Seite - 191 - in Biodiversity and Health in the Face of Climate Change

191 2015; Carrus et  al. 2015; Saw et  al. 2015; Wolf et  al. 2017), as was appraisal theory (Johansson et  al. 2014). Four studies (Duarte-Tagles et  al. 2015; Jones 2017; Rantakokko et  al. 2018; Wheeler et  al. 2015) did not articulate a theory for why or how biodiversity may be related to better health and well-being. 9.3.1.4 Biodiversity Assessment There was considerable variation across the 16 studies on the organisational level at which biodiversity was studied, the data collection method used, and the type of environment/organism investigated (see Table  9.2). Seven studies assessed biodi- versity at the ecosystem or habitat level. Measurement across these studies included use of secondary, geographically-referenced data to determine land cover and land use diversity using the Shannon Diversity Index (Rantakokko et  al. 2018; Wheeler et  al. 2015), eco-region diversity using the Margalef Diversity Index (Duarte-Tagles et  al. 2015) and access to protected areas (Saw et  al. 2015). Investigator categorisa- tion of ecosystem/habitat biodiversity was used to classify environments into low, medium and high biodiversity biotopes (Johansson et  al. 2014) or low vs. high bio- diverse green spaces (Carrus et  al. 2015). Participants’ perception of habitats/eco- system was used in one study; the Scania Green Score uses interpreted satellite imagery-derived land use data (i.e. mixed forest and marshes, beaches, sand plains and bare rock, biotopes and national parks) to map perceived biodiversity (‘lush, rich in species’) of an environment (Annerstedt van den Bosch et  al. 2015). At the species community level, 6 studies assessed biodiversity in terms of species rich- ness for various taxa (i.e. birds, butterflies, plants, trees, fish/crustaceans). Species richness was measured using standard ecological field survey techniques (Cox et  al. 2017; Cracknell et  al. 2016), secondary data (Wheeler et  al. 2015) or investigator categorisation of species richness (e.g. low vs. high based on assessment of content in images or videos (Cracknell et  al. 2017; Wolf et  al. 2017)). Participants’ percep- tion of species richness was employed in 3 studies (Marselle et  al. 2015, 2016; White et  al. 2017). At the species community level, abundance of a specific taxo- nomic group (i.e. birds, fish/crustaceans) was also assessed in 2 studies using stan- dard ecological survey techniques (Cox et  al. 2017), and investigator categorisation of stimuli (i.e. low vs. high abundance; Cracknell et  al. 2017). At the single species level, Jones (2017) investigated biodiversity loss and ecosystem health through the loss of North American ash trees (Fraxinus spp.) following the presence of the inva- sive species emerald ash borer (EAB) (Agrilus planipennis). This was assessed using secondary data. 9.3.1.5 Mental Health and  Well-being Assessment There was considerable variation in the outcomes considered and the measures used among the studies (Fig.  9.3). Mental health was assessed in 7 studies (Annerstedt van den Bosch et  al. 2015; Cox et  al. 2017; Duarte-Tagles et  al. 2015; Foo 2016; 9 Review of  the  Mental Health and  Well-being Benefits of  Biodiversity