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Journal of Resources, Energy and Development (JREaD)
Vol.7(2) September 2010
Print ISSN : 0975-7554
Online ISSN : 0975-7562

Urban biodiversity: an essay on natural capital and social innovation using Delhi as an example^*

Meher Bajwa: Mehar Bajwa works for Bridge to India—an environmental consultancy fi rm, which conducts research and analysis in renewable energy, resource management, and urban
planning in India.
Email meher.bajwa@bridgetoindia.com

Abstract

Urbanization is rapidly emerging as one of the most potent forces to shape the global environment. There is already immense pressure on urban natural capital; local biodiversity has been isolated and overshadowed by urban sprawl. The irreversible loss of native biodiversity has an impact on multi-scale ecosystem functioning. It has become critical to reconcile these issues to ensure that urban development is sustainable and, in fact, betters the quality of life. This essay explores the interactions between urban biodiversity, natural capital, and people in urban human ecosystems. A strong scientific basis through continual mapping, monitoring, and assessment is required to communicate the implicit connection between biodiversity and the quality of life to the public and policy-makers. Grassroots innovation, public participation, and local governance are critical to maintaining urban biodiversity. A natural capital and ecosystem approach are strongly recommended to ensure that urbanization becomes more sustainable and cities are able to reduce their ecological footprint.

* The content of this paper was fi rst prepared as part of a Master’s level thesis at School of Oriental and African Studies, University of London, London, UK, under the guidance of Prof. Vaughan Redfern. The paper has subsequently been revised according to the helpful comments of an anonymous reviewer at TERI.

Introduction

In this age of uncertainty, one thing most can agree with is that the future falls within a rapidly expanding urban landscape where cities are becoming megacities. Megacities, defined as having a population greater than ten million, are characterized by several positive trends such as growing incomes, more women in the workplace, better facilities for health and education, and so on. They are also complex, multi-scalar human ecosystems, subject to growing socio-economic disparity, informal and unplanned land use, and alarming environmental damage. Cities are emerging as major factors in determining not just local but global biodiversity and ecosystem functioning (Coulomb 2008; Sassen 2010).

Biodiversity is the variability of life and this essay concerns itself with the organization of life in urban human ecosystems. Biodiversity regulates and monitors the health of ecosystems. Without biodiversity, the material and energy flows of the planet would stagnate. In the international year of biodiversity, we are faced with unprecedented exponential rates of extinction (Global Biodiversity Outlook 2010). The importance of biodiversity has primarily been studied in a rural context—now urban biodiversity is being recognized not simply for local ecosystem functioning and quality of life, but also for its role in maintaining regional and global biodiversity. As recently as 2008, with the holding of the Curitiba meeting, the international community has begun taking concrete steps to recognize the importance of urban biodiversity and the involvement of local governments in cities.²

Biodiversity is an integral part of natural capital, which can be defined as ‘physical assets that deliver economic value through the provision of ecosystem services’ (Voora and Venema 2008). A living tree would be considered natural capital; however, cutting it for firewood deems the asset as being spent. Urban natural capital includes biodiversity, air, parks, city forests, lakes, rivers, waterways, urban farms, scenic views, and open recreational areas. Natural capital provides a practical approach within which biodiversity maintenance and urban development could be integrated.

This brings us back to cities, which are complex, contextual, open systems whose limits cannot be defined. Megacities, such as Delhi, are a ‘heterogenous mosaic’ (Pickett 2006) that cut across administrative boundaries. Historically, cities have been focal points of power, consumption, and security and have always been serviced by their hinterlands. In an age of climate change, political and food insecurity, it makes sense for cities to reduce their dependence on resources that lie far outside their boundaries. Many believe that sustainable cities are a pipe dream for idealists (Webb 2008; Galef 2009). Others believe sustainable urbanization is an unavoidable path to global sustainability (Coulomb 2008). A ‘sustainable city’, as defined by the Sustainable Cities Institute, is one that continues to reduce its dependence on the environment and strives for a lower ecological footprint. The possibility of ‘sustainable megacities’ merits serious enquiry as it promotes sustainable lifestyles at an individual level as well as provides a measure of natural resource accountability through policies on a larger-scale.

There has been a lack of research done so far on urban ecosystems, especially a cross-cutting view of all sectors and how they work together (Pickett and Cadenasso 2006). Even where research on urban ecosystems takes place, it usually concentrates on an ecological viewpoint, rarely integrating with multi-dimensional concepts such as sustainable development. A diverse set of viewpoints, recommendations, and solutions are required that integrate with the socio-economic fabric of the region.

Elements such as poverty and inequality are critical factors in emerging megacities. In cities such as Delhi, unregulated and informal processes define the normal course of life for most inhabitants. It is not enough to consider humans as demographic entities from an ecological viewpoint, but one must consider their social and political institutions (Pickett 2006). Human behaviour is now seen as an integral part of the urban ecosystem, rather than an external driver. Ecological processes are interacting directly with economic, political, and social systems (IIED 2006). These systems are multi-scalar and multi-dimensional. The challenge lies in translating these complex concepts into meaningful material for policy-making. This paper examines social innovation or emergent self-organization among communities in Delhi and makes recommendations that can lead to biodiversity maintenance and urban ecosystem resilience. It is based on the premise that maintaining urban biodiversity and natural capital are desired paths to sustainability as they increase the quality of life while reducing the ecological footprint of cities (Henwood and Pidgeon 2002; Manning 2008).

² The Convention of Biological Diversity (CBD) adopted decision IX/28 in 2008, to recognise the role of cities in maintaining biodiversity. ICLEILocal Governments in Action and the International Union Conservation of Nature and Natural Resources (IUCN) have started a Local Action for Biodiversity (LAB) programme that currently involves 21 cities worldwide.

