Jim, “it can inspire national organizations, including FAO, are assisting countries and confidence in its capacity to care for all its urban and peri-urban local governments to better integrate forests into city governance. forests”. The article makes recommendations aimed at mitigat- The article by Calaza and co-authors examines the role of UPF ing existing problems in the management of heritage trees and as part of an overall strategy to develop green infrastructure – the improving professional practice. term used to describe the network of green spaces and water The world will continue to urbanize for decades to come. systems delivering multiple economic, social and environmental Villages will become towns, towns will become cities, and cities values and benefits to an area. The article presents international will become megacities. Ensuring that these urban expanses are perspectives on the importance of good design in UPF and both liveable and sustainable is a massive challenge to which suggests that it can help solve a number of urban problems. UPF advocates and practitioners must rise. Safeguarding and Dobbs and co-authors use case studies in Australia, Brazil, sustainably managing forests and other green spaces in cities Colombia and the United States of America to demonstrate the will be crucial for the health and well-being of the planet and benefits that urban and peri-urban forests can provide for city its inhabitants. u residents. They also discuss some of the challenges that urban forest planners and managers will need to meet in years to come. In another article, Nowak sets out a four-step process for assessing, modelling and monitoring urban forest structure, which can have a profound impact on the benefits and costs of urban and peri-urban forests. This process, says Nowak, enables the development of local forest management plans that optimize forest structure to enhance human well-being. Urban and peri-urban forests are often under pressure from poor urban development, and better ways of governing them 3 © SIMONE BORELLI Urban forests in the global context

S. Borelli, M. Conigliaro and F. Pineda

Cities can lead the way in meeting he last century has been charac- number of people living in urban areas the Sustainable Development terized by (among other things) and, overall, 53 per cent of the world’s Goals and other globally increasing urbanization, with cities urban population (United Nations, 2014). established objectives by deploying Tworldwide expanding in both number and Managing urbanization poses huge urban and peri-urban forestry. size. For example, the world urban popula- challenges. Cities can be hubs of socio- tion increased from 746 million people economic development, but the rapid in 1950 to 4 billion in 2015 (more than pace of urban growth and the limited a fivefold increase), and this growth is resources available to accommodate expected to continue in coming decades, increasing demand for food and basic with low- and middle-income countries services can also present huge barriers projected to more than double and triple for the equitability and sustainability of their urban populations, respectively, city development (United Nations, 2016). by 2050 (United Nations, 2016). Of the Particularly in less-developed countries, world’s regions, Africa and Asia are exponential urban population growth has urbanizing fastest: Africa had the highest not been matched by a corresponding urbanization rate of all the regions between increase in the availability of goods and 1995 and 2015; and Asia (already home services such as clean drinking water, to 17 megacities1) has by far the largest Above: A scene in an urban park Simone Borelli, Michela Conigliaro and in Viterbo, Italy. Urban and peri- Florencia Pineda are in the Forestry Policy and 1 A megacity is a city with more than 10 million urban forests are a crucial part of a Resources Division, Forestry Department, FAO. inhabitants. sustainable future for the planet

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adequate housing and sanitation, and URBAN ISSUES IN as UN-Habitat. The second Habitat con- energy. In most less-developed countries, THE GLOBAL AGENDA ference, held in Istanbul, Turkey, in 1996, urbanization has translated largely into The international community and the ended with the endorsement of the Habitat unplanned urban expansion accompanied United Nations have widely acknowledged Agenda, a policy document containing more by unsustainable production and con- that rapid, unplanned urban growth can than 100 commitments and 600 recom- sumption patterns, leading, in turn, to the drive poverty and inequality, especially in mendations for member countries, setting overexploitation of natural resources in newly urbanizing countries. As far back a plan of action and urban sustainability and around urban areas. As a result, cities as 1976, the first Habitat conference (held goals for the new millennium. have become more vulnerable to natural in Vancouver, Canada) drew international In 2015, urban sustainable development disasters and to the effects of climate attention to the need to consider and discuss was also at the heart of the two main change, and many urban and peri-urban the challenges posed by increasing urbani- global development agreements endorsed communities are highly exposed to food zation. Among other things, it led to the by the international community: the 2030 insecurity and poverty. creation of the United Nations Commission Agenda for Sustainable Development and This article outlines the international on Human Settlements – an intergovern- the Paris Agreement on climate change. response to the urgent need to better mental body – and the United Nations Building on the Millennium Development manage urbanization, specifically through Centre for Human Settlements, the two Goals, the 2030 Agenda (which includes the establishment, management and sustain- precursors of the United Nations Human 17 Sustainable Development Goals – able use of urban and peri-urban forests. Settlements Programme, commonly known SDGs) calls on countries to “mobilize

Participants in the Habitat III BORELLI © SIMONE conference, held in Quito, Ecuador, in 2016, enjoy the ecosystem services provided by trees

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Residents and tourists in Ljubljana, Slovenia, enjoy outdoor leisure time in the shade of a large tree. There is evidence of an inverse relationship between tree canopy cover and crime rates. Green spaces increase social cohesion and provide documented health benefits © SIMONE BORELLI © SIMONE

efforts to end all forms of poverty, fight The Habitat III conference, held in spaces in improving living standards in inequalities and tackle climate change, Quito, Ecuador, in 2016, put equality cities, increasing community cohesion, while ensuring that no one is left behind”. and socio-economic and environmental improving human wellness and health, The 2030 Agenda recognizes urban sustainability at the heart of discussions and ensuring sustainable development, sustainability as a key element for on sustainable urban development. The with the text of the NUA echoing the achieving sustainable development and main outcome of that conference was the wording of the SDGs. Thus, countries includes a specific goal on urban devel- endorsement of the New Urban Agenda commit themselves to the promotion of opment (SDG 11): “make cities and (NUA), which sets out a global strategy safe, inclusive, accessible and green public human settlements inclusive, safe, resil- for addressing urbanization issues in spaces (SDG 11) that: ient and sustainable”. About one-third coming decades. According to the NUA, • provide urban dwellers with multi- of the 231 indicators in the SDG Global cities must develop urban strategies that functional areas designed for social Monitoring Framework are related directly are people-centric, helping their citizens interaction and inclusion (SDGs 10 to urban policies with clear impacts on to thrive rather than simply survive. The and 11); cities and human settlements and can be NUA is based on three “interlinked” • contribute to human health and well- measured at the local level (UN-Habitat, principles: leave no one behind; ensure being (SDG 3); 2017). sustainable and inclusive urban economies; • promote economic exchange, cultural The key role of cities in achieving and ensure environmental sustainability. expression and dialogue among a the sustainability goals set in the Paris The NUA builds on the assumption that wide diversity of people and cultures Agreement was recognized at the 22nd well-planned and -managed urbanization (SDG 8); and Conference of the Parties to the United can be a powerful tool for sustainable • are designed and managed to ensure Nations Framework Convention on development in both developing and human development and build Climate Change, held in Marrakech, developed countries. It also stresses its peaceful, inclusive and participatory Morocco, in 2016. Parties agreed that, links with the 2030 Agenda and its role societies (SDGs 10 and 16), as well as given that cities are the main source of in implementing the latter. to promote living together, connectiv- carbon emissions and contain most of the ity and social inclusion.2 human population (UN-Habitat, 2011), the ROLE OF URBAN FORESTS most important efforts for climate-change IN THE NUA AND THE SDGs 2 The NUA addresses these bullet points in para- mitigation and adaption will have to be The NUA and the SDGs, particularly graphs 13b, 13h, 14c, 37, 38, 51, 53, 65, 67, 71, implemented in urban areas. SDG 11, highlight the importance of green 100 and 109.

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Urban forests, social cohesion and and most consistent for the percentage and storing atmospheric carbon dioxide. human health of green space within a 1-km radius of Also, trees provide shade and reduce wind If properly planned and managed, people’s homes. A report by The Nature speeds, thereby indirectly lowering carbon urban and peri-urban forests – defined Conservancy (2017) considered that, given emissions by reducing the need for air con- as “networks or systems comprising all the increasingly well-documented benefits ditioning and heating and thereby cutting woodlands, groups of trees, and individual of urban and peri-urban forests for human emissions from power plants (Nowak et al., trees located in and around urban areas” health, “there is a strong business case for 2013). Shaded surfaces can be 11–25 °C (FAO, 2016) – can make valuable contribu- more investment in urban trees”; thus, “the cooler than the peak temperatures of tions to the quality of urban green spaces. health sector (whether public or private unshaded materials (Akbari et al., 1997); In Baltimore, United States of America, institutions) could supply some financial shading, therefore, can extend the useful for example, a strong inverse association resources that help partially pay for activi- life of street pavement by as much as ten was observed between crime rates and ties in the urban forestry sector”. years, thus reducing emissions associated tree-canopy cover (adjusting for many with petroleum-intensive materials and the confounding factors); this association was Socio-economic development operation of heavy equipment required true for both public and private lands but In the NUA, green spaces are no longer to repave roads and haul away waste was strongest for public lands that were viewed simply as aesthetic features (McPherson and Muchnick, 2005). accessible to all (Troy, Grove and O’Neil- in landscapes but as drivers of socio- Urban areas are generally warmer than Dunnea, 2012). A study on the collective economic development that can be their surroundings – typically by 1–2 °C efficacy3 of various urban features found leveraged to increase socio-economic but by as much as 10 °C in certain climatic that parks are considered community value, including by increasing property conditions (Bristow, Blackie and Brown, assets. They bring people in surrounding values, facilitating business and public and 2012; Kovats and Akhtar, 2008). Urban areas to common places to participate in private investments, and providing liveli- and peri-urban forests can reduce this leisure activities – at times when people hood opportunities for all (SDGs 8 and 10). “heat island” effect by providing shade are most likely to be open to what they Hedonic models used to determine the and reducing urban albedo (the fraction see around them and more receptive to effects of green spaces and urban and peri- of solar radiation reflected back into the others because they are pursuing recrea- urban forests on house sale prices have environment) and by cooling through tion together and sharing common spaces found, for example, that the presence of evapotranspiration (Romero-Lankao and (Cohen, Inagami and Finch, 2008). green spaces within 80–100 m of a home Gratz, 2008; Nowak et al., 2010). Another study, in the Netherlands increases its price by 7 percent (Conway People in urban areas face many poten- (Maas et al., 2009), found, after adjust- et al., 2010). Wolf (2003) used contingent tial climate-related risks, such as the ing for socio-economic and demographic valuation methods to assess correlations increased incidence and severity of storms characteristics, that less green space in between variations in urban forest char- and flooding. Urban trees can contribute people’s living environment coincided acter and shopper behaviour in a number to stormwater management in a number of with feelings of loneliness and with a of cities in the United States of America, ways. Stormwater run-off can be reduced perceived shortage of social support. finding that consumers were 9–12 percent by the evaporation of rainfall intercepted Overall, information collected through more likely to make their purchases in by tree canopies and through transpiration, interviews showed that people with more shopping districts that had trees than in and stormwater quality can be improved green space in their living environments comparable districts without trees. by the retention of pollutants in soils and felt healthier, had experienced fewer health plants (Stovin, Jorgensen and Clayden, complaints in the previous 14 days, and Environmental benefits 2008). Reducing stormwater flows also had a lower self-rated propensity for psy- In line with SDG 13 (climate action) and reduces the risk of hazardous combined chiatric morbidity than those with less SDG 15 (life on land), the NUA calls for sewer overflows (Fazio, 2010). access to green areas. The study also the sustainable management of natural By increasing social cohesion, urban and found that the relationship between green resources in cities and human settlements peri-urban forests can help prevent deaths space and health indicators was strongest in a manner that protects and improves related to, among other things, the effects urban ecosystems and their ecosystem of climate change. Community stability is 3 Collective efficacy, a form of social capital, is a services, reduces greenhouse gas emis- an essential component of effective long- standardized and well-tested aggregate measure sions and air pollution, and promotes term sustainable strategies for addressing of individual perceptions of “social cohesion disaster risk management. Urban and climate change (Williamson, Dubb and among neighbors combined with the willingness to intervene on behalf of the common good” peri-urban forests and trees help mitigate Alperovitz, 2010). For example, the death (Sampson, Raudenbush and Earls, 1997). climate change by directly capturing rate in the severe 1995 Chicago heatwave

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A family in the Republic of Korea look out over a forest canopy. Cities have the opportunity to lead the way towards a greener and healthier planet that ensures the well-being of all people by investing in nature-based solutions as a key tool for achieving sustainable urban development © SIMONE BORELLI varied greatly by neighbourhood, due in organizations (NGOs) are playing cru- programmes aimed at helping achieve part to differences in community cohesion cial roles in closing knowledge gaps by SDG 11, and it is collaborating increas- (World Health Organization, undated). conducting action research, providing ingly with partner organizations such as policy guidance and building institutional UN-Habitat on urban–rural linkages and ROLE OF INTERNATIONAL capacities. Such organizations also facili- land tenure. ORGANIZATIONS tate dialogue between countries and cities UN-Habitat works in human settlements There is increasing evidence that and with civil society to increase people’s worldwide – from villages to megacities. government institutions are no longer awareness of the need to live more sustain- The United Nations Environment the only important actors in decision- ably (Al Mubarak and Alam, 2012) and, Programme (UNEP) addresses the role making processes, and a key ingredient ultimately, to achieve the full integration of cities in climate change through its of sustainable urban and peri-urban forest of urban and peri-urban forests and city Urban Environment Unit. Integrating their management, therefore, is inclusive govern- planning and governance. complementary expertise, UN-Habitat ance (Lawrence et al., 2013). Civil-society FAO supports its member countries and UNEP have developed the Greener actors are increasingly recognized as through the development of technical Cities Partnership, which advocates and important partners in policy discussions and guidelines and regional networks and promotes environmental sustainability in in promoting the potential benefits of urban the implementation of field projects. In urban development and the mainstreaming and peri-urban forests. Intergovernmental addition to its work on urban and peri- of environmental considerations in urban organizations and non-governmental urban forestry, FAO has initiatives and policymaking. For more than two decades,

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Trees line this green space in the Greener Cities Partnership has been Environmental NGOs and international Belgium. Urban and peri-urban trees and forests provide a wide range of an incubator of ideas for collaboration organizations such as the World Wide environmental benefits, in addition and innovation while also serving local, Fund for Nature (WWF), the International to their contributions to social national and international stakeholders Union for Conservation of Nature (IUCN), cohesion and human well-being through various activities. The Nature Conservancy and Conservation Launched in 2016, United for Smart International are playing growing roles Sustainable Cities (U4SSC) is a joint in urban and peri-urban forest govern- areas and integrate them into all sectors, initiative of 16 United Nations agencies ance (Duinker et al., 2014). The aim of created the Urban Conservation Strategies and programmes to assist in achieving WWF’s One Planet Cities Challenge, for Specialist Group. This group works to SDG 11. Coordinated by the International example, is to support cities in enabling strengthen the ability of the conservation Telecommunication Union and the United all their citizens to thrive while respect- community to serve urban people, places Nations Economic Commission for ing the planet’s ecological limits. WWF’s and institutions. Europe, U4SSC has developed a set of Urban Solutions for a Living Planet is a 100 Resilient Cities is a not-for-profit international key performance indicators platform for showcasing best practices in organization dedicated to helping cities and a related data-collection methodology sustainable urban development. WWF become more resilient to the physical, to assess the contributions of information also works with urban planners around the economic and social challenges they face. and communication technology to the world through its Financing Sustainable The 100RC global network provides cit- creation of smarter and more sustainable Cities programme to promote investment ies with resources to develop resilience cities. A number of the key performance in sustainable urban infrastructure. strategies. For example, the network gives indicators are designed to assess the avail- In 2000, IUCN’s World Commission on guidance on establishing the position of ability, accessibility and management of Protected Areas, a global network to help “chief resilience officer” in governments to green and natural spaces in cities. governments and others plan protected lead resilience efforts and provides access

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to innovative solutions, service providers, to enhance communication and network- USA, United States Forest Service, Northern and potential partners from the private, ing among practitioners, scientists and Research Station. public and NGO sectors. Membership decision makers, support the NUA and Cohen, D.A., Inagami, S. & Finch, B. 2008. of the 100RC network enables cities to optimize the potential of urban and peri- The built environment and collective effi- learn from and help each other in achieving urban forests in achieving the SDGs. cacy. Health and Place, 14(2): 198–208. common objectives. Thus, the first World Forum on Urban Conway, D., Li, C.Q., Wolch, J., Kahle, C. Forests will be held in Mantova, Italy, & Jerrett, M. 2010. A spatial autocorrela- CONCLUSION on 28 November–2 December 2018 with tion approach for examining the effects of Achieving the goals and targets of the 2030 the aim of highlighting positive examples urban greenspace on residential property Agenda for Sustainable Development, the of urban and peri-urban forest planning, values. Journal of Real Estate Finance and Paris Agreement and other agendas and design and management. These examples Economics, 41: 150–169. strategies requires a joint effort to move will be drawn from cities with diverse Duinker, P.N., Steenberg, J., Ordóñez, C., from global commitment to local imple- cultures, forms, structures and histories Cushing, S. & Perfitt, K. R. 2014. Governance mentation. Through urban and peri-urban that have used urban and peri-urban for- and urban forests in Canada: roles of non- forestry and greening solutions, cities have estry and green infrastructure to develop government. Paper and presentation. In: the opportunity to lead the way towards a economic and ecosystem services and Proceedings of Trees, People, and the Built greener and healthier planet that ensures strengthen social cohesion and public Environment II Conference (International), the well-being of all people. To do so involvement. The event will bring together Birmingham, UK, 2–3 April 2014. requires that city administrators: representatives of international organi- FAO. 2016. Guidelines on urban and peri- • involve all key stakeholders in the zations, national and local governments, urban forestry, by F. Salbitano, S. Borelli, governance of urban and peri-urban research and academic institutions, NGOs, M. Conigliaro & Y. Chen. FAO Forestry forests; urban planners, urban foresters, arborists, Paper No. 178. Rome (also available at www. • develop policy and legal frameworks landscape architects and designers, and fao.org/3/a-i6210e.pdf). that support the integration of urban professionals from many other sectors to Fazio, J.R., ed. 2010. How trees can retain and peri-urban forests and other exchange experiences and lessons learned. stormwater runoff. Tree City USA Bulletin green spaces in overall “green cities” Participants will also discuss long-term No. 55. Nebraska City, USA, Arbor Day policies; and collaboration on the development of Foundation. • invest in nature-based solutions as urban and peri-urban forest strategies Kovats, S. & Akhtar, R. 2008. Climate, a key tool for achieving sustainable and the identification of nature-based climate change and human health in Asian urban development. solutions towards a greener, healthier and cities. Environment and Urbanization, 20: Networking and the exchange of experi- happier future. u 165–75. ences and knowledge among cities and Lawrence, A., De Vreese, R., Johnston, M., disciplines are also crucial for achieving Konijnendijk van den Bosch, C.C. & the global goals set by the international Sanesi, G. 2013. Urban forest governance: community (FAO, 2016). The C40 towards a framework for comparing Cities Climate Leadership Group, Local approaches. Urban Forestry and Urban Governments for Sustainability (ICLEI), Greening, 12: 464–473. URBACT and the Carbon Neutral Cities Maas, J., van Dillen, S.M.E., Verheij, R.A. Alliance are some of many active national, References & Groenewegen, P.P. 2009. Social contacts regional and global networks that are shar- as a possible mechanism behind the relation ing experiences and making joint efforts Akbari, H., Kurn, D.M., Bretz, S.E. & between green space and health. Health and to increase the sustainability of urban Hanford, J.W. 1997. 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Nowak, D.J., Greenfield, E.J., Hoehn, R. The Nature Conservancy. 2017. Funding United Nations. 2016. Urbanization and & LaPoint, E. 2013. Carbon storage and trees for health: an analysis of finance and Development: World Cities Report sequestration by trees in urban and commu- policy actions to enable tree planting for 2016. Nairobi, United Nations Human nity areas of the United States. Environmental public health. Arlington, USA, The Nature Settlements Programme (also avail- Pollution, 178: 229–236. Conservancy. able at http://wcr.unhabitat.org/wp-content/ Nowak, D.J., Stein, S.M., Randler, P.B., Troy, A., Grove, J.M. & O’Neil-Dunnea, J. uploads/sites/16/2016/05/WCR-%20Full- Greenfield E.J., Comas, S.J., Carr, M.A. 2012. The relationship between tree canopy Report-2016.pdf). & Alig, R.J. 2010. Sustaining America’s and crime rates across an urban–rural Williamson, T., Dubb, S. & Alperovitz, G. urban trees and forests. A Forests on the gradient in the greater Baltimore region. 2010. Climate change, community stability, Edge Report. Gen. Tech. Rep. NRS-62. Landscape and Urban Planning, 106: and the next 150 million Americans. College Newtown Square, USA, United States Forest 262–270. Park, USA, The Democracy Collaborative. Service, Northern Research Station. UN-Habitat. 2011. Cities and Climate Change: Wolf, K.L. 2003. Public response to the urban Romero-Lankao, P. & Gratz, D.M. 2008. Global Report on Human Settlements 2011. forest in inner-city business districts. Journal Urban areas and climate change: review London, Earthscan. of Arboriculture, 29(3): 117–126. of current issues and trends. Issues paper UN-Habitat. 2017. UN-Habitat for the World Health Organization. Undated. for the 2011 Global Report on Human Sustainable Development Goals [online]. Climate change and human health – risks Settlements. UN-Habitat. [Cited 16 December 2017]. and responses. Summary [online]. World Sampson, R.J., Raudenbush, S.W. & Earls, F. https://unhabitat.org/un-habitat-for-the- Health Organization. [Cited 8 December 1997. Neighborhoods and violent crime: sustainable-development-goals 2017]. www.who.int/globalchange/summary/ a multilevel study of collective efficacy. United Nations. 2014. World Urbanization en/index3.html u Science, 277(5328): 918–924. Prospects: the 2014 Revision. Highlights. Stovin, V.R., Jorgensen, A. & Clayden, A. New York, USA, Department of Economic 2008. Street trees and stormwater manage- and Social Affairs, United Nations. ment. Arboricultural Journal, 30(4): 297–310.

Unasylva 250, Vol. 69, 2018/1 11 © PEDRO CALAZA Building green infrastructure and urban landscapes

P. Calaza, P. Cariñanos, F.J. Escobedo, J. Schwab and G. Tovar

Urban and peri-urban forests are he accelerated growth of the human (World Health Organization, 2017). Climate the most important components population has been accompanied change, which is leading to increases in of green infrastructure in by a process of rapid and often floods and heatwaves, is complicating cities – when well planned, Tpoorly planned urban development, dra- the situation. designed and managed. matic changes in lifestyle and poor dietary A major global challenge is to design habits. Today, largely due to emigration and customize cities to overcome such from rural areas, more than 54 percent problems. A possible strategy, supported of the world’s population lives in cities. by the European Union (EU), involves Pedro Calaza is Professor of Landscape The combination of globalization, rapid “nature-based solutions”. The EU empha- Architecture at Escuela Gallega del Paisaje, 1 Spain, Dean of Colegió Oficial de Ingenieros unplanned urbanization, and ageing sizes green infrastructure in cities for Agronomos, Spain, and a member of the Silva populations is leading to an increase in its multifunctionality, multiscalability Mediterranea Working Group on Urban and the incidence of non-communicable dis- and governance attributes. Urban and Peri-urban Forestry (FAO WG7). Paloma Cariñanos is Professor of Botany at the eases, the major cause of global mortality peri-urban forests are arguably the most University of Granada, Spain, and a member of FAO WG7. Francisco J. Escobedo Montoya is Professor at Above: Grand Parc, Versailles 1 The EU defines green infrastructure as “a stra- Del Rosario University, Colombia. Gardens, France. Sustainably tegically planned network of high-quality natural James Schwab is a consultant and urban managed urban and peri-urban and semi-natural areas with other environmen- planning specialist based in the United States of forests can provide a wide range of tal features, which is designed and managed America. ecosystem services that will increase to deliver a wide range of ecosystem services Germán Tovar is a specialist in the Office of the the resilience of cities and societies and protect biodiversity in both rural and urban Mayor of Bogotá, Colombia. to shocks and rapid change settings” (European Commission, 2013).

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important elements of green infrastructure, technological societies, UPF has evolved conserving, regulating and incorporating connecting cities with nature and provid- from a practice with a limited purpose, the use of urban and peri-urban forests. ing a wide range of ecosystem services. such as growing certain tree crops and Recently, too, Brazil, China and other This article examines the role of urban beautifying landscapes, to a strategic developing countries have started using and peri-urban forests as part of an overall approach for meeting economic, social and UPF to increase food security, create jobs, strategy to develop green infrastructure by environmental objectives. Increasingly, conserve biodiversity and mitigate the presenting various international perspec- the scientific, practical, management and impacts of climate change. Rapid urban tives on the importance of proper design planning knowledge, tools and lessons growth in Africa and South Asia provides in urban and peri-urban forestry (UPF). derived from UPF – mostly from Australia, an opportunity to adopt the latest findings In so doing, we propose that UPF can Canada, Germany, the United Kingdom of and knowledge on UPF to address food help solve urban problems through multi- Great Britain and Northern Ireland, and security, human health and the environ- scalar, context-specific, socio-ecologically the United States of America – are being ment in cities. relevant strategic approaches. used to help solve the problems caused by increasing urbanization. European and A SOLUTION FOR IMPROVING North American countries have established Leidsebosje, Amsterdam, the Netherlands. Urban and peri-urban forestry is WELFARE IN MODERN CITIES UPF teaching and research institutions evolving from a limited practice of As rural and agricultural communi- and developed national-level and local tree-growing to the strategic use of trees ties have transformed into urban and political and regulatory tools and laws for to address multiple economic, social and environmental issues © PEDRO CALAZA © PEDRO

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1 000 km 1 000 Continent and global International organizations

2 Ecoregion Nation Organizations

Watershed Region

Tree cover Municipality

Groups of trees Neighbourhood

Tree Home/ family 10 m 10 2 Individuals

1 Socio-ecological scales related to cities, participatory processes are taking events, such as drought, heat and heavy urban forests, their management and ecosystem services place for the development of adaptive rains. Extreme heat events – such as those management plans and governance in order in France in 2003, 2006 and 2017 – can to integrate urban and peri-urban forests have major impacts on human health in as essential components of city planning cities. A heatwave in the United States Nevertheless, UPF science, practices and and management. China, through national of America in 1995 caused the deaths of technologies need to continue to evolve decrees, has fostered large-scale urban more than 700 people, most of them elderly (Livesley, Escobedo and Morgenroth, reforestation to create green spaces for and disabled. The casualties of extreme 2016). UPF is more than planting or prun- recreation and to mitigate air pollution heat events most commonly occur in ing trees – urban and peri-urban forests and improve public health. Costa Rica and neighbourhoods that lack social support are part of multiscalar socio-ecological some Andean countries have developed for the most vulnerable people and where ecosystems (Figure 1) that provide a range tools such as payments for ecosystem there is less access to human services of benefits and incur costs. Therefore, services, which are helping improve the and to shaded areas. UPF is increasingly ensuring that UPF makes an optimal management of peri-urban forests to being used to reduce the impacts of such contribution to the resilience and sustain- maintain water quality and conserve bio- extreme heat events in cities (Livesley, ability of modern cities requires long-term diversity. In Japan and Scandinavia, UPF Escobedo and Morgenroth, 2016), includ- planning, knowledge of the biophysical, is being used as a strategy for reducing ing in tropical America and Asia. Urban socio-ecological and socio-economic stress and thereby improving public health. and peri-urban forests can also mitigate context, and participatory approaches Chile recently implemented policies on other extreme weather events: in some (Livesley, Escobedo and Morgenroth, urban and peri-urban forests as a way of parts of the Caribbean, the conservation 2016). offsetting industrial-sector greenhouse of urban trees and mangroves seems to gas emissions. have reduced the damage caused by recent Solving diverse problems hurricanes (Escobedo et al., 2009). Many Australia and China – two countries with Climate change North American cities are implementing very different political systems – are both Climate change is expected to increase the measures to incorporate green infrastruc- using UPF to solve problems. In Australian incidence and severity of extreme weather ture as a way of increasing resilience.

