Seite - 176 - in Biodiversity and Health in the Face of Climate Change

176 mental health and well-being. However, more studies reported non-significant results. The evidence is not yet of the extent necessary to characterise the role of biodiversity in relation to mental health or well-being. Future interdisciplinary research directions are discussed. Keywords Mental health · Mental well-being · Biodiversity · Species richness · Synthesis · Review Highlights • Research into the health and well-being effects of biodiversity has grown since Lovell et  al. (2014). • We update Lovell et  al. (2014) and focus on the impact of biodiversity on mental health and well-being. • 16 recently published studies on biodiversity and mental health and well-being were identified. • Synthesis of results found some evidence that biodiversity promotes better men- tal health and well-being. • Overall, more studies reported non-significant effects. 9.1 Introduction Contact with natural environments facilitates diverse health and well-being benefits (Bowler et  al. 2010; Frumkin 2001; Hartig et  al. 2014; Irvine and Warber 2002; Keniger et  al. 2013). However, in this body of research the natural environment is often “treated as uniform” (Dallimer et  al. 2012, p.  48), as studies commonly com- pare broad urban and natural environment categories (e.g.  Hartig et  al. 2003; Korpela et  al. 2016) or analyse the amount of, or proximity to, green space (e.g.  Groenewegen et  al. 2012; Triguero-Mas et  al. 2015). Whilst a substantial amount of literature investigates the impact of nature or green space on health and well-being, little is known about the contribution that different qualities of the natu- ral environment, such as biodiversity, have on mental health and well-being. Systematic reviews of the mental health or well-being benefits from contact with nature do not include studies that assess the biodiversity of the natural environment (e.g. Bowler et  al. 2010; Dadvand et  al. 2015; Thompson Coon et  al. 2011). This same body of literature on the mental health or well-being effects of nature is also present in systematic reviews of the health benefits of biodiversity (e.g. Horwitz and Kretsch 2015; Hough 2014; Whitmee et  al. 2015), resulting in a closed loop of examined literature. To date, only one systematic review has explicitly investigated the health and well-being benefits from contact with biodiversity (Lovell et  al. 2014). While the authors found some evidence for a positive benefit from exposure to biodiversity, overall, the synthesis of 15 quantitative studies showed no clear pat- tern of results for the effects of biodiversity on human health and well-being. M. R. Marselle et al.