Monetary valuation of urban forestry based on the magnitude of the crown in Piracicaba/Brazil

Abstract

Urban forestry provides important ecosystem services, however, it increasingly competes for space with large gray surfaces, which can make it a secondary element in the city planning. The monetary valuation of urban trees appears, then, as one more alternative capable of showing the relevance of these living beings. There are several methods that perform this calculation, however, they are complex and are not within reach of the population, which aims for better weather conditions. The objective of this research was to develop a simplified method of valuation based on the relationship between the area of the crown, the Leaf Area Index (LAI) and an average parameter BRL/m² of crown found in the literature, that is, on the magnitude of the crown, since most ecosystem services come from it. The LAI can be estimated using fisheye lenses at a reasonable price (less than BRL 25.00), while the canopy area can be measured in loco (or ground truth calibration). The present study was carried out in Piracicaba/SP/Brazil, in which the 60,146 urban trees can return approximately BRL 41 million (USD 8.2 million) per year in ecosystem services. Investigations like this, the so-called Nature-based Solutions (NbS), may assist in urban planning, management and formulation of public policies, and even as payment for environmental services (Urban Property and Land Tax discounts) to residents who have trees in front of their house.