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Economic, social and various agencies with differing objectives. citywide functionality, therefore, is lacking. environmental benefits Parks, water bodies, railway easements, The lack of cohesion reduces the effective- The science and practice of UPF have roads, conservation areas and other spaces, ness of UPF in influencing city landscapes evolved as understanding of the benefits which might all feature trees, may be man- and the lives of residents. The challenge has increased and with the adoption of aged in very different ways by different facing many cities is to create institutional new technologies (Livesley, Escobedo agencies. Many such agencies, especially structures that allow the comprehensive and Morgenroth, 2016). For example, the those with no statutory conservation func- planning and management of the forest measurement of energy savings due to the tion (and therefore no budget for it), may estate across a city. Most cities lack an shading effects of trees has changed the completely ignore tree management. A agency able to regulate, monitor and coor- public discussion on the costs and benefits key challenge for cities, therefore, is to dinate the forest management actions of of green infrastructure. Trees are not only increase coordination and collaboration the various public agencies, and the lack of aesthetic amenities, they are also strat- among agencies to bring to bear a con- coordination among agencies also reduces egies for economic investment and savings. sistent approach to the management of the potential for the participation of private Depending on the context, only relatively urban and peri-urban forests. Such an companies and civil society. One city that minor efforts are needed to determine intersectoral approach may produce better does feature such an institutional architec- and promote the social and environmental results than centralizing forest manage- ture is Bogotá, Colombia: the municipal benefits of urban and peri-urban forests. ment in a single agency.

THE PUBLIC ADMINISTRATION OF Multisectoral approach Bosque de Chapultepec, Mexico City, URBAN AND PERI-URBAN FORESTRY In many places, urban and peri-urban for- Mexico. A challenge facing many cities is to create institutional structures Most cities divide public spaces among, est management is still site-specific and that allow the comprehensive planning and deliver administration through, fragmented, and the concept of achieving and management of urban forests across land uses and tenure © FRANCISCO J. ESCOBEDO MONTOYA J. ESCOBEDO © FRANCISCO

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2 Institutional structure for urban tree management in Bogotá, Colombia

Determines the urban tree management policy SECRETARÍA DISTRITAL DE AMBIENTE Carries out urban silvicultural planning for Bogotá (Environmental Authority of Bogotá) Monitors, evaluates and regulates the entities involved in urban tree management

Administers the georeferenced census of urban trees Botanical Garden of Bogotá Advises other entities on tree-cover management Conducts research on urban trees

Carry out root-pruning on trees that are causing damage to 19 local mayorships platforms and sidewalks

Carries out tree-pruning throughout the city following a pruning Unidad Administrativa Especial de Servicios plan, by species, type of pruning and intervention cycle Públicos (Special Public Services Unit) Maintains a census of urban trees

Instituto de Desarrollo Urbano (Institute of Urban Manages trees in the construction of public works Development – public)

Empresa de Acueducto, Alcantarillado y Aseo de Manages trees in and around the city’s water system Bogotá (Water and Aqueduct Company of Bogotá) (i.e. rivers, streams and canals)

Agencia de Infraestructura Nacional (National Manages urban trees in railway easements Infrastructure Agency)

Codensa and Grupo Energía de Bogotá (electricity Manage trees of potential risk to the electricity supply supply companies)

Instituto de Recreación y Deporte (Institute for Manages trees in city parks Recreation and Sports)

Firefighters and Instituto Distrital de Gestión de Riesgos y Cambio Climático (District Institute for Manage trees of potential risk in fires and other disasters Risk Management)

Collects, in a separate account, funds paid for harvesting rights District Treasury of Bogotá and fines paid for damaging urban forest resources

Fondo Distrital para la Gestión de Riesgo y Cambio Climático (District Fund for Risk Disburses funds to reduce the risks posed by urban trees Management and Climate Change)

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environmental authority there coordinates important criterion in species selection political effort and a clear justification, as the management of 31 public agencies that, in the establishment of urban and peri- established in the urban forest master plan. to a greater or lesser extent, have roles in urban forests. Maintenance costs are also Such plans are essential tools, therefore, for UPF (Figure 2). important. In Bogotá, for example, the tree enabling municipalities to plan new urban species caucho sabanero (Ficus andicola) and peri-urban forests in the flux created Master plans is being planted less and less. This native by urban growth dynamics. A good starting point for a coordinated species is resilient, well adapted to the approach to UPF is to conduct a geo- area and well accepted by residents; it MULTISCALAR DESIGN: referenced tree census to provide the has proven prone to pests and diseases, FROM INDIVIDUAL TREES TO basis for analysis and the development and however, meaning that maintenance costs COMPREHENSIVE STRATEGIES implementation of an urban forest master are ten times higher than for other species. The design of urban and peri-urban forests plan. In general, the most sensitive issues Providing space for forests in new urban should consider various scales, from the in such plans are those associated with risk and peri-urban areas is often a significant individual tree to the citywide forest (FAO, management, tree felling, and maintaining challenge because of land scarcity and 2016). It should also address the structural, the existing forest stock. Underlying – but high land values. The urban growth model, functional, ecological, landscape, social less visible – aspects are increasing the which may be either low-density or high- and cultural requirements for ensuring provision of goods and ecosystem services; density (or on a scale between these two multifunctionality. species selection; biodiversity conserva- extremes), is a major determinant of Among structural aspects, the mor- tion; the connectivity of green spaces; and policies on the creation of public green phology of species (e.g. trees, bushes pest and disease management. space. Allocating large blocks of land in and grasses) and their distribution in the UPF generally attracts only small industrial or residential areas for ecological available space should be considered with budgets; therefore, longevity is an connectivity or recreation requires strong a view to creating environments with

A London plane tree (Platanus spp.) in front of the Strausberger Platz, Berlin, Germany. The design of urban and peri- urban forests should consider various scales, from the individual tree to the

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The publicly accessible Saxon (“Saski”) Garden, Warsaw, Poland. Urban and peri-urban forests should be politically neutral places that enable environmental justice and the integration of social groups © PEDRO CALAZA © PEDRO

varying vertical structures. Species may be weather events will depend on the main- aesthetics and improve health. The general selected to favour certain ecosystem func- tenance of ecological processes. Ensuring aim is to achieve a multisensory experi- tions. Tree size, longevity and growth type urban and peri-urban connectivity is essen- ence, producing views, sounds, smells and are other elements to consider in design tial for maintaining ecological processes other stimuli that reinforce the sense of (Gustavsson, 2002); a diversity of species such as succession and transition. connection between humans and nature. with different morphologies and functions Landscape design is important for Finally, the sociocultural element should occupying different ecological niches conveying the “message” of UPF. For be a priority; urban and peri-urban forests reduces the risk of widespread mortality example, a lack of geometric lines in should be politically neutral places that in the face of a given threat and may also planting arrangements will help convey enable environmental justice and the mean lower maintenance requirements. a sense of spontaneity and closeness to integration of social groups (O’Brien Access and infrastructure are two of the nature; geometric designs, in contrast, can et al., 2017). It is essential to consider most relevant functional aspects of urban convey closeness to urban design (Bell the “forest culture” – that is, the way in and peri-urban forest design. All residents et al., 2005). The planting of individual which a community views and uses urban should have access to a diverse range of trees should take the environment into and peri-urban forests according to their open spaces to meet their varying needs account: for example, trees planted in diversity and biogeographical features. and expectations, regardless of age, ethnic- historically important places should not In northern Europe, for example, forest ity, culture or disability. The elimination disrupt the landscape but rather become designs should take into account the of physical and legal barriers to urban and a discreet part of it. On the other hand, need both for light and for contact with peri-urban forests is not only the best way the role of tree alignment zones in new nature; in the Mediterranean, urban and of ensuring that all people have access to areas is to strengthen architecture and peri-urban forest designs should provide a healthy environment, it is a principle 2 cooling shade and be conducive to the 2 Environmental justice is the fair treatment and of environmental justice that should be meaningful involvement of all people regard- prevailing outdoor lifestyle. promoted by design and planning (Nilsson, less of race, colour, national origin or income Table 1 summarizes a range of Sangster and Konijnendijk, 2011). with respect to the development, implementation international approaches to urban and peri- and enforcement of environmental laws, regula- The resilience of cities in the face of tions and policies (United States Environmental urban forest planning to achieve various climate change and associated extreme Protection Agency, undated). objectives.

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TABLE 1. International experiences in urban and peri-urban forestry Country City Name Goal Description Germany Berlin Biotope Area To regulate new urban development with Part of the area to be developed is to be used for green Factor (1984) an ecological approach spaces in which the original vegetation is to be kept or new plant cover planted. Guidelines are provided for landscape planning and design, species protection, and conservation. One of the main advantages of the Biotope Area Factor is that it is flexible in the design of the urban forest and enables stakeholder participation. Since the Biotope Area Factor was introduced in the design and planning of green areas, the provision of vegetation in heavily populated areas has significantly reduced the impacts of climate change, such as heatwaves, flooding and storms Sweden Mälmo Green Space To regulate urban development for new The approach is similar to the Biotope Area Factor, with Factor (2001) urbanization areas using an ecological various versions and biotopes approach USA Seattle Urban Forest •• To create an ethical model of urban The management plan is framed within the Trees for Seattle Stewardship forest management for all stakeholders Strategy, which brings together all efforts on forests in the Plan •• To make specific improvements with city. A section of the strategy focuses on the design and Seattle Green a view to achieving a net increase safety of street trees and their role as elements for reducing Factor in the functions of urban forests and driving speeds, crime and domestic violence without the associated economic, social and reducing the important aesthetic values they provide. environmental benefits The Seattle Green Factor is an adaptation of the Mälmo •• To increase forest cover by 30 percent Green Space Factor, which is being incorporated into other •• To strengthen the health and longevity cities in the United States of America of urban forests, improve the quality of species and eliminate invasive species Australia Sydney Greening •• To protect and maintain existing urban Strategy aimed at developing and protecting urban and Sydney Plan, forests peri-urban forests 2012 •• To increase canopy cover •• To improve biodiversity •• To increase knowledge and commitment in the community Sweden Umeå Young urban To develop new urban forests Young urban forests have been created by regenerating forests previous forests or by planting trees, the latter seeking to perform predetermined functions entailing specific forest treatments that need to be permanently maintained. An experimental study was carried out in Umeå on a 2.1-hectare plot that had been reforested 20 years before. In this forest, 12 small forest compartments were created using various thinning methods, with different functions and traditions, creating areas for relaxing and meditating in isolation; children’s play areas; natural-looking spaces; areas subject to heavy management for aesthetic purposes; and various samples of local forest types Norway Akerselva To create multisensory environments A corridor was created along the Akerselva River to enable (Oslo) downtown residents to travel to nearby parks hosting 14 “quiet areas” for contemplation USA New Program To ensure accessibility The aim is for every inhabitant to have a green area within a York PlaNYC: 2030 10-minute walking distance Singapore To provide opportunities to be outdoors The integration of 200 km of pathways through elevated and enjoy nature runways to enable inhabitants in different parts of the city to access parks Japan Nagoya To promote actions to actively support Conserve 10 percent of land next to the city boundaries as nature conservation an unmanaged area and protect it as a nature reserve USA Phoenix To encourage actions to actively support 17 000 hectares of desert were purchased to avoid the nature conservation negative effects of urban expansion, and this area was designated as a nature conservation site USA Portland To invest in social infrastructure that Investment of more than 5 percent of the annual city budget helps urban dwellers understand nature in biodiversity. The aim is to attain one of the highest tree- canopy covers among the nation’s cities (29.9 percent)

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TREE SPECIES SELECTION nitrogen oxides, ozone, and fine particulate grow strong and healthy will maximize AND PLANTING DESIGN IN matter such as soot, dust, pollen, and emis- carbon sequestration. The use of large- URBAN LANDSCAPES sions from diesel vehicles); and oxygen stature trees can multiply the bottom-line Tree planting is an important tool for production. Such services improve human benefits of urban and peri-urban forests: improving cities, but it needs to be done health (e.g. asthma and related illnesses) in one theoretical study of trees at age 30 properly; often, trees are selected for use or and help reduce other complex air-quality (projected to life expectancy), the annual planting with no technical criteria. Many problems (such as ground-level ozone, benefits generated were USD 55 for large strategies can be used for incorporating smog and the urban “heat island” effect). trees, USD 33 for medium-sized trees, and trees in cities. For example, FAO (2016) In Spain, one of the goals of Barcelona’s only USD 23 for small trees (McPherson identifies five main types of urban and recently published Urban Forest Master et al., 2003). peri-urban forests: 1) peri-urban forests Plan 2017–2037, therefore, is to increase and woodlands; 2) city parks and urban tree canopy cover by 5 percent of the land Diversity forests (> 0.5 hectares); 3) pocket parks area, thus achieving a forest cover in the The Santamour rule (sometimes called and gardens with trees (< 0.5 hectares); city of 30 percent. the “10 percent” rule) proposes maxi- 4) trees on streets or in public squares; and mum percentages for tree species, genera 5) other green spaces with trees. All these Big trees and families in a plantation (Figure 3). are important resources for the spatial Cities need big trees, and one of the aims This rule, which was proposed by Frank design and planning of an urban and peri- of design, therefore, should be to maximize Santamour (1990), a geneticist at the United urban forest estate. Urban and peri-urban tree size. Large-stature trees deliver up States National Herbarium, states that no forest design should comply with basic to eight times the benefits compared with more than 10 percent of any one species, no landscape design principles addressing small trees (United States Forest Service, more than 20 percent of any one genus, and unity and structure, scale, proportion and 2004); even at maturity, small-stature trees no more than 30 percent of any one family balance, space division and definition, light do not come close to providing the same should be planted; others have proposed a and shade, colour, texture and shape. magnitude of benefits. A strategically “5 percent” rule. The objective behind the Trees bring buildings closer to the human located large-stature tree can contribute rule is to maximize protection against pest scale, and they enable the creation of significantly to mitigating the urban heat outbreaks. Thus, another important goal of spaces by providing a range of textures, island effect and conserving energy. the Barcelona Urban Forest Master Plan light, shapes and seasonality (Arnold, Choosing tree species that will be large is to achieve a tree diversity in which no 1980). Trees can be customized to suit at maturity, planting these on suitable species represents more than 15 percent almost any situation, thus addressing sites, and managing them to ensure they of the total. Urban forest design should problems such as stormwater management and climate change and achieving specific aesthetic objectives. Tree 1 Genus 1 Leaf area Species Species Tree 2 Genus 2 Although, in general, the more trees in a 1 2 Genus 3 city the better, the most important param- Tree 3 eter is canopy cover because of the role that leaf area plays in the services provided by urban and peri-urban forests. The leaves of No. of trees of the No. of trees No. of trees of the same species of the same family trees provide the most important ecosystem same genus < 20% < 10% of the total < 30% of the total services of UPF – such as the maintenance of water quality; thermal regulation; the capture of volatile organic compounds and other air pollutants (e.g. sulphur dioxide,

3 The Santamour rule for biodiversity in forest plantations

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also aim for an adequate age distribution largely determine the long-term costs among urban designers. The best way to – that is, trees of a range of ages to enable and benefits. bridge such gaps in urban development planning for tree senescence and adequate UPF knowledge and management tech- and management is in multidisciplinary and sequential removal and replacement niques continue to improve, but major teams – because green infrastructure of dead or dying trees. gaps remain and, in most countries, there is multifunctional and cuts across all is a lack of awareness and knowledge urban sectors. Planting Adequate tree-planting practices are essential for meeting urban and peri-urban forest Box 1 objectives, and preparation of the planting The Stockholm system for stormwater management site is also crucial: it is better to plant a tree that costs 1 euro in a hole that costs The City of Stockholm uses large stones (“large-stone skeleton soils”) to provide a high-quality 50 euro than a 50-euro tree in a 1-euro environment for tree roots that improves tree growth in urban environments and encourages hole. Several examples exist of planting stormwater infiltration and effective gas exchange. The technique involves forming a wide base systems customized to local needs; the of large (100–150 mm) angular stones covered with an aeration layer (washed granite stones City of Stockholm, Sweden, for example, 63–90 mm in size). A surface layer suitable for vehicles or pedestrians, and its subgrade, is employs a hybrid system for the sustain- installed over a geotextile layer placed on top of the aeration layer. able management of stormwater (Box 1). The Stockholm system prioritizes aboveground/belowground gas exchange and voids in the Engineering approaches, such as the use growing medium over the abundant provision of loam soil. It enables a high degree of water of cells and floating soils, can help achieve infiltration while enhancing the effectiveness of aeration (water expels any carbon dioxide consistent results in varying conditions built up in the voids, thereby avoiding the risk of root poisoning). Through condensation, the (Urban, 2008; TDAG, 2014). aeration layer offers better moisture retention in the warm season. A study in the United States of America The Stockholm system continues to be studied; a recent development is the use of biochar using the i-Tree model conducted a cost– as a filter for pollutants and to better retain nutrients and water. benefit life-cycle analysis of 1 million Benefits of the Stockholm system trees over a 50-year period (MacDonagh, • The substrate has high load-bearing capacity, including resistance to lateral forces 2015). The two treatments were: 1) urban (e.g. heavy vehicular traffic). trees planted using a modern technique • The system uses similar construction practices to those used in the industry, facilitating in which the pavement is suspended over its incorporation in the construction sector. adequate uncompacted soil volume, giving • The system can be implemented for existing trees, including mature trees. trees a lifespan of more than 50 years; and • Tree growth rates are very high – but the system needs more study because it has been 2) urban trees planted with insufficient in place for less than ten years. uncompacted soil volume, in which the Limitations of the Stockholm system trees have an estimated lifespan of only • Installation costs are high. 13 years and therefore need to be replaced • Existing soil is not reused. three times over the 50-year period and • The system is not technically complicated, but it requires rigorous implementation. will die before they grow sufficiently large to provide significant ecological and Source: City of Stockholm, 2009. financial benefits. The study projected that, after 50 years, the first treatment generated a net profit of USD 25 billion TABLE 2. Calculation of benefits and costs for tree life cycles, 1 million trees, (i.e. USD 25 000 per tree; Kestrel Design with inadequate and adequate planting Group, 2011), while the second resulted Inadequate planting Adequate planting in a net cost of USD 3 billion (Table 2; Benefit after 50 years USD 2.718 billion USD 41.769 billion MacDonagh, 2015). This finding is con- Cost after 50 years USD 5.812 billion USD 16.342 billion sistent with other research, such as that of Fowler (2011). Thus, although the Life-cycle net benefit (cost) after (USD 3.064 billion) USD 25.427 billion 50 years initial cost of best-practice planting may be relatively high, the long-term benefits Investment return after 50 years -47% 250% are immense. Planting many trees is good, Value after 50 years USD 3.064 billion USD 25.427 billion but decisions on the methods used will Source: MacDonagh, 2015.

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CONCLUSION available at http://foretag.stockholm.se/ well-being: introduction. In: K. Nilsson, Urban and peri-urban forests are the most PageFiles/192562/100322%20GH_HB%20 M. Sangster, C. Gallis, T. Hartig, S. de Vries, important components of green infra- STHLM%20-%20Engelsk%20version.pdf). K. Seeland & J. Schipperijn, eds. Forests, structure, providing landscape solutions Escobedo, F.J., Luley, C.J., Bond, J., trees and human health. Dordrecht, the for several urban problems, including Staudhammer, C. & Bartel, C. 2009. Netherlands, Springer. climate change. It is essential that UPF Hurricane debris and damage assess- O’Brien, L., De Vreese, R., Atmis, E., science, practice and technologies continue ment for Florida urban forests. Journal of Olafsson, A.S., Sievänen, T., Brennan, M., to develop. Multiscalar, multidisciplinary, Arboriculture, 35(2): 100–106. Sánchez, M. et al. 2017. Social and envi- long-term planning is key to optimizing European Commission. 2013. Building a green ronmental justice: diversity in access to and the advantages and ecosystem services of infrastructure for Europe. Luxembourg (also benefits from urban green infrastructure. UPF and for guaranteeing solutions that available at http://ec.europa.eu/environment/ Examples from Europe. In: D. Pearlmutter, meet the specific needs of a given city nature/ecosystems/docs/green_infrastruc- C. Calfapietra, R. Samson, L. O’Brien, and its social and demographic context, ture_broc.pdf). S. Krajter Ostoić, G. Sanesi & R.A. del Amo, provide equitable access, and ensure envi- FAO. 2016. Guidelines on urban and peri- eds. The urban forest: cultivating green ronmental justice. It is imperative that tree urban forestry, by F. Salbitano, S. Borelli, infrastructure for people and the environ- species are selected to ensure adequate M. Conigliaro & Y. Chen. FAO Forestry ment, pp. 7–20. Switzerland, Springer. biodiversity, appropriately sized trees, the Paper No. 178. Rome. Santamour, F.S., Jr. 1990. Trees for urban maintenance of ecosystem functions, and Fowler, D. 2011. Achieving the goal of 25% planting: diversity, uniformity and common affordable maintenance. Planting systems canopy coverage in Phoenix by 2030. sense. Proceedings of the 7th Conference of should be used that guarantee and leverage Unpublished master’s thesis on landscape the Metropolitan Tree Improvement Alliance, ecosystem benefits throughout tree life architecture. Tempe, USA, Arizona State 7: 5765. cycles. Contemporary UPF approaches are University. TDAG. 2014. Trees in hard landscapes: a guide being applied in various contexts world- Gustavsson, R. 2002. Afforestation in for delivery. UK, Trees & Design Action wide, and regulatory frameworks have and near urban areas. In: T.B. Randrup, Group (TDAG). been developed to integrate and design C.C. Konijnendijk, T. Christophersen & United States Environmental Protection urban and peri-urban forest experiences K. Nilsson, eds. COST Action E12: urban Agency. Undated. Environmental definition and achieve multiple purposes. Ultimately, forests and trees, pp. 286–314. Proceedings [online]. [Cited 23 November 2017]. www. UPF is a socially acceptable, politically No. 1. Luxembourg, European Commission. epa.gov/environmentaljustice effective, economically efficient and thus Kestrel Design Group. 2011. Investment vs. United States Forest Service. 2004. The large sustainable tool. u returns for healthy urban trees: lifecycle tree argument. The case of large-stature cost analysis. Deeproot. trees vs. small-stature trees. Davis, USA, Livesley, S.J., Escobedo, F.J. & United States Forest Service. Morgenroth, J. 2016. The biodiversity of Urban, J. 2008. Up by roots: healthy soils in urban and peri-urban forests and the diverse the built environment. International Society ecosystem services they provide as socio- for Arboriculture. ecological systems. Forests, 7(12): 291. DOI: World Health Organization. 2017. 10.3390/f7120291 Noncommunicable diseases. Fact sheet, MacDonagh, P. 2015. 1 million trees: vision updated June 2017 (also available at: www. References or nightmare? [online]. Deeproot. [Cited who.int/mediacentre/factsheets/fs355). u 3 December 2017]. www.deeproot.com/ Arnold, H.F. 1980. Trees in urban design. blog/blog-entries/1-million-trees-vision- New York, USA, Van Nostrand Reinhold or-nightmare Company. McPherson, E.G., Simpson, J.R., Peper, P. J., Bell, S., Blom, D., Rautamäki, M., Xiao, Q., Maco, S.E., Hoefer, P.J. & Castel-Branco, C., Simson, A. & Davis, D. 2003. Northern mountain and Olsen, I.A. 2005. Design of urban forests. prairie community tree guide: benefits, costs In: C. Konijnendijk, K. Nilsson, T. Randrup and strategic planting. Albany, USA, Pacific & J. Schipperijn, eds. Urban forests and Southwest Research Station, United States trees. Berlin, Springer. Forest Service. City of Stockholm. 2009. Planting beds in Nilsson, K., Sangster, M. & Konijnendijk, C.C. the City of Stockholm. Stockholm (also 2011. Forests, trees and human health and

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The benefits of urban and peri-urban forestry

C. Dobbs, A.A. Eleuterio, J.D. Amaya, J. Montoya and D. Kendal

Forests in cities produce goods rbanization places pressure on Urban and peri-urban forests provide reg- and generate ecosystem services adjacent natural resources in and ulating, cultural and provisioning services that improve the well-being of around cities by competing for that can be of both local and global impor- citizens and increase the resilience Uspace and demanding products from them. tance. Regulating services include climate of cities to shocks. Well managed, however, these natural regulation (e.g. cooling), carbon storage, resources can improve the lives of urban air pollution removal and flood regulation dwellers by providing ecosystem services.1 (Dobbs, Escobedo and Zipperer, 2011). Urban and peri-urban forests comprise Cultural services include natural heritage, all the trees and associated vegetation recreation, aesthetics, knowledge transfer Cynnamon Dobbs is a researcher at the Department of Ecosystems and Environment at found in and around cities. They occur and “sense of place” (Dobbs, Escobedo Pontificia Universidad Católica de Chile, Chile. in a range of settings, including in man- and Zipperer, 2011). Provisioning ser- Ana Alice Eleuterio is Professor at the aged parks, natural areas (e.g. protected vices – which are especially relevant to Department of Rural Development and Food Security, Universidade Federal da Integração areas), residential areas and informal green city dwellers in developing countries – Latino-Americana, Brazil. spaces; along streets; and around wetlands include products such as food, woodfuel, Juan David Amaya is Professor at Javeriana and water bodies. clean water and medicines (Shackleton University, Colombia. Juliana Montoya is a researcher in the et al., 2015). Urban and peri-urban forests Biodiversity in Urban–Regional Environments 1 Here we define ecosystem services as the bene- programme, Humboldt Institute, Colombia. fits derived from nature that are consumed or Above: Panoramic view of Dave Kendal is a researcher at the School of enjoyed by humans, increasing their well-being the ecological network of the Ecosystem and Forest Sciences, University of and exerting positive influences on human health Valle de Aburrá, northwestern Melbourne, Australia. (Coutts and Hahn, 2015). subsector of Medellín, Colombia

