A Formulaic Expert Method to Integrate the Evaluation and Valuation of Heritage Trees

2005 | Professor C.Y. Jim, University of Hong Kong

Urban trees serve important environmental, social and economic functions, but similar to other natural endowments they are not customarily depicted in monetary terms. The needs to augment protection, funding and community support for urban greening call for proper valuation. Heritage trees (HTs), the cream of urban-tree stock, deserve special attention. Existing assessment methods do not give justice to outstanding trees in compact cities deficient in high-caliber greenery, and to their social-cultural-historical importance. They artificially separate evaluation from valuation, which should be a natural progression from the former. Review of tree valuation methods suggested the formula approach to be more suitable than contingent valuation and hedonic pricing, and provided hints on their strengths and weaknesses. This study develops an alternative formulaic expert method (FEM) that integrates evaluation and valuation, maximizes objectivity, broadly encompasses the key tree, tree-environment and tree-human traits, and accords realistic monetary value to HTs. Six primary criteria (dimension, species, tree, condition, location, and outstanding consideration) branched into 45 secondary criteria, each allocated numerical marks. Each primary criterion was standardized to carry equal weight, and a tree’s maximum aggregate score was capped at 100. A Monetary Assignment Factor (MAF) to consign dollar value to each score unit was derived from three-year average per m2 sale price of medium-sized residential flats. The applicability of FEM was tested on selected HTs in compact Hong Kong. The aggregate score of a tree multiplied by MAF yielded monetary value, which was, on average, 66 times higher than the result from the commonly-adopted Council of Tree and Landscape Appraisers method. The computed tree values could be publicized together with multiple tree benefits to raise understanding and awareness and rally support to protect HTs. The property-linked FEM could be flexibly applied to other cities, especially to assess HTs in compact developing cities.

Year: 2005

Funding Duration: 1-3 years

Grant Program: John Z. Duling

Grant Title: Development of a Formulaic Expert Method to Integrate the Evaluation and Valuation of Heritage Trees

Researcher: C Y Jim

Key words: compact city; formulaic expert method; heritage tree; monetary value; property-linked valuation; tree evaluation; tree protection; tree valuation; urban ecology; urban tree

Peer Reviewed Publications from Grant:

• Jim, C.Y. (2006) Formulaic expert method to integrate evaluation and valuation of heritage trees in compact city. Environmental Monitoring and Assessment (Springer, New York) 116: 53-80. View the Publication >

General Audience/Trade Publications: none

Presentations: none

For more information on this project, contact the researcher via TREE Fund at treefund@treefund.org.