The urban context: urban biodiversity has a major impact on the health and well being of citizens

By 2030, five billion people (58%) will be living in cities (UNFPA 2007) and over 575 million (41%) of India’s population will live in urban areas (UNDP 2009). Thus, while the pace of urbanization in India is relatively slower, it will still account for 11.5% of the global urban population. From 1971 to 2001, the urban population of India had more than doubled from 109 to 285.35 million ³ (27.8%), and that of Delhi had almost quadrupled from 3.6 to 12.9 million (Economic Survey of Delhi 2008–09). Although the projected growth rate is not as high, the UN estimates that Delhi will further double its population to about 28 million by 2025. It is not simply the scale that is staggering, but the implications. Delhi, one of India’s most water-scarce cities, has a per capita water usage (255 litres). Greater than that of London (161 litres); groundwater in Delhi, according to the Delhi Groundwater Board, is overdrawn by 190 million cubic metres annually. Only 10% of the daily generation of 20 million cubic metres of sewage is treated, allowing the rest to pollute ground and surface water (Chaudhary, Jacks, and Gustafsson 2002). The rapid decline of previously abundant urban wildlife, such as the House Sparrow (Passer domesticus), is inadequately explained and requires more research (Harvey, Devasar, and Grewal 2006; Khera, Das, Shrivastava, and Jain 2009).

Delhi is regarded as one of the greenest capitals in the world with 21 m ² of green space available per capita. According to the Delhi Human Development Report (2006), the quality of the environment has improved, particularly that of ambient air pollution. Another achievement has been the increase in tree and forest cover ⁴, from 16 km2 in 1990 to about 268 km ² in 2001. Delhi’s natural capital primarily includes 7777 hectares (ha) of protected Ridge forest, ⁵ and the river Yamuna, along with its rich alluvial floodplain, flowing through the eastern part of the city (see Figure 1). The tree cover in Delhi is 11% and the forest cover accounts for 8% (MoEF 2005) but there is minimal official monitoring or measuring of biodiversity in the city.

Megacities inevitably outgrow their infrastructure leading to congestion, encroachment, and resource pollution. The river Yamuna, which runs through Delhi, has been choked by sewage, hospital waste, and industrial pollution. Delhi generates 3296 million litres per day (MLD) of sewage, half of which flows untreated into the Yamuna (WaterAid India 2005). Delhi has about four hundred water bodies, most of which have been degraded or encroached (MoUD 2007). Most of Delhi is serviced by canal water; however, there is a shortfall of about 1290 MLD. ⁶ The city relies on large hydropower projects for its municipal water supply such as the controversial Tehri dam and Renuka dam that are strongly opposed by civil society. ⁷The Ridge forest has shrunk from occupying 6.69% of the city’s total area in 1992 to 5.52% in 2004 (Figure 2) due to illegal quarrying and construction. The same map shows a disappearing Yamuna floodplain.

Urban conditions are tough on street trees, especially those that are already aging. Trees suffer from limited root space, air and water pollution, nutrient-deficient soil, toxic chemical use, soil compaction, underground cables, and injuries to trunks and branches by hanging nails and boards. Trees often die or get affected by diseases well before reaching maturity. Older trees in Central Delhi fare worse than those in the rest of Delhi (see Table 2). Water supplied by the Yamuna has been declared unfit for irrigation of urban trees (FRI 2010).

This degradation of urban biodiversity and natural capital has a direct and indirect impact on the health and well being of local residents. Worldwide studies list several benefits of urban natural capital (primarily forests) including increased groundwater, less water pollution, improvements in air pollution, flood control, erosion control, noise reduction, and energy savings by reducing the urban heat island effect (IADB 1997; Akbari, Pomerantz, and Taha 2001; Jim and Chen 2008; Manning 2008). At least 640 hectares of the south-central Ridge have been declared a protected water recharge zone. Fam, Mosley, Lopes, Mathieson, Morison, and Connellan (2008) list several benefits of urban green space on health and obesity and recommend that irrigation for healthy trees is important even during periods of drought. A recent study by the American Chemical Society shows that even five minutes of exercise in natural surroundings can have positive effects on one’s health and mental well being (Barton and Pretty 2010). Green areas with water seemed to provide additional benefits. Other benefits of urban natural capital include provision of food and fodder, as well as the beautification of the city. A former sanitary landfill in Delhi was converted into a horticultural garden. ⁸ Street trees function as a green network that can serve recreational and ecological needs by creating sheltered public spaces, managing rainwater runoff, and creating corridors for urban biodiversity. The value of biodiversity has been highlighted for ecosystem functioning and resilience (IUCN 2008).

A slight ambiguity arises while defining urban biodiversity and the quality of urban natural capital. It could be argued that urban biodiversity includes not only indigenous flora and fauna but also domesticated species that have adapted to the area and function well in a human ecosystem (Gyllin 1999). This is a reasonable assumption, provided the introduced species do not unduly interfere with the functioning of the ecosystem and hamper native biodiversity. There are several examples of this within Delhi; the Tamarind tree (Tamarindus indica) was introduced from East Africa prior to the 2nd century and now flourishes in the southern and eastern parts of the city (Krishen 2006). Initially, it is unclear whether introduced species will become invasive or harmful for the environment. At times, species are considered harmful simply due to their exotic nature. The Eucalyptus tree (Eucalyptus tereticornis), introduced from Australia, has acquired a negative public image for its supposedly excessive water consumption, a view that has proven to be a fallacy. Although a study by Sangha and Jalota (2005) has shown that the value of ecological services is greater in Sheesham plantations, which are native, compared to Eucalyptus plantations, this does not mean that the latter is harmful to the environment. Native vegetation is valuable as it is better suited to local habitats and increases the resilience of natural ecosystems. Indigenous biodiversity contributes to a sense of local identity and ownership. There have been cases where native biodiversity in cities has safeguarded a species, the population of which has fallen in regional non-urban areas.

Scale is an important consideration. One should be careful about promoting species richness in areas that have fewer, but rare and, thus, more valuable species as this could adversely affect species richness on a larger scale, say at a regional level (Gyllin 1999). Biodiversity, thus, benefits from qualitative as well as quantitative planning. It is important to note that the abundance of natural capital does not necessarily denote a higher degree of biodiversity. What should be determined is how the ‘quality’ of natural capital impacts ecosystem functioning and local as well as regional biodiversity indices. Likewise, the quality of urban natural capital is not often judged from the standpoint of biodiversity, but is based on the utilization factor.

Urban space is an increasingly valuable commodity. In cities such as Delhi, the urban poor have often been marginalized for the sake of the environment. The real urban India lives in slums or sub-standard housing. The percentage of people under the poverty line has almost doubled from about 8% in 1999 to 14.7% in 2006 with the most affected living in urban areas (Economic Survey of Delhi 2008/09). In 1999, approximately 10 million people (78%) in Delhi were living in sub-standard settlements (Wateraid India 2005). Latest reports put the figure at 49%⁹as many of these have been systematically relocated to the peripheries of the city. Relocation is done ostensibly to promote a ‘Clean and Green Delhi’, however, urban sprawl is more damaging to regional biodiversity. Unregulated expansion has resulted in colonizing of the ‘urban fringe’ or peri-urban areas, which have the richest species diversity (IIED 2006b).

