Seite - 198 - in Biodiversity and Health in the Face of Climate Change

198 Biodiversity levels were not equally covered by the 24 studies (see Fig.  9.4). Fifteen studies assessed biodiversity at the ecosystem/habitat level, with clear decreases to the single species level. However, the number of studies investigating biodiversity at these other levels has  increased since Lovell et  al. (2014). 9.3.2.1 Pattern of  Results To identify patterns in the results, we examined studies by biodiversity level and mental health and well-being outcomes (Table  9.5). We also identified the specific biodiversity variable that was measured (e.g. habitat types, birds) next to each result. The purpose was to gain insight into when biodiversity influences mental health and well-being and when it does not. Mental Health and  Well-being Outcomes We started by looking at the results by outcome measure to determine if either out- come was more influenced by biodiversity. Nine studies investigated mental health outcomes, the majority of which were published after 2012, demonstrating a growth area for the field since Lovell et  al. (2014). Mental well-being was investigated in 19 of the 24 studies. Two-thirds of the results (65%) pertaining to the influence of 15 10 5 0 Number of studies since Lovell et al. (2014) Number of Lovell et al. (2014) studies Ecosystem /Habitat Species richness Perceived species richness Single speciesAbundance Cumulative number of studies by biodiversity level Fig. 9.4 Biodiversity levels addressed by the 24 studies on the mental health and well-being effects of biodiversity. The sum may exceed 100% because studies address more than one level of biodiversity M. R. Marselle et al.