Urban Vegetation, Wellbeing and Pro-environmental Behaviour: A Socio-ecological Experiment in Wellington City, New Zealand

The challenges ahead for sustainability and biodiversity conservation require a better understanding of the relationship human beings have with the natural environment. The evidence that nature has a positive influence on human wellbeing is extensive but there is uncertainty about the influence of urban vegetation in the immediate vicinity of residents’ homes. Current research is also inconclusive as to the mechanisms that underlie the relationship between nature, human wellbeing and pro-environmental behaviour. I investigated whether engagement with urban nature influenced the wellbeing and pro-environmental behaviour (PEB) of residents of Wellington City, New Zealand. Engagement with nature was specified by the amount of vegetation cover in urban neighbourhoods and participation in a community-planting scheme. Wellbeing was assessed by measures of mental and physical health and satisfaction with life. Firstly, I aimed to describe the population of people who participated in the community planting scheme and identify the motivation, barriers and benefits associated with participation. Secondly, I aimed to test hypotheses about the relationship between urban residents and the natural environment using Structural Equation Modelling (SEM): 1. Exposure to vegetation in residents’ immediate neighbourhood and/or participation in the planting scheme has a positive influence on residents’ wellbeing and PEB. 2. The effect of nature on wellbeing or PEB is mediated by a number of socio-psychological constructs, such as Connection with Nature, use of nature for Psychological Restoration, Neighbourhood Satisfaction, (both social and natural aspects of the neighbourhood) and Environmental Attitude. PEB also mediates the nature-wellbeing relationship. Finally, I wanted to determine if adding socio-demographic variables and the amount of time residents spent outdoors could improve the models. A stratified random sample of 20 neighbourhoods across Wellington City was selected. The neighbourhoods varied in their amount and type of vegetation cover. The amount of vegetation cover was determined by site visits and using maps, with a 5 x 5 m ² grid, which showed vegetation cover and property boundaries. I quantified the mediator and wellbeing variables using existing measures, some of which were modified, and by developing some constructs based on the literature. The usefulness of these constructs was confirmed by an Exploratory Factor Analysis in SPSS. I conducted a postal survey during October 2012 of 1200 households in the 20 neighbourhoods of Wellington City to test my hypotheses. Thirty-six percent of surveys were returned (N = 428) which resulted in 423 useable surveys. Respondents who participated in the planting scheme were more likely to be married or in a partnership, highly educated and New Zealand Europeans. They also had a greater connection with nature, used nature more for psychological restoration and had stronger higher environmental attitudes and PEB those respondents who did not participle in the planting scheme. The most frequently reported barrier to participation was the lack of time and the most commonly reported benefits corresponded to the stated motivation, which was to improve the appearance of participants’ immediate neighbourhood. A priori mediation models were specified. Structural Equation Modelling followed by Information Theoretic model selection and inference using Akaike Information Criterion identified the leading influences and tested the hypotheses for wellbeing and PEB. All the a priori models fitted the data. Model selection resulted in two parsimonious models being identified, the Wellbeing model and the Pro-environmental Behaviour model. The Wellbeing model explained 16%, 13% and 3% of the variance in mental health, life satisfaction and physical health, respectively. Both the amount of neighbourhood vegetation and participation in the planting scheme were associated with the wellbeing measures. Neighbourhood Satisfaction (both nature and social), the use of nature for Psychological Restoration and Pro-environmental Behaviour were significant mediators. The Pro-environmental Behaviour model explained 38% of the variance in PEB. Participation in the planting scheme was associated with increases in PEB but the level of neighbourhood vegetation was not. Connection with Nature was the sole mediator of the relationship between participation in the planting scheme and PEB. Socio-demographic characterisations and the amount of time people spent outdoors were not necessary to explain wellbeing or PEB beyond the effect of neighbourhood vegetation or participating in the planting scheme. A final combined model, Wellbeing +Pro-environmental Behaviour, explained more of the variance in mental health (22%), satisfaction with life (16%) and PEB (45%) than the individual Wellbeing and Pro-environmental Behaviour models but did not explain physical health. Connection with Nature and Environmental Attitude were additional mediators and the amount of neighbourhood vegetation level influenced PEB. The strength of the effects of vegetation level and the planting scheme on the wellbeing measures were about the same as in the Wellbeing model. This was a less parsimonious model. I have demonstrated that the resources invested into greening Wellington City added significantly to the quality of residents’ lives, via their relationship with nature and increased wellbeing, and were associated with increases in PEB. I have identified mediators that synergistically facilitate the relationship between urban vegetation, a community planting scheme, PEB and human wellbeing and helped clarify the positive effect of vegetation in the immediate vicinity of residents’ homes on residents’ wellbeing. The effect of biologically depauperate neighbourhoods on residents’ quality of life requires further investigation. My findings suggest the promotion of time in nature and increases in the amount of urban planting, particularly trees, may be an effective public health intervention and also result in increased PEB. The demonstrated diversity of nature’s benefits and value may provide motivation for greater investment in urban greening and broader conservation initiatives by government.