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also contribute to biodiversity in urban actions. All components of this framework countries, who still rely heavily on wood areas (Alvey, 2006) and help build cul- can influence a city’s resilience to social energy for cooking and heating. Urban tural diversity, thereby increasing urban and environmental stresses and shocks dwellers can also make good use of the resilience to environmental shocks and (Dobbs, Martinez-Harms and Kendal, products of fruit trees and medicinal stresses (Colding and Barthel, 2013). This 2017). plants in private and community gardens, article explores, through case studies, the residential areas and streets (Fuwape and benefits that urban and peri-urban forests Forest ecosystem services Onyekwelu, 2011). Jamun trees (Syzygium can provide for citizens and discusses some Urban and peri-urban forests in good condi- cumini) in public areas of New Delhi, of the challenges that urban forest planners tion perform various ecosystem functions. India, for example, produce fruits that are and managers will need to accommodate Through shading and evapotranspiration, sold to pedestrians and motorists (Singh, in years to come. for example, they can reduce summer day- Pandey and Chaudry, 2010). time temperatures by up to 6 °C (depending THE BENEFITS OF URBAN AND on the city’s latitude; Skoulika et al., 2014). Urban agriculture PERI-URBAN FORESTS A large tree can intercept up to 190 litres The planting and growing of trees in Figure 1 provides a framework for the of water in a rain event, thereby reducing urban areas contributes to the economic role of urban and peri-urban forests in the water run-off and the risk of flooding and strength and multifunctionality of urban provision of ecosystem services, thereby landslides. Urban and peri-urban forests agriculture (de Bon, Parrot and Moustier, shaping the well-being of urban dwellers. filter air pollution, which is deposited on 2010), providing sources of income and Preferences for certain ecosystem services leaves, thereby acting as passive sinks employment opportunities. Urban food affect policymaking and decision mak- for particulate matter (Nowak, 1994); production is not only beneficial as a ing and the value assigned to ecosystem particulate matter accumulation rates of service, it also increases food availability services, ultimately affecting the structure 10–70 micrograms per cm2 of leaf area at the local scale, thus shortening sup- and composition of the urban and peri- have been recorded (Sæbø et al., 2017). ply chains for some products (e.g. leafy urban forest estate through management vegetables) and thereby reducing the nega- Forest products tive impacts associated with long supply 1 Urban and peri-urban forests are impor- chains. Shorter supply chains also result Framework for the ecosystem tant sources of wood for construction and in fairer product values and lower costs services provided by urban and fuel, especially for people in developing for consumers, therefore improving food peri-urban forests security at many levels (de Bon, Parrot and Moustier, 2010) and contributing to Urban and peri-urban forests Ecosystem services community resilience (Salbitano, Borelli Functions Regulating, cultural, and Sanesi, 2015). and provisioning Structure and processes On the other hand, many cities worldwide composition are experiencing major shifts in property Landscape rights from public to privately owned lands Forest and an associated lack of community access Tree Human well-being to public lands that can hinder the effectiveness of urban agriculture in the provision of Benefits and values ecosystem services (Colding and Barthel, 2013). Moreover, urban agricultural plots Management and can serve as sinks (e.g. as receptacles of conservation residential solid and organic waste) and sources of environmental pollution, includ- Human preferences ing pesticides, herbicides and fertilizers (de Bon, Parrot and Moustier, 2010). Policymaking and decision making Social interactions, culture and well-being Resilience People in urban communities can lose contact with nature (Maller et al., 2006). Source: Adapted from Dobbs, Martinez-Harms and Kendal (2017). There is a trend towards people spending

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less time in natural areas, parks and Biodiversity urban and peri-urban forests in their deci- forests than in the past, with both adults The role of urban and peri-urban forests sion making, planning and regulations, and children adopting more sedentary and in biodiversity conservation can be sig- both formally and informally. Here we individualistic behaviours in preference to nificant: data on bird presence compiled provide examples of cities in which for- group activities that use open public spaces in 54 cities and on plants in 110 cities, estry is becoming a mainstream option for (Taylor and Kuo, 2006). Urban forests can for example, show that a large proportion creating sustainable and resilient cities. foster cultural services such as a sense of of taxa are native, and some are endemic community, place and satisfaction because (Aronson et al., 2014). In Australia, Providing ecosystem services they provide spaces in which people can hundreds of threatened native species occur in Colombia come together and interact socially (de in cities, many of them largely dependent Various Colombian cities have developed Vries et al., 2013). People become attached on urban habitats (Ives et al., 2016). explicit greening actions in recent years, to places where they feel relaxed and Biodiversity can play an important role and studies have shown the benefits of comfortable, incorporating those places in increasing the resilience of urban forests urban and peri-urban forests. In the Aburrá into self-identity (Stoner and Rapp, 2008). to external shocks and stressors, such as metropolitan area, it was estimated that Additionally, by spending time outdoors, climate change (Gomez-Baggethun et al., urban trees save 6 712 megagrams of car-

people tend to exert themselves more, 2013). Diversity is needed at different taxo- bon dioxide emissions per year (MgCO2/yr) boosting their physical health (Dinnie, nomic levels (Kendal, Dobbs and Lohr, – equivalent to the yearly emissions of 1 428 Brown and Morris, 2013; Giles-Corti et al., 2014). For example: average petrol-engine cars – by avoiding

2013). Urban forests also have restorative • Genetic diversity contributes to resis- the emission of 5 090 MgCO2/yr due to effects and can lead to improved mental tance to pests and diseases. savings in electric cooling and sequestering

health. For example, attention fatigue • Species diversity ensures a variety 2 077 MgCO2/yr (Reynolds et al., 2017). In can be ameliorated by spending time of functions (to provide multiple Medellín, large urban and peri-urban trees walking in green areas (Taylor and Kuo, ecosystem services) and functional represent only 1.33 percent of the total tree 2006). Exposure to nature can reduce the redundancy (to minimize the risk of population but sequester more than 25 per- symptoms of depression and the risk of loss of particular services). cent of carbon emitted annually in the city developing mental disorders (Annerstedt • Genus and family diversity can help and remove almost 10 tonnes of particulate et al., 2015). reduce the incidence of particular pollution (Restrepo et al., 2016). Research pests and diseases (e.g. emerald ash on the cultural and economic benefits of Financial benefits borer and myrtle rust). urban and peri-urban forests shows that Urban and peri-urban forests can provide • Age diversity should be maintained 80 percent of residents in Bogotá, Cali financial benefits. For example, the pres- in urban and peri-urban forests to and Pereira are interested in interacting ence of mature trees can increase property maintain the provision of ecosystem with nature (Ordóñez-Barona and Duinker, values by 2–15 percent, and the presence of services over time and to reduce the 2014). Bogotá residents also perceive that tree cover in a residential area can increase risk of uniform senescence of large urban forests provide other positive ser- real estate prices by up to 9 percent (Wolf, areas of forest. vices, such as shading and temperature 2017). Trees in commercial areas can • Structural diversity (that is, the diver- regulation (Rojas, 2013). Using spatial boost shopping by providing a welcoming sity of tree species, vegetation strata econometric techniques, Carriazo and environment for retail stores and shaping and density) is important for promot- Tovar (2016) found a significant positive consumer expectations (Wolf, 2017). ing fauna conservation in cities by relationship between the presence of urban The demand for urban forest products and increasing the number and complexity forests and a reduction in theft, suggesting ecosystem services depends on their per- of habitats (Lindenmayer, Franklin that psychological precursors of violent ceived importance to urban dwellers, which and Fischer, 2006). behaviours, such as mental fatigue, could can vary according to socio-economic, be lower in urban populations with greater cultural and political realities, psycho- CASE STUDIES OF URBAN AND contact with nature (Kuo and Sullivan, logical well-being, physical health, power PERI-URBAN FORESTS 2001). inequities, and the biophysical location of A growing body of evidence from North This accumulated knowledge and the city (Ordóñez-Barona, 2017). Urban America, Europe, the Global South and information has been incorporated into forest food and fuel production, for exam- elsewhere corroborates the contribu- policies in Colombia. A partnership ple, may be more important in developing tions of urban and peri-urban forests to between the Humboldt Institute and the countries, especially for some groups, than the well-being of urban dwellers. Local Ministry of Environment and Sustainable in developed countries. governments are increasingly including Development (Ministerio de Ambiente y

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An aerial view of El Poblado Park, Aburrá, Colombia, where urban trees store large amounts of carbon and provide residents with shade and other ecosystem services © ÁREA METROPOLITANA, VALLE DE ABURRÁ

Desarrollo Sostenible) has produced strat- organization, has developed a long-term Recognizing the benefits: egies and management tools to facilitate programme called The Urban Forest Open Tree Map land planning, leading to an increase in Initiative with the aim of involving Recognizing the benefits of urban and social connectedness with urban and peri- local communities in increasing canopy peri-urban forests, a number of cities in urban forests and in the success of policy cover and building resilience to climate the United States of America have made implementation (Montoya et al., 2017). change. Actions include planting and car- information on the location, species and ing for trees; supporting residential and care of urban trees available to the local Tackling climate change with urban neighbourhood strategies for rainwater and global communities using the Open and peri-urban forests in Los Angeles collection; and restoring forests in depleted Tree Map platform,3 which can also be Los Angeles, in the United States of areas. The ten-year goal of the initiative deployed to create future scenarios for America, is highly vulnerable to the is to increase canopy cover in the city by tree populations. Several local govern- impacts of climate change, such as 25 percent, reduce inequities in forest dis- ments are using Open Tree Map to manage increases in the frequency and severity tribution, and source at least 50 percent of and communicate information on their of flooding, drought and wildfire. People the water supply locally. The initiative also urban and peri-urban forests and as a living under social constraints are most intends to supply information and to work decision-making tool to help deliver eco- vulnerable to the consequences of such with all levels of government to create system services and create a pathway to events. TreePeople,2 a not-for-profit progressive policies for the use of urban sustainability. and peri-urban forests, changing laws and 2 www.treepeople.org regulations where necessary. 3 www.opentreemap.org

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Increasing participation for Other university-supported projects have increasing urban heat. Recognizing that integrated urban planning investigated other benefits of urban and a healthy forest is crucial for maintaining In Foz do Iguaçu, Brazil, researchers at peri-urban forests, such as their role in the well-being of people, the City devel- the Federal University of Latin American shaping children’s perceptions of socio- oped an urban forest strategy aligned with Integration (Universidade Federal da ecological systems. In that project, children its climate adaptation and open-space Integração Latino-Americana) have participate in field trips to urban gardens strategies (City of Melbourne, undated). mapped urban and peri-urban forests as and natural areas within their neighbour- The image below is a visualization of the part of a federally supported regional hoods and interview elderly residents about City’s urban forests of the future, in which initiative on the management and conser- local environmental history. These activi- trees are present in streets and parks and vation of Atlantic forests. The framework ties help the children develop social skills on rooftops. City planners used participa- generated by this initiative, the Atlantic and increase their environmental aware- tory methods – strong communication and Forest Municipal Plan, provides informa- ness, and they expose children to local engagement, including online visualization tion on the state of urban natural areas. arrangements in the use and conservation and a popular “email a tree” function – In addition to mapping, the plan includes of private and community green areas. to involve residents and commuters in environmental perception studies, risk establishing a clear vision and goals for the assessment and scenario analysis; it Planning with urban and City’s urban forests. The strategy is being also involves diverse stakeholders. The peri-urban forests implemented through ten precinct plans, aims of the plan are to increase public The City of Melbourne, Australia, has participation in decision making and to changed its management of urban for- establish strategies for integrating urban ests in line with the challenges it faces: A visualization of the future planning and environmental conservation. climate change, population growth and urban forests in the City of Melbourne, Australia © CITY OF MELBOURNE OF © CITY

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which put the principles of the strategy 2012). Demand for food and other eco- according to the needs of individual cit- into practice while integrating community system services will increase worldwide ies, as determined by their biophysical views. Complementing this, and recogniz- as populations grow. Urban expansion will contexts and the values and preferences ing the importance of the community in affect biodiversity hotspots, such as the of their communities. Planning urban generating and transferring knowledge, Eastern Afromontane, the Guinean Forests and peri-urban forests that contribute to the City of Melbourne created the Citizen of West Africa, and the Sri Lanka hotspots the sustainability and resilience of cities Forester Program, under which citizens are (Seto, Güneralp and Hutyra, 2012). Urban requires a multidisciplinary approach in enlisted to collect data on, among other and peri-urban forests can be thought of which planners, urban designers, landscape things, trees, tree genetics, habitats and as green networks that can connect rural architects, urban foresters, engineers, park pollinators. Recently, the City created the and urban areas, parks and other natural managers and communities work together Urban Forest Fund, which, in partnership areas in and around cities. Such forests to develop effective policies, management with the private sector, unlocks financial can enable fauna mobility and increase regimes and regulations. The extent to support to deliver more greening on private people’s connection with nature – requir- which communities are involved in the properties and therefore more benefits for ing urban planning initiatives and policies policymaking process will be a determi- the community. that operate at several scales and involve nant of the success of urban and peri-urban diverse stakeholders. Planning needs forest policies because community support FUTURE DIRECTIONS to become a multidisciplinary process, is essential, in the long term, for successful Of the many challenges facing urban and involving not only a range of government implementation. peri-urban forests and their management, institutions but also the communities who Access to data on the quality, quantity climate change, population growth and inhabit the cities. and distribution of urban and peri-urban social inequalities are the most widespread forests is another prerequisite for and locally important. Social inequalities successful planning and management. Social inequalities affect access to, and Policies must incorporate both scientific Climate change the distribution of, ecosystem services. knowledge and people’s preferences and Climate change increases the risks to This is especially relevant in cities in less- values. Finally, a monitoring system is urban and peri-urban forests, which must developed regions, such as Latin America. needed to evaluate the implementation of be capable of surviving extended periods Therefore, management strategies and policies; citizen science programmes are a of severe drought and extreme heat and policy decisions that address only the eco- promising measure for obtaining ongoing rain events. Urban forest plans must logical dimension of ecosystem services information on the status of urban and reduce the likelihood of catastrophic tree may increase socio-ecological vulner- peri-urban forests and for communicating losses due to pests and diseases (Dobbs, ability (Laterra et al., 2016). with and educating citizens. u Martinez-Harms and Kendal, 2017). Creating institutional spaces to allow the Approaches to tree planting and landscape blooming of local governance processes design based on ornamental features and for urban and peri-urban forests, involving historical performance will not necessar- social networks of people of various ages, ily work in the future; rather, species will genders, ethnicities, socio-economic back- need to be selected for the probable future grounds, education and values, is essential climate. Creating a genetically and func- for building resilient communities. Civic tionally diverse pool of species in cities participation is likely to lead to innovative will be crucial for ensuring resilience to actions adjusted to local realities that cre- References climate change (Kendal, Dobbs and Lohr, ate and sustain long-term linkages between 2014) and the maintenance of vital eco- cultural and biological diversity. Alvey, A.A. 2006. Promoting and preserv- system services (Dobbs, Martinez-Harms ing biodiversity in the urban forest. Urban and Kendal, 2017). Understanding the socio-ecological Forestry and Urban Greening, 5: 195–201. context of urban forests Annerstedt, M., Ostergren, P.-O., Grahn, P., Population growth To develop sustainable and resilient cities, Skarback, E. & Wahrborg, P. 2015. Moving It has been estimated that, globally, urban it is necessary to understand the contexts in to serene nature may prevent poor mental areas will have expanded by 185 percent which these urban dynamics occur. Urban health: results from a Swedish longitudi- by 2030 compared with circa 2000, espe- and peri-urban forests will not succeed by nal cohort study. International Journal of cially in China, India and other Asian simply copying what other cities are doing; Environmental Research and Public Health, countries (Seto, Güneralp and Hutyra, plans and management must be adjusted 12: 7974–7989.

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Improving city forests through assessment, modelling and monitoring

D. J. Nowak © DAVID LORENZ WINSTON/UNITED STATES FOREST SERVICE FOREST STATES WINSTON/UNITED © DAVID LORENZ

Methods for estimating the rban and peri-urban forests potential costs must be weighed against the costs and benefits of urban and produce numerous benefits for benefits when developing natural resource peri-urban forests are increasingly society. These include moderating management programmes. accurate and easy to apply. Uthe climate; reducing energy use in build- To sustain or enhance the benefits of ings; sequestering atmospheric carbon urban and peri-urban forests for society, dioxide; improving air and water quality; it is important to understand the exist- mitigating rainfall run-off and flooding; ing forest structure, how this structure providing an aesthetic environment and affects the magnitude of the benefits and recreational opportunities; enhancing costs, and how the forest structure and human health and social well-being; and therefore benefits change over time. With lowering noise impacts (Dwyer et al., such understanding, managers can guide 1992; Nowak and Dwyer, 2007; Dobbs, forest structure to maximize benefits for Martinez-Harms and Kendal, 2017). society. Significant advances have been Inappropriate landscape design, tree selec- made in recent years on urban and peri- tion and tree maintenance, however, can urban forest monitoring and assessment increase environmental costs (e.g. through pollen production and chemical emissions Above: The monitoring and assessment that contribute to air pollution), energy use of urban and peri-urban forests enables David J. Nowak is at the United States Forest the development of management plans Service in Syracuse, New York, United States in buildings, waste disposal, infrastruc- that optimize forest structure and the of America. ture repair, and water consumption. These benefits such forests provide

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and in quantifying the benefits and costs often choose what species to plant, where interpretation provides a cost-effective and associated with the resource. Many of and when to plant them, and what trees accurate means of assessing tree and other the benefits are not easily measured in are removed from the landscape. These cover attributes; it lacks specific informa- the field, and modelling techniques must actions directly influence structure and tion on cover location, however. therefore be used to estimate their magni- consequently the benefits derived from If cover locations are needed, tree-cover tude. This article provides an overview the urban and peri-urban forest resource. maps can provide both tree-cover estimates of a four-step process for easily assess- and specific locations of cover elements ing, modelling and monitoring urban and Bottom-up or top-down? (e.g. to be integrated into a geographic peri-urban forest structure and benefits. There are two basic ways of quantifying information system). Tree cover and distri- Through this process, local management structure in urban and peri-urban forests: bution are important parameters of urban plans can be developed that optimize forest 1) top-down aerially based approaches; and and peri-urban forest structure because structure to enhance the health and well- 2) bottom-up ground-based assessments. they provide a simple way of conveying being of current and future generations. Top-down assessments provide basic the magnitude and distribution of the metrics on tree cover (e.g. percentage tree forest resource. More detailed data on STEP 1: ASSESSING FOREST cover) and other cover types, and they can forest structure (e.g. species composi- STRUCTURE map the specific locations of such elements. tion, the number of trees, tree size, tree Forest structure is a key variable because Tree cover can often be estimated condition, leaf area, leaf biomass and tree it is what managers manipulate to influ- by interpreting aerial photographs or biomass) are often needed, however, to ence forest benefits and values. Structure by developing tree-cover maps using represents the physical attributes of the moderate-to-high-resolution imagery forest, such as the abundance, size, species, (e.g. Nowak, 2012a). If only the amount Healthy tree leaves are crucial for health and location of trees. Managers or percentage of tree cover is needed, photo the provision of many of the benefits of urban and peri-urban forests © DAVID LORENZ© DAVID WINSTON/UNITED STATES FOREST SERVICE

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assess the benefits and costs and to guide while diameter measures are essential for urban and peri-urban forests. With these, management. Although various aerially estimating carbon storage. Leaf and tree the value of benefits can be estimated using based approaches are being researched and biomass can be modelled from these core valid economic estimates and procedures. developed to derive specific tree informa- tree variables. Other important attributes Thus, three crucial elements are needed in tion, the best existing approach for deriving for estimating urban and peri-urban forest sequence to value the benefits of urban and many tree variables is field measurement. benefits are crown competition (important peri-urban forests and to aid their man- Field data on urban and peri-urban forest for estimating tree growth and carbon agement: structure  benefits values. structure can be obtained from inventories sequestration) and location around build- Errors with precursor elements will lead to or by sampling. For large tree populations, ings (important for estimating energy errors in subsequent estimates (e.g. errors field data in conjunction with aerially conservation). Numerous benefits of urban in forest structure will lead to errors in based assessments will likely provide the and peri-urban forests can be modelled estimating benefits and values). best and most cost-effective means for from these tree variables, in conjunc- assessing urban and peri-urban structure. tion with other local information (e.g. on STEP 2: MODELLING URBAN AND The most important parameters are spe- weather, pollution and demographics). PERI-URBAN FOREST BENEFITS, cies, diameter, crown dimensions, and tree There is interdependence between urban COSTS AND VALUES condition. This information is helpful to and peri-urban forest structure, benefits Information on forest structure can aid managers for population management and and economic valuation. Valuation is managers by revealing species composi- in assessing risks to the resource, and it dependent on good estimates of the tion, sizes, locations and potential forest is also essential for estimating benefits magnitude of the benefit provided, and risks (e.g. species composition can reveal and costs. benefit estimates require good estimates potential risks posed by insects and of forest structure and how it affects disease infestations). Understanding the Attributes for modelling benefits. Benefits and values cannot be links between urban and peri-urban forest For most benefits, the most important adequately quantified without good data structure and the benefits those forests tree attribute is leaf area. Although not on forest structure. Combining accurate provide is essential for optimizing the directly measured in the field, this vari- data with sound procedures for quantifying benefits through management. Because able can be modelled from information on benefits will produce reliable estimates many benefits cannot be measured easily species, crown size and crown condition, of the magnitude of benefits provided by in the field (e.g. air pollution removal),

A colour-enhanced aerial image of SERVICE FOREST STATES UNITED New York City, United States of America. The structure and benefits of urban and peri-urban forests vary across landscapes as forest cover and human populations vary

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models are used to estimate benefits, costs selection tools; mobile data entry appli- et al., 2006; Graca et al., 2017; Nowak and values based in part on the measured cations; tabular and graphic reporting and et al., 2007, 2010, 2013; Rogers et al., 2015; data on forest structure. Once the benefits exporting; and automatic report genera- Selmi et al., 2016). have been quantified, various methods of tion. Assessments of urban and peri-urban The other tools in i-Tree are: market and non-market valuation can be forests have been conducted using this • i-Tree Species – selects the most applied to characterize their monetary model in numerous cities globally, includ- appropriate tree species based on value (e.g. Hayden, 1989). ing Barcelona, Spain; Calles, Mexico; desired environmental functions and Various models exist for quantifying Chicago, United States of America; geographic area; forest benefits; freely available models London, United Kingdom of Great Britain • i-Tree Hydro – simulates the effects include InVEST (Natural Capital Project, and Northern Ireland; Medellín, Colombia; of changes in tree cover and impervi- undated), Biome-BGC (Numerical Milan, Italy; New York, United States of ous cover on run-off, stream flow and Terradynamic Simulation Group, undated) America; Perth, Australia; Porto, Portugal; water quality; and numerous tools for assessing forest Santiago, Chile; Seoul, Republic of Korea; • i-Tree Canopy* – allows users to carbon (e.g. United States Forest Service, Strasbourg, France; and Toronto, Canada easily photo-interpret Google aerial 2016a). Few models quantify urban and (Chaparro and Terradas, 2009; Escobedo images to produce statistical estimates peri-urban forests, however. The most comprehensive model developed to date TABLE 1. Benefits and costs of trees currently quantified and in development for quantifying urban and peri-urban in i-Tree forest structure, benefits and values is Ecosystem effect Attribute Quantified Valued 1 i-Tree, a freely available suite of tools Atmosphere Air temperature   developed by the United States Forest Avoided emissions   Service through a public–private part- Building energy use   nership. i-Tree is based on peer-reviewed Carbon sequestration   science and can be used globally, and it   has more than 180 000 users in 130 coun- Carbon storage tries; it was designed to accurately assess Human comfort  local forest structure and its impacts on Pollen  benefits, costs and values (Table 1). Model Pollution removal   results have been validated against field measurements (e.g. Morani et al., 2014) to Transpiration  provide sound estimates of the benefits of Ultraviolet radiation   urban and peri-urban forests. The model Volatile organic compound emissions  focuses on estimating forest structure and Community/social Aesthetics/property value   the magnitude of services received (e.g. Food/medicine  tonnes of carbon removed). It then relies on 1  economic valuation (e.g. dollars per tonne Health index removed) to estimate the value of a given Forest products2   service. The model uses various economic Underserved areas  estimates; users can adjust many of these if Terrestrial Biodiversity  local economic values are available. Invasive plants   i-Tree Eco Nutrient cycling The core programme of the i-Tree suite is Wildlife habitat  i-Tree Eco. This model, which can be used Water Avoided run-off   globally, uses sample or inventory data and Flooding   local environmental data to assess and Rainfall interception  forecast forest structure, benefits, threats   and values for any tree population (Nowak Water quality et al., 2008). i-Tree Eco includes plot Notes:  = attribute currently quantified or valued in i-Tree;  = attribute in development in i-Tree; 1 = developing a health index based on mapping of green viewing (“forest bathing”); 2 = estimating product potential based on forest structure (e.g. timber, wood pellets, ethanol). 1 www.itreetools.org Source: Nowak (2017).

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A tree-lined street in Honolulu, Hawaii, of land-cover types. Historical imagery peri-urban forest management and plan- United States of America. The design in Google Earth can also be used in ning. Many new forest benefits and costs of urban and peri-urban forests is important for minimizing potential analysing changes in land-cover types; are being added to the model (Table 1). negative effects, such as trapping • i-Tree Design – links to Google Maps Assessments and modelling in the pollutants near roadways and enables users to quantify the cur- United States of America indicate that rent and future benefits of trees on there are an estimated 5.5 billion trees their properties; (39.4 percent tree cover) in urban areas is to guide such forests towards desirable • MyTree – easily assesses the benefits nationally, containing 51.5 million hec- outcomes that maximize benefits for pres- of one to a few trees using a phone via tares of leaf area and 40 million tonnes of ent and future generations. A crucial step a mobile web browser; and dry-weight leaf biomass. Annually, these towards achieving this goal is to develop an • i-Tree Landscape – allows users to trees produce a total of USD 18.3 billion urban and peri-urban forest management explore tree canopy, land cover, tree in value, comprising air pollution removal plan that optimizes forest structure over benefits, forest and health risks, and (USD 5.4 billion), reduced building energy time. Data from local assessments and basic demographic information any- use (USD 5.4 billion), carbon sequestration modelling, in conjunction with inputs from where in the United States of America (USD 4.8 billion) and avoided pollutant residents, can be used to develop plans to and to prioritize areas for tree planting emissions (USD 2.7 billion) (Nowak and sustain or enhance urban and peri-urban and protection. Greenfield, in press). forest structure and benefits. These plans i-Tree is being developed through a col- can be as simple as detailing the means laborative effort among numerous partners STEP 3: DEVELOPING (e.g. funding) for attaining desired tree- to better understand and quantify how MANAGEMENT PLANS cover goals at specific locations, or they changes in forest structure will affect Urban and peri-urban forests change can provide detailed information on plant- benefits and values and to aid in urban and constantly, and the goal of management ing rates by species and location.

