The urban tree estate impacts on the quality of urban life through the provision of a series of benefits that are ecological, aesthetic, social and economic in nature. Most of these benefits do not have a market price, and exact information on the type of values people attach to urban trees is scarce. The optimal allocation of resources towards the management of this natural asset is therefore problematic.This study measures by contingent valuation the perceived monetary value of avoiding a 20% decrease in the urban tree estate of 15 cities in Aotearoa New Zealand. The results reveal that, on average, households would be willing to pay around (2003) NZD 184 annually for the avoidance of a 20% reduction in their local urban tree estate, with the commitment covering a period of 3 years. Half of the households would be willing to pay less than NZD 105, while the other half would be willing to pay more. Whether residents were willing to pay was influenced by the magnitude of the requested contribution (bid), the perceived seriousness of the 20% loss, qualification and the strongest motivation for taking care of trees. When using volunteer work as a metric for the valuation, 66% of the sample agreed to contribute 4 h of volunteer work and 55% of those who refused to pay the contingent bid said yes to contributing in this form.Half the sample was dissatisfied with the number of trees in their cities, the great majority wanting more trees. The respondents indicated different importance levels for a series of benefits and negative effects associated with city trees. Aesthetics, fresh air and trees representing nature in the city and bringing wildlife into the urban environment were the most highly regarded benefits, while trees causing drainage problems generated the most concern. The diverse motives given for interest in city trees highlighted the difficulties associated with measuring the total economic value of changes in this urban natural capital due to the non-use, bequest and existence value components.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.