³ Government of India, Census 2001 http://censusindia.gov.in/Census_Data_2001/Census_Newsletters/Newsletter_Links/eci_3.htm

⁴Forest cover is defi ned as tree canopy density above 10% over an area greater than 1 hectare. Tree cover includes all patches or scattered trees in areas of under 1 hectare (FSI 2009).

⁵The Ridge was notifi ed (declared protected) as a reserved forest under section IV of the Indian Forest Act 1927 in May 1994.

⁶CSE, Rain water harvesting, Delhi water scenario, http://www.rainwaterharvesting.org/index_fi les/about_delhi.htm

⁷Hindustan Times, Activists say dam it! to CM for Renuka barrage, 4 July 2010, http://www.hindustantimes.com/Activists--say-dam-it-to-CMfor-Renuka-barrage/Article1-567423.aspx

⁸DDA, offi cial website, http://dda.org.in/greens/millenium_parks.htm

⁹Times of India, Half of city lives in slums, April 28 2010, http://timesofindia.indiatimes.com/city/delhi/Half-of-city-lives-in-slums-and-illegalcolonies-MCD-/articleshow/5866268.cms

Urban human ecosystems: complex, dynamic, adaptive, socio-ecological systems

Urban natural capital falls in various domains of ownership, from individuals to communities and to the private and public sectors. Human beings are the keystone species of urban ecosystems. Small daily decisions of individuals, such as commuting, recycling, waste disposal, and water use have a significant cumulative impact on local and distant ecosystems (IIED 2006). According to a UN report, natural light has dimmed by about 10%–25% in Delhi due to human-made atmospheric brown clouds ¹⁰—formed of atmospheric pollutants due to dust, biomass of burning, and vehicular emissions. Air pollution is just one example of a cumulative effect that has a targeted impact on biodiversity. Lifestyle choices, such as the use of insecticides, unleaded petrol, and radiation from telecom towers, could possibly be responsible for Delhi’s declining bird diversity. This city-scale natural resource mismanagement affects ecosystem services, which in turn affect biodiversity, thereby resulting in a positive feedback loop.

Not all species are negatively impacted in urban human ecosystems. Urban processes alter species composition and diversity by promoting ‘urban adapted’ species, often at the expense of native species. Habitat loss is a key consideration in the face of urban sprawl and has resulted in some wildlife species such as the leopard and hog deer disappearing completely, whereas others such as the Rhesus macaque (Macaca mulatta) have colonized human inhabited areas. Rock pigeons have successfully usurped the nesting spaces of House sparrows (Khera, Das, Shrivastava, and Jain 2009). Granivorous bird species are more likely to be successful than insectivorous species given rampant pesticide use and ubiquitous organic waste (Grimm, Faeth, Golubiewski, Redman, Wu, Bai, and Briggs 2008). Urbanization might also increase species for which natural predators have been eliminated; habitat loss leads to fewer frogs, which are a natural control measure for mosquito populations (Raghavendra, Sharma, and Dash 2008) Sometimes new habitat types are created. According to Grimm, Faeth, Golubiewski, Redman, Wu, Bai, and Briggs (2008), urbanization increases plant diversity due to exotic cultivation by humans and a heterogeneous ‘patchwork’ of habitats. Delhi is a prime example of this mosaic with each patch of land being under different ownership, thereby exhibiting, often radically, different landscapes. The increased edge effect of fragmented ‘human-dictated’ habitats may promote bird diversity at localized areas. On the other hand, there is a negative relationship between human introduced species in Delhi, such as the invasive Acacia tree (Prosopis juliflora) and bird diversity, but more research is needed (Khera 2009). While competition between local species occurs even in rural and wild habitats, the degree and influence of human activities cannot be underestimated. Hope, Gries, Zhu, Fagan, Redman, Grimm, Nelson, Martin, and Kinzig (2002) acknowledge that the measure of human intervention has its basis in socio-economic status. In Delhi, public areas around corporate headquarters and richer neighbourhoods are greener and better maintained. This ‘luxury effect’ has been reported by Hope, Gries, Zhu, Fagan, Redman, Grimm, Nelson, Martin, and Kinzig (2002), although further research is needed. According to noted botanist Pradip Krishen (2006), urban planners in Delhi intentionally overlooked deciduous native vegetation in favour of exotic evergreen trees. Hingot (Balantes roxbughii), a native tree, was deliberately sidelined due to its untidy appearance but still flourishes in the Ridge. New varieties of genetically engineered flora have been created to cater to a growing ornamental plant market (Krishen 2006). Urban environments, thus, represent highly experimental zones where the dominant vegetation over time is not indigenous. According to Krishen (2006), Delhi has about 252 species of trees, the majority of which are naturalized; six native ridge trees still exist, four are extinct locally, and one, the Dhau (Anogeissus pendula) is highly endangered.

Megacities are constantly evolving landscapes and a key driver of a city’s policies could well be its history. Past decisions can install frameworks that seem to have a life of their own (Goodstein 1995). Ongoing investments in this ‘legacy framework’ can strengthen the resistance to change. Urban ecosystems have been partly shaped through path dependence and partly due to economic aspirations. Central Delhi (Lutyen’s), built during the British rule, provided for wide green belts, lush parks, and gardens, thus, becoming historically greener. This low-density area now has heritage status and new constructions are strictly regulated. Old Delhi, which constitutes remnants from the Mughal era, also had tree-lined streets, but being a densely populated trading area, these trees have since disappeared.¹¹ In 1914, the British began the afforestation of the Ridge, unwittingly introducing the rampant Acacia to Delhi. Since Independence, the low-lying wetlands in South West Delhi have disappeared under industrialization.

Most processes in megacities are unregulated and informal (Kraas 2007). The informal sector primarily operates in public spaces, thereby having a direct relationship with urban natural capital and biodiversity. Informal waste management systems depend on rag pickers, metal and paper recyclers, and street animals that forage through garbage lying on streets. Street animals, such as cows and pigs, serve ecological functions such as turning waste into manure to fertilize as well as propagate vegetation through seed dispersal. At the same time, they pose a threat to young saplings and urban vegetable gardens. There is no formal collection system for construction waste, which is often thrown in forested areas. Informality is a characteristic emergent property of developing megacities.

