Seite - 260 - in Biodiversity and Health in the Face of Climate Change

260 involved, and the age group of the participants (e.g. Ward Thompson 2013). For example, playing (informal) football requires a large amount of open space with significant buffer zones separating the activity from other uses (Golicnik and Ward Thompson 2010). Such space would not tend to be particularly biodiverse. Runners and cyclists may prefer more open environments, whilst walkers may select more structured habitats. Site management may exploit such preferences to avoid con- flicts (and even collisions) on shared tracks (Santos et  al. 2016). People report greater enjoyment of outdoor exercise compared to equivalent exercise performed indoors (Thompson Coon et  al. 2011). However, Shanahan et  al. (2016) identify a knowledge gap in understanding which characteristics of nature are important in promoting physical activity. Exercise also benefits the immune system (Pedersen et  al. 2007): general exercise releases myokines, and this effect is greater in colder environments, such as when exercising outdoors in a temperate climate. Myokines induce an inflammatory/pro-inflammatory response control, influencing the func- tion of chronic inflammation, and can positively affect cognition, reduce depression and reduce inflammatory responses associated with osteoporotic disease (Kaji 2016).  For a detailed discussion on green space  interventions to promote physical activity, see Hunter et  al. Chap. 17, this volume. 11.2.6 Mental Health While the direct association between appreciation of different levels of biodiversity and well-being are clear, this is less so for mental health (as measured by the absence of mental disorders such as anxiety or depression). However, there is a clear link between access to natural environments and mental health (World Health Organization 2016). Bragg and Atkins (2016) suggest that three key components (being in the envi- ronment, meaningful activities within the environment, and the social context) can positively influence mental health. Both active participation in greenspace and observ- able greenspace are significant in achieving mental health benefits (Nutsford et  al. 2013), and horticultural activities programmes for older people lead to reduced levels of depression and improved life satisfaction (Masuya et  al. 2014). There is some evi- dence that exposure to ‘beautiful’ nature (potentially equating to perceived biodiver- sity) promotes socially desirable behaviours (Zhang et  al. 2014). Beyer et  al. (2014) suggested that greening could be useful within a population mental health strategy. For a more in-depth discussion on mental health and biodiversity,  see de Vries and Snep Chap.8, this volume, and Marselle et  al. Chap. 9, this volume. 11.2.7 Physical Health  – Infectious Disease (Disease/Pathogen Reduction) The links between biodiversity and infectious disease are complex. Although Bernstein (2014) suggested a possible swamping of disease transmission agents by larger spe- cies diversity, Wood et  al. (2014) identified no such reduction for many diseases, P. A. Cook et al.