Managing multiple ecosystem services

Abstract

As human populations continue to grow, there is increasing demand to manage landscapes to increase the provisioning of multiple ecosystem services. However, this is challenging due to the negative (trade-off) and positive (synergistic) relationships that often exists among services. Understanding where and why these relationships occur should facilitate the implementation of better policies and strategies that can effectively manage multiple services simultaneously. However, our current understanding of what drives ecosystem service relationships, and the consequences for managing ecosystem services, remains limited. In this thesis, I address this by demonstrating the importance of understanding the drivers behind ecosystem service provision and the resulting trade-offs and synergies, and then apply this understanding to manage complex landscapes for multiple ecosystem services.In chapter 1, I discuss the conceptual theory behind ecosystem service relationships and how this information could be used to effectively manage multiple ecosystem services. I then outline the steps I undertake in this thesis to demonstrate this. I then conduct a literature review in chapter 2 to determine how the drivers of ecosystem service relationships, and the mechanisms linking these drivers to ecosystem service outcomes, are currently being investigated in assessments of ecosystem service synergies and trade-offs. I find that the majority of assessments of ecosystem service relationships do not explicitly identifying the drivers of these relationships. This is strongly related to the methods used to identify the trade-offs and synergies, with the less commonly used process-based approaches better equipped to explicitly identify the drivers underpinning ecosystem service relationships.I then develop models to identify the drivers underpinning the provisioning of multiple cultural ecosystem services in urban public greenspace, using the urban parks network of Brisbane, Australia, as a case study in chapter 3. Using data derived from a social survey and remotely sensed data, I demonstrate that the use of public parks for four cultural services (opportunities for physical exercise, nature interactions, relaxation and social interactions) are associated with spatial, environmental and facility characteristics of urban parks. However, physical exercise and social interactions are also driven by the socio-demographic characteristics of the people visiting the parks to receive these services. These results suggest that by introducing management actions that target specific variables within urban parks it may be possible to facilitate the provision of multiple cultural ecosystem services simultaneously.I then build upon the findings of chapter 3 to assess the implications of ecosystem service trade-offs and synergies on the management of multiple ecosystem services across the Brisbane parks network in chapters 4 and 5. In chapter 4, I conduct a scenario analysis to identify the trade-offs and synergies among the cultural ecosystem services identified in chapter 3 and carbon storage, and how these relationships vary under different revegetation management strategies commonly implemented in urban parks. I find that the relationships among the ecosystem services depend on the type of revegetation management strategy considered. This indicates that careful consideration of relationships among services could ensure the implementation of strategies that minimise trade-offs among services. In chapter 5 I use this underlying model to identify the optimal spatial allocation of multiple management actions to achieve targeted increases in the provision of carbon storage and the same set of cultural services across the Brisbane park network. I also consider the consequences of considering social equity in ecosystem service access and management and compare socially equitable and inequitable optimal solutions. I find that implementing strategies that consist of multiple management actions achieve greater increases in multiple ecosystem services. Furthermore, I find that accounting for social equity restricts the extent to which ecosystem service can be increased to, while also increasing management costs.Finally, in chapter 6 I synthesise the main findings of the previous chapters, and discuss the contributions of this thesis to the literature and future research directions. Currently, few studies explicitly identify the drivers of ecosystem service relationships, but this thesis demonstrates that considering drivers is vital to managing multiple ecosystem services effectively. Although this can be challenging, explicitly incorporating these drivers into assessments of ecosystem service relationships can ensure more effective management of multiple ecosystem services across landscapes. Ideally, to improve the management of multiple ecosystem services simultaneously, future research should focus on working towards more causally-explicit approaches to identify ecosystem service relationships, and on incorporating social equity into ecosystem service management strategies.