Postdoctoral Research Fellow, The University of Melbourne
What happens to animals and people when trees are removed from urban green spaces
Urban trees can help solve many urban sustainability problems, including the effects of urbanization on nature and people, and climate change. While many cities have ambitious targets to plant more trees, many municipalities also spend millions of dollars removing trees every year. Large, old trees sometimes pose a hazard to human safety and hinder construction activities, and hence are often removed. Given that the services that trees provide are more significant as trees age and increase in size, when large trees are removed there is a rapid loss, absence, and slow recovery environmental services, such as shade and control of storm-water runoff. However, today there is no clear understanding of the biodiversity, psychological, and social effects of tree removal. This is because very few experimental studies focused on measuring these effects have been carried out. The team I lead is currently undertaking an innovative before-after-control-impact experimental investigation on the impact of tree loss on biodiversity and psycho-social parameters in the City of Melbourne. The study focused on the changes in animal behaviour and psycho-social processes. For this wee are tagging possums with radio collars and tracking people's movements as well as assessing their well-being, before and after trees are removed from selected sites. We would be thrilled to present our results at the first-ever World Urban Forest Forum so we can share our novel research with the global community in charge of tree-care and maintenance in cities. Our research could significantly improved the way urban trees are evaluated for their social and biodiversity services.
Abstract: Publication date: June 2017 Source:Current Opinion in Environmental Sustainability, Volumes 26–27 Author(s): Christopher D Ives, Matteo Giusti, Joern Fischer, David J Abson, Kathleen Klaniecki, Christian Dorninger, Josefine Laudan, Stephan Barthel, Paivi Abernethy, Berta Martín-López, Christopher M Raymond, Dave Kendal, Henrik von Wehrden In sustainability science calls are increasing for humanity to (re-)connect with nature, yet no systematic synthesis of the empirical literature on human–nature connection (HNC) exists. We reviewed 475 publications on HNC and found that most research has concentrated on individuals at local scales, often leaving ‘nature’ undefined. Cluster analysis identified three subgroups of publications: first, HNC as mind, dominated by the use of psychometric scales, second, HNC as experience, characterised by observation and qualitative analysis; and third, HNC as place, emphasising place attachment and reserve visitation. To address the challenge of connecting humanity with nature, future HNC scholarship must pursue cross-fertilization of methods and approaches, extend research beyond individuals, local scales, and Western societies, and increase guidance for sustainability transformations.
Pub.: 26 Jun '17, Pinned: 16 Mar '18
Abstract: Cities are rapidly expanding world-wide and there is an increasing urgency to protect urban biodiversity, principally through the provision of suitable habitat, most of which is in urban green spaces. Despite this, clear guidelines of how to reverse biodiversity loss or increase it within a given urban green space is lacking.We examined the taxa- and species-specific responses of five taxonomically and functionally diverse animal groups to three key attributes of urban green space vegetation that drive habitat quality and can be manipulated over time: the density of large native trees, volume of understorey vegetation and percentage of native vegetation.Using multi-species occupancy-detection models, we found marked differences in the effect of these vegetation attributes on bats, birds, bees, beetles and bugs. At the taxa-level, increasing the volume of understorey vegetation and percentage of native vegetation had uniformly positive effects. We found 30–120% higher occupancy for bats, native birds, beetles and bugs with an increase in understorey volume from 10% to 30%, and 10–140% higher occupancy across all native taxa with an increase in the proportion of native vegetation from 10% to 30%. However, increasing the density of large native trees had a mostly neutral effect. At the species-specific level, the majority of native species responded strongly and positively to increasing understorey volume and native vegetation, whereas exotic bird species had a neutral response.Synthesis and applications. We found the probability of occupancy of most species examined was substantially reduced in urban green spaces with sparse understorey vegetation and few native plants. Our findings provide evidence that increasing understorey cover and native plantings in urban green spaces can improve biodiversity outcomes. Redressing the dominance of simplified and exotic vegetation present in urban landscapes with an increase in understorey vegetation volume and percentage of native vegetation will benefit a broad array of biodiversity.
Pub.: 23 Feb '17, Pinned: 16 Mar '18
Abstract: •Understanding how the public values the urban forest can enhance management.•Values were explored using mixed methods with 1289 participants/respondents in four Canadian and three Colombian cities.•Quantitative, survey-based research methods: elicit aesthetic and environmental values.•Qualitative, collective, experiential research methods: elicit all values and enrich psycho-social and natural-ecological themes.
Pub.: 01 Jul '17, Pinned: 16 Mar '18