1. Valuing the city’s trees- An evaluation of CAVAT and i-Tree Forest Assessments Using Public Perception of Ecosystem services
Hazel Mooney Student Sustainability Research Conference 2019
With thanks to: United Bank of Carbon, The Woodland Trust,
University of Leeds Sustainability Service and Leeds City Council

2. What are ecosystem services?
Benefits provided by the natural environment, to people, including regulating, provisioning, cultural and supporting services (MA, 2005)
Provisioning services- goods that humans obtain from ecosystems
Regulating services- benefits provided by regulatory processes
Cultural services- ‘non material benefits obtained’
Supporting services- essential to the functioning of the prior 3 categories
Ecosystem services provide the opportunity to largely improve quality of life (DEFRA, 2007)
In the UK, 90% of people live in urban areas (Dallimer et al. , 2012)
Urban trees ‘all trees within the urban realm, in public and private spaces, along linear routes, waterways and In amenity areas’ (Doick et 2019)
Ecosystem services
Supporting
Soil protection,
biodiversity, nutrient cycling
Provisioning
Wood, fruit, chemicals
Cultural
Environmental education, recreation, aesthetic
Regulating
Climate regulation, air pollution regulation, water regulation

3. Services provided by trees
Arboricultural assessments across the globe have placed emphasis on the regulating and cultural services provided by trees (Nowak et al., 2009; Trees for Cities, 2018; Doick et al., 2017; Tree Council., 2008)
Regulating services:
Air pollution regulation
Carbon sequestration and storage
Avoided run-off and flood alleviation
Mitigation of the Urban Heat Island effect
Ecosystem services
Supporting
Soil protection,
biodiversity, nutrient cycling
Provisioning
Wood, fruit, chemicals
Cultural
Environmental education, recreation, aesthetic
Regulating
Climate regulation, air pollution regulation, water regulation

4. Cultural services
Ecosystem services
Supporting
Soil protection,
biodiversity, nutrient cycling
Provisioning
Wood, fruit, chemicals
Cultural
Environmental education, recreation, aesthetic
Regulating
Climate regulation, air pollution regulation, water regulation
Culture and spirituality Aesthetic value and appreciation Education Health and recreation Psychological wellbeing

5. Natural capital
Natural capital is the Earth’s stock of natural assets including forests, minerals, land, oceans, and the flow of services we receive from those (Peedle, 2019).
The purpose? To enhance and maintain the delivery of ecosystem services from the natural environment by accounting for their asset value, to aid decision making.
Both i-Tree and CAVAT apply the concept of natural capital, to capture the value of the ecosystem services they assess, to the people who benefit from them

6. Research Aim
By investigating public perception of ecosystem services provided by trees, can this inform how we assess and manage urban forests?
Objectives:
1) To measure the ecosystem services provided by trees in Middleton and Leeds and identify the value of those.
2) To identify the value that trees in Middleton and Leeds provide as amenity assets
3) To evaluate the public perception of both ecosystem and amenity services provided by trees and how these are valued.

7. Data collection
2 survey methods used to capture ecosystem services provided by trees across the city
2 survey sites- Leeds University Campus and Middleton Park Ward
Regulating services- i-Tree Eco (objective 1)
Cultural services- Community Asset Valuation for Amenity Trees (CAVAT) (objective 2)
Public questionnaire- investigating the public perception of services provided by trees, and the monetization of them (objective 3)

8. i-Tree Results
Conversions using UK government values of carbon (BEIS, 2017) and social damage costs (GOV, 2017)
Trees on Campus found to have higher values than Middleton
Average £679 Campus, £267 Middleton
Carbon sequestration values make the largest contribution
Campus trees ~2x more valuable
Correlation test: strongest influence on i-Tree output- DBH
Total plot value
Campus
Middleton
i-Tree
£92,416
£39,541
CAVAT
£944,283
£500,321

9. Average values for input variables of CAVAT
CAVAT Results
CAVAT values take into account population density- how many people are benefitting from that tree
Trees on Campus found to have higher values than Middleton
Average £6943 Campus, £3747 Middleton
Contrasts in each of the measured variables  higher output for Campus
Correlation test: no strong influence of one variable, all make equal contributions
Average values for input variables of CAVAT
Variable
Middleton
Campus
DBH (cm) 19 28
Location 60 70
Structure 67 77
Health 73 97
Amenity 5 2
Life expectancy (years) 92 90

10. Public perceptions
Study questionnaire: key questions How do the public perceive the different ecosystem services?
Which services are best understood?
What are the most valuable attributes of trees?
What are the least valuable attributes of trees?
What value to the public estimate the trees to be worth?
Natural capital serves to inform decision makers
How beneficial is natural capital for presenting the services as a value?
Leeds City Council reported that they receive 4,500 s per year regarding forest management, with only 55% resulting in any action (LCC, 2018)
The public want to be involved in urban forest management, but do their cases conflict with the priorities of the local authority?

11. Questionnaire Results

12. Monetary values

13. Conclusions and recommendations
How effective are the survey methods at representing the trees as they are perceived by the public? How can this information be used by local authorities? Any recommendations for management of urban forests? What opportunities are there for further research? Limitations of the study

14. References
Hazel Mooney,