¹⁰ UNEP, Wide Spread and Complex Climatic Changes Outlined in New UNEP Project Atmospheric Brown Cloud Report, 13 November 2008, http://www.unep.org/Documents.Multilingual/Default.asp?DocumentID=550&ArticleID=5978&l=en

¹¹ Trees in Old Delhi were cut down following the attempted assassination of Viceroy Hardinge in 1912 (Krishen 2006).

Informal networks and social innovation: emerging solutions at the grassroots level

Paul Hawken, in his book Blessed unrest, examines how the worldwide environmental movement is an invisible and informal entity. This is typified in an urban human ecosystem. ¹² Cave and Ruet (2010) describe how innovative informal solutions emerge to compensate for the lack of basic services provided by the state. This is especially noted in the governance of public goods and services. According to Lee (2006), cities in developing nations require alternative ‘grassroots’ approaches over classical environmentalism. Local governments lack the infrastructure and means to implement large-scale environmental policies (Lee 2006; Dutt 2008). Agenda 21, a UN programme, advocates the need for building on local knowledge and decentralizing community action. ¹³ In Delhi, most successful environmental acts have been spearheaded by individuals and mandated by the judicial system, rather than the legislative bodies or through lobbying by the non-governmental organizations (NGOs). Notable Supreme Court victories include mandating Compressed Natural Gas use for commercial vehicles and the notification of the Ridge. The court, however, has been ineffective in other cases such as illegal mining and large-scale encroachments in the Ridge. ^14,15

Projects are accomplished due to the resourcefulness of individuals. People are being increasingly recruited for tree-plantation drives by forest departments that provide saplings and technical expertise at no cost. Maintenance of such a large number and type of urban habitats is virtually impossible without local involvement. Large-scale community afforestation drives have been planned in Delhi—such as planting 25 000 trees in the memory of the 1984 anti-Sikh riots—one for each deceased person (Phoolka 2009). Even on a smaller scale, residents take care of neighbouring green belts using their own resources and tend herbal gardens at home. ¹⁶

NGOs play a pivotal role in raising awareness, advocacy, coordinating projects, and building capacity to sustain projects in urban areas. A notable mention needs to be made for the Ridge Bachao Andolan, an advocacy group that was formed of several NGOs who came together for the specific purpose of protecting the Ridge and succeeded.

Similar to biofeedback mechanisms in biological organisms or James Lovelock’s Gaia theory, megacities require early indicators to monitor sustainability. Public participation and a sound knowledge network could serve this purpose. ¹⁷ The Delhi Bird Club, formed in the 1950’s, began as an informal group that now conducts regular bird watching events across Delhi. While these annual surveys are crucial, they usually take place in biodiversity parks and sanctuaries, not in urbanized zones. Monitoring of indicator species (especially birds such as the House sparrow) could prove crucial to providing early feedback for urban ecosystems. Social innovation, triggered by these feedback systems, could transpire in the market and civil society. Adaptable niche initiatives can emerge depending on the need of the hour.

Social entrepreneurs are examples of innovation within the private sector and successfully integrate socio-economic missions with environmental concerns. Prakash Environmental Group¹⁸ is a social enterprise that has occupied a niche in urban waste management since 2001 by collecting and converting household and office waste to compost and recycled paper, which is delivered back to clients. The group comprises engineers from diverse backgrounds and is, thus, able to affect change at all levels. Their strengths are scientific waste management, an aggressive awareness campaign, and differential pricing. A Pune-based company, ELT India Enterprise, has completed five green wall and green roof projects in New Delhi using technology imported from Canada. The company offers a customized solution to select plants best suited for local conditions, but, this does not necessarily serve to increase plant diversity. There is a small but growing body of research on the role that green roofs can play in biodiversity conservation (Baumann 2006; Brenneisen 2006; Köhler 2006). By extension, green walls play a similar role in providing a habitat for flora and fauna, especially birds and invertebrates. Another company, Blue Water Solutions, is promoting decentralized non-chemical water treatment and anti-mosquito film products. An extraordinary example of urban ecological entrepreneurs are the local people who ‘employ’ Langur monkeys (Semnopithecus spp.) to chase off the disruptive Rhesus macaque in urban areas in Delhi. ¹⁹ The real challenge would be involving the small trades industry, which is unable to afford an environmentally friendly attitude. Trading volumes have a significant impact on the environment. Larger corporations seem to be willing to co-operate with local initiatives, but not take on a leadership role.

The main challenges in restoring natural capital are financial resources and lack of political will (Lee 2006). This has also been seen in the stalling of many environmental projects in Delhi. But, the bigger issue still might be the sustainability of such projects due to lack of long-term ownership. Maintenance is a critical issue that projects, such as tree-planting drives, do not take into account either due to lack of awareness, expertise or resources. This shows that it is once again difficult to escape the ‘human’ element in urban ecosystems.

Almost every notable natural capital restoration programme, even if initiated by individuals, involves cross-sectoral collaboration; whether it is planting indigenous trees²⁰ or setting up rainwater harvesting units. Each sector brings its strengths to the table—NGOs and academic institutions provide the expertise, the private sector provides the funds, and the public sector sanctions the project. Ownership and long-term viability of these projects is usually in question if local capacity building is not done sufficiently. The responsibility falls on NGOs, which are vital for collaborations as they link people to the private sector and/or government.

The inclusion of the poor is very important as inequalities can lead to conflict (Dutt 2008). In Delhi, slums receive only about 14 litres per capita per day (lpcd) whereas preferred localities receive 450 lpcd (NCT 2010). The urban poor set up their own infrastructure for housing, sewage, water, waste management, and transit, only to be subjected to relocations. A well-publicized case is the Bhati Mines area in Delhi, which was declared as the Asola Wildlife Sanctuary in 1991. About 30 000 migrant workers who had been living in the area for over 15 years were forced to move out of the newly notified protected zone. ²¹ This is contrasted with farmhouses, resorts, and shopping malls that have been allowed to remain standing in other parts of the protected Ridge. Most cases of urban environment management appear to offer fragmented resolutions, with different agencies being responsible. ²²

¹²Researchers agree that megacities are complex, dynamic, adaptive, socio-ecological systems (Rees 1998; Kraas 2007; Torrens 2007; Grimm et al 2008). Torrens (2007) and Coloumb (2008) also stress that there are multiple levels where dynamic growth and inter-linkages occur. Torrens highlights the bottom-up drivers as crucial. Therefore, grassroots and social innovation is key to driving change in urban ecosystems. Trends and drivers in megacities are largely unknown and the high level of complexity makes it diffi cult to comprehend or even be aware of all consequences of action. According to Kraas (2007), integrated solutions involving “international, interdisciplinary, intercultural and multi-stakeholder action is required on all levels.”

