Page - 150 - in Biodiversity and Health in the Face of Climate Change

150 of safety (Potschin and Haines-Young 2011). From this perspective, the cascade model can also work upstream, from the ecosystem benefit to its related ecosystem function. For example, if human beings receive a benefit from a nature-based solu- tion for flood protection, then that flood protection measure is considered to be an ecosystem service, and its related function (e.g. slow passage of water) can be con- sidered an ecosystem function (Potschin and Haines-Young 2011). Importantly, biodiversity can have different roles in this cascade. Biodiversity can serve as a regulator of the underpinning ecosystem processes (e.g. through pol- linating insects), as an ecosystem service (e.g. as a harvestable crop that provides food or timber) or as a benefit (e.g. an emblematic species that is valued for its aesthetics, and may be enjoyed through wildlife watching) (Mace et  al. 2012). While mechanisms and linkages between biodiversity, ecosystem functions and ecosystem services are still being explored (Cardinale et  al. 2012), and there has been a recent debate over the terminology and the utilitarian viewpoint of the eco- system service approach (Díaz et  al. 2018; Peterson et  al. 2018), the Ecosystem Service Cascade Model still holds. 7.4.1 Connection to  Health and  Well-being in  the  Ecosystem Service Cascade Model Human well-being is not explicitly discussed in the Ecosystem Service Cascade Model. Instead, the Model focuses on benefits derived from biodiversity and eco- system services. Most of the research on the benefits of ecosystem services for human health and well-being focusses on the physical health benefits from provi- sioning and regulating ecosystem services (Sandifer et  al. 2015). However, a devel- oping area of literature investigates the mental well-being benefits from cultural ecosystem services (e.g. Bryce et  al. 2016; Fish et  al. 2016; Hegetschweiler et  al. 2017; O’Brien et  al. 2017). The exact casual pathways linking biodiversity to physi- cal and mental health and well-being through the Cascade Model are little under- stood (Sandifer et  al. 2015). 7.5 Discussion Interest in the mental  health and well-being benefits from biodiversity is growing (see Marselle et  al. Chap. 9, this volume). This chapter presents a general descrip- tion of six frameworks that can offer perspective on the relationships between bio- diverse natural environments and mental well-being. The aim was to provide an overview of these frameworks to enable future researchers to theoretically ground their investigations of biodiversity and mental well-being relationships. The frame- works are largely from the field of environmental psychology and represent the majority of theories used in biodiversity and health research (Lovell et  al. 2014). Table  7.2 provides a summary of these six frameworks. M. R. Marselle