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Urban tree cover is on the decline in the United States of America (Nowak and Greenfield, 2012). Management plans need to consider various forces that are likely to alter forest structure over time, Assess forest including forces that decrease tree cover structure (e.g. development, storms, insects and diseases, and old age) and increase tree cover (e.g. tree planting, natural regeneration and invasive species). In the United States of America, it is estimated that two- thirds of the existing urban forest is from natural regeneration (Nowak, 2012b). The influence of tree planting tends to increase in cities in grassland and desert areas, in Develop/implement more densely populated cities, and on land urban and Model benefits uses that are highly managed in relation to peri-urban forest and costs trees (e.g. residential lands). Planning for management plan both human- and nature-driven changes in urban and peri-urban forests will facilitate better management plans that can sustain forest structure and benefits over time.

STEP 4: MONITORING CHANGE IN 1 URBAN AND PERI-URBAN FORESTS 2016); 26 cities were monitored in 2017, and Cycle of urban and peri-urban forest The last step in the assessment process is new cities will be added to the monitoring assessments and monitoring for sustaining forest benefits over time to remeasure the forest periodically (i.e. programme over the next few years (United monitoring) to determine how it is chang- States Forest Service, 2016b). ing and whether management goals are being met. This step is a remeasurement of KEY FINDINGS • Monitoring urban and peri-urban the forest structure, as conducted in step 1, The main points made in this article can forests is crucial for assessing change thereby restarting the cycle of modelling be summarized as follows: and evaluating management plans. benefits and evaluating or updating man- • Understanding and accounting for the The United States of America has agement plans (Figure 1). The evaluation benefits provided by urban and peri- recently begun a national urban for- cycle (e.g. every 5–10 years) can ensure that urban forests enables better planning, est monitoring programme in several the structure of the urban and peri-urban design and economic decisions for cities and states. forest is progressing in the desired fashion using those forests to improve envi- • Future assessments, monitoring and to sustain benefits and values for society. ronmental quality and human health management plans can help lower An increasing number of cities globally and well-being. costs and sustain the benefits of urban are assessing their urban and peri-urban • Data on urban and peri-urban forest and peri-urban forests. u forests so as to better understand the structure (e.g. species composition benefits and costs. The United States Forest and tree locations), and how that struc- Service Forest Inventory and Analysis pro- ture affects benefits and values, are Disclaimer: The use of trade names in this gramme, in partnership with states and crucial for such improvement. article is for the information and conveni- cities, is undertaking long-term urban forest • i-Tree is a simple and freely available ence of readers. Such use does not constitute monitoring in the United States of America. set of tools for assessing and valu- official endorsement or approval by the This programme collects urban forest data ing the impact of trees and forests – United States Department of Agriculture annually to assess forest structure, benefits from the scale of local forest parcels or the United States Forest Service of any and values and changes in these over time. to regional landscapes – on environ- product or service to the exclusion of others The first city to complete a baseline assess- mental quality and human health and that may be suitable. ment was Austin, Texas (Nowak et al., well-being.

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Bulletin NRS-INF-24-13. Newtown Square, Nowak, D.J., Hoehn, R., Crane, D.E., USA, United States Forest Service, Northern Stevens, J.C. & Walton, J.T. 2007. Assessing Research Station. urban forest effects and values: New York City’s Nowak, D.J. 2012b. Contrasting natural regenera- urban forest. United States Forest Service References tion and tree planting in 14 North American Northern Research Station Resources Bulletin cities. Urban Forestry and Urban Greening, NRS-9. Newtown Square, USA, United States Chaparro, L. & Terradas, J. 2009. Ecological 11: 374–382. Forest Service, Northern Research Station. services of urban forest in Barcelona. Nowak, D.J. 2017. Assessing the benefits and Numerical Terradynamic Simulation Group. Bellaterra, Spain, Centre de Recerca Ecològica economic values of trees. In: F. Ferrini, Undated. Biome-BGC [online]. University of i Aplicacions Forestals, Universitat Autònoma C.C. Konijnendijk van den Bosch & A. Fini, Montana. [Cited January 2016]. www.ntsg.umt. de Barcelona. eds. Routledge handbook of urban forestry, edu/project/biome-bgc Dobbs, C., Martinez-Harms, M.J. & pp. 152–163. Abingdon, UK, Routledge. Rogers, K., Sacre, K., Goodenough, J. & Kendal, D. 2017. Ecosystem services. In: Nowak D.J., Bodine, A.R., Hoehn, R.E., Doick, K. 2015. Valuing London’s urban F. Ferrini, C.C. Konijnendijk van den Bosch Edgar, C.B., Hartel, D.R., Lister, T.W. & forest: results of the London i-Tree Eco Project. & A. Fini, eds. Routledge handbook of urban Brandeis, T. J. 2016. Austin’s urban forest, London, Treeconomics. forestry, pp. 51–64. Abingdon, UK, Routledge. 2014. United States Forest Service Northern Selmi, W., Weber, C., Rivière, E., Blond, N., Dwyer, J.F., McPherson, E.G., Schroeder, H.W. Research Station Resources Bulletin NRS-100. Mehdi, L. & Nowak, D. 2016. Air pollution & Rowntree, R.A. 1992. Assessing the benefits Newtown Square, USA, United States Forest removal by trees in public greenspace in and costs of the urban forest. Journal of Service, Northern Research Station. Strasbourg city, France. Urban Forestry and Arboriculture, 18(5): 227–234. Nowak, D.J., Crane, D.E., Stevens, J.C., Urban Greening, 17: 192–201. Escobedo, F.J., Nowak, D.J., Wagner, J.E., Hoehn, R.E., Walton, J.T. & Bond, J. United States Forest Service. 2016a. Carbon: Luz de la Maza, C. & Rodriguez, M. 2006. 2008. A ground-based method of assess- tools for carbon inventory, management, and The socioeconomics and management of ing urban forest structure and ecosystem reporting [online]. [Cited January 2016]. www. Santiago de Chile’s public urban forest. Urban services. Arboriculture and Urban Forestry, nrs.fs.fed.us/carbon/tools Forestry and Urban Greening, 4: 105–114. 34: 347–358. United States Forest Service. 2016b. Urban forest Graca, M.S., Goncalves, J.F., Alves, P.J., Nowak, D.J. & Dwyer, J.F. 2007. Understanding inventory and analysis (FIA) [online]. [Cited Nowak, D.J., Hoehn, R., Ellis, A., the benefits and costs of urban forest eco- 15 December 2016]. www.fs.fed.us/research/ Farinha-Marques, P. & Cunha, M. 2017. systems. In: J. Kuser, ed. Urban and community urban/fia.php.u Assessing mismatches in ecosystem services forestry in the Northeast, pp. 25–46. New York, proficiency across the urban fabric of Porto USA, Springer. (Portugal): the influence of structural and Nowak, D.J. & Greenfield, E.J.2012. Tree and socioeconomic variables. Ecosystem Services, impervious cover change in U.S. cities. Urban 23: 82–93. Forestry and Urban Greening, 11: 21–30. Hayden, F.G. 1989. Survey of methodologies for Nowak, D.J. & Greenfield, E.J. In press. U.S. valuing externalities and public goods. EPA- urban forest statistics, values and projections. 68-01-7363. Washington, DC, United States Journal of Forestry. Environmental Protection Agency. Nowak, D.J., Hoehn, R.E., Bodine, A.R., Morani, A., Nowak, D., Hirabayashi, S., Greenfield, E.J., Ellis, A., Endreny, T.E., Guidolotti, G., Medori, M., Muzzini, V., Yang, Y., Zhou, T. & Henry, R. 2013. Fares, S., Scarascia Mugnozza, G. & Assessing forest effects and values: Toronto’s Calfapietra, C. 2014. Comparing modeled urban forest. United States Forest Service ozone deposition with field measurements in a Northern Research Station Resources Bulletin periurban Mediterranean forest. Environmental NRS-79. Newtown Square, USA, United States Pollution, 195: 202–209. Forest Service, Northern Research Station. Natural Capital Project. Undated. InVEST: Nowak, D.J., Hoehn, R., Crane, D.E., Integrated valuation of ecosystem services Stevens, J.C. & LeBlanc, C. 2010. Assessing and tradeoffs [online]. [Cited January 2016]. urban forest effects and values: Chicago’s www.naturalcapitalproject.org/invest urban forest. United States Forest Service Nowak, D.J. 2012a. A guide to assessing Northern Research Station Resources Bulletin urban forests. United States Forest Service NRS-37. Newtown Square, USA, United States Northern Research Station Resources Forest Service, Northern Research Station.

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The changing governance of urban forests

C.C. Konijnendijk, P. Rodbell, F. Salbitano, K. Sayers, S. Jiménez Villarpando and M. Yokohari

Demand for forests and other rees, woodlands and other vegeta- Better urban and peri-urban forestry green spaces is leading to new tion make crucial contributions to (UPF) programmes are needed in com- models of urban governance. the health, well-being and resil- munities worldwide. The interdisciplinary Tience of urban communities. A body of field of UPF operates in a complex context, evidence has accumulated in recent years with rapidly changing conditions, drivers Cecil C. Konijnendijk van den Bosch is Professor on, for example, the roles of urban forests and “storylines” (such as biodiversity loss, of Urban Forestry at the University of British in mitigating the impacts of climate change and the need to adapt cities to climate Columbia, Canada. Phillip Rodbell is Urban and Community Forestry and urban “heat islands” (Roy and Byrne, change and to enhance public health), and Program Leader, United States Forest Service, 2014; Dobbs, Martinez-Harms and Kendal, many issues compete for the attention of Northeastern Area, United States of America. 2017), and the case has also become strong decision makers and local communities Fabio Salbitano is Associate Professor at the University of Florence, Italy, and a regular advisor to for urban forests and other green spaces (Sheppard et al., 2017). FAO’s urban and peri-urban forestry programme. as important contributors to public health Kevin Sayers is Program Coordinator for Urban and (e.g. van den Bosch, 2017). Urban forests Community Forestry at the Michigan Department of Natural Resources, United States of America. are often under pressure, however, from Local action organized by Sarah Jiménez Villarpando is an urban forester development and urban densification, poor The Greening of Detroit in Michigan, working in Cochabamba, Bolivia (Plurinational management and their low political status with seed funding from the federal and State of). state governments, is a governance Makoto Yokohari is Professor of Landscape (Haaland and Konijnendijk van den Bosch, model that has built a constituency Planning at the University of Tokyo, Japan. 2015). for city forest management across the United States of America © THE GREENING OF DETROIT

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An expanding global urban forestry who gets what, when and how (UNDP, nurturing of sustainable local programmes community, and increasing networking 2009). and institutions that protect existing tree and knowledge exchange supported by Knowledge of urban and peri-urban for- cover across all lands. Delivered in part- organizations such as FAO, has resulted in est governance and the different shapes nership with state forestry agencies, the greater knowledge and acceptance of good and models it can take is still limited. programme supports a network of state practices in urban forest design, planning Therefore, we need to study examples coordinators and technicians in every and management. To date, however, only of governance models across the world state and reaches more than 7 800 cities, limited attention has been given to the and draw lessons from them. There is an towns and villages serving 200 million way in which decisions on urban forests emerging body of research on urban forest residents nationwide. These communities are made at the strategic level. Who is governance (e.g. Bentsen, Lindholst and have local laws protecting trees, and nearly involved in such decisions, and who is Konijnendijk, 2010; Lawrence et al., 2013; 70 percent employ professional staff and left out? What are the main storylines? Buizer et al., 2015; Sheppard et al., 2017), have management plans in place. How is decision making organized, and but much more work is needed, involving, One model partnership is between who takes the lead? All these questions for example, more cases from develop- the United States Forest Service and need attention. ing countries. In this article, we illustrate the Michigan Department of Natural the diversity of urban forest governance Resources (DNR). The state of Michigan From education to governance using three promising examples. The first lies within the Great Lakes basin, sur- Traditionally, UPF professionals have introduces a well-established, public- rounded by the world’s largest freshwater focused efforts on educating politicians sector-led UPF programme in the United lake system, and the majority of the state’s and raising citizen awareness about the States of America. The second presents a nearly 10 million residents live on roughly importance of urban trees and wood- case of emerging urban forest governance 11 000 km2 (13 percent of the land area). lands. We have come to realize, however, in a difficult developing-country context The state concentrates its urban work in that UPF needs to move beyond this to in Bolivia (Plurinational State of). The 300 communities, with an average 21 per- find ways of including a wider set of third examines an innovative govern- cent tree canopy. stakeholders in decision making and ance approach in Tokyo, Japan, involving The provision of federal funds management (Sheppard et al., 2017). public–private partnerships. (USD 344 000 in 2017) to the state through In forestry in general, there is grow- the urban forest programme is driven by ing interest in emerging, often complex PUBLIC-SECTOR LEADERSHIP a DNR forest action plan developed in multi-actor decision making – processes AND CIVIL-SOCIETY PARTNERSHIP collaboration with a statewide advisory captured in the concept of “governance”. IN MICHIGAN (governing) council. The programme’s Previously, public actors such as state The United States Forest Service has a focus is to: forest authorities tended to dominate unique programme across all states and • reduce threats from invasive pests; forest policy, planning and manage- territories of the United States of America • build local community capacity to ment, but this is less the case today. In to support state and local governments manage urban forest resources; UPF, municipal forestry and parks (or in improving the extent and condition • maintain community quality of life planning and engineering) departments of their urban and peri-urban forests. and economic resilience; and still play leading roles, but increasingly Authorized in 1978 and expanded in • reforest urban and peri-urban areas. they must involve other actors. Thus, we 1990 with the help of non-governmental The funding supports state technical can see a movement from governance partners, the programme builds capacity assistance and non-governmental partner- by government to governance with (and and strengthens local action to plant and ships that help deliver services and engage sometimes even without) government protect trees and forests for the economic, a growing network of professional and (Konijnendijk van den Bosch, 2014). social, environmental and psychological volunteer leaders. More than 50 percent of Definitions of governance vary widely. benefits they provide (United States Forest funds are allocated in grants to local gov- All recognize, however, a strategic shift in Service, 2017). ernment to build public- and private-sector which a range of government actors share The national programme has focused capacity in tree planting, tree inventory, (or transfer) decision making and rule on local governance since its inception. management planning and education and setting with (or to) civil society and busi- Although tree planting is recognized training. nesses (Lawrence et al., 2013; Sheppard as an important entry-level activity that Detroit (population 711 000), in et al., 2017). Governance involves deci- engages people and organizations, the real Michigan, provides an example of how sions, negotiation and a range of power target has been local tree inventories and the federal programme is delivered relations among stakeholders to determine management planning and the creation and locally. The city has a storied history

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Unplanned urban development of local park and tree investment dat- diversify its tree population, and rebuild is causing the deterioration of environmental quality in Cochabamba, ing back to its founding in 1701, and it its forestry division to conduct regular Bolivia (Plurinational State of). boasts 1 986 hectares of parkland in a maintenance. With a strong constituency Pressure from a citizens’ group has total area of 360 km2. In the mid-twentieth for trees in Detroit, the future looks bright. led to the development of an urban forest strategy in the city century at the height of its population The pattern is similar in other Forest (1.8 million people), the city reportedly Service and state work in cities across had 250 000 street trees; by 1990, however, the country. Sustaining long-term rela- changed dramatically in the last decade, it had lost half its tree canopy to Dutch tionships, leveraging local capacity and however, due to poor urban governance and elm disease, and thousands more trees investing in credible, science-based planning, which transformed the Garden were subsequently lost to the emerald approaches are key to creating govern- City into a chaotic urban complex with ash borer. Since 2000, with DNR lead- ance and building local commitment for severe socio-environmental problems. ership, the United States Forest Service successful city forest management. Many of these problems are strongly asso- has supported The Greening of Detroit, a ciated with a substantial decrease in tree non-governmental organization, to engage COCHABAMBA: A COMMUNITY and vegetation cover in both established residents in restoration planting and tree CALLS FOR BETTER GOVERNANCE urban settings and new urban development maintenance. In 2010, the Forest Service With 630 000 residents, Cochabamba is the zones. The city’s environment has been and DNR funded a multiyear, citywide fourth-largest city in Bolivia (Plurinational under pressure from rapid and unplanned street-tree inventory that identified the State of), and it is situated at the centre of urban expansion. Pervious soils tradition- species and condition of 175 000 public a larger metropolitan area with 1.2 million ally covered by vegetation and trees have trees. Using i-Tree tools,1 the inventory residents. Cochabamba’s urban population been converted to impervious surfaces. collectively valued the city’s street trees at is growing by almost 2.5 percent per year. The few native trees remaining on public USD 29 million; this convinced city lead- Located at 2 500 m above sea level on an roads, sidewalks and parks have been ers to fund and implement a management inter-Andean plateau, the city has a mild replaced with exotic ones because of the plan to address dead and dangerous trees, climate compared with elsewhere in the latter’s allegedly more rapid growth. The region. Because of this, it is also known as exotic trees are declining, however, and 1 www.itreetools.org; see also article on page 30 the “Garden City” and the “City of Eternal are not being replaced, and the loss of tree of this issue. Spring”. Conditions in the city have cover has accelerated.

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Members of the grassroots collective “No to the Felling of Trees” march in Plaza 14 de Septiembre, Cochabamba, in

Faced with deteriorating environmental and criteria and sets the course for a new and green spaces. Initially, the collective quality, Cochabamba residents began model of urban forest management and was opposed to any intervention that expressing concern about what was hap- planning. would harm the city’s trees and did not pening to the city environment as well as Local citizens played a crucial role in want to negotiate with the mayor’s office. with the municipal administration and its the development of this plan by stressing Many members of the collective, although management choices. Before the approval the need for better protection of exist- passionate about trees, had only basic of the Municipal Tree Law in 2017, the ing trees and for afforestation initiatives. knowledge about the need for the proper management of public green spaces was Community involvement was encouraged management of urban trees and forests. To based on a 1998 tree ordinance and on a through a process of active tree citizen- address this, Sarah Jiménez and a few of regulation for the protection and control ship. The grassroots collective No to the her urban-forestry colleagues conducted a of green spaces dating from 2003. Both Felling of Trees (No a la tala de árboles long process of education within the group. these documents lacked clear legal and – “the collective”), was created in March The collective initially rejected the pro- administrative procedures as well as tech- 2016 to defend the city’s trees. Sarah posed municipal urban forest master plan, nical support for their implementation. Jiménez Villarpando, an urban forester, and the negotiation expanded to include The weak municipal structure has been participated in it from the beginning, and other interested parties. The process was unable to develop effective tree care and it soon gained popularity in social media, long and delicate, and the collective’s strat- forest management. reaching nationwide attention within a few egy was to put pressure on the municipal Facing this critical situation, in 2016 weeks and inspiring similar spontane- authorities while maintaining the techni- the municipal administration promoted ous actions in other cities. The collective cal content of the plan. Eventually, the the preparation of an urban forest master made public announcements about the collective accepted a modified plan and plan as a planning tool with a compre- mistreatment of trees. Although apoliti- the Municipal Tree Law that followed. hensive vision for addressing prevailing cal, it could be considered radical, and The strong commitment of the citizens problems and finding solutions. The plan it was highly critical of the mayor and and public institutions, and the common defines strategic, technical, administra- especially of EMAVRA, the company recognition of the importance of urban tive, normative and institutional guidelines responsible for managing the city’s trees trees to the city’s future, encouraged the

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various municipal bodies to finally collab- investment by the Tokyo Metropolitan that fulfil environmental-quality criteria orate with civil society. The Municipal Government and local municipalities in set by the government. One of the criteria Tree Law was adopted on 3 October 2017, creating public green spaces cannot be is the creation of a substantial area of in tribute to the National Day of the Tree expected because of the stagnant financial green space that is permanently open to (traditionally held on 1 October). condition of those bodies. the public. The application of this system Meanwhile, a growing concern for envir- has enabled the development of more than PUBLIC–PRIVATE PARTNERSHIPS onmental conservation has led real estate 700 green spaces in central Tokyo, includ- FOR NEW URBAN FORESTS IN TOKYO developers and enterprises to contribute to ing the headquarters of Mitsui Sumitomo Increasing green open spaces has been a the improvement of the urban environment Marine Insurance, which has 4 700 m2 major challenge for many Japanese cities, as part of their corporate social responsi- of green space at its base that is open to and Tokyo is no exception. Although the bility policies. To encourage the private the public. western third of Tokyo is mountainous and sector to participate actively in the creation Another prominent regulation under covered mainly by forests, only 3 percent of green spaces, which can help conserve the Urban Green Space Conservation of the land area in the core of the city is biodiversity, improve the urban climate Act establishes a system for certifying the dedicated to green spaces. The Tokyo and provide recreational opportunities, the public accessibility of privately owned Metropolitan Government and local munici- Government of Japan approved several new green spaces. This system encourages the palities in Tokyo have worked persistently regulations on building design and urban creation of green spaces for public use on to increase public green spaces, especially planning. The “overall design system”, privately owned vacant lands by providing parks, but increases have mainly been in established in the Building Standards Act, landowners with financial incentives such the suburbs and there has been no major is a good example. The aim is to improve as tax concessions. The Kashiniwa pro- improvement in the central area. Although the quality of development projects by ject, established in 2012 in Kashiwa City the shortage of green spaces in central providing bonus volume- or height-control (near Tokyo), was used as a model for the Tokyo is a major public concern, further allowances to buildings on project sites system: it brings together the owners of

The headquarters of Mitsui Sumitomo Marine Insurance in Tokyo has 4 700 m2 of publicly accessible green space at its

base. A new model MAPS © GOOGLE of public–private partnership is helping create new green space in this densely populated city

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vacant land and citizens who want to create and funds by means of partnerships with cities. Deliverable 6.1, EU 7th Framework green spaces for public use and supports states, cities and non-profit-making organi- project GREEN SURGE (also available such matches by providing landowners zations, as the case of The Greening of at: http://greensurge.eu/products/planning- with financial incentives. Detroit illustrates. Ultimately, a top-down governance). In the history of open green spaces in governance structure has become blended Dobbs, C., Martinez-Harms, M. & Kendal, D. Japanese cities, there used to be a robust in a co-governance model in which local 2017. Ecosystem services. Chapter 4 in: “wall” between the public and private communities play leading roles. F. Ferrini, C. Konijnendijk van den Bosch realms. Public open spaces such as parks The case of Tokyo presents a third & A. Fini, eds. Routledge handbook of urban were created only by the public sector on approach to governance. There, businesses forestry. Abingdon, UK, Routledge. publicly owned lands, and the private sec- are becoming drivers of urban forest Haaland, C. & Konijnendijk van den Bosch, C. tor had no interest in contributing to the establishment and even governance. In 2015. Challenges and strategies for urban creation of publicly available green spaces. dynamic, densely populated cities such green space planning in cities undergoing As corporate social responsibility policies as Tokyo, land comes at premium prices, densification: a review.Urban Forestry and have become more integral to the activi- and retrofitting the urban core with urban Urban Greening, 14(4): 760–771. ties of private enterprises, however, and forests or other green components is very Konijnendijk van den Bosch, C. 2014. From in light of the United Nations Sustainable difficult for local authorities. A new avenue government to governance: contribution to Development Goals, this is no longer the towards greening can be created, however, the political ecology of urban forestry. In: case. The private sector is actively seeking if businesses see benefits in greening their L.A. Sandberg, A. Bardekjian & S. Butt, opportunities to play substantial roles in properties, encouraged by co-governance eds. Urban forests, trees and greenspace: the “public” domain. The future of open in the form of public–private partnerships. a political ecology perspective, pp. 35–46. green spaces in central Tokyo relies on such Faced with the challenge of creating Abingdon, UK, Routledge. successful public–private partnerships. healthy living environments for their citi- Lawrence, A., De Vreese, R., Johnston, M., zens, cities across the world are increasingly Sanesi, G. & Konijnendijk van den Bosch, TAILOR-MADE GOVERNANCE FOR recognizing urban and peri-urban forests C.C. 2013. Urban forest governance: towards SUCCESSFUL URBAN FORESTRY as key components. Good governance is a framework for comparing approaches. The three cases described in this article required to make urban forest programmes Urban Forestry and Urban Greening, 12(4): illustrate the wide variety of urban forest effective while also ensuring that the 464–473. governance approaches in place across benefits are shared equitably. Learning Roy, S. & Byrne, J.A. 2014. A systematic the world. No single model will work from the successes and failures of existing quantitative review of urban tree benefits, everywhere: each city and urban forest governance approaches and models is an costs, and assessment methods across cities will need its own, tailor-made approach. important part of the process of developing in different climatic zones. Urban Forestry In Cochabamba, where good governance better urban forest governance. u and Urban Greening, 11: 351–363. was absent, it took a bottom-up initiative Sheppard, S., Konijnendijk van den Bosch, C., by a group of concerned citizens to move Croy, O., Palomo, A.M. & Barron, S. 2017. towards better urban forest governance Urban forest governance and community and laws. Many cities in the developing engagement. In: F. Ferrini, C. Konijnendijk world face similar conditions and lack van den Bosch & A. Fini, eds. Routledge basic governance and urban forest pro- handbook of urban forestry, pp. 205–221. grammes. When resources are limited, the Abingdon, UK, Routledge. involvement of local communities and non- UNDP. 2009. A guide to UNDP democratic profit-making organizations is essential. References governance practice. New York, USA, United Nevertheless, municipal authorities will Nations Development Programme (UNDP). continue to play crucial roles, too, because Bentsen, P., Lindholst, A.C. & United States Forest Service. 2017. Urban they usually have formal responsibility for Konijnendijk, C.C. 2010. Reviewing eight and Community Forestry Program [online]. public street trees, parks and woodlands years of urban forestry and urban greening: [Cited 5 October 2017]. www.fs.fed.us/ and for city master planning. At the other taking stock, looking ahead. Urban Forestry managing-land/urban-forests/ucf end of the spectrum, in the United States and Urban Greening, 9(4): 273–280. van den Bosch, M. 2017. Live long in nature of America, a federal government initia- Buizer, M., Elands, B., Mattijssen, T., and long live nature! Commentary. The tive to support urban forestry in states and van der Jagt, A., Ambrose, B., Gerőházi, E. Lancet Planetary Health, 1(7): e265–266. u cities has been in place since 1978. The & Møller, M.S. 2015. The governance programme has evolved to leverage effort of urban green spaces in selected EU