¹³UNEP, Agenda 21, http://www.unep. org/Documents.Multilingual/Default. asp?documentid=52

¹⁴There is continued controversy over ‘illegal’ constructions in the South Central Ridge at Vasant Kunj. The TERI campus claims to be just outside the legally notifi ed Ridge boundary although local environmentalists disagree . Five neighbouring shopping malls have been judged to be within the Ridge but have been allowed to remain standing.

¹⁵The Hindu, Construction in Vasant Kunj Ridge environmentally unsound, 9 August 2006, http://www.hinduonnet.com/2006/08/09/stories/2006080922700300.htm

¹⁶Home Herbal Gardens, an initiative launched by TERI

¹⁷ At a macro-level, indicators such as the Genuine Progress Indicator could be used to monitor sustainability http://www.rprogress.org/sustainability_i ndicators/genuine_progress_indicator.htm

¹⁸ Prakash Environmental Group, offi cial website http://pegindia.com

¹⁹ Mumbai Mirror, Langur paid more than man at Delhi University, 5 July 2007, http://www.mumbaimirror.com/index.aspx?Page=article§name=News%20-%20Nation§id=3&contentid=2007070502555731ee198799

²⁰ ExpressIndia (2009) Capital avenues: govt thinks local to green city’s roads. 22 July 2009. ExpressIndia Retrieved from: http://www.expressindia.com/latest-news/capital-avenue-govtthinks-local-to-green-citys-roads/492357/

²¹ India Environment Portal, Delhi Ridge – A lifeline in Danger, Down to Earth, Vol. 5, May 1997, http://www.indiaenvironmentportal.org.in/node/12359

²² The Ridge is jointly managed by DDA, Army, CPWD, MCD, NDMC, Forest Dept and the Sports Authority of India,

Challenges and recommendations for Delhi

In Delhi, there is no single body concerned with biodiversity at a megacity level. Megacities are growing past fixed administrative boundaries, encouraging fragmented agendas. Within the city, there are many agencies responsible for environmental issues at a local level, which implies absence of critical mass and accountability. This paper proposes defining guidelines that can provide direction not only to policy-makers and urban planners, but also to social innovators and civil society. Adopting the natural capital approach and the ecosystem approach would ensure an equitable and sustainable distribution of public goods and services. Both these approaches are rooted in a strong scientific basis, knowledge networks, and local action.

Ecosystem approach: a network to cultivate natural and social capital

Due to the stiff competition for urban space, it is sometimes unclear whether a piece of land is better suited as a protected forest such as the Ridge—a natural heritage site—or a biodiversity park. This illustrates the need for an ecosystem-based approach rather than a species or agenda-based approach. Needless to say, within an ecosystem, if a certain species is endangered and poses no threat to other species, then it should have an integrated species survival plan. Endangered native trees such as the Dhau and Jhand in Delhi have a narrow range and need special consideration in urban areas. Similarly, compensatory afforestation ²³ needs to have a scientific qualitative basis instead of relying on numbers. These new ‘city forests’ require more maintenance and might not grow to adulthood, thereby providing less value than the already mature trees that formed an integral part of the city’s natural heritage. The trees replaced are usually in the interiors of the city, where space is more valuable, and are substituted by saplings that are located in remote and uninhabited peri-urban edges of the city where there is already ample vegetation and no restoration is required. This compensatory restoration is not a preferred method of biodiversity conservation as there is likely to be a loss of genetic diversity. There is no provision to ensure that rare endemic tree species are not replaced by invasive exotic species, therefore, the ecological balance is disrupted. Species selection to promote native or naturalized biodiversity requires more planning and foresight. In an arid city such as Delhi, native drought-resistant species should be encouraged over exotic species that compete for greater resources.

As far as natural capital is concerned, the proximity to the community proposes major questions or areas of concern. Would large green belts circumventing the core of the city be enough to provide ecosystem functioning? Should each local settlement have its own forest, similar to its own parks? For ecosystem functioning, large areas of green space, such as the Ridge, are necessary; but for social and mental health benefits, biodiversity needs to be more locally integrated. Protected forests shelter urban wildlife such as jackals (Canis aureus) and nilgai (Boselaphus tragocamelus), although there is not much monitoring and, thus, many encroachments. There is little direct interaction between these protected areas and the local citizens. A controversial and recent addition to Delhi’s landscape is government sanctioned biodiversity parks. It may be noted that they are situated in ecologically sensitive zones such as the Ridge and the Yamuna floodplains. Although they serve the purpose of increasing human-nature interaction, it remains to be seen whether increased human activity in these parks will disrupt biodiversity or inculcate a respectful appreciation of urban biodiversity. Construction and human activity should be minimized in ecologically sensitive zones to avoid the irrevocable loss of natural capital and biodiversity. Instead, what Delhi needs are greenways and waterways, forming a ‘green and blue network’, mapped to existing topographical conditions. This natural capital network can cultivate social capital by providing public areas for interaction, thereby enhancing the health, awareness, ecological appreciation, and quality of life for citizens as well as engendering urban biodiversity. These could consist of public and private spaces. For instance, garden networks are now being promoted to emphasize urban biodiversity, specifically wildlife, in the UK. ²⁴

²³ Delhi Tree Preservation Act, which states that permission from the respective forest departments is required for tree felling; developers manage to gain this right via ‘compensatory afforestation’, which requires at least 10 trees to be planted for every tree felled.

²⁴ Science Daily, Gardeners must unite to save Britain’s wildlife, experts urge, 26 January 2010,

Natural capital approach: an economic basis for urban biodiversity

The urban economy is inextricably linked to natural ecosystems. Urban natural capital attracts residents, businesses, and tourists as well as increases property values while reducing public spending. A shift to natural capitalism and a steady state economy would encourage efficient use of natural resources (Ryan 2003; Lawn 2008). Approaches such as the Natural Capital Approach (NCA), suggested by the International Institute for Sustainable Development (IISD), could provide a practical framework for such a transition. The NCA would integrate urban economic development with ecosystem management that is based on spatially grounded information. ²⁵ This would result in an economic framework within which to evaluate management strategies that could best promote the health of the urban ecosystem. As most development policies have an economic basis, these strategies could then translate easily to policy decisions. NCA methodologies need to be developed, assessed, and standardized for urban areas such as Delhi.

