University of Melbourne, Australia
The number of publications on urban ecosystem services (ES) has increased dramatically in recent years. While numerous studies have investigated ES provision from the public realm (e.g., public green spaces, urban parks and reserves, streetscapes) (Lovell & Taylor, 2013), fewer have explicitly accounted for the provision of public ES from residential gardens and, more generally, the private realm (e.g., Cameron et al., 2012; Larson et al., 2015). This article will highlight some major opportunities and limitations regarding the private provision of public ecosystem services (PPPES) in order to offer some stimuli for further research and facilitate interactions between researchers and urban practitioners interested in ES provision.
Table 1: Opportunities and limitations in the private provision of public ecosystem services (PPPES) in urban areas.
|Extent, continuity and security of ES provision||Variability of ES provision|
|Spatial distribution of ES provision||Less control on services/disservices provision|
|Bottom-up approach, engagement||Costs|
|Education, information||Conflicting private interests|
|Innovation, drive for change||Lack of information/knowledge on PPPES|
|Future generations, social responsibility||Lack of planning, regulatory schemes, incentives|
Public and Private Providers
In many cities worldwide, private ES providers outnumber public providers. In Australia, for example, there are more than 6.7 million homeowners managing private gardens versus 52,000 recreational parks and reserves managed by public authorities (Fig. 1). A greater number of ES providers is likely to i) enhance the overall ES provision within the urban landscape and ii) ensure better continuity and security of ES provision over time (Table 1). For example, the overall habitat provision for biodiversity is frequently higher in residential gardens (Goddard et al., 2010), as compared to public urban parks within a neighbourhood. Moreover, while the loss of one or few private gardens might not impact the local biodiversity, the disappearance of a single large public green space might have significant detrimental effects. Compared to public green spaces, private ones tend to be more scattered and widespread within the urban matrix. Therefore, PPPES can theoretically help to de-centralize ES provision for some key services such as urban heat island mitigation or stormwater infiltration, which require a landscape-explicit approach.
The first limitation of PPPES derives directly from the vast numbers of private and public providers involved. Private ES provision is likely to be more spatially variable compared to public provision. Private residential gardens are managed following an immense variety of practices and intensities, which can have contrasting effects on ES provision including the generation of some ecosystem disservices. For example, the application of insecticides and pesticides for garden pest control can also have deleterious effects on beneficial biodiversity in the neighbouring properties. PPPES is also likely to be more temporally dynamic compared to public ES provision. Social norms, economic drivers, personal preferences and attitudes tend to change faster compared to factors driving public ES provision such as legislative frameworks and policies. In the last few years, the increasing car ownership and the preference for larger houses have caused many yards to be paved with indirect negative effects on water runoff generated by private properties. Homeowner associations can represent potential partners able to ensure and encourage PPPES continuity and control its variability. These associations already work to pose limits to landscaping and gardening activities (e.g., Martin et al., 2003), but they could also be engaged to incorporate standard PPPES-friendly practices within a large number of private ES providers (Lerman et al., 2012).
A Co-Benefit Approach to PPPES
Compared to public providers, private providers lack a formal mandate for ES provision. Additionally, most private ES providers are not even aware that their properties, assets or gardens are generating (or might generate) valuable ES for their communities. Consequently, private ES providers tend to internalize direct and indirect costs connected to ES provision. Conversely, public providers can obtain substantial financial benefits and savings from PPPES. This poses some further risks for ES provision. First, socio-economic differences might be reflected in PPPES. Without regulation, PPPES could be unbalanced towards wealthy subsurbs, exacerbating social segregation and inequalities. Balancing private-public ES provision based on socio-economical factors and incentivizing PPPES in wealthy areas while increasing public ES provision in poorer areas could be beneficial to homogenize ES provision across urban landscapes. Secondly, private investments in ES provision are likely to be more volatile than public ones. Private ES providers might avoid unnecessary expenses linked to ES provision during periods of financial constraints, economic stagnation or crisis. Lastly, public initiatives to stimulate voluntary and compulsory PPPES generally offer little incentive to private ES providers, potentially discouraging new actors to join these programs. Adequate monetary and non-monetary benefits (e.g., grants, tax deductions, etc.) should be incorporated in public programs targeting PPPES, particularly where private ES providers face significant costs (e.g., depaving backyards or planting wildlife gardens).
A co-benefit approach could be implemented to favor PPPES. Private ES providers could be given free trees and shrubs to be planted in their gardens determining i) private benefits, such as higher property values typically observed in leafy suburbs, and ii) public benefits, such habitat provision for biodiversity, urban heat island mitigation or stormwater interception. Third parties related to private owners could be also engaged to set PPPES standards using a co-benefit approach. In the Little Stringybark Creek Initiative in Melbourne, Australia, developers and builders receive monetary benefits proportional to the amount of water retained by the newly built developments through the installation of water tanks, raingardens and green roofs. Indirectly, home buyers become private ES providers, generating public benefits such as runoff prevention and reduction of pollutants discharged in urban waterways. Private-public co-benefits schemes could ultimately spread finanacial burdens more evenly among ES providers facilitating the overall ES provision. They could be also applied to increase the number of private ES providers in areas where their presence is typically low (city centers and central business districts), promoting the creation of private green infrastructures, such as green roofs, walls and facades.
The Need for Greater Participation in Ecosystem Service Provision
While it is apparent that regulatory, planning and educational frameworks will be necessary to regulate PPPES, these are likely to be more successful if based on bottom-up approaches rather than traditional top-down mechanisms. New ideas and need for change arise more frequently amongst citizens rather than governments or politicians. For that reason, PPPES should be designed around positive community change and embrace popular innovation. Zmyslony & Gagnon (1998) described “Neighbours mimicry” as the tendency of neighbours to reciprocally copy garden features, planting structure and composition. They suggested this mechanism to be used to promote city council strategies which require people’s actions, such as those necessary for PPPES.
Regrettably, recent evidence suggests that younger generations will be increasingly living in dwellings without backyards, being progressively detached from gardening and nature. In Australia, “the death of the Australia backyard” has been finally predicted, as well as the end of “the quarter acre block dream”. Further investigations are urgently needed to determine whether PPPES will represent a viable strategy for urban practitioners to enhance ES provision in the next generation of sustainable, green and prosperous cities.
Alessandro Ossola is a Ph.D. Researcher in Urban Ecology, Urban Biodiversity, Ecology and Conservation Research Group and Green Infrastructure Research Group, Faculty of Science, Department of Forest and Ecosystem Sciences at The University of Melbourne, Burnley, Australia.
Header Image: Park in Melbourne, Australia. Credit: Greg Brave/Shutterstock.com