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Forests as nature-based solutions for ensuring urban water security

N. Nagabhatla, E. Springgay and N. Dudley

Increasing international attention he era of globalization is giving projected to reach 9.55 billion) (UNDESA, is an opportunity to deploy rise to unprecedented trends and 2014). Minimizing the resultant stress on smart, green, cost-effective water patterns in the flows of humans urban areas and natural capital and ensur- management policies in towns and Tand natural capital. Most prominently, the ing water security will require increased cities and their hinterlands. speed and magnitude of the shift from attention and smart planning. rural to urban living are having direct Water security is “the capacity of a Nidhi Nagabhatla is P rogram me Officer at the impacts on water demand and supply. population to safeguard sustainable access United Nations University Institute for Water, Cities might occupy only a small propor- to adequate quantities of acceptable- Health and Environment. She is also at the School of Geography and Earth Sciences, McMaster tion (roughly 2 percent) of the world land quality water for sustaining livelihoods, University, Ham ilton, Canada. area but they account for 60 percent of total human well-being, and socio-economic Elaine Springgay is Forestry Officer in the world energy consumption and 70 percent Forestry Policy and Resources Division, Forestry Department, FAO, Rome. of greenhouse gas emissions (BP, 2017). In Visakhapatnam, Andhra Pradesh, Nigel Dudley is at the School of Earth and 2014, about 54 percent of the global popula- India, an urban centre of more than Environmental Sciences, University of Queensland, tion was urban; this is projected to increase 5 million people, is preparing to Brisbane, Australia. He is also a consultant with become a smart, green city. The need Equilibrium Research, Bristol, United Kingdom to 60 percent by 2030 and to 66 percent for nature-based solutions to address of Great Britain and Northern Ireland. by 2050 (when the total population is urban water insecurity is increasingly apparent, here and worldwide © PREM NAGABHATLA

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Recreational fishing in Windsor, Ontario, Canada. Fishing is a common urban activity requiring unpolluted water and healthy ecosystems

development, for ensuring protection against water-borne pollution and water- related disasters, and for preserving ecosystems in a climate of peace and political stability” (UN-Water, 2013). Economic water scarcity, the deterioration and destruction of water infrastructure, unsustainable development and ecological degradation are putting pressure on water- supply systems. High population densities and large industries mean that addressing urban water security is a key priority. Water security in both urban and rural landscapes is affected by hydro-climate dynamics (and climate change), migration flows, demography and supply-based water management practices. Water is at the core of urban planning and is crucial for socio-economic development and healthy ecosystems; its links to the health, welfare and productivity of populations are made clear in many recent research and development reports, including the UN-Water (2013) synthesis report. Scientists sug- 3

gest that only about 200 000 km of the NAGABHATLA © NIDHI water supply – less than 1 percent of the total available fresh water – is allocated for ecosystems in supply-oriented water management planning (Boberg, 2005). On the other hand, water demand for human consumption has almost doubled in the last century, and the world is projected to face human well-being and biodiversity bene- nature-based solutions approaches to a 40 percent global water deficit under a fits” (Cohen-Shacham et al., 2016). The protect, sustainably manage and restore business-as-usual scenario (WWAP, 2015). nature-based solutions approach is founded natural and managed systems and address Ensuring a sustainable water supply is on the concept that ecosystems innately societal challenges, human well-being and crucial for the survival and sustainable have various mechanisms that produce ecosystem services in an efficient and development of urban areas, and it looms services, which, in turn, provide social adaptable manner (MacKinnon, Sobrevila as a major global challenge in coming and ecological co-benefits for communi- and Hickey, 2008). Nature-based solutions years. ties. For example, forests and trees provide involve the use of green and blue infra- ecosystem services such as erosion control structure in its original form or designed Nature-based solutions and water regulation that help protect water according to ecological principles to sup- Nature-based solutions are “actions to resources, manage stormwater, ensure ply ecological services. protect, sustainably manage and restore domestic water supplies, build resil- This article addresses the roles of urban natural or modified ecosystems that ience to climate change and reduce the and peri-urban forests – including forested address societal challenges effectively risk of disasters. Development agencies, watersheds in the hinterlands of cities – as and adaptively, simultaneously providing including the World Bank, are promoting nature-based solutions for increasing water

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security. Because the focus of this article is are prioritizing the water-security agenda result of urbanization, aging infrastructure on forested landscapes, the terms “nature- and recognizing the need for innovative, and hydro-climatic variability. In October based solutions” and “green infrastructure” cross-cutting approaches that integrate 2017, the World Water Council, with the are used synonymously. grey and green infrastructure; there is an support of the Government of Morocco and urgent need to create “water-smart” and the United Nations Framework Convention CITIES NEED TO BE WATER-SMART “climate-resilient” cities (Nagabhatla and on Climate Change (UNFCCC), convened The need for nature-based solutions to Metcalfe, 2017). an international meeting aimed at main- address water insecurity is increasingly Global demand for water is projected to taining water as an important element of apparent. Traditionally, urban managers exceed supply in coming decades, but many climate talks and to focus on water for have focused on increasing water supply cities are already facing water crises as a food and urban resilience. It has been rather than managing demand. This has led to a heavy reliance on large-scale grey- infrastructure schemes such as large dams “The capacity of a population to safeguard sustainable access to adequate What is quantities of acceptable quality water for sustaining livelihoods, human and massive embankments along rivers and well-being, and socio-economic development, for ensuring protection against water-borne pollution and water-related disasters, and for preserving coastal zones, which have proven expen- Water Security? ecosystems in a climate of peace and political stability.” sive – with high environmental, social and Working definition, UN-Water, 2013 political costs – but have failed to address TRANSBOUNDARY excessive water use. The outcome of this GOOD COOPERATION myopic approach has been the further Sovereign states discuss and GOVERNANCE coordinate their actions to meet deepening of water demands and the Adequate legal regimes, the varied and sometimes institutions, competing interests exacerbation of water crises in urban and infrastructure for mutual benefit. and capacity peri-urban areas. are in place. Water management in towns, cities DRINKING WATER AND and municipalities needs to evolve from HUMAN WELL-BEING Populations have access to safe, conventional approaches towards innova- sufficient and affordable water to meet basic needs for drinking, sanitation tive management strategies that combine ECONOMIC and hygiene, to safeguard health and well-being, natural (or “green”) and grey infrastructure ACTIVITIES AND and to fulfill basic human rights. and include other multifaceted dimensions, DEVELOPMENT Adequate water supplies are available such as good governance, microfinancing for food and energy production, for community-scale interventions, water- industry, transport and tourism. ECOSYSTEMS Ecosystems are preserved and can related conflict management, pricing deliver their services, on which both nature and people rely, policies, and strategies for disaster risk including the provision of freshwater. reduction and community resilience. Box 1 (see page 46) provides examples of recent moves in this direction. The UN Water for Life Decade (2005– WATER-RELATED 2015) brought together development actors, HAZARDS AND PEACE CLIMATE CHANGE agents and institutions to address water Populations are resilient to water-related hazards AND including floods, droughts security. Among other things, it gave rise to POLITICAL and pollution. the conceptual framework for water secu- FINANCING STABILITY Innovative sources of financing rity shown in Figure 1, which is designed to The negative effects of conflicts are complement funding by the public avoided, including reduced water quality sector, including investments from and/or quantity, compromised water infrastructure, the private sector and guide efforts to address the cross-cutting, human resources, related governance, and social or political systems. micro-financing schemes. multidimensional aspects of water-related Water is central to achieving a larger sense of security, sustainability, development and human well-being. decision making (Mehta and Nagabhatla, UN-Water supports the inclusion of water security in the post-2015 development agenda as part of the 2017), including urban water manage- Sustainable Development Goals. ment. Increasingly, the global academic Achieving water security requires collaboration across sectors, communities, community and development agencies disciplines and political borders, to reduce the risk of potential conflicts over water resources, between sectors and between water users or states.

www.un.org/waterforlifedecade/water_cooperation www.unwater.org 1 The water-security Source: UN-Water (2013). version October 2013 conceptual framework

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estimated that protecting water sources, Box 1 including forests and trees on agricultural Nature-based solutions, urban development and land, could improve water quality for community resilience more than 1.7 billion people living in cities globally – over half the world’s urban Recent examples of nature-based solutions to water insecurity in an urban development population (Abell et al., 2017). context include the following: • The European Union’s Connecting Nature project is being implemented in 11 European FORESTS AND WATER cities, one of seven European projects seeking nature-based solutions for smart cities and It has been estimated that forested water- climate change. The total investment of the suite of projects is EUR 150 million; the aim sheds supply approximately 75 percent of is to help the transition to more sustainable and resilient cities (Thompson, 2017). the world’s accessible freshwater resources • China is investing heavily in innovative green infrastructure such as green roofs on build- (Millennium Ecosystem Assessment, ings and urban wetlands, with the central goals of flood control, water conservation and 2005). Forests increase soil infiltration, increasing the resilience of city inhabitants (Zweynert, 2017). Shenzhen, an emerging soil water-holding capacity and ground- smart city in Guangdong Province, is becoming an icon of international environmental water recharge; regulate flows; reduce leadership by adoption a “green city” agenda. It is incorporating the concepts of green soil erosion and sedimentation; and energy, resilient communities and intelligent city infrastructure in its planning as part of contribute to cloud cover and precipita- a nature-based solutions approach (Kam Ng, 2017). tion through evapotranspiration (Ellison • Architects and urban planners in the Syrian Arab Republic are considering “people-centred” et al., 2017). Some forest ecosystems, housing strategies using local resources and approaches to infrastructure development in particularly tropical montane cloud forests an effort to create resilient cities (Zekavat, 2017). and dryland forests, increase net water • Taking note of intense weather, devastating hurricanes and frequent flooding episodes in flow by condensing water from moist air urban spaces, architects in the United States of America are proposing green solutions on their leaves, which then drips to the that will embed and deploy ecological services and the benefits of forested and aquatic ground. Forests also help reduce flooding landscapes in the management of urban development (Lee, 2017). and the associated risks to property and human safety.

The maintenance of coastal vegetation and forest fringes NAGABHATLA © NIDHI in Shenzhen, China, is a nature-based solution to urban problems and part of creating a smart, green city

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Healthy natural forests generally provide higher-quality, purer water than most Box 2 other land uses. An estimated 1.4 billion Addressing water security through greening infrastructure people benefit from forests due to reduc- in Lima tions in sediments and nutrients in water supplies (Abell et al., 2017). According Lima, Peru, is the second-largest desert city in the world after Cairo, Egypt, and its 10 million to Dudley and Stolton (2003), one-third inhabitants put immense pressure on the surrounding environment and its natural resources, of the world’s 105 largest cities (selected including water and forests. Lima is in the Pacific Coast Basin, which has lost approximately by geographical area) receive a significant 75 percent of its historical tree cover (Qin et al., 2016), and this vegetation loss has been proportion of their drinking water from associated with changes in the region’s natural dry and wet seasons and an increased incidence forested protected areas such as national of droughts, floods and landslides (Barrett, 2017). The Pacific Coast Basin now supplies only parks and wilderness areas. Investing in about 2 percent of the city’s water.* the protection and sustainable management The balance between water supply and demand is strained, with a high risk of water scarcity; of forested water catchments can reduce for example, water demand exceeded the renewable water supply in the dry season in 2015. costs associated with water treatment With Lima projected to grow by 1.4 percent per year, the scenario of demand exceeding sup- (Ernst, 2004; WWAP, 2015). Maintaining ply is likely to become more frequent. Foreseeing this situation, the Peruvian Government high water quality by investing in green adopted the Law on the Mechanism for Ecosystem Service Compensation (2015) to guide infrastructure may reduce the capital costs and oversee the process of introducing green infrastructure nationally. The law was based of conventional treatments such as coagu- on research by Gammie and de Bievre (2015), which showed that integrating existing grey lation, flocculation and sedimentation and infrastructure with green infrastructure in the watersheds supplying Lima’s water could more advanced treatment processes like reduce the dry-season deficit by 90 percent, and this would be achieved at a lower cost than membrane filtration and activated carbon. by adding grey infrastructure alone. The new law is an opportunity for the water sector to It is estimated that the protection of forests harmonize nature-based solutions with ongoing grey infrastructure projects. as green infrastructure for water can cost Nature-based solutions such as reforestation, pastoral reforms and wetland restoration, as less than USD 2 per person per year, which well as other low-impact approaches such as the rehabilitation of amunas,# have been planned would be fully offset by savings from and are being implemented. Funding for the work will be provided by Lima’s water utility reduced water treatment (World Bank, authority, Servicio de Agua Potable y Alcantarillado de Lima (SEDAPAL), which has agreed 2012; Abell et al., 2017). to earmark almost 5 percent of its water tariff (estimated at USD 110 million between 2015 and FAO (2015) reported that approximately 2020) to address water management; 3.8 percent of the tariff will be invested in climate-change 25 percent of forests globally are managed adaptation and disaster risk reduction, and 1 percent will be spent on green infrastructure for soil and water protection, a proportion projects to close the gap between Lima’s water demand and supply. SEDAPAL is develop- that rose steadily from 1990 to 2015. ing a novel green infrastructure master plan to enhance and complement grey infrastructure Although the global forest average has (SEDAPAL, 2016). Lima, therefore, is pioneering a new generation of integrated water and increased, however, the area of tropical landscape management, providing an example for other municipalities and countries to follow. and subtropical forests managed for soil and water protection has declined, due mainly to * Most of the city’s water supply comes from the Rímac, Chillón and Lurín watersheds in the Andes deforestation and conversion to other land and the Alto Mantaro watershed on the Amazonian side of the Andes. uses in Africa and Latin America. Tropical # Amunas are stone canals built in the Andes by the Wari culture between 600 and 1000 CE, before and subtropical forests may be dispropor- the rise of the Incas. Before modern times, amunas captured water from rivers in the mountains during the rainy season and took it to places where it could infiltrate rocks that fed year-round tionately important for water availability springs further down the mountains, so maintaining river flow during the dry season (Pearce, 2015). because of their contributions to regional precipitation through high rates of evapotranspiration and water recycling; mass Nature-based solutions in cities through a fee paid by downstream water deforestation and conversion, on the other The notion of conserving and managing for- companies and other users benefiting hand, has been associated with reduced pre- ests for water supply is not new, and many from the improved management. In Quito, cipitation downwind (Ellison et al., 2017). nature-based solutions to water supply are Ecuador, and Costa Rica, for example, PES For example, recent droughts and water working effectively worldwide today. Some schemes are in place to maintain green scarcity affecting São Paulo, Brazil, and its are using payment schemes for ecosystem infrastructure for the vital water-related eco- 21.3 million inhabitants have been linked services (“PES schemes”), whereby indi- system services it provides; similar schemes to deforestation in the Amazon (Fearnside, viduals or communities are incentivized are being implemented in other parts of 2005; Nobre, 2014; Watts, 2017). to protect and sustainably manage forests Latin America, such as Lima, Peru (Box 2).

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Lake Ontario and forest near the A comparable PES scheme is working sites for gathering data on water.2 Other industrialized “steel” city of Hamilton, Ontario, Canada. The city is encouraging successfully in Viet Nam, bringing money countries are in the process of develop- nature-based solutions to help achieve and other incentives to forest conservation ing information bases. Some countries environmental sustainability and providing local communities with are using innovative economic and finan- powerful stakes in success. Cities in China cial instruments to tackle urban water are using forest restoration to help manage management, such as pollution taxes for of the forest that has supplied clean water flooding, and local forest restoration has managing costs related to decontamination to Istanbul, Turkey, for thousands of years also reduced flooding in Malaga, Spain.1 and for generating operational revenues remains uncertain because it has no formal Discussions on “smart” and “climate- (OECD, 2012). protection (Aydin et al., 2013). resilient” cities are underway in some In other places, however, conditions Some tropical cities, especially coastal countries, such as Australia, the United appear to have moved backwards. Jakarta, cities with mangrove ecosystems, are Kingdom of Great Britain and Northern Indonesia, receives a large fraction of its making conscious efforts to review their Ireland, and the United States of America, water from two national parks, both of urban and peri-urban forest management where national agencies provide spatially which face serious problems of illegal strategies using a disaster risk reduction distributed, easily accessible and often- deforestation. In Africa, the rapidly grow- “lens”. Mangrove ecosystems act as pro- free data and information. The United ing port of Mombasa, Kenya, receives clear tective shields against the effects of wind States Geological Survey, for example, and plentiful water from the Chillu Hills, and wave erosion, storm surges and other has a network of 1.5 million hydrometric a protected area, but the forests there are coastal hazards that affect people and being illegally cut and degraded. The fate infrastructure (FAO, 2007). In addition, 1 Large, frequent or exceptional precipitation coastal vegetation, especially mangrove 2 events can overwhelm both natural and engi- In contrast, Water Survey Canada’s Hydro- forests, can treat wastewater and remove neered defences – but forests can mitigate a metric Program operates just a few thousand significant proportion of minor to moderate such sites, which are particularly sparse in the chemical contaminants (mainly total flooding events. north (Bakker, 2009). suspended solids and heavy metals such

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as phosphorous, zinc, cadmium, lead and The cross-cutting nature of the SDGs, example, includes only swamp forests, nickel) (Tam and Wong, 1997; Boonsong, and the high level of commitment among mangroves, and forests temporarily or per- Piyatiratitivorakul and Patanaponpaiboon, countries to implement them, gives impe- manently inundated by water (UN-Water, 2003), thereby mitigating coastal pollution tus to the recognition of the links between 2017). These forests undoubtedly have a (Spalding et al., 2014). Other studies have forests and urban water security, including role in disaster risk reduction, but other shown that mangrove forests can improve in the monitoring and reporting of pro- forests with potentially significant value water quality, especially in areas with gress towards a more sustainable world. for water-related ecosystem services are intensive aquaculture (Peng et al., 2009). Especially relevant SDGs are SDG 6 (clean unrecognized, such as forests managed Urbanization is leading to the rapid water and sanitation), SDG 11 (sustain- for water supply and other forest types proliferation of medium-sized cities able cities and communities), SDG 13 known to have strong roles in hydrologi- (1 million inhabitants or more) in devel- (climate action), and SDG 15 (life on land). cal cycles (e.g. riparian and cloud forests). oping countries, where water supply is The links between forests and water are Indicator 15.1.2 focuses only on protection often poorly or optimistically planned explicitly mentioned in SDG targets 6.6 for biodiversity and not other functions, and where there is a low level of under- and 15.1 and implied in SDG target 11.a, such as water-related ecosystem services. standing about the benefits of maintaining which calls for the support of “positive None of the SDG targets considers the tree cover in catchments. It is projected economic, social and environmental links spatial distribution or health of forests. that, by 2025, 800 million people will be between urban, peri-urban and rural areas Thus, although the SDGs provide impor- living in countries or regions with abso- by strengthening national and regional tant backing for nature-based solutions lute water scarcity, and two-thirds of the development planning”. as means for ensuring water security, world’s people could be under water-stress Although the links between forests and they could be greatly strengthened by the conditions (UNESCO, 2006). Decisions water are recognized, however, they are not inclusion of a wider set of goals relating to address water security have generally adequately accounted for in the indicators to forests and water supply. For example, already been made in the world’s major used for monitoring. Indicator 6.6.1, for it would be useful to have an indicator for cities, but there are opportunities to adopt nature-based solutions in rapidly emerging cities in Africa and Asia. Nature-based solutions Protect, sustainably manage and restore natural ecosystems in WATER SECURITY AND urban areas SUSTAINABLE DEVELOPMENT Address societal and climate challenges in designing Water security is attracting increasing interventions to ensure human policy attention. International deliberations well-being and biodiversity benefits from the 1970s onwards (e.g. Habitat I in 1976, Habitat II in 1996 and Habitat III Sustainable Development New Urban Agenda in 2016), the Earth Summit, Rio+20, Goals (to 2030) (to 2025) climate-change discussions at the SDG 6: Clean water and Outlines the pathway towards sanitation sustainable cities and human UNFCCC, the Millennium Development SDG 11: Sustainable cities Urban settlements Goals (2000–2010) and, most recently, the and communities water Resilient cities – urban Sustainable Development Goals (SDGs), as SDG 13: Climate action security governance and planning set out in the 2030 Agenda for Sustainable SDG 15: Life on land Urban water management Development (United Nations, 2015), along Other targets that directly or indirectly link to urban and with global agreements such as the New forested landscapes Urban Agenda and the Sendai Framework (Figure 2), have all taken note of urban Sendai Framework issues, sometimes explicitly and at other (2015–2030) times as embedded objectives, goals Urban infrastructure and urban and targets. planning is designed to reduce the impact of natural disasters Developing strategies that reduce loss to economic, physical and 2 environmental assets of a country Global agreements with and communities goals or targets related to urban water security

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SDG 6.5 (on integrated water resource a priority. In both cases, it is clear that Urban communities are just as vulnerable management) addressing the health of for- smart, strategic approaches are required to as rural communities to natural hazards. ested watersheds that are sources of urban manage water demand, including nature- It is important, therefore, that they build water. Existing data, such as FAO’s global based solutions. their capacity, evaluate their vulnerability, forest resources assessments (e.g. FAO, and participate in designing and imple- 2015) and the World Resources Institute’s CONCLUSION menting resiliency approaches, including Global Forest Watch–Aqueduct Tool, could Water is a multisectoral issue. Ensuring nature-based solutions, in the face of the be incorporated in the measurement of water security in urban, peri-urban and risks posed by environmental and climate existing indicators to recognize the inter- rural contexts, therefore, requires a com- variability. Designing and planning for connection of forests and water, improve mon framework and understanding and water security requires collaboration the analysis of progress towards the SDGs, a coherent policy approach among the among stakeholders at the local to global and better inform management decisions water, forest, land, urban, climate-change, scales. Increasing green cover is also part at the national and local levels. energy and other sectors. The acknowledg- of the equation: smart, sustainable, forest The goals and targets of the 2030 Agenda ment of urbanization as an issue in global landscape protection strategies and invest- for Sustainable Development, along with sustainable development frameworks is ment plans will emphasize the security other global agreements, require countries encouraging for the future of urban and protection of urban and peri-urban to look for innovative, smart, collaborative centres and their associated landscapes. forests as green infrastructure for water. and sustainable solutions to urban issues. The recognition of integrated grey–green In many cases, such strategies and plans For example, the recently convened Water approaches for addressing water security will require a better understanding of the Desalination Symposium Africa 2017 fea- and the conceptual framework proposed by interconnections between urban ecosystem tured discussions between government, UN-Water (Figure 1) should be of interest, services and sustainable urban develop- industry, academics and traders on ways of therefore, to many stakeholders – such ment planning and interventions. tackling the water shortage in Cape Town, as urban and regional planners, water Future innovations to improve urban South Africa, using a multistakeholder managers and policymakers, international water security will likely involve the inte- approach. Similarly, a recent water crisis companies and organizations with large grated design of urban spaces to include, in Bangalore, India, raised the alarm on water “footprints”, not-for-profit institu- for example, constructed wetlands, green the need to make urban water security tions steering change, and communities. roofs and retention ponds. Overall, the

The forested landscape NAGABHATLA © PREM surrounding densely urban Hong Kong, China, is a source of water and other ecological benefits for city dwellers

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increasing acknowledgment, in global BP. 2017. BP Statistical Review of World Energy adaptation: nature-based solutions from sustainable development frameworks, June 2017. London (also available at www. the World Bank portfolio. Washington, DC, of the importance of urbanization is an bp.com/content/dam/bp/en/corporate/pdf/ World Bank. opportunity to address water security energy-economics/statistical-review-2017/ Mehta, P. & Nagabhatla, N. 2017. Without in cities through innovative, long-term bp-statistical-review-of-world-energy- water, nothing is secure. UNU-INWEH nature-based solutions. u 2017-full-report.pdf). Policy Brief Issue 3. Hamilton, Canada, Cohen-Shacham, E., Walters, G., Janzen, C. United Nations University (UNU) Institute & Maginnis, S. eds. 2016. Nature-based for Water Environment and Health solutions to address global societal chal- (INWEH). lenges. Gland, Switzerland, International Millennium Ecosystem Assessment. Union for Conservation of Nature. 2005. 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Unasylva 250, Vol. 69, 2018/1 53 © DAVID PEARLMUTTER© DAVID The role of urban and peri-urban forests in reducing risks and managing disasters

P. Cariñanos, P. Calaza, J. Hiemstra, D. Pearlmutter and U. Vilhar

There is a pressing need to take he unplanned urbanization process There is a need, therefore, for policies forests fully into account in that many cities have undergone in and measures that reduce or eliminate city risk reduction and disaster recent decades to accommodate long-term risks to people and property management plans. Tpopulation growth has contributed to the due to hazards and which strengthen the daily exposure of urban communities to resilience of cities and their structural ele- environmental risks that threaten their ments in the face of increasingly extreme health and well-being. In addition to the stressors. The creation of UN-Habitat poor living conditions in many cities, in 2002 led to the development of strat- residents face the risks posed by extreme egies for achieving and increasing urban Paloma Cariñanos is Professor of Botany at the natural hazards such as storms, floods, resilience to natural or human crises. The University of Granada, Spain, and a member of the Silva Mediterranea Working Group on Urban and fire and drought, which climate change is United Nations Plan of Action on Disaster Peri-urban Forestry (FAO WG7). exacerbating. Most regions of the world Risk Reduction for Resilience, developed Pedro Calaza is Professor of Landscape are exposed to natural hazards that cause in 2013, identifies measures to strengthen Architecture at Escuela Gallega del Paisaje, Spain, Dean of Colegió Oficial de Ingenieros significant economic damage and the loss support for countries and communities Agronomos, Spain, and a member of FAO WG7. of human lives. The risks posed by natural in managing disaster risk, including the Jelle Hiemstra is Senior Scientific Researcher, hazards may be amplified in urban areas by Trees and Urban Green, at Wageningen University and Research, the Netherlands. human interventions, potentially leading to Above: Urban trees can dramatically David Pearlmutter is Professor of Architecture at situations of accumulated risk and perma- reduce the radiant surface temperature Ben-Gurion University, the Negev, Israel. nent vulnerability (Figure 1). All sectors of paved areas and moderate the thermal Urša Vilhar is Research Fellow at the Department stress experienced by pedestrians of Forest Ecology, Slovenian Forestry Institute, of urban populations are exposed to these (note that blue and purple in the thermal and a member of FAO WG7. risks, but the poor are especially vulnerable. image indicate relatively cool areas)

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1 Disaster risk as the product Natural causes Human causes of hazard and vulnerability

implementation of the Sendai Framework for Disaster Risk Reduction 2015–2030. Natural hazards Technological hazards Among the priority lines of action in the × × Sendai Framework are enhancing disaster preparedness for effective responses Vulnerability and “building back better” in recovery, (physical, economic, social and environmental factors) rehabilitation and reconstruction. This means not only promoting resilience in = new and existing infrastructure but also identifying areas that are safe for human Disaster risk for … settlements and preserving ecosystem functions (UNISDR, 2009). Fauna Soil Cultural One of the key measures for increasing Humans Flora Water goods Climate resilience in urban settings is the rein- forcement of urban ecosystems to ensure they have the capacity to reduce risks and manage disasters. Urban green infrastruc- Feedback ture, of which urban and peri-urban forests are the backbone, can boost resilience to Source: International Federation of Surveyors (2006). disasters and help minimize the intensity of associated impacts. The establishment of urban green infrastructure adheres to TABLE 1. Urban hazards and the role of urban and peri-urban forests in the basic principles of proactive resilience risk reduction – efficiency, diversity, interdependence, Hazard Role of urban and peri-urban forests strength, flexibility, autonomy, planning Natural and adaptability (Table 1) (Bell, 2002). This article presents examples of the role Strong winds (e.g. Act as barriers; reduce wind speed; work as protection screens cyclones, hurricanes) of urban and peri-urban forests in reducing the impact of hazards, both natural and those Flooding and drought Reduce stormwater volumes and flood risk; increase precipitation interception; increase water infiltration and groundwater recharge caused by human interventions. It also looks at how hazards presented by urban and Landslides Increase stability of steep slopes by reducing surface run-off and erosion peri-urban forests can be managed, thereby increasing urban resilience in light of the Soil loss Prevent soil erosion; reduce impact of raindrops on soil surfaces; improve soil-water retention challenges to be faced in coming decades. Extreme heat and Cool by shading, evapotranspiration, etc.; protect from hot and cold cold events, urban winds URBAN HAZARDS ASSOCIATED “heat island” effect WITH CLIMATE CHANGE Wildfires Reduce fire intensity, flammability and spread when properly Climate change is often considered synony- designed and managed mous with global warming, but we are Biodiversity loss Conserve species and habitats; limit spread of invasive species living in an era of climatic uncertainty – Pests and diseases Limit spread and impacts with localized events that have usually been considered extreme becoming increasingly Anthropogenic frequent (Meir and Pearlmutter, 2010). Air pollution Sequester carbon; reduce ozone formation; capture particulate and Communities around the world are experi- gaseous pollutants; reduce emission of allergens encing upsurges in catastrophic storms, Pests and diseases Provide buffer against invasive species flooding, heatwaves and droughts, and Reduced physical Provide pleasant spaces that increase well-being, social cohesion these disruptive events will likely become and mental health and interaction, and leisure activities, etc. more pronounced in the future.