While urban ecosystems themselves cannot be measured directly, the use of qualitative indicators such as air and water quality, biodiversity, and soil fertility provides a comparative measure of ecosystem health. Rather than solely relying on forest and tree cover, it is strongly recommended that Delhi monitor its biodiversity by implementing the City Biodiversity Index (CBI), which has 26 indicators measuring (1) native biodiversity, (2) ecosystem services, and (3) governance. ²⁶

There is rampant encroachment from both the formal and informal sectors, thus, natural capital still requires protection. An answer might be an independent, accountable, ‘function-based’ commission with a civil society presence, perhaps comprising “concerned citizens and scientists above political and monetary affiliations” (Soni and Parikh 2008). This commission would adjudicate matters of illegal encroachments. Effective enforcement can only become a reality when there is public participation and fair investigative reporting by the media. Legislative tools such as Public Interest Litigations (PIL) and the Right to Information (RTI) Act have created some level of accountability through mandated audits and a stipulated time limit to guarantee a response. ²⁷

There are several arguments by which one can advocate conserving urban natural capital and biodiversity. The classical environmental approach, or the ‘green’ agenda, focuses on diminishing habitats and species decline (Lee 2006). A second argument, or the ‘brown agenda’, promotes better health through provision of ecosystem services such as clean drinking water and unpolluted air (IIED 2006). Other arguments for maintaining urban biodiversity are fundamentally social (Kilvington and Allen 2004). According to UNESCO, the actions resulting from cultural diversity are directly responsible for changes in biological diversity. In India, the Peepal tree (Ficus religiosa) is sacred and in many cases will not be cut down even if it disrupts development. Political motivations include beautification of the city, which can form part of the government’s public relations campaign to attract investment and tourism. These multiple motivations provide a basis for maintaining urban biodiversity in several developmental settings.

²⁵ Biotope and sociotope mapping could provide a basis for this. More sophisticated approaches involving artifi cial intelligence based simulation models are a possibility for the future but more work needs to be done (Torrens 2008).

²⁶ Singapore Index on Cities Biodiversity, http://www.cbd.int/authorities/gettinginvolved/cbi.shtml

²⁷ RTI uncovered 4,400 pending corruption cases against 3,400 employees of the Municipal Corporation of Delhi, TOI May 2009, http://timesofi ndia.indiatimes.com/Cities/3400-MCDstaffers-facing-graft-cases/articleshow/4573433.cms

Local knowledge networks and local action: a stronger level of awareness before one sees a committed grassroots movement emerging

Megacities are ‘hotspots’ of global change (Kraas 2007), therefore, continuous research and learning is essential. There is minimal institutional research on urban biodiversity in Delhi. There needs to be more collaborative research at all levels, not just to monitor the health of species populations in biodiversity zones, but, also to establish urban ecological patterns. Introduced or exotic species need to be cautiously evaluated, especially with regard to resource use. Many health issues related to the environment are inadequately addressed by policy or implementation, for instance, pesticide use, mercury, e-waste, and sewage treatment. A strong scientific basis, monitoring, and evaluation would communicate the clear connection between biodiversity and quality of life to the public and officials. An increased awareness of how society and health are directly affected by ecosystem services might provide the soundest basis for collaboration, as they strongly promote the human element. Delhi’s citizens should be made more aware of biodiversity within urban areas, for instance, through the use of public signage with information on the type of species, its utilization, and benefits as well as maintenance requirements. Similarly, citizens need to be made aware of ‘hidden’ natural capital such as small water bodies, the wetlands, and the Yamuna floodplains.

Despite the immense potential to achieve change, public participation is still woefully low. Sensitization and reinforcement is required, perhaps through the use of social networking and Internet media. Engaging grassroots at any scale, especially regionally or globally, requires a technological platform. ‘Open source’ networks promote collaborative problem solving—this approach has several successful case studies from Linux to Wikipedia. There are currently several networking websites for biodiversity and sustainable urban development available at a global and national level. However, the majority of Indian websites have incomplete data and are unprofessionally managed. Online databases could list successful case studies of collaborations with local communities to restore ecosystems and enhance biodiversity. Information should be shared in a professional and efficient manner through case studies on ‘lessons learned’ that could assist in replication. Small-scale partnerships have demonstrated success in Delhi, thus, the plan should be to scale up to city and megacity levels.

Social pressure methods have been used to publicly ‘label’ offenders that did not participate in local recycling and energy-use programmes, with mixed results. The debate on whether incentives work better than taxes and penalties is a valid one. Local environmentalists have been considering economic incentives such as ‘water credits’ in a system similar to ‘carbon credits’. Other economic benefits could serve to increase public participation. In Delhi, communities have been able to earn income by creating and selling compost, organic fruits, and vegetables to local residents. It is imperative to understand the necessity of placing a monetary value on ecosystem services to understand their importance. This might not be required if natural capital already had an intrinsic value, which might be the case for individuals and communities that have developed clear ownership and a relationship with their surrounding environment. There needs to be a stronger level of awareness before one sees a committed grassroots movement emerging. The ‘Bhagidari’ (‘partnership’) programme sought to establish a stronger citizen-government link and promote decentralized civic management (UNDP 2000). Community groups have grown from 20 groups in 2000 to about 1700 groups, covering 3 million people in 2006 (Delhi Human Development Report 2006). Community-based governance integrates political and social systems and is, therefore, sustainable, provided financial support is available. ²⁸