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Urban heat island effect are transpiring freely (Shashua-Bar and and financial concerns globally. Increased The urban “heat island” effect is a com- Hoffman, 2004); a lack of water in urban urbanization alters the hydrology of an monly observed example of local climate areas is often a constraint, however. area, reducing the infiltration capacity of change, which is intensified by a city’s In the United Kingdom of Great Britain soils and increasing both surface-water size, density and material composition. and Northern Ireland, London is likely to run-off and peak discharges (Vilhar, 2017). One of the main catalysts of urban heat face increasingly frequent heat events in The increased incidence of flooding in islands is the replacement of vegetated ter- coming years, with potentially significant cities demonstrates that the existing grey rain with “dry” urban landscapes, thereby effects on public health and the associated infrastructure for conveying stormwater reducing the cooling achieved through risk of hundreds of deaths in heatwaves. to wastewater treatment facilities or into evapotranspiration (Pearlmutter, Krüger The city established a climate-change surface waters was not designed for cur- and Berliner, 2009) and – most importantly adaptation strategy in 2010 that identifies rent rainfall intensities. In most urbanized for human thermal stress – by the shading the risks to public health posed by climate watersheds, too, the area of impervious of pedestrians. Heat stress is intensified by change and sets out the actions needed to surfaces is increasing. Urban and peri- unshaded urban surfaces, which absorb manage them. An action now underway urban forests have great potential to reduce solar energy and re-radiate heat and reflect is to leverage the benefits of urban forests stormwater run-off by increasing evapo- solar energy directly onto the bodies of by increasing the number of green roofs transpiration and water infiltration into pedestrians. and street trees and the quantity and the soil (Gregory et al., 2006) and by the The most effective general strategy for quality of green spaces. The objective is interception of precipitation by tree crowns mitigating the urban heat island effect to increase tree cover in Greater London (Kermavnar and Vilhar, 2017). Tree roots is the cultivation of trees in and around by 10 percent and achieve a total green and leaf litter stabilize soil and reduce cities. The magnitude of the “park cool cover of 50 percent by 2050 (Mayor of erosion (Seitz and Escobedo, 2008). island” effect – that is, the reduction of air London, 2017). Floods are the most frequent disasters temperature in urban green spaces relative in many areas of Asia and the Pacific. to their built-up surroundings – is typically Floods and storms Ten of the countries most exposed to in the range of 3–5 °C but can reach nearly Overwhelming stormwater volumes and flood risks in the region (Afghanistan, 10 °C (Hiemstra et al., 2017). Tree canopies flooding in urbanizing cities associated are especially beneficial for shading when with deteriorating drinking-water quality Flooding after heavy rain in they are broad and dense and their leaves have become major health, environmental Ljubljana, Slovenia. Tree roots are helping protect the soil from erosion © IZTOK SINJUR

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Bangladesh, Cambodia, China, India, reduce earthquake impacts and provide example, and more than 100 fatalities. Indonesia, Myanmar, Pakistan, Thailand community gathering points and tempo- Since 2005, the country has been imple- and Viet Nam) are riparian, and trans- rary shelter (Saxena, 2016). menting the Portuguese National Plan for boundary floods occur frequently, causing Prevention and Protection Against Fires large-scale impacts (Luo et al., 2015). In Forest fires in the Mediterranean (Oliveira, 2005), which is intended as the Bangladesh, practices under implemen- Forest fires, especially at the wildland– main approach for addressing one of the tation to reduce the impacts of flooding urban interface, pose an increasing threat country’s chief threats. Among the meas- include the development of advanced to cities in the face of climate change. ures indicated in the plan is the progressive simulated weather forecasting to enable People cause more than 90 percent of forest replacement of eucalypt forests: the the evacuation of large numbers of people fires in the Mediterranean region, where, country has more than 900 000 hectares several days in advance of flooding events, on average, more than 800 000 hectares of plantations of these trees, the leaves and the planting of flood-resistant trees, and burn each year. Droughts have lengthened bark of which are highly flammable. The stronger regional cooperation to coordi- in recent decades, leading to an increase abandonment of agricultural lands and the nate response measures (Basak, Basak in the number, extent and recurrence of expansion of urban centres have brought and Rahman, 2015). fires and the scale of human and economic eucalypt forests closer to the peri-urban losses (Gonçalves and Sousa, 2017). fringe, increasing the risk of fire at the Hurricanes and windstorms Martínez, Vega-García and Chuvieco urban–rural interface. Hurricanes and other windstorms are pre- (2009) found that the main factors asso- dicted to occur at an increased frequency ciated with high forest fire risk in Spain Threats to biodiversity and severity due to global warming (e.g. were landscape fragmentation, agricultural Tree pests and diseases have spread in the Atlantic: Bender et al., 2010). Like abandonment and development processes. globally and are causing considerable other kinds of infrastructure, trees can On the other hand, policies to encourage damage. For example, Dutch elm disease be damaged by high winds and storms, the afforestation of abandoned agricultural (Ophiostoma ulmi and O. novo-ulmi) was but they can also contribute to hurricane- land had little effect on fire occurrence. transported from Asia to the Americas resistant landscapes. Duryea, Kampf and Portugal has experienced high recent Littell (2007) studied ten recent hurricanes losses due to fire: there were more than Urban trees can pose hazards: this tree and their impacts on more than 150 urban 500 fires in the summer of 2017, for has fallen on a children’s playground, although fortunately no one was hurt tree species to assess the factors that make trees wind-resistant. Trees best able to survive storms are compact and have a major taproot and well-developed secondary roots, a well-tapered trunk, a low centre of gravity, and open, flexible and short branches. Trees in groups of five or more are also more likely than individual trees to survive high winds. Only 3 percent of more than 14 000 historic trees in New Orleans, United States of America, were lost during Hurricane Katrina in 2005; most of the survivors were oaks, with many of the characteristics listed above. The lessons learned from the study by Duryea, Kampf and Littell (2007) and others are being put to use in areas devastated by the successive hurricanes that hit the Caribbean and the Gulf of Mexico in 2017. Risk mitigation and disaster management © PEDRO CALAZA © PEDRO plans developed by the local government of Kathmandu, Nepal, after the earthquake in 2015 include the development of urban forests and open spaces as measures to

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and Europe during the twentieth century Risks CONCLUSION by means of infected logs, resulting in a Vegetal substances can be toxic to humans, In an era in which extreme natural events pandemic in the Northern Hemisphere. and trees and other plants can emit vola- are becoming more frequent, there is a In the United Kingdom of Great Britain tile organic compounds and particulate pressing need to develop and implement and Northern Ireland alone, Dutch elm material that can adversely affect human risk reduction and disaster management disease caused the deaths of about 28 mil- health (Cariñanos et al., 2017). Some of the plans in cities to reduce vulnerability and lion mature elms in 1970–1990, many of most frequently used species in urban and exposure to risks and improve adaptive them in urban and peri-urban areas, and peri-urban forests worldwide have been capacity. Urban and peri-urban forests the subsequent death of about 20 million identified as the main causative agents of are key components of such plans, both to young elms (Brasier, 2008). human pollen allergies (Cariñanos and minimize the impacts of disasters and the Many cities are adopting policies to Casares-Porcel, 2011). damage they cause and to restore, rebuild ensure sufficient tree species diversity People are also at risk of being hurt and rehabilitate urban ecosystems in the in cities to reduce the impacts of pests, or killed by falling trees. For example, aftermath. The multifunctionality of urban diseases and other factors that might other- a 200-year-old oak fell on a crowd of and peri-urban forests, their effectiveness wise cause the decimation of urban trees. In people on the island of Madeira, Portugal, in mitigating flooding, extreme heat events Canada, one of the objectives of the City of in August 2017, killing 13 and injuring and strong winds, and the hazards they Kelowna Sustainable Urban Forest Strategy nearly 50 (Minder and Stevens, 2017). themselves pose, make it imperative that is to increase species diversity across the The risks posed by urban and peri-urban they are taken into consideration in action city to avoid the catastrophic loss of trees forests can be managed by implement- plans for disaster risk reduction. through pests, diseases and climate change. ing an urban tree hazards plan (Calaza The increasing risk to human health and The strategy calls for the diversification of Martínez and Iglesias Díaz, 2016). For welfare posed by human activities such the species used as street trees so that ten or example, the Master Plan for the Trees of as air, water and soil pollution also indi- more species are represented at 10 percent the Jardines del Buen Retiro in Madrid, cates the need to install and manage urban or less of the total street-tree population. Spain, includes a tree risk management green infrastructure, especially urban and Ornamental species compatible with the plan that, among other things, establishes peri-urban forests, as a measure to protect city’s climatic conditions are being intro- a risk management protocol for the park. people, built infrastructure and habitats. duced (Blackwell and Associates, 2011). Finally, given the transnational charac- Urban areas can contain relatively high Benefits ter of some of the impacts of disasters, levels of biodiversity (Alvey, 2006). Cities Numerous studies have highlighted the transboundary and regional cooperation are adopting management practices to con- role of green infrastructure in general, is crucial for developing policies and serve and promote such diversity, including and urban and peri-urban forests in par- strategies for risk preparedness and disas a means to increase resilience in the ticular, in promoting human health. Many aster impact mitigation and coordinating face of environmental change. initiatives have been launched – some response measures. u supported by national health services and  HUMAN HEALTH RISKS the World Health Organization – aimed AND BENEFITS at encouraging the use of urban and Modern urban living can have negative peri-urban forests for physical activities impacts on public health and the qual- and other forms of outdoor recreation to ity of life of citizens. According to the improve human health (World Health World Health Organization, an estimated Organization, 2010). 12.6 million deaths each year are attrib- Green spaces, including urban and utable to unhealthy urban environments peri-urban forests, can provide a form of (Prüss-Ustün et al., 2016), with air, water natural therapy that helps people recover References and soil pollution, chemical exposure from traumatic events, such as disasters. and climate change linked to more than Activities with potentially therapeutic Alvey, A. 2006. Promoting and preserving bio- 100 types of ailment; cardiovascular and benefits include planting gardens for peace diversity in the urban forest. Urban Forestry respiratory diseases are among the top and reconciliation and caring for surviv- and Urban Greening, 5: 195–201. ten causes of environment-related deaths. ing trees or planting new trees in areas Basak, S.R., Basak, A.C. & Rahman, M.A. Urban and peri-urban forests pose risks affected by war, terrorist attacks or natural 2015. Impacts of floods on forest trees to human health but can also have a wide disasters (Tidball et al., 2010). and their coping strategies in Bangladesh. range of health benefits. Weather and Climate Extremes, 7: 43–48.

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Bell, M. 2002. The five principles of organiza- thermal comfort and the role of urban green- Against Fires: the first step. International tional resilience. Gartner Newsletter, February. ing. In: D. Pearlmutter, C. Calfapietra, Forest Fire News, 33: 30–34. Bender, M.A., Knutson, T.R., Tuleya, R.E., R. Samson, L. O’Brien, S. Krajter Ostoić, Pearlmutter, D., Krüger, E.L. & Berliner, P. Sirutis, J.J., Vecchi, G.A., Garnes, S.T. & G. Sanesi & R. del Amo, eds. The urban 2009. The role of evaporation in the energy Held, I.M. 2010. Modeled impact of anthro- forest: cultivating green infrastructure balance of an open-air scaled urban surface. pogenic warming on the frequency of intense for people and the environment, pp. 7–20. International Journal of Climatology, 29: Atlantic hurricanes. Science, 327: 454–458. Future City 7. Cham, Switzerland, Springer 911–920. DOI 10.1002/joc.1752 Blackwell and Associates. 2011. City of International Publishing AG. 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“Edible” urban forests as part of inclusive, sustainable cities

J. Castro, S. Krajter Ostoić, P. Cariñanos, A. Fini and T. Sitzia © PALOMA CARIÑANOS

Urban and peri-urban forests eeding an increasingly urban popu- of urban food forests and trees (referred can produce a range of foods to lation and ensuring the economic to here generally as urban food forests supplement local diets and provide and social well-being of urban and also sometimes as tree-based edible a focus for community activity. Fdwellers will be the primary challenge for landscaping), can help address a range of cities in coming decades. The impacts of problems caused by rapid and unplanned José Castro is Professor of Landscape climate change are expected to slow down urbanization, such as food scarcity, pov- Ecology at the Polytechnic of Bragança, Portugal, and a member of the Silva urban economic growth, exacerbate envi- erty, the deterioration of human health and Mediterranea Working Group on Urban and ronmental degradation, increase poverty well-being, air pollution, and biodiversity Peri-urban Forestry (FAO WG7). and erode urban food security. Many cities loss (FAO, 2016). Silvija Krajter Ostoić is Research Associate and Head of Department at the Croatian Forest are on a quest for more sustainable urbani- The use of edible plants in urban and Research Institute, and a member of FAO WG7. zation pathways that will enable effective peri-urban forestry varies among cities Paloma Cariñanos is Professor of Botany at the responses to the increasing socio-economic and is influenced by historical, cultural University of Granada, Spain, and a member of FAO WG7. and environmental challenges they face. and socio-economic factors. Overall, it has Alessio Fini is Associate Professor of In the search to “make cities and human tended to be neglected in modern cities. Arboriculture and Urban Forestry at the settlements inclusive, safe, resilient and Department of Agricultural and Environmental Sciences – Production, Landscape and sustainable” (Sustainable Development Above: The pomegranate (Punica Agroenergy, University of Milan, Italy, and a Goal 11 in the United Nations Sustainable granatum) – “granada” in Spanish – member of FAO WG7. Development Agenda 2030), interest is is the heraldic symbol of the city of Tommaso Sitzia is Assistant Professor at the Granada, Spain, where it appears University of Padova, Italy, and a member of increasing in growing local food. Edible on streets throughout the town. It FAO WG7. green infrastructure, mainly in the form produces a highly nutritious fruit

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This article explores the potential of urban herbs that were sold locally to raise funds urban food forest (McLain et al., 2012) is and peri-urban forests as sources of food for maintenance. probably the best-studied. Seattle Public and the role that urban food forests can In the Industrial Revolution in the nine- Utilities owns the Beacon Food Forest, play in fostering sustainable cities. teenth century, however, the edible elements but the forest’s fruit trees were planted of urban landscapes tended to be replaced by community volunteers, many of whom WHAT ARE URBAN FOOD FORESTS? by ornamental vegetation. Today, most continue to work in the forest and maintain Clark and Nicholas (2013) defined urban cityscapes are largely devoid of edible com- the orchards. Ongoing participation gives food forests and trees as “the intentional ponents and instead feature traditional shade community members a sense of steward- and strategic use of woody perennial trees, lawns and other soil-cover plantings. ship and pride in the space. food-producing species in edible urban Urban food forest typologies are influ- Lemon Grove – a municipality of landscapes to improve the sustainability enced by city histories. In Central America, 26 000 inhabitants in California – is and resilience of urban communities”. As for example, native gardens of multistrata preparing to grow public orchards in city an “edible landscaping” practice, urban agroforestry systems coexist with colonial parks as part of efforts to preserve the city’s food forestry involves a combination of cityscapes featuring large trees and exotic history and small-town charm. Issues to be agriculture, forestry and agroforestry in plants (González-García and Gómez-Sal, addressed in selecting sites for fruit trees urban areas to supply cities with food. It 2008). Socio-economic circumstances may include proximity to roadways and side- may involve various species of fruit and also play a role: in Berlin, Germany, the esti- walks; accessibility for mobility-impaired nut trees, berry bushes, vegetables, herbs, mated fruit-tree density is still significantly individuals; access for maintenance; and edible flowers and other ornamental plants. higher in the eastern part of the city than in input from community members and The integration of urban food forests the west (8.6 trees/ha versus 1.6 trees/ha) garden experts (Federman, 2017). into the infrastructure of a city can pro- (Larondelle and Strohbach, 2016). The San Francisco Urban Orchard vide urban dwellers with many benefits. Project provides ongoing resources for There is evidence that urban food forests EFFORTS TO APPLY URBAN FOOD the planting and maintenance of publicly can motivate stewardship practices and FORESTRY WORLDWIDE accessible fruit trees. The programme part- give inhabitants opportunities to interact The applicability of urban food forestry ners with local not-for-profit organizations with nature and each other (McLain et al., and its efficacy in addressing social and to plant fruit- and nut-tree orchards and to 2012); enable the development of more environmental challenges depend on a assist community-based groups in their resilient food systems and promote social range of social, environmental and other roles as local stewards of green spaces and environmental sustainability (Yates, local factors. Only a few examples exist (SF Environment, undated). 2014); improve social cohesion and well- of modern efforts to encourage urban food Barnum is one of eight city parks in being and strengthen local communities forestry, and these are mostly limited to Denver, Colorado, with urban orchards. (Lwasa et al., 2015); enhance biodiversity relatively small urban settings. It is in what used to be one of the city’s (Dennis and James, 2016); and provide In Todmorden, West Yorkshire, in the least desirable neighbourhoods, but things economic benefits for both municipalities United Kingdom of Great Britain and took a turn for the better when Denver and citizens (Lafontaine-Messier, Gélinas Northern Ireland, volunteers grow fruit, Urban Gardens – a not-for-profit organi- and Olivier, 2016). herbs and vegetables for everyone to share; zation that supports community gardens Tree-based edible landscaping in urban they do so without paid staff, buildings in the city – purchased a vacant lot. This areas has been practised since ancient or funding from statutory organizations. is now a community orchard that grows times. Ancient Egyptian and Persian gar- The volunteers also run events to help red currants, raspberries, grapes and dens combined fruit trees with flowers, strengthen the local community; income winter squash among fruit trees (Extreme ponds, pot plants, vine-clad pergolas and is generated through donations and fees Community Makeover, 2016). places to sit in winter sun or summer shade. for talks and tours (Incredible Edible Classical ornamental gardens had water Todmorden, undated). In Copenhagen, Developing countries channels, pools, fountains and cascades Denmark, in contrast, citizens do not Rapid urbanization in many developing cooling the air, flowers producing scents, collect fruit from urban forests because it countries is leading to increased urban and fruit trees providing food and shade. is widely perceived that doing so would poverty and pressure on green spaces. Medieval monastic gardens produced fresh break social norms (Yates, 2014). Edible landscaping is often in the form fruit and vegetables, as well as flowers of small-scale subsistence agriculture, and and medicinal herbs. Renaissance estates United States of America such gardens represent significant propor- had plots and terracotta pots for growing Among examples of urban food forestry tions of urban green infrastructure. Even flowers and producing fruit, vegetables and in the United States of America, Seattle’s in inner-city areas, residents cultivate

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roadsides and riverbanks, along railroads, Disputes arise about who can plant, har- crops but do not care for “doubt tenure” on vacant private lands and in parks, based vest or otherwise use urban forests when trees. In South Africa, homestead fruit and on minimal user rights such as informal laws or ordinances do not specify rights nut trees are important sources of food, rents, leases and inheritances. In Taipei, for the use of common areas (Rana, 2008). especially in informal settlements, where Taiwan Province of China, however, the Fear of eviction is a strong disincentive for the poorest people live. Residents of new law forbids the planting of fruit trees and people to introduce food trees and shrubs. low-cost housing make especially exten- vegetables in parks and public spaces In illegal settlements in Kathmandu and sive use of urban tree products harvested (Chang et al., 2016). Lalitpur, Nepal, people grow seasonal food in public urban spaces because they have fewer homestead trees than residents in informal areas and townships (Kaoma and Shackleton, 2014). Urban food forestry is not widely implemented in Asia and the Pacific, but innovative urban forestry practices are evolving in the region (Kuchelmeister, 1998). In China, residents can harvest fruit in many parks; in Queensland, Australia, residents and schools maintain edible public parks, producing fruit, herbs, flowers and vegetables (Kuchelmeister, 1998).

Africa Agroforestry gardens are probably the most significant type of urban green space in West African countries (Fuwape and Onyekwelu, 2011). In arid and semiarid areas, it is common practice to establish windbreaks to protect urban areas and enhance soil productivity (Kuchelmeister, 1998). Urban forest practices that contribute to food security include collecting wild edible plants, planting fruit-bearing street trees, and establishing medicinal public parks. Fruit trees are planted in many residential compounds, especially those on urban fringes and in new urban settlements. Despite the marked differences in the sociospatial and environmental settings of Botswana, Cameroon, Côte d’Ivoire, South Africa and the United Republic of Tanzania, wild food trees are integral to most urban and peri-urban households in small and mid-sized cities in those countries. This applies not only to poor families lacking access to productive soils

An educational initiative in Chinandega, Nicaragua, is designed to help protect urban fruit trees, such as this large mango tree (Mangifera indica). Fruit trees are common in indigenous

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In public areas of impoverished districts in Cabo Verde, people plant, care for and protect fruit trees in preference to ornamental trees © JOSÉ CASTRO

but also to those with a higher standard of local food production from urban food Russo et al. (2017) analysed more than of living (Schlesinger, Drescher and forests, and there have been few attempts 80 peer-reviewed publications focusing on Shackleton, 2015). A study in Senegal to explore the adaptation and application urban ecosystem services and disservices. nearly three decades ago (Brun, Reynaud of local practices in other contexts or to They identified eight typologies of edible and Chevassus-Agnes, 1989) found that scale them up. The lack of research prob- green infrastructure, including edible urban food forests did not make a signifi- ably reflects the general bias of studies forest gardens and edible urban forests, cant contribution to food consumption and on urban ecosystem services in western which were addressed in 38 percent of the nutrition but were instrumental in improv- Europe and North America, where cities publications. Some publications showed ing the income and social status of women today depend mostly on outside sources urban food forestry to be a multifunctional and increasing their awareness of evolving of food (Larondelle and Strohbach, 2016). urban landscape practice combining an food habits in urban areas. Although edible urban landscapes were extended range of ecosystem services In Cabo Verde, the extent of urban food widely used for centuries in the European efficiently in cities and integrating the forestry varies according to the actors Mediterranean, the contributions of such provision of food with environmental, involved. Trees planted and managed by landscapes to the livelihoods of modern sanitary, social, cultural and economic municipalities are mostly ornamental, while urban communities are far from fully co-benefits. Evidence of the trade-offs those planted and cared for by residents explored. Of existing experiments, none has between the supporting, provisioning, are usually fruit trees (e.g. Carica papaya, explicitly addressed the food-provisioning regulating and cultural services of urban Mangifera indica and Terminalia catappa). aspects of urban trees (Valette, Perrin food forests is lacking, however. and Soulard, 2012). A recent review of Also lacking is a conceptual framework ISSUES FACING URBAN FOOD urban food forestry collected information that would enable the synthesis and analy- FORESTS AND TREES on 37 initiatives worldwide (Clark and sis of existing knowledge on urban food Research and literature on urban food Nicholas, 2013): it evaluated 30 urban forest forestry. Such a framework is needed to forestry are scarce, despite the long history master plans in various cities and found integrate the relevant aspects of urban of growing forest foods in urban areas. that human food security was a primary food forestry into urban planning, such Most existing studies report specific cases objective in only four of them. as the area required, species, knowledge,

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management, governance, and financial they are used for urban food forestry to forestry may be due to soil characteristics and human resources. As to the area avoid health risks posed by the uptake by and the plant species used. needed, Richardson and Moskal (2016) plants of pollutants such as heavy metals. Another health risk that can occur from calculated that a 58-km buffer around Species selection and cultural techniques the consumption of raw fruit produced in Seattle would be required to meet 100 per- can also help prevent the accumulation of urban food forests is an allergic reaction cent of the city’s food needs. pollutants in the edible parts of plants: known as oral allergy syndrome. This In most countries, the actual and poten- the translocation of pollutants absorbed can occur in sensitized individuals due to tial contribution of urban food forestry by roots to edible parts, as well as the cross-reactions between aeroallergens and to sustainable and resilient urban devel- amount of airborne pollutants penetrat- food allergens – such as between pollen opment models is unknown. Although ing the fruit epicarp, has been shown to produced by species in the Cupressaceae research into, and the practice of, urban differ widely by species (von Hoffen and family and the fruit of Prunus persica, agriculture is growing, urban food forestry Säumel, 2014). giving rise to “cypress–peach syndrome” has been implemented systematically in Vegetables from urban and peri-urban (Popescu, 2015). only a few countries, and its practices are farming may contain unacceptable quanti- Unharvested fruit can be hazardous and little explored. ties of trace elements (Nabulo et al., 2012; unsightly when they drop from trees, and Samsøe-Petersen et al., 2002; Säumel et al., they can also attract vermin and pests. Risks of urban food forestry 2012); on the other hand, some studies Highly perishable crops require quick Certain risks are associated with the have found it possible to produce healthy processing, such as canning, freezing or implementation of urban food forestry. food from fruit trees grown along streets drying, or sufficient people to quickly Poe et al. (2013), for example, pointed in large cities (von Hoffen and Säumel, consume surplus supplies (Brown, 2016). out that the toxicological profiles of 2014). The apparent discrepancy between Most widely used fruit tree species urban soils should be investigated before studies on the health risks of urban food belong to only a few families or genera

Orange trees planted as part of a new urban development in Porto, Portugal. Urban food forestry involves a combination of urban agriculture, forestry and agroforestry techniques and

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(e.g. Rosaceae in temperate environments). can provide a pathway towards sustainable But the use of a small number of species urban development. Developed countries may challenge the 30–20–10 biodiversity have started to rediscover urban tree-based rule proposed by Santamour (1990) to edible landscaping but, in most cases, food maximize protection against pest out- production is still not the primary objec- References breaks.1 Many commonly grown fruit tive of urban and peri-urban forestry. In trees are indeed very sensitive to pests developing countries, knowledge gaps need Brown, S.P. 2016. Edible landscaping. and pathogens, but this can be managed to be identified to stimulate research on ENH971. Gainesville, USA, Environmental through wise, inventory-based species strategies to consolidate traditional models Horticulture Department, Florida selection. New releases and the restora- of tree-based edible landscaping and to Cooperative Extension Service, Institute of tion of ancient resistant cultivars of widely foster new approaches. Food and Agricultural Sciences, University used species, as well as the use of minor, The potential of urban food forests is of Florida. neglected species with edible uses, might still far from adequately exploited, and Brun, T., Reynaud, J. & Chevassus-Agnes, S. help improve the tolerance of urban food there is a need to develop modelling tools, 1989. Food and nutritional impact of one forests to pests and diseases. advanced design principles, and efficient home garden project in Senegal. Ecology of management and governance strategies. Food and Nutrition, 23(2): 91–108. Urban food forestry strategies Initiatives are needed to gather knowl- Chang, S.E., Yang, Z.J., Duo, M.Y. & The development of an urban food forestry edge on existing efforts and to fully assess Hsiao, T.H. 2016. Participatory agri- strategy requires a broad range of exper- issues associated with food safety, such cultural humanities for the new ruralism tise to ensure a comprehensive approach. as the risks posed by soil, water and air tea-community revitalization in Taiwan. It involves the integration of knowledge pollution. Environment–Behaviour Proceedings from social and environmental sciences Further research is needed to identify Journal, 1(3): 251–256. and disciplines such as urban forestry and the species, compositions and configura- Clark, K.H. & Nicholas, K.A. 2013. arboriculture, urban agriculture, urban tions that will maximize the benefits of Introducing urban food forestry: a multi- ecology, landscape and urban architec- urban food forests for local communities functional approach to increase food security ture, economics, policy and governance. and minimize the risks to human health. and provide ecosystem services. Landscape Effective, efficient collaboration among Cultivars and genotypes are needed that Ecology, 28(9): 1649–1669. experts, policymakers, local governments, are adapted to harsh urban environments, Dennis, M. & James, P. 2016. User participa- the private sector and citizens is essential especially in the context of climate change. tion in urban green commons: exploring to ensure effective urban food forestry. Collaboration – subnationally, nationally the links between access, voluntarism, bio- and internationally – among scientists, diversity and wellbeing. Urban Forestry and CONCLUSION citizens, policymakers and city managers Urban Greening, 15: 22–31. The examples in this article show that is crucial for establishing a robust con- Extreme Community Makeover. 2016. Park urban food forestry can be applied in ceptual framework for urban food forests. it at Barnum [online]. Extreme Community diverse contexts and to meet various It is also desirable to compile traditional Makeover. [Cited 2 October 2017]. www. objectives. Urban food forests and trees tree-based edible landscaping practices to extremecommunitymakeover.org/lifestyle/ are located mostly on formal and informal guide the design of projects in which food park-it-at-barnum public land, and implementing an urban production is the central objective. Urban FAO. 2016. Guidelines on urban and peri- food forest approach depends on owner- food forests are potentially a valuable urban forestry, by F. Salbitano, S. Borelli, ship, local rules, norms, policies, and an multifunctional component of the broader M. Conigliaro & Y. Chen. FAO Forestry effective governance model. Comparative green infrastructure of the cities of the Paper No. 178. Rome. studies and lessons learned are needed to future and can help achieve the Sustainable Federman, K. 2017. Urban edible landscapes understand the most effective approaches Development Goals. u in Lemon Grove: city park orchards, com- in different contexts. munity gardens, and school gardens. USA, The consideration of urban food for- San Diego State University. ests and trees and their integration into Fuwape, J.A. & Onyekwelu, J.C. 2011. Urban regional, national and local urban policies forest development in West Africa: benefits and challenges. Journal of Biodiversity and 1 Under this rule, no more than 30 percent of trees Ecological Sciences, 1: 77–94. in the same family, 20 percent of trees in the same genus, and 10 percent of the same species González-García, A. & Gómez-Sal, A. 2008. should be planted. See also the article on page 11. Private urban greenspaces or “patios” as a

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Protecting heritage trees in urban and peri-urban environments

Some individual trees perform eople have held trees in high esteem systems. Many mythologies, legends and especially important cultural and awe since antiquity. Primitive folklores are associated with beloved or functions, and strong community peoples recognized that trees were feared trees, indicating a continued and involvement is crucial for their Pnotably bigger, stronger, more majestic widespread human deference to them. conservation and management and longer-lived than most other organ- Many indigenous cultures have bestowed in urban settings. isms. Intimate interactions with nature a sacred standing on individual trees and have increased human awareness of trees groves, seeing them as deities or the abodes progressively; over time, particular trees of certain spirits. have instilled in people a sense of frater- The pragmatic contributions of trees to nity, fear, generosity, providence, ubiquity, farming communities in soil and water immortality, eternity and divinity. conservation and microclimatic ameliora- As benevolent providers and protectors tion are well recognized. In East Asia, of humans, certain trees have acquired such contributions have been practised special status. Beginning with admiration systematically as feng shui or geomancy and respect, attitudes evolved to adora- (Han, 2001; Coggins et al., 2012). Such tion and reverence and then to veneration and worship (Taylor, 1979; Dafni, 2006). Above: Traditional villages in southern Traversing geographical, temporal and China are protected by upslope feng C.Y. Jim is Chair Professor, Department of shui (geomancy) groves. This photo Geography, University of Hong Kong, Hong cultural divides, tree worship is com- shows the well-preserved tradition in Kong, China. mon in many ancient polytheistic belief the village of Lai Chi Wo, Hong Kong

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indigenous knowledge reflects the TABLE 1. Designation criteria for the evaluation of heritage trees traditional wisdom of learning from and Criterion Rating score mimicking nature to create a harmoni- 1 2 3 ous and healthy milieu for humans and 1 Tree height (m) < 15 15–30 > 30 to tackle the capriciousness and harshness of nature. Translated into adaptive prac- 2 Crown spread (m) < 15 15–30 > 30 tices, feng shui has provided a collective 3 Diameter at breast height (m) < 1 1–2 > 2 community-based and holistic resource- 4 Tree age (yrs) < 100 100–300 > 300 management system (Gadgil, Berkes and 5 Tree performance Low Medium High Folke, 1993) that has fostered the persis- 6 Ecological function Low Medium High tence of agrarian cultures for millennia. In modern societies, systematic forest 7 Scenic/landscape dominance Low Medium High management by governments or other 8 Personality/event association Low Medium High agents sometimes recognizes and protects 9 Natural/cultural bequest Low Medium High sacred trees. Associated with human settle- 10 Spiritual/mythical connotation Low Medium High ments, such trees may be subsumed in urban and peri-urban forestry, but local of soils, which could be inadvertent due notable management practices and certain customs may also continue to defend them to misconceptions (Jim, 2005). Original activities of citizens, and concludes with in unwritten codes. Superstitious trad- natural soils are commonly compacted, lessons learned. itions include taboos, the infringement of added to, removed or polluted, and the which could incur the wrath of deities and most valuable topsoil horizons – with DESIGNATION AND TYPOLOGY bring dire consequences (Laird, 2004). high organic matter content and nutri- Table 1 shows the ten physical and cultural For centuries, the fear of supernatural ent stock – are often degraded or lost. criteria adopted in various jurisdictions retribution has protected many precious Surface sealing and associated soil com- for the identification of heritage trees, trees. The attendant cultural internaliza- paction can harm and restrict root growth. with three levels of significance. The tion and social regulation, expressed as Iconic trees attract many visitors, who key physical tree dimensions are height, village sanctions, including punitive meas- may damage soil structure and cause the crown spread and diameter at breast ures, have strengthened local enforcement compaction or loss of topsoil; such trees height (American Forestry Association, (Berkes, Colding and Folke, 2000). sometimes have literally been loved to undated), which are measured in the In managing urban forests, outstanding decline and demise. In dense cities, the field using accurate instruments such as trees – whether or not associated with trad- routine response to heavy foot traffic is laser hypsometers. Trees that have crown itional sanctity – are often given special to install impermeable concrete, asphalt spreads wider than 30 m, are above 30 m care. Among dozens of epithets used in the or other paving materials, which causes in height, or have diameters greater than literature, such trees have been labelled as additional damage. Awareness needs to be 2 m at breast height are generally regarded champion, monumental and heritage trees raised that soil problems have contributed as landscape giants. There is a preference (Jim, 2017a). There are clear indications of significantly to poor tree health and long- for trees older than 100 years, and those the continued reverence attached to trees, term deterioration. exceeding 300 years are widely rated as but the dilution of traditional taboos in Urban forest managers, as the modern exceptional. cities calls for substitute protection based custodians of this natural-cum-cultural Other criteria recognize crucial attrib- on statutory and administrative measures. heritage, are charged with ensuring the utes such as tree performance,1 ecological long-term welfare of heritage trees in function and scenic or landscape domi- The impacts of urbanization urban and peri-urban environments. By nance. Some trees vividly demonstrate on heritage trees sharing research and practices, tailor- the outstanding traits of a species in form, Increasing urbanization by intensification made measures can be developed to structural integrity or vigour. Veteran trees and sprawl has the potential to threaten ensure the continued robustness and accommodate assorted microhabitats, urban forests (FAO, 2016) and to deci- survival of heritage trees. This article, offering complex micro-ecosystems mate the tiny but vital cohort of iconic which draws on literature and extensive inhabited by diverse flora and fauna (Read, heritage trees. For example, subterranean field studies, focuses on such trees in 2000). Cultural dimensions are expressed tree habitat is widely neglected. Heritage cities and their fringes with a view to trees in urban and peri-urban environ- improving their conservation worldwide. 1 “Tree performance” refers to general tree health ments often suffer from the ill treatment It evaluates designation yardsticks, surveys and structural integrity.

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1 Site typology for Site typology for heritage trees heritage trees in urban and peri-urban settings

ecologically and culturally significant Emulated Remnant Created 1 Site origin natural natural artificial (Jim, 2013). Heritage trees can be classified based on site and tree characteristics to facilitate understanding, management and conser- Low-density High-density vation. Figure 1 provides a typology of 2 Site environs Greenfield built-up built-up tree sites based on seven criteria, each with three states, that influence habitat quality and hence the past growth of a given heritage tree and its prognosis. Site 3 Belowground Moderately Seriously Spacious origin may be remnant natural, emulated space confined confined natural or created artificial, reflecting the degree of naturalness and habitat quality. Site environs are characterized by building Moderately Badly density, which may impose microclimatic 4 Soil quality High-grade degraded degraded stresses such as heat load and shading. Within a site, the size of the belowground space affects crown development. Soils may be high-quality or degraded due to Completely 5 Natural topsoil Partly lost Largely intact human disturbance. The extent to which lost the natural topsoil has been retained affects tree growth. The site surface may be open, or it may be sealed by imperme- Semi- able materials (e.g. concrete), affecting 6 Soil sealing Open soil Impermeable permeable root development. Grade change – either by burying existing soil with added soil or by removing the original soil – is injurious to roots (Jim, 2017b). 7 Soil grade Raised Original Lowered Figure 2 provides a typology of heritage trees based on seven key attributes (the photo on page 70 gives an indicative typology for a tree in the Meiji Shrine in Tokyo, Japan). Provenance is about whether in the criteria “personality/event asso- trees are intimately linked to landmark a tree is inherited from pre-urbanization ciations” tied to local history; “natural/ historical events or notable persons, vegetation or planted after urban develop- cultural bequest”; and “spiritual/mythical thereby bestowing social–cultural val- ment (or it could have been transplanted). connotation”. For example, trees associ- ues (Blicharska and Mikusinski, 2014). The decision to preserve a tree may have ated with personalities might be those Trees planted by dignitaries on important been made consciously, with an accom- planted on the occasion of the coronation dates have commemorative significance. panying protection and management plan, of a king. Trees associated with events Others may be actively worshipped, as or the tree may have survived by default. could be those planted or designated to evidenced by shrines, altars or associated The presence of companion trees could commemorate an important event, such paraphernalia. Some trees grow spontane- indicate better habitat conditions than as a battleground victory. Trees associated ously on artificial structures such as old those pertaining to solitary specimens. with local beliefs might be those consid- buildings and masonry retaining walls Determining the relative age of trees can ered the abodes of spirits or deities with and in archaeological ruins. Specimens help in identifying those veterans in need mystical or religious connections. Some of unusual size and form are likely to be of special care (Fay, 2002). The biomass

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2 Tree typology for Heritage tree typology heritage trees in urban and peri-urban settings

form, together with the selection criteria 1 Tree Inherited Cultivated provenance used. The information contained in such registers varies from the bare minimum (e.g. species and location) to detailed survey and assessment data, digital maps and 2 Transplant access guidelines (e.g. City of New York, In situ Transplanted history undated; Jim, 1994). In some jurisdictions, trees in private lands are excluded from the administrative ambit and therefore may not benefit from 3 Tree Conscious By default systematic assessment, care and protection. preservation In cities experiencing rapid expansion and redevelopment, such neglected trees are prone to damage or felling – and residents 4 Companion Cultivated Natural may not know what has been lost. Trees on Solitary trees neighbours neighbours the grounds of private institutions, especially religious establishments, usually receive a certain level of care, despite a lack of official input. For religious rea- 5 Relative Mature Veteran Semi-mature sons or because of taboos associated with tree age the harming of sacred trees, such trees are less likely to be damaged by owners, managers and visitors than trees on 6 Live crown Medium High Low other forms of non-public land. Because ratio (60–80%) (>80%) (<60%) religious grounds tend to persist in urban landscapes, they are often valuable sites for heritage trees. Their low-density, low-rise built form and freedom from construction Moderately Little Severely 7 Soil grade works are conducive to tree preservation. restricted restriction restricted In contrast, residential and commercial land uses are subject to urban renewal, in situ intensification and infilling, all of which can degrade site quality and cause structure can be evaluated as a function EXEMPLARY MANAGEMENT tree damage or removal. of the live crown ratio (that is, the ratio PRACTICES Some cities have established comprehen- of the height of the crown containing live People have been protecting and caring sive heritage-tree databases, tree laws and foliage to the height of the tree) and soil– for heritage trees since ancient times and management agents to improve manage- root integrity,2 indicating the net outcome continue to do so today, often with little ment and conservation; such databases, if of site history and contemporary factors. or no government input. In cities, however, continually updated, facilitate the timely The structural integrity of stems and roots heritage trees are usually managed by formulation of action plans. Some admin- may have been compromised by natural urban forest administrations. The manage- istrations assign sufficient resources and or human impacts. ment practices reviewed here are derived well-trained professional and technical staff from diverse sources (for the sake of to ensure appropriate tree care, and some brevity, they are mostly unreferenced). have active publicity and public-education 2 That is, field evidence showing that the soil in the area embodying the tree roots has not been Some cities have established official reg- programmes that present information disturbed or cut away. isters of heritage trees in printed or digital in accessible forms. Such programmes,

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including public lectures and guided field to arrest the decline of old or degraded Heritage trees require a high standard tours, disseminate relevant knowledge and heritage trees. These focus on relieving of arboricultural care, and inexperienced messages, raise awareness among citizens, problems of soil compaction and the deg- or ill-informed tree management can have and increase public support for heritage- radation of soil structure, composition and detrimental impacts. Common mistreat- tree maintenance and conservation. properties and on increasing the moisture- ments include excessive or frequent branch Succinct, attractive information plaques holding capacity of soils and nutrient pruning, improper branch tipping, the pref- are installed at tree sites to convey conser- supply. Soil treatments are restricted to erential removal of lower branches, and vation messages. In addition to providing only a portion of sites to avoid shocking aggressive crown reduction and thinning. basic information on the species, plaques the trees. Often, the site soil is loosened For veteran trees, an inadequate under- may include statements about the cultural- to a prescribed depth by various means, standing of the multiple microhabitats they historical background of a tree or site, its such as the use of air spades,3 drilling provide for a diverse assemblage of flora association with local events and per- inclined bore holes, and opening narrow and fauna has led to overzealous sanitiza- sonalities, and interesting ecological and radial trenches (Beijing District Standard, tion treatments (Woodland Trust, 2008). ethnobotanical functions. Information on 2009). The poor site soil is replaced with connections with traditions, deities and a soil mix enriched with mature compost. This old camphor tree (Cinnamomum other supernatural objects is sometimes Research is needed on soil improvement camphora) in the grounds of the Meiji included, together with problems affecting techniques to arrest tree decline and boost Shrine in Tokyo is venerated as a wishing tree. Note the open wooden tree health, arboricultural treatments, and growth (Layman et al., 2016). frames installed below the tree potential threats. In some jurisdictions, canopy for hanging wooden placards, 3 QR codes are provided to direct interested Air spades are field tools that use compressed on which wishes are written. The air to generate a supersonic air jet that can approximate typology of this tree, as per people to further web-based information. blow away soil particles while retaining most Figure 2, would be: 1) cultivated; 2) in situ; Some cities have developed techniques of the roots. 3) conscious; 4) cultivated neighbours; 5) mature; 6) high; 7) little restriction © C.Y. JIM

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The proper management of heritage trees the economic and social contributions of to increase community awareness of the requires knowledge of a wide range of trees are attracting research and com- diverse roles played by heritage trees and aspects – such as the tree’s ecology, growth munity attention (Becker and Freeman, interest in their protection. Strong public habits, microclimate, soil science, and cul- 2009). Recent studies have combined tree support for heritage trees will increase tural significance, and the threats posed by evaluation and economic valuation to link the willingness of policymakers to assign the urban environment – and specialized tree value more intimately with inherent adequate funding and staff. In this way, skills. To mitigate risks at sites with above- tree attributes (Jim, 2006). It is important iconic heritage trees can play crucial roles average pedestrian traffic, a compromise that the findings of such studies are made in rallying attention and support for urban needs to be found between ecology and publicly available in accessible language and peri-urban forestry. safety (English Nature, 2000). Outstanding trees affected by development can sometimes be retained, given sympathetic urban design. For example, building footprints and road alignments can be reconfigured or shifted to avoid impacts on protected trees. Construction activities near preserved trees can be adjusted to minimize impacts, and precau- tionary measures can be taken to protect roots and stems. Future site conditions should be designed to enable sustained tree health, with sufficient good-quality space to accommodate crown and root expansions. Roadside heritage trees can be protected from trenching damage by diverting excavation alignments or by adopting trenchless or no-dig techniques (Jim, 2003). Where circumstances do not allow in situ preservation, transplanting may be considered as a last resort. Transplanting a large tree demands multidisciplinary collaboration between tree experts and engineers (Jim, 1995). Phased root pruning is conducted well in advance. The root ball should be large enough to accommodate sufficient roots and strong and rigid enough to prevent deformation by the moving and lifting operations. The recipient site should be chosen or prepared to match as closely as possible the donor site in terms of aboveground and soil conditions. Advocates of trees in urban spaces have tended to emphasize the environmental and ecological benefits but, increasingly,

This old Japanese cedar (Cryptomeria japonica), situated next to a path leading to shrines © C.Y. JIM in the Takao Mountains in western Tokyo, is protected and worshipped as a sacred tree

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This century-old Chinese banyan (Ficus microcarpa) was originally designated as the sacred (“deity of the earth”) tree protecting its Hong Kong village from harm but was subsequently used as a wishing tree. The tree received thousands of paper offerings, which were tied to oranges and thrown by visitors to hang on the branches, causing considerable damage. This mass vandalism was stopped only after a large branch fell, injuring several people © C.Y. JIM © C.Y.

Citizen endeavours operations. Good examples of such groups fortune for themselves and their loved ones Many people living in urban environments include Big Trees in Bangkok, Thailand, in all sorts of personal and interpersonal have considerable respect for trees due and the Conservancy Association in domains, such as romantic love, family to both tradition and modern environ- Hong Kong, China, which alert citizens relationships, friendship, health, work mental education (Zhang et al., 2007), to threats to urban trees and help prevent and study. Votive or token offerings are and this can be harnessed to boost tree their damage or removal. Overall, with transmitted to wishing trees in various protection efforts. Self-initiated citizens’ well-organized involvement, participation, modes. Burning paper incense, candles and green groups have played pivotal roles in education and engagement, citizens can be joss sticks is a common ritual in East Asia. protecting heritage trees by engaging com- effective tree guardians and also partners Some cultures treat certain trees as living munities and raising public awareness and with governments in promoting green temples and like to pray, sing and meditate knowledge (FAO, 2016). In such groups, urban spaces and nature conservation. near them and to ambulate around them. In members are coached in tree assessment Japan and the Republic of Korea, a com- techniques to become “citizen tree war- THE PROS AND CONS OF mon passive and non-intrusive approach is dens” to participate in basic tree care. Most WISHING TREES to write wishes on small wooden placards importantly, they monitor site conditions In some places, there is a belief that that are hung on racks near heritage trees to prevent degradation and guard against the deities or spirits residing in certain (see photo page 70). The placards are usu- harm to heritage trees. Citizen tree war- heritage trees will respond benevolently to ally removed each day to provide space for dens and green groups play important roles people’s requests, and such trees have been new ones. At some sites, visitors pay to in many cities by alerting governments, designated as wishing trees. This prac- keep their placards in weatherproof glass non-governmental organizations and the tice is probably a residual expression of cabinets for longer periods. media to risks posed to heritage trees and ancient polytheistic beliefs and associated Sometimes, intrusive or even damag- have launched many concerted tree-saving paganism and idolatry. Wishers seek good ing actions are adopted to convey wishes

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from people to trees. In Western countries, also speaks volumes about the attitudes • The special skills of heritage-tree care, such actions include hammering nails, pins of the community to nature and about including pruning and the treatment or coins into tree trunks. Less injurious citizen welfare. From the above analysis, of veteran trees, must be mastered to methods are also used, such as tying cloth the following recommendations can be deliver high-calibre results. or ribbons to branches, and irrigating trees proposed to management authorities to • Practices and activities that are harmful with alcoholic libations. Some people hang mitigate existing problems and improve to heritage trees must be averted at the material offerings on trees, such as apples, professional practice: earliest possible stage, which requires meat, candy and cigars. These practices • Heritage trees are a crucial part of vigilance (for example through well- are seldom adopted in Asia. In East Asia, urban forests, and their in-depth informed citizens’ groups). and especially on mainland China, people assessment, regular monitoring, and • Ongoing, adequately funded research write their wishes on pieces of paper which high-order and specialized care is is needed to study locally specific are folded and tied onto small branches. warranted. issues affecting heritage trees and to A more aggressive method of conveying • Local capacity to manage heritage inform mechanisms for the effective wishes to trees was invented in the 1990s trees can be nurtured through the transfer of knowledge from research in a village in Hong Kong. Apparently education of high-level urban forest to practice. trying to boost sales, hawkers used string managers and arborists. • The economic valuation of heritage to tie wish papers to oranges, and these • A dedicated urban and peri-urban trees can help raise awareness of the projectiles were thrown at a century-old forestry unit could be established in benefits such trees generate for soci- Chinese banyan (Ficus microcarpa) tree government to ensure the implemen- ety and to muster support for urban in an attempt to lodge the “wishes” on it. tation of recommended actions in a forestry. In the early 2000s, the tree was assaulted timely and professional manner. • Green non-governmental organiza- daily with hundreds of oranges (with • Statutory measures are essential tions can develop partnerships and wishes attached), and the official tourism for supplementing administrative synergies with government and pri- organization promoted the practice to local approaches and ensuring sufficient vate bodies to further the cause of and overseas visitors. Many small branches safeguards against the destruction of heritage trees. u were broken. In removing the tokens so that heritage trees. the tree could receive a fresh barrage each • A well-maintained, detailed database day, the entwined strings were forcibly of heritage trees, and a regular and pulled away, causing extensive damage systematic monitoring programme, to foliage and branches and creating will enable the timely prognosis of numerous wounds open to pest and fungal threats posed to heritage trees and invasion. The daily cycles of attack and effective preventive care. dislodgement over several years seriously • It may be possible to save declining References enfeebled the tree. Eventually, in 2005, a heritage trees and prolong their safe large branch fell and hurt several throw- service life with dedicated rejuvena- American Forestry Association. Undated. ers, whereupon the authorities stopped the tion plans. The national register of big trees. practice (Leisure and Cultural Services • For long-term tree health, the qual- Washington, DC. Department, 2005). Unfortunately, the ity of aboveground and belowground Becker, N. & Freeman, S. 2009. The economic practice has been mimicked in other cities habitats must be assiduously ensured value of old growth trees in Israel. Forest and religious establishments on mainland and acute and chronic stresses abated. Policy and Economics, 11: 608–615. China, damaging many heritage trees • The neglect of tree risk assessment, Beijing District Standard. 2009. Technical (Huitu.com, 2017). Inexplicably, such which is particularly important for regulations for protection and rejuvenation collective vandalism is often endorsed or the management of veteran heritage of ancient & famous woody plants. Beijing. condoned by authorities. trees in compact urban areas, requires Berkes, F., Colding, J. & Folke, C. 2000. urgent attention. Rediscovery of traditional ecological LESSONS LEARNED • Heritage trees should be transplanted knowledge as adaptive management. If a city can take excellent care of the only as a last resort. It is technically Ecological Applications, 10(5): 1251–1262. cream of its tree stock, its heritage trees, feasible, however, to move large Blicharska, M. & Mikusinski, G. 2014. it can inspire confidence in its capacity to heritage trees without causing undue Incorporating social and cultural significance care for all its urban and peri-urban forests. harm or jeopardizing long-term of large old trees in conservation policy. The extent of care shown for heritage trees performance. Conservation Biology, 28: 1558–1567.