It is important, at this point, to consider whether it is possible for cities to accommodate a growing population and increasing per capita levels of consumption in the quest for better standards of living. In light of this, the necessity for smarter development and urban environmental management to strive for a better quality of life also becomes a question that cannot be ignored. Delhi has many cases of the poor losing out to the environment, however, policy-makers and pro-poor groups must realize that green and brown agendas are not mutually exclusive. Case studies have shown that the governed use of natural resources is only possible if the government provides sustainable infrastructure for the marginalized (WWICS 2004). Biodiversity and natural capital can exist alongside infrastructure for marginalized sectors. Instead of being relocated to make space for natural capital, if the poor were provided with livelihoods connected to local biodiversity, then they could establish a mutually beneficial relationship. Silvipasture, that is, grazing livestock, is a commonly observed practice in and around New Delhi. Urban agriculture (beekeeping, fish farming, orchards, vegetable gardens, medicinal plants, and agro-forestry) offers many possibilities for inclusion of the poor as well as self-reliance and a measure of food security (IADB 1997). In Delhi, several trees serve food and medicinal purposes such as Khair (Acacia catechu), Sonjna (Moringa oleifera), and Bael (Aegle marmelos) (Krishen 2006). While urban farming has its benefits, it should strive to be small-scale, organic, and rely on drip irrigation practices that have proved successful in arid regions. In fact, non-resource intensive practices would be easier to sustain for the poor. Biodiversity is a provider of jobs for the informal sector, which encompasses the more marginalized sections of society. In Delhi, several rural migrants are self-employed gardeners. A different Delhi, not too long ago, harboured mini-entrepreneurs that showcased wild biodiversity in urban areas. There were snake-wallahs, dancing bears, and elephant rides for children. Animal rights groups have put an end to these practices citing inhumane conditions for the wild animals. However, inspiration from the past can be drawn to engineer alternative relationships between a city’s local biodiversity and its people, with a motivation to educate rather than entertain.

²⁸ The government has decentralized management of parks and green belts to respective Resident Welfare Associations (RWAs). They pay an insuffi cient INR 1 (USD 0.02) / sq. m. to a maximum of INR 10 000 (USD 220) / month to RWAs for maintenance.

Conclusions

The value of biodiversity is applicable, not simply in the rural or urban context, but in the human context. Scientific studies have proved the existence of the bond between humans and nature—that a natural and healthy ecosystem is intrinsic to life and human well-being. The irreversible loss of native biodiversity has an impact on multi-scale ecosystem functioning. The public and policy-makers must recognize that proactively managing urban biodiversity and natural capital is imperative.

A direct relationship between urban biodiversity and local people needs to be inculcated through networks of green and blue spaces. City dwellers must have access to and be responsible for ecosystem functions. Market-driven innovations like social enterprise and eco-entrepreneurship engage the grassroots, resulting in informal networks that are often more efficient than formal networks and can be tapped for sustainability and conservation. The basis of this change is increasing awareness and local capacity building, which must be an aggressive cross-scale campaign. Increasing public participation can safeguard local biodiversity from the negative effects of urbanization. Local awareness can also have a far-reaching positive impact on regional and global biodiversity through more sustainable lifestyles.

Innovative solutions exist without compromising urban development. Developers and planners need to break free of a myopic view that urbanization cannot or should not be more sustainable and ecologically oriented. Urbanization is not a pronouncement for inevitable biodiversity loss and natural resource degradation. It is the set of formal and informal urban processes that must be reconsidered. Cities should interface more successfully with their natural surroundings instead of becoming concrete islands. Following the complementary ecosystem and natural capital approach with a strong scientific basis will provide a guideline for planners and policy-makers and engender collaborative understanding.

Although cities have historically relied on their hinterlands, a fundamental shift towards more self-reliant spaces is required in order to minimize the impact that urbanization has on the global environment. This would augment local resource security in an increasingly insecure world. Innovation is constantly
required in cities to make the best use of finite resources. A strong interdependence is evident, as urban biodiversity and natural capital also require human intervention in the form of ecosystem management.

‘Sustainable megacities’—some would consider the term an oxymoron, others a viable long-term objective. To this author, no concept outlines the inherent paradox in the field of sustainable development more and yet provides hope for a better future. The challenge as well as the opportunity lies within the complexity of cities, which have, much like nature itself, become sites of interdependencies and innovation.

References

Akbari H, Pomerantz M, Taha H. 2001.Cool surfaces and shade trees to reduce energy use and improve air quality in urban areas. Solar Energy 70(3): 295–310 pp.

Barton J and Pretty J. 2010. What is the best dose of nature and green exercise for improving mental health? a multi-study analysis. Environmental Science & Technology 44(10):3947–3955 pp.

Baumann N. 2006. Ground-nesting birds on green roofs in Switzerland: preliminary observations. Urban habitats, Green Roofs and Biodiversity 4(1):37–50 pp.

Brenneisen S. 2006. Space for urban wildlife: designing green roofs as habitats in Switzerland. Urban Habitats, Green Roofs and Biodiversity 4(1):27–36 pp.

Cave J and Ruet J. 2010. When emerging cities set standards, in CITIES: Steering towards sustainability, pp. 221–231, P Jacquet, R K Pachauri, L Tubiana. New Delhi: TERI.

Chaudhary V, Jacks G, Gustafsson J. 2002. An analysis of groundwater vulnerability and water policy reform in India. Environmental Management and Health 13(2/3): 175 pp.

Coulomb M. 2008. Urban ecology: taking measure of the coming megacity’s impact. Arizona State University. Details available on , last accessed on 20 August 2009

Dutt S. 2000. Megacities of joy: a case study of Calcutta’s environmental problems in the age of globalization. Australian Journal of International Affairs 54(3): 373–388 pp.

Planning Department, Government of the National Capital Territory of Delhi. 2008/09. Economic Survey of Delhi. Details available on http://www.delhi.gov.in/wps/wcm/connect/DoIT_Planning/planning/our+services/economic+survey+of+delhi

Eleventh Five-year Plan. 2007–2012. Inclusive growth: vision and strategy. New Delhi: Planning Commission, Government of India

Fam S, Mosley E, Lopes A, Mathieson L, Morison J, Connellan G. 2008. Irrigation of urban green spaces: a review of the environmental, social, and economic benefits. Cooperative Research Centre for Irrigation Futures. Technical Report No. 04/08

FSI. 2009. India state of the forest report. Forest Survey of India. Details available on http://www.fsi.nic.in/sfr_2009.htm

Galef J. 2009. Sustainable urbanization: bold vision or oxymoron? Metropolis. Details available on , last accessed on 19 June 2009

Goodstein E. 1995. The economic roots of environmental decline: property rights vs. Path dependence. Journal of Economic Issues 29(4): 1029–1053 pp.

Grimm N B, Faeth S, Golubiewski N, Redman C, Wu J, Bai X, Briggs J M. 2008. Global change and the ecology of cities. Science 319 (5864): 756–760 pp. Details available on , last accessed on 20 August 2009

Harvey B, Devasar N, Grewal B. 2006. Birds of Delhi and Haryana. New Delhi. Rupa Publishing

Hope D, Gries C, Zhu W, Fagan W F, Redman C L, Grimm N B, Nelson A L, Martin C, Kinzig A. 2002. Socioeconomics drive urban plant diversity. Proceedings of the National Academy of the Sciences of the United States of America 100(15): 8788–8792 pp.

IIED. 2006a. Ecological urbanization. Environment and Urbanization Brief 13 18(1):1-6 pp.

IIED.2006b. Towards a real world understanding of less ecologically damaging patterns of urban development. Environment and Urbanization Brief 14 18(2):1-6 pp.

Jim C and Chen W. 2008. Assessing the ecosystem service of air pollutant removal by urban trees in Guangzhou (China). Journal of Environmental Management 88(4): 665–676 pp.

Khera N. 2009. Interrelationships of birds and habitat features in urban green spaces. New Delhi: Department of Natural Resources, TERI

Khera N, Das A, Srivastava S, Jain S. 2009. Habitat-wise distribution of the House Sparrow (Passer domesticus) in Delhi. Urban Ecosystems 13(1):147-154 pp.

Kilvington M and Allen W. 2004. Social aspects of biodiversity in the urban environment. Presented at 2003 Conference of the Royal New Zealand Institute of Horticulture Greening the City: bringing biodiversity back into the urban environment. Proceedings in publication.

Köhler M. 2006. Long-term vegetation research on two extensive green roofs in Berlin. Urban Habitats, Green Roofs and Biodiversity 4(1): 3–26 pp.

Kraas F. 2007. Megacities and global change: key priorities. Cologne: Department of Geography, University of Cologne

Krishen P. 2006. Trees of Delhi: A field guide. India: Dorling Kindersley

Lawn P. 2008. How much progress has recently been made in India? Finding out with the use of the Genuine Progress Indicator. International Journal of Environment and Sustainable Development. Details available on http://www.inderscience.com/search/index.php?action=record&rec_id=21902&prevQuery=&ps=10&m=or

Lee K N. 2006. Urban sustainability and the limits of classical environmentalism. Environment and Urbanization 18(1): 9–22 pp. Details available at http://eau.sagepub.com/content/18/1/9.full.pdf+html

Lovelock J.1979. Gaia: a new look at life on earth. London: Oxford University Press

Manning W. 2008. Plants in urban ecosystems: essential role of urban forests in urban metabolism and succession toward sustainability. International Journal for Sustainable Development & World Ecology 15(4): 362–370 pp.

MoEF. 2008. National Biodiversity Action Plan. New Delhi: Ministry of Environment and Forests, Government of India

MoUD. 2007. Master Plan of Delhi – 2021. New Delhi: Ministry of Urban Development, Government of India

Mukhopadhyay P. 2010. India: when urban lifestyles determine the climate. CITIES: Steering towards sustainability, pp. 69–79, P Jacquet, R K Pachauri, L Tubiana. New Delhi: TERI. 271 pp.

NCT. 2010. State of the Environment Report for Delhi, 2010. New Delhi: Department of Environment and Forests, Government of NCT of Delhi

Phoolka H S. 2009. Planting 25 000 trees in Delhi on 25th anniversary of November 1984 carnage. New Delhi: Gyan Sewa Trust Press release

Pickett S and Cadenasso M. 2006. Advancing urban ecological studies: frameworks, concepts, and results from the Baltimore Ecosystem Study. Austral Ecology 31(2): 114–125 pp.

Pickett S and Cadenasso M. 2008. Linking ecological and built components of urban mosaics: an open cycle of ecological design. Journal of Ecology 96(1):8–12 pp.

Raghavendra K, Sharma P, Dash A P. 2008. Biological control of mosquito populations through frogs: opportunities and constraints. Indian Journal of Medical Research 128(1): 22–25 pp.

Rees W. 1998. The built environment and the ecosphere: a global perspective. Green Building Conference’ 98. Details available on http://www.greenbuilding.ca/gbc98cnf/speakers/rees.htm

Rees W. 1999. Scale, complexity, and the conundrum of sustainability. Planning Sustainability, pp. 101–127, M Kenny and J Meadowcroft (ed.). London, New York: Routledge.

Ryan P. 2003. Sustainability partnerships: eco-strategy theory in practice? Management of Environmental Quality 14(2/3) 256 pp.

Sangha K K and Jalota R K. 2005. Value of ecological services of exotic eucalyptus tereticornis and native dalbergia sissoo tree plantations of North-Western India. Conservation and Society 3(1):
92–109 pp.

Sassen S. 2010. Bridging the Ecologies of Cities and of Nature, in CITIES: Steering towards sustainability, pp. 203–213, P Jacquet, R K Pachauri, L Tubiana. New Delhi: TERI. 271 pp.

Soni V. 2007. Three waters – an evaluation of urban groundwater resource in Delhi. Current Science 93(6): 760–761 pp.

Soni V and Parikh S. 2008. Nature has rights too. Infochange India News and Features April 2008. Details available on http://infochangeindia.org/200804087022/Environment/Analysis/Nature-has-rights-too.html

Torrens P M. 2008. Modelling megacity futures. Symposium on megacities. Sonny Astani Department of Civil and Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, 10 November 2008

UNDP. 2000. Regional environmental governance programme for Asia Pacific. Case Study proposal: Bhagidari: Citizen - Government Partnership. Details available on http://www.undp.org/capacity2015/asia/docs/case_study/Bhagidari%20Proposal.htm

UNFPA. 2007. State of the World Population 2007. Details available on http://www.unfpa.org/swp/2007/english/introduction.html

UN Habitat. 1995. Urban problems mushrooming first ever database. Details available on http://www.un.org/Conferences/habitat/unchs/press/bestpr.htm

Voora V A and Venema H D. 2008. The natural capital approach: a concept paper. Canada: Environment Canada – Policy Development Division

WaterAid. 2005. Profiling “informal city” of Delhi. Report by WaterAid India.

Webb F.2008. Special report: future cities. CNN Traveller. Details available on , last accessed on 19 June 2009

WWICS. 2004. Comparative urban studies project: forum on sustainable infrastructure and service delivery for the urban poor. Regional Focus: Asia. 24–25 June 2004. New Delhi, India.

Urban biodiversity: an essay on natural capital and social innovation using Delhi as an example*