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City of New York. Undated. The great trees Jim, C.Y. 1994. Champion trees in urban Hong Laird, S.A. 2004. Trees, forests and sacred of New York City. New York, USA. Kong. Hong Kong Flora and Fauna Series. groves. In: C.R. Elevitch, ed. The overstory Coggins, C., Chevrier, J., Dwyer, M., Hong Kong, China, Urban Council. book: cultivating connections with trees, Longway, L., Xu, M. & Tso, P. 2012. Jim, C.Y. 1995. Transplanting two champion 2nd edition, pp. 30–34. Holualoa, USA, Village fengshui forests of southern China: specimens of mature Chinese banyans. Permanent Agriculture Resources. culture, history and conservation status. Journal of Arboriculture, 21: 289–295. Layman, R.M., Day, S.D., Mitchell, D.K., ASIA Network Exchange, 19(2): 52–67. Jim, C.Y. 2003. Protection of urban trees from Chen, Y., Harris, J.R. & Daniels, W.L. Dafni, A. 2006. On the typology and the wor- trenching damage in compact city environ- 2016. Below ground matters: urban soil ship status of sacred trees with a special ments. Cities, 20: 87–94. rehabilitation increases tree canopy and reference to the Middle East. Journal of Jim, C.Y. 2005. Monitoring the performance speeds establishment. Urban Forestry and Ethnobiology and Ethnomedicine, 2: 26. and decline of heritage trees in urban Urban Greening, 16: 25–35. English Nature. 2000. Veteran trees: a guide Hong Kong. Journal of Environmental Leisure and Cultural Services Department. to risk and responsibility. Peterborough, Management, 74: 161–172. 2005. Inspection report for the large wishing- UK, Veteran Trees Initiative. Jim, C.Y. 2006. Formulaic expert method to making tree at Fong Ma Po Village. Hong FAO. 2016. Guidelines on urban and peri- integrate evaluation and valuation of heri- Kong, China, Hong Kong Government. urban forestry, by F. Salbitano, S. Borelli, tage trees in compact city. Environmental Read, H. 2000. Veteran trees: a guide to good M. Conigliaro & Y. Chen. FAO Forestry Monitoring and Assessment, 116: 53–80. management. Peterborough, UK, English Paper No. 178. Rome. Jim, C.Y. 2013. Drivers for colonization Nature, Veteran Trees Initiative. Fay, N. 2002. Environmental arboriculture, and sustainable management of tree- Taylor, J.W. 1979. Tree worship. Mankind tree ecology and veteran tree management. dominated stonewall ecosystem. Ecological Quarterly, 20(1): 79–141. Arboricultural Journal, 26(3): 213–238. Engineering, 57: 324–335. Woodland Trust. 2008. What are ancient, Gadgil, M., Berkes, F. & Folke, C. 1993. Jim, C.Y. 2017a. Urban heritage trees: natural- veteran and other trees of special interest? Indigenous knowledge for biodiversity cultural significance informing management Ancient Tree Guide 4. Grantham, UK. conservation. Ambio 22(2–3): 151–156. and conservation. In: P.Y. Tan & C.Y. Jim, Zhang, Y., Hussain, A., Deng, J. & Han, K.T. 2001. Traditional Chinese site selec- eds. Greening cities: forms and functions, Letson, N. 2007. Public attitude toward tion – feng shui: an evolutionary/ecological pp. 279−305. Singapore, Springer Nature. urban trees and supporting urban tree pro- perspective. Journal of Cultural Geography, Jim, C.Y. 2017b. Constraints to urban trees and grams. Environment and Behavior, 39(6): 19(1): 75–96. their remedies in the built environment. In: 797–814. u Huitu.com. 2017. Wishing tree photographs F. Ferrini, C. Konijnendijk van den Bosch [online]. [Cited 12 October 2017]. http://soso. & A. Fini, eds. Routledge handbook of huitu.com/search?kw= %E8%AE%B8%E6 urban forestry, pp. 273−290. Abingdon, %84%BF%E6%A0%91&page=2 UK, Routledge.

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Cities worldwide are increasingly aware that trees and Greener, cooler, healthier cities forests make cities greener, cooler and healthier The need for greener and healthier cities was highlighted in two major regional meetings on urban forestry – Asia and the Pacific, and Latin America – in 2017. The two events explored the benefits of urban Its purpose was to discuss how best to make cities in the region trees and forests for the millions of people living in cities and megacities greener, healthier and more sustainable and resilient in the face of in the two regions and their role in mitigating climate change. climate change. More information: www.fao.org/peru/noticias/detail-events/es/c/ Asia-Pacific Urban Forestry Meeting 892705 The second Asia-Pacific Urban Forestry Meeting, co-organized by To complement these regional initiatives, FAO is organizing, with FAO, discussed and endorsed an action plan to help countries in partners, the World Forum on Urban Forests, to take place in Mantova, the region develop sound urban and peri-urban forest practices. Italy, on 28 November–1 December 2018 (see the article on page 3 The meeting, which was held in Seoul, the Republic of Korea, on and the announcement on the inside front cover). 13–15 September 2017, followed up on the first Asia-Pacific Urban Forestry Meeting, held in Zhuhai, China, in 2016. The first meeting Sustainable wood for a sustainable world culminated in the Zhuhai Declaration, a declaration of intent to Sustainable wood value chains that are environmentally friendly, increase trees and forests in cities and to make cities greener, cooler socially responsible and economically sound are an integral part and healthier. The regional plan of action launched at the second of sustainable landscapes and key to making progress towards the meeting builds on the Zhuhai Declaration. It includes a set of robust Sustainable Development Goals (SDGs), according to the experts who urban forestry actions to be implemented by countries to increase met at the Sustainable Wood for a Sustainable World global meeting the sustainability and resilience of urban development in the region. at FAO headquarters in Rome on 31 October–1 November 2017. More information: www.fao.org/asiapacific/news/detail-events/ The meeting, which was attended by more than 100 delegates from en/c/1036873 40 countries, was organized by FAO and its Advisory Committee on Sustainable Forest-based Industries in collaboration with the Latin American and Caribbean Forum on Urban Forestry Center for International Forestry Research, the Finance Alliance for The Latin American and Caribbean Forum on Urban Forestry, Sustainable Trade, the International Tropical Timber Organization, Silviculture and Landscape Restoration for Urban Forests and Green the World Bank and the World Wildlife Fund. Areas, organized by FAO in collaboration with the Latin American Sustainable wood value chains and products are especially relevant Development Bank, was held in Lima, Peru, on 7–9 June 2017. to SDG 8 (decent work and economic growth), SDG 12 (responsible

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consumption and production), SDG 13 (climate action) and SDG 15 regional forestry commissions function as important liaison institutions (life on land). Meeting participants agreed that, to enhance local between country-level and global issues. They also help identify livelihoods, there is a need to connect global, regional and local value regional trends, needs and specific areas of intervention that should chains and to diversify forest products beyond wood to make effective be considered in a well-designed global plan of action for forestry. use of “baskets of value chains”. Sustainable forest management The regional forestry commissions contribute to dialogues with was repeatedly cited as a significant component of sustainable other regional forestry institutions and organizations, and most have landscape management. technical working groups or subregional chapters, which, among The meeting emphasized the crucial role of sustainable wood other things, implement projects that benefit from collaboration value chains in mitigating climate change through carbon storage in among countries in the region. standing forests and harvested wood products and the substitution Of the most recent round of regional forestry commission meetings, of fossil-based raw materials and products. The contribution of five had taken place by February 2018 (with the sixth planned for wood to climate-change mitigation in the construction sector was March 2018). It has addressed the following items: also highlighted. • a study on sustainable forestry for food security and nutrition Increasing investments to promote sustainable wood value chains conducted by the Committee on World Food Security High-level requires the assessment of investment barriers and opportunities Panel of Experts; along value chains and the securitization and monetization of the • input for the upcoming Global Forest Resources Assessment full range of forest products and services. The creation of a virtual 2020 and streamlining forestry reporting; multistakeholder investment promotion facility would help tailor • outcomes of the 22nd Conference of the Parties (COP) to the finance to support sustainable wood value chains. United Nations Framework Convention on Climate Change, The global meeting constituted the start of an initiative by FAO and COP 13 of the Convention on Biological Diversity, the 12th meeting partners to strengthen the role of sustainable wood value chains in of the UNFF, and other institutional global fora; and sustainable development. • a new strategic document for FAO in forestry, as well as input to FAO governance. FAO’s regional forestry commissions Other important issues discussed at one or more commission meet- Established by the FAO Conference between 1947 and 1959, the six ings included gender; social protection; community-based forestry and regional forestry commissions represent FAO’s institutional presence farmer organizations; communication in forestry; urban forestry; forests in forestry at the macro-regional level worldwide. The commissions in landscape restoration; and initiatives to combat desertification. convene every two years to bring together heads of forestry and Regional inputs on these and other issues are essential for adapting experts in the six major regions worldwide to address policy and strategies, policies and projects to the characteristics and needs of technical issues in their respective areas of influence. each region. In reporting their inputs and recommendations to the FAO Committee The official reports of the regional forestry commission meetings of Forestry (COFO), which is the biennial global forum for all forestry will be presented at the 24th Session of COFO, scheduled to take issues, and to the United Nations Forum on Forests (UNFF), the place at FAO headquarters in Rome in July 2018.

An officer inspects rough-sawn boards at Dakar port, Senegal. Sustainable wood © FAO/MARCO LONGARI © FAO/MARCO value chains that are environmentally friendly, socially responsible and economically sound are crucial for making progress towards the Sustainable Development Goals

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WORLD OF FORESTRY

United Nations adopts Strategic Plan for Forests 3. Increase significantly the area of protected forests worldwide The first-ever United Nations (UN) Strategic Plan for Forests, and other areas of sustainably managed forests, as well as the adopted by the UN General Assembly on 27 April 2017, provides an proportion of forest products from sustainably managed forests. ambitious vision for global forests in 2030. The plan features a set 4. Mobilize significantly increased, new and additional financial of six Global Forest Goals and 26 associated voluntary, universal resources from all sources for the implementation of sustainable targets to be reached by 2030. It is designed to serve as a reference forest management and strengthen scientific and technical framework for the forest-related work of the UN system and to foster cooperation and partnerships. enhanced coherence, collaboration and synergies among UN bodies 5. Promote governance frameworks to implement sustainable and partners. The plan also serves as a framework to enhance forest management, including through the UN Forest Instrument, the coherence and guide and focus the work of the International and enhance the contribution of forests to the 2030 Agenda for Arrangement on Forests and its components. The six Global Forest Sustainable Development. Goals are: 6. Enhance cooperation, coordination, coherence and synergies on 1. Reverse the loss of forest cover worldwide through sustainable forest-related issues at all levels, including within the UN system forest management, including protection, restoration, and across member organizations of the Collaborative afforestation and reforestation, and increase efforts to prevent Partnership on Forests, as well as across sectors and relevant forest degradation and contribute to the global effort of stakeholders. addressing climate change. One of the targets in the plan is to increase forest area by 3 percent 2. Enhance forest-based economic, social and environmental worldwide by 2030, which would be an increase of 120 million benefits, including by improving the livelihoods of forest- hectares. The plan builds on the vision of the 2030 Agenda for dependent people. Sustainable Development and recognizes that real change requires decisive, collective action, within and beyond the UN system. PHOTO BY IISD/PETER WOOD (ENB.IISD.ORG/FORESTRY/UNFF/WGSS/20JAN.HTML)

Co-Chairs Mohammad Ali Zarie Zare, Iran (Islamic Republic of), and Hans Hoogeveen, the Netherlands, shake hands at the end of the UNFF Working Group and Special Session. The session was held on 16–20 January 2017 at UN headquarters in New York, USA, to, among other things, develop a proposal for a UN strategic plan on forests for 2017–2030

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Reducing Inequality in a Turbulent World: indigenous land rights is vital for mitigating and preventing these Scaling-up Strategies to Secure Indigenous, devastating conflicts, achieving the Sustainable Development Goals Community, and Women’s Land Rights and the commitments of the Paris Agreement, and ensuring peace More than 300 people from 58 countries gathered in Stockholm, and justice. Sweden, on 4–5 October 2017 to raise awareness of community Three strategy sessions at the conference (on rural and indigenous land rights as a prerequisite for decreasing inequality and delivering women’s rights and leadership in collective lands; strategies and on global goals; assess the status of promising instruments to mechanisms to scale up implementation from the local to the national secure community rights; and encourage greater action, support level; and connecting and leveraging international support structures and commitment from key stakeholders. Participants hailed from to advance indigenous and community land rights) developed action indigenous and community organizations, the private sector, civil plans to increase recognition of community land rights. All sessions society and governments. The conference was co-organized by the included speakers from the private sector, whose recommendations Rights and Resources Initiative, Sida, the Stockholm Environment were highlighted in a plenary session on the second day of the Institute, the Swedish International Agriculture Network Initiative, conference. and the International Foundation for Science. For the first time, the conference included an “innovation zone”, This conference was the third in a series, following similar meetings which highlighted the use of technology and other innovative in Interlaken and Bern, Switzerland, in 2013 and 2015. The series is strategies to secure rights. designed to take stock of the global state of indigenous, community There is growing recognition of the importance of community land and rural women’s land rights, raise awareness of the importance of rights, both as a matter of human rights and as a crucial solution to these rights, catalyse new partnerships, and develop a shared path global problems, including inequality and climate change. There is forward for scaling up the recognition of rights. also unprecedented momentum and growing commitment from all Research launched on the eve of the Stockholm conference found sectors to secure and respect these rights. Conference participants that 61 percent of land-based conflicts between companies and identified ways to connect and leverage global and grassroots efforts communities since 2001 are unresolved. Securing community and to drive change.

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BOOKS

Helping countries assess their standing forests Increasing food security with sustainable woodfuel

Voluntary guidelines on national forest monitoring. FAO. 2017. Rome. Sustainable woodfuel for food security. A smart choice: green, renewable and ISBN 978-92-5-109619-2. affordable. FAO. 2017. Rome. ISBN 978-92-5-109962-9. Establishing and running a national forest monitoring system (NFMS) Food insecurity and a high dependence on woodfuel as a primary is a complex scientific-technical process and an organizational and cooking fuel are characteristics common to vulnerable groups of institutional challenge. An NFMS exercise has a direct link to policy people in developing regions worldwide. With adequate policy because it informs management and decision makers about the and legal frameworks in place, however, woodfuel production and sustainable use of forest resources and the efficient protection and harvesting can be sustainable and a main source of green energy. conservation of forest ecosystems. Accordingly, an NFMS supports Moreover, the widespread availability of woodfuel, and the enormous governments in fulfilling their obligations to continually develop, market for it, presents opportunities for employment and sustainable monitor and report on forest resources, which may include trees value chains, providing additional reasons for promoting this energy outside forests as well as other land-cover classes. The aim of source. This paper explains how sustainable woodfuel is linked closely these voluntary guidelines is to assist in the creation and operation to food security and provides insights into how the linkages could be of NFMSs. They include good-practice principles, guidelines and a strengthened at all stages of woodfuel production, trade and use. general framework. The document also incorporates a set of decision- Available online: www.fao.org/3/a-i7917e.pdf support tools for planning and implementing a multipurpose NFMS grounded in nationally appropriate and scientifically sound practice, taking into consideration domestic information needs and reporting requirements. Available online: www.fao.org/3/a-i6767e.pdf Also available online in: Arabic – www.fao.org/3/a-i6767a.pdf Chinese – www.fao.org/3/a-i6767c.pdf French – www.fao.org/3/a-i6767f.pdf Russian – www.fao.org/3/a-i6767r.pdf Spanish – www.fao.org/3/a-i6767s.pdf

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Mainstreaming gender in forest policies in Kosovo What do zero-deforestation commitments mean

Gender, rural livelihoods and forestry: assessment of gender issues in Kosovo’s for forestry? forestry. FAO. 2017. Rome. ISBN 978-92-5-109797-7. Potential implications for the forest industry of corporate zero-deforestation The main purpose of the research reported in this publication is to commitments. Discussion paper prepared for the 58th Session of the FAO Advisory identify and analyse the role of women and men in the forest sector Committee on Sustainable Forest-based Industries. 2017. FAO. Rome. in Kosovo and their ownership and use of forests. The report also This paper analyses the implications for the forest industry of zero- analyses gender issues within the institutional, policy and legal deforestation commitments made by consumer-goods customers framework that governs forest management in Kosovo and makes and financiers and the benefits that could arise, and it makes recommendations on how to mainstream gender in forest policies. recommendations to enable the forest industry to take advantage The research is part of a project titled, “Support to implementation of the benefits and minimize the risks. The paper, which addresses of the forest policy and strategy in Kosovo” (GCP/KOS/005/FIN), recommendations made by the FAO Advisory Committee on funded by the Government of Finland, which aims to increase the Sustainable Forest-based Industries, provides background information forest sector’s contribution to the national economy through the on the zero-deforestation movement, building on earlier work by the sustainable use of forest resources, taking into account multipurpose Advisory Committee and FAO. forestry, the economic, social and environmental benefits of forests, Available online: www.fao.org/3/a-i8042e.pdf and the sector’s contributions to the mitigation of climate change. The study shows that women have limited access to decision making and information compared with men. Rural communities – especially women – identify high unemployment as the main obstacle they face. The report demonstrates the interests of rural women in improving their skills in the collection, processing and marketing of non-wood forest products. Consequently, the report shows the importance of improving women’s access to information, capacity development and decision making. It concludes by emphasizing that non-wood forest products have strong potential for reducing food insecurity and poverty in the study regions, particularly when both women and men are supported effectively. Available online: www.fao.org/3/a-i7421e.pdf Also available online in: Albanian – www.fao.org/3/i7421sq/I7421SQ.pdf Serbian – www.fao.org/3/i7421sr/I7421SR.pdf

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Improving energy access for displaced people The potential of agroforestry for landscape in Uganda restoration

Rapid woodfuel assessment: 2017 baseline for the Bidibidi settlement, Uganda. Agroforestry for landscape restoration: exploring the potential of agroforestry 2017. FAO & United Nations High Commissioner for Refugees (UNHCR). 2017. to enhance the sustainability and resilience of degraded landscapes. 2017. Rome and Geneva, Switzerland. ISBN 978-92-5-109947-6 (FAO). A. Hillbrand, S. Borelli, M. Conigliaro & A. Olivier. Rome, FAO. Uganda is host to more than 1 million refugees who have fled famine, Agroforestry has considerable potential for restoring degraded conflict and insecurity in the neighbouring countries of Burundi, the forests and agricultural lands and thereby contributing to landscape Democratic Republic of the Congo and South Sudan. The recent restoration, but constraints limit its adoption. This brief makes the influx of refugees from South Sudan prompted one of Uganda’s following key points: most severe humanitarian emergencies and led to the establishment • Agroforestry can provide many ecosystem services. It is a suitable of the Bidibidi settlement in Yumbe District in August 2016. The tool for landscape restoration because it can enhance physical, settlement is now the world’s largest refugee-hosting area, with chemical and biological soil characteristics, thereby increasing 272 206 refugees settled on a land area of approximately 250 km2 soil fertility, controlling erosion and improving water availability. in a total assigned area of 798 km2; the settlement constitutes • Agroforestry systems that provide permanent tree cover can be more than half the population of the host district. The settlement valuable forest and landscape restoration options, especially in has increased pressure on the environment due to tree felling for initiatives in which neither natural forest restoration nor full sun settlement establishment and to meet ongoing household demand crops are viable. for woodfuel for cooking and heating. • Agroforestry can enhance livelihoods in rural communities by FAO and UNHCR initiated a joint rapid woodfuel assessment providing a variety of food, fodder and tree products, which in March 2017 to determine woodfuel supply and demand in the increase food and nutrition security, generate income and area. The assessment had three components: 1) an assessment of alleviate poverty. woodfuel demand; 2) an assessment of woodfuel supply; and 3) the • The restoration of degraded landscapes using agroforestry can identification of interlinkages, gaps, opportunities and alternative increase the resilience of communities to shocks, including scenarios. Data and information were obtained through a desk review drought and food shortages, and help mitigate climate change. of existing documents, field surveys and remote-sensing analysis. • The widespread uptake of agroforestry requires an enabling Among other findings, the report estimates that 12–15 percent of the legal and policy environment that guarantees rights to – and total land area of the Bidibidi settlement would need to be planted ownership of – trees and land, provides farmers with incentives, with fast-growing species to provide a sustainable woodfuel supply. promotes investment, and facilitates the marketing of agroforestry Each household would need to dedicate a minimum woodlot area of products. 50 m × 50 m exclusively to growing wood for energy. Available online: www.fao.org/3/b-i7374e.pdf Available online: www.fao.org/3/a-i7849e.pdf Also available online in Spanish: www.fao.org/3/b-i7374s.pdf

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Protecting forest-dependent communities The role of smallholder forest organizations in

Social protection for forest-dependent communities. Policy brief. 2017. N. Tirivaye, climate-change mitigation and adaptation O. Rodriguez, T. Juvenal & Qiang Ma. Rome, FAO. Smallholder forest producer organizations in a changing climate. 2017. Forest and Forest-dependent communities are usually located in remote rural Farm Facility. Rome, FAO. areas characterized by low levels of market development and poor National organizations and networks of smallholder forest producers access to public goods and social services. They must deal constantly play important roles in climate-change mitigation and adaptation, with the consequences of market failure and are particularly exposed spanning political and practical action. Innovative and successful to risks and repeated shocks. A wide range of environmental, climate action builds on the strengths of each organization and economic, health-related, demographic, social and political factors harnesses the support of the membership base and organizational are key sources of vulnerability in these communities. alliances in multi-actor networks. Since the implementation of FAO’s five new Strategic Objectives, This publication summarizes the findings of a review of the innovative social protection has become an important area of focus for the ways in which smallholder forest producer organizations in developing Organization. This policy brief, developed by FAO in collaboration countries are contributing to climate-change mitigation and adaptation. with the United Nations University–Maastricht Economic and Social The review was carried out by the Finnish Agri-Agency for Food Research Institute on Innovation and Technology, uses a global and Forest Development and the Finnish Environment Institute in literature review and country case studies in Burkina Faso, China collaboration with the Forest and Farm Facility. and Uganda to explore the need for more social protection for forest- The Forest and Farm Facility is a partnership between FAO, dependent communities. Among other things, the brief recommends the International Institute for Environment and Development, the the inclusion of environmental and poverty-alleviation objectives in International Union for Conservation of Nature, and AgriCord. social protection and forestry interventions and raising awareness Available online: www.fao.org/3/a-i7404e.pdf of the potential synergies between them. Available online: www.fao.org/3/a-i7008e.pdf

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FAO’s approach to climate change Investing in trees to improve health

FAO strategy on climate change. 2017. Rome, FAO. Funding trees for health: an analysis of finance and policy actions to enable tree Three outcomes frame FAO’s strategy on climate change: planting for public health. R. McDonald, L. Aljabar, C. Aubuchon, H.G. Birnbaum, 1. Enhanced capacities of Member Nations on climate change C. Chandler, B. Toomey & J. Daley, et al. 2017. Arlington, USA, The Nature through FAO leadership as a provider of technical knowledge Conservancy. and expertise. Every year, up to 4 million people die worldwide as a result of air 2. Improved integration of food security, agriculture, forestry and pollution, which has lifelong impacts on people’s health through fisheries in the international agenda on climate change through ailments such as asthma, cardiac disease and stroke. Each summer, reinforced FAO engagement. thousands of unnecessary deaths result from heatwaves in urban 3. Strengthened coordination and delivery of FAO’s work on climate areas. Studies have shown that trees are a cost-effective solution for change. both these challenges, but investment in urban forestry is perpetually The strategy on climate change sets FAO on a path to deliver on underfunded. the Sustainable Development Goals (SDGs), particularly SDGs 1, 2 This report examines the link between trees and public health, which and 13. In operational terms, it is an integral part of FAO’s Strategic recent science has shown is robust and economically significant. Framework, Medium Term Plan, and Programme of Work and Budget. One way to overcome the funding barrier for urban forestry, say the The strategy will be implemented through a plan of action designed authors, is to more closely link the goals and funding of the health to strengthen FAO’s existing capacities, especially in decentralized sector with the goals and funding of urban forestry agencies. The offices, and it sets out the results to be delivered by FAO through its authors urge all cities to explore ways of creating links between the Strategic Programmes. health sector and urban forestry agencies, using one of the potential Available online: www.fao.org/3/a-i7175e.pdf models discussed in the report. Also available online in: Available online: http://tinyurl.com/ydauygzn French – www.fao.org/3/a-i7175f.pdf Spanish – www.fao.org/3/a-i7175s.pdf

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Creating sustainable urban environments

Routledge handbook of urban forestry. 2017. F. Ferrini, C.C. Konijnendijk van den Bosch & A. Fini. Abingdon, UK, Routledge. ISBN: 9781138647282 (hardback); 9781315627106 (ebook) More than half the world’s population now lives in cities. Creating sustainable, healthy and aesthetic urban environments is therefore a major policy goal and research agenda. This comprehensive handbook provides a global overview of the state of the art and science of urban forestry. It describes the multiple roles and benefits of urban green areas in general and the specific role of trees; reviews the various stresses experienced by trees in cities and tolerance mechanisms, as well as cultural techniques for either preconditioning or alleviating stress after planting; and outlines the sound planning, design, species selection, establishment and management of urban trees. The handbook shows that the close involvement of local urban communities who benefit from trees is key to success. Available for purchase at: www.routledge.com/Routledge-Handbook- of-Urban-Forestry/Ferrini-Konijnendijk-van-den-Bosch-Fini/p/ book/9781138647282

peri-urban forestry peri-urban and urban on Guidelines Spanish: Spanish: French: English: Spanish: French English, and in Available FAO Forestry Paper No. 178 Yujuanand Chen by Fabio Salbitano, Simone Borelli, Michela Conigliaro cities for forest products and ecosystem services that will meet the present and future needs of globally applicableA guide to developing forests www.fao.org/3/a-i6210f.pdf www.fao.org/3/a-i6210e.pdf www.fao.org/3/a-i6210s.pdf

ISBN 978-92-5-130383-2 ISSN 0041-6436

[email protected] 9 789251 303832 I8707EN/1/02.18 www.fao.org/